bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of porcine zonae pellucidae immunisation on ovarian follicular development and endocrine function in domestic ewes (Ovis aries)
Authors: Stoops M. A. , Liu I. K. M. , Shideler S. E. , Lasley B. L. , Fayrer-Hosken R. A. , Benirschke K. , Murata K. , van Leeuwen E. M. G. , Anderson G. B.
Published: July 2006

Domestic ewes (Ovis aries) were immunised with porcine zonae pellucidae (pZP) or pZP conjugated to keyhole limpet haemocyanin (KLH) in adjuvant(s) to examine the feasibility of the species to serve as a model for further development of pZP-based vaccines in ungulates. Two immunisation groups were employed, with a third group receiving only adjuvant (n = 5 per group). Early in the study, oestrous activity was monitored by the use of a vasectomised ram fitted with a marking harness. Eventually, ewes were exposed to an intact ram for breeding. In addition, weekly serum and every-other-day faecal samples were collected to measure pZP antibodies and progesterone metabolite concentrations respectively. At the conclusion of the study, fecundity was established, and ovarian tissue was examined. Ewes immunised against pZP : KLH with adjuvant produced minimal antibody absorbance levels, displayed normal oestrous cycles, became pregnant upon introduction of the intact ram and exhibited normal ovarian histopathology. Ewes immunised against pZP with adjuvant produced high antibody absorbance levels, were acyclic following primary immunisation and were infertile. Examination of the ovarian tissue revealed atrophic changes that included: (1) the absence of growing follicles; (2) significant reduction in the number of primordial follicles; and (3) the presence of abnormal granulosa cell clusters lacking oocytes. Antisera displayed immunoreactivity to the major components of pZP, and immunohistochemical labelling of ovarian tissue showed specificity to the ZP. These data are the first generated in an ungulate species showing deleterious effects of pZP immunisation on folliculogenesis and oestrous cyclicity.
In vitro effects of epidermal growth factor, follicle stimulating hormone and testosterone on mouse spermatogonial cell colony formation
Authors: Anjamrooz S. Hadi , Movahedin Mansoureh , Tiraihi Taki , Mowla S. Javad
Published: July 2006

The complex process of spermatogenesis is regulated by various factors. In the present study, the in vitro effects of epidermal growth factor (EGF), follicle stimulating hormone (FSH) and testosterone on spermatogonial cell colony formation were investigated, and the best colonising factor was chosen for treating cells before transplantation. Sertoli and spermatogonial cells were isolated from neonatal mouse testes. The identity of the cells was confirmed through analysis of morphology, alkaline phosphatase activity, immunoreactivity and transplantation. Co-cultured Sertoli and spermatogonial cells were treated with EGF, FSH and testosterone before colony assay. Results indicated that EGF is the best factor for in vitro colonisation of spermatogonial cells, but transplantation of the EGF-treated group did not show any significant change compared with the control groups. In conclusion, EGF increased in vitro colonisation of spermatogonial cells, but, as a result of differential effects, did not influence transplantation efficiency.
Secretion patterns of luteinising hormone, follicle-stimulating hormone and 17β-oestradiol during oestrus and the mid-luteal phase of the oestrous cycle in mithun (Bos frontalis)
Authors: Dhali A. , Mishra D. P. , Karunakaran M. , Mech A. , Rajkhowa C.
Published: July 2006

The present study reports the pulsatile secretion of gonadotrophins and 17β-oestradiol (OE2) on the day of oestrus and at the mid-luteal phase of the oestrous cycle in mithun (Bos frontalis). The frequency of luteinising hormone (LH) and follicle-stimulating hormone (FSH) pulses was found to be greater (P < 0.05) on the day of oestrus than at the mid-luteal phase. In contrast, the amplitude of the LH and FSH pulses was greater (P < 0.01) at the mid-luteal phase than on the day of oestrus. A synchronised (P < 0.01) LH and FSH secretion pattern was found only at the mid-luteal phase. A pulsatile secretion pattern for OE2 in the peripheral circulation was evident for both phases of the oestrous cycle. The frequency of the OE2 pulses did not differ significantly in different phases of the oestrous cycle. In contrast, the amplitude of the OE2 pulses and the basal OE2 concentration were found to be greater (P < 0.01) at the mid-luteal phase than on the day of oestrus. A synchronised (P < 0.01) LH and OE2 secretion pattern was observed in both phases of the oestrous cycle. In contrast, a synchronised (P < 0.05) FSH and OE2 secretion pattern was found only on the day of oestrus. In conclusion, a different pattern of LH and FSH secretion was observed in both phases of the oestrous cycle, mainly on the day of oestrus, which indicates a differential regulatory mechanism of LH and FSH release. In addition, as in cattle, OE2 exerts a positive feedback on LH and FSH release on the day of oestrus and on LH release at the mid-luteal phase of the oestrous cycle in mithun. Also, as in cattle, the greater basal plasma OE2 concentration and increased amplitude of OE2 pulses exert a negative feedback on FSH release at the mid-luteal phase of the oestrous cycle.
Obesity is associated with altered metabolic and reproductive activity in the mare: effects of metformin on insulin sensitivity and reproductive cyclicity
Authors: Vick M. M. , Sessions D. R. , Murphy B. A. , Kennedy E. L. , Reedy S. E. , Fitzgerald B. P.
Published: July 2006

In mares, obesity is associated with continuous reproductive activity during the non-breeding season. To investigate the effect of obesity and associated alterations in metabolic parameters on the oestrous cycle, two related studies were conducted. In Experiment 1, obese (body condition score > 7) mares were fed ad libitum or were moderately feed restricted during the late summer and autumn months. Feed restriction did not alter the proportion of mares entering seasonal anoestrus. However, obese mares exhibited a significantly longer duration of the oestrous cycle, significant increases in circulating concentrations of leptin and insulin, and decreased insulin sensitivity and concentrations of thyroxine compared with feed-restricted mares throughout the experiment. Experiment 2 was designed to investigate the effects of administration of the insulin-sensitising drug metformin hydrochloride on insulin sensitivity and the characteristics of the oestrous cycle in obese mares. In a dose–response trial, metformin increased insulin sensitivity after 30 days following administration of 3 g day–1, but not 6 or 9 g day–1, compared with controls receiving vehicle only. However, there were no differences in insulin sensitivity or oestrous cycle characteristics between control and metformin-treated groups when the 3 g day–1 dose was tested for a longer period of 2 months. These results demonstrate that obesity is associated with aberrations in the oestrous cycle and perturbations in several markers of metabolic status. The results also indicate that metformin is not an effective long-term monotherapy for increasing insulin sensitivity in horses at the doses tested. Additional studies are needed to examine possible effects of increasing insulin sensitivity on reproductive activity in obese mares.
Utilizing the information content in two-state trajectories
Authors: Flomenbom Ophir , Silbey Robert J.
Published: July 2006

The signal from many single-molecule experiments monitoring molecular processes, such as enzyme turnover by means of fluorescence and opening and closing of ion channel through the flux of ions, consists of a time series of stochastic “on” and “off” (or open and closed) periods, termed a two-state trajectory. This signal reflects the dynamics in the underlying multisubstate on–off kinetic scheme (KS) of the process. The determination of the underlying KS is difficult and sometimes even impossible because of the loss of information in the mapping of the multidimensional KS onto two dimensions. Here we introduce a previously undescribed procedure that efficiently and optimally relates the signal to all equivalent underlying KS. This procedure partitions the space of KS into canonical (unique) forms that can handle any KS and obtains the topology and other details of the canonical form from the data without the need for fitting. Also established are relationships between the data and the topology of the canonical form to the on–off connectivity of a KS. The suggested canonical forms constitute a powerful tool in discriminating between KS. Based on our approach, the upper bound on the information content in two-state trajectories is determined.
Flanking sequences profoundly alter polyglutamine toxicity in yeast
Authors: Duennwald Martin L. , Jagadish Smitha , Muchowski Paul J. , Lindquist Susan
Published: July 2006

Protein misfolding is the molecular basis for several human diseases. How the primary amino acid sequence triggers misfolding and determines the benign or toxic character of the misfolded protein remains largely obscure. Among proteins that misfold, polyglutamine (polyQ) expansion proteins provide an interesting case: Each causes a distinct neurodegenerative disease that selectively affects different neurons. However, all are broadly expressed and most become toxic when the glutamine expansion exceeds ≈39 glutamine residues. The disease-causing polyQ expansion proteins differ profoundly in the amino acids flanking the polyQ region. We therefore hypothesized that these flanking sequences influence the specific toxic character of each polyQ expansion protein. Using a yeast model, we find that sequences flanking the polyQ region of human huntingtin exon I can convert a benign protein to a toxic species and vice versa. Further, we observe that flanking sequences can direct polyQ misfolding to at least two morphologically distinct types of polyQ aggregates. Very tight aggregates always are benign, whereas amorphous aggregates can be toxic. We thereby establish a previously undescribed systematic characterization of the influence of flanking amino acid sequences on polyQ toxicity.
Child protection in Sweden: Are routine assessments reliable?
Authors: Cocozza Madeleine , Gustafsson Per A. , Sydsjö Gunilla
Published: July 2006

Aim:To study the validity of the decision not to investigate mandatory reports of suspected child maltreatment.Methods:Written files of 220 reports indicating possible child maltreatment were analysed and re‐evaluated. As a measure of the justification for the decisions, a 5‐y follow‐up study was done.Results:We determined that 76% of the reports still indicated child maltreatment after the initial assessment was done. In the follow‐up study, 45% of the children had been investigated. The social worker used the family as the only source of information in 74% of the cases, in 6% someone outside the family was contacted, and in 11% no further information in addition to the report was collected. In 9%, data on information sources were missing.

Conclusion:The findings are rather discouraging, as they challenge the belief that a report is a means of ensuring that maltreatment does not continue. The study shows that, depending upon the way in which the initial assessments are made, maltreated children may run a risk of not being identified, even though the maltreatment has been reported. This suggests that there may be a need for national guidelines concerning the reporting of maltreatment.
Hypothermia in the resuscitation of the neonate: A glance in my rear‐view mirror
Authors: Westin Björn
Published: July 2006

Recent research indicates that the outcome of perinatal hypoxia‐ischaemia can be improved by hypothermia. This was actually first observed about 40 years ago, as discussed in this article. Clinical application of whole‐body hypothermia in the asphyxiated neonate showed a positive effect. Reference is made to previous review articles on the subject. A large experimental study indicated that the degree of protection against hypoxic‐ischaemic damage, as judged by the conditioned avoidance response, was dependent on the fall in body temperature. The earlier reported resistance against hypothermia in the asphyxiated neonate is discussed and analysed.

Conclusion: Experimental and clinical evidence suggest that hypothermia may be of value in resuscitation of the neonate.
Endophytic fungus decreases plant virus infections in meadow ryegrass (
Lolium pratense
)
Authors: Lehtonen Päivi T , Helander Marjo , Siddiqui Shahid A , Lehto Kirsi , Saikkonen Kari
Published: July 2006

We studied the effects of fungal endophyte infection of meadow ryegrass (
Lolium pratense
=
Festuca pratensis
) on the frequency of the barley yellow dwarf virus (BYDV). The virus is transferred by aphids, which may be deterred by endophyte-origin alkaloids within the plant. In our experiment, we released viruliferous aphid vectors on endophyte-infected and endophyte-free plants in a common garden. The number of aphids and the percentage of BYDV infections were lower in endophyte-infected plants compared to endophyte-free plants, indicating that endophyte infection may protect meadow ryegrass from BYDV infections.
Gut reaction by heartless shrimps: experimental evidence for the role of the gut in generating circulation before cardiac ontogeny
Authors: Spicer John I
Published: July 2006

Before the appearance of a functional heart in many invertebrate species, the assumption was that general body movements provide circulatory function. Consequently, I investigated the frequency of gut movements in the brine shrimp,Artemia franciscana, immediately post-hatch to the point when a functional heart appeared. Prior to cardiac ontogeny, movements of internal musculature and gut provided pre-cardiac circulatory currents with the rate of gut movements increasing when swimming limbs were impeded. There was also some evidence that gut movements were responsive to low oxygen, indicating a possible regulatory function for the gut in early circulation. Overall, this suggests that general body movements are not always adequate to provide internal circulation in small, heartless individuals.
Parent–offspring conflict and motivational control of brooding in an amphipod (Crustacea)
Authors: Dick Jaimie T.A , Elwood Robert W
Published: July 2006

Models of parent–offspring conflict concerning levels of caregiving centre on conflict resolution by offspring control, compromise or offspring ‘honest signalling’ that parents use to maximize their own fitness. Recent empirical studies on motivational control of parental feeding of offspring are interpreted as supporting the latter model. Here, we examine parental care in an amphipod,
Crangonyx pseudogracilis
, which directs care to embryos in a brood pouch. Embryo removal and transplantation elucidated causal factors that determine levels of caregiving. In the short-term, females with all embryos removed reduced care activities, but partial embryo removal did not affect caregiving, evidence of ‘unshared’ parental care. In the long-term, females with all embryos removed ceased care. Thus, females have a maternal state that is maintained by stimuli from offspring. Transplantation of early/late stage embryos among females originally carrying early/late stage embryos revealed that stimuli from embryos indicate their age-dependent needs, but only modify caregiving within the constraints of a changing endogenous maternal state. Thus, we demonstrate that mothers and offspring share motivational control of care. However, we highlight the inappropriate use of motivational data in reaching conclusions about the resolution of parent–offspring conflict.
Elastic–plastic modelling of shaped charge jet penetration
Authors: Novokshanov Roman , Ockendon John
Published: July 2006

This paper concerns the mathematical modelling of high-rate penetration of a metal target by a shaped charge device that produces a high-velocity jet. A key objective is to predict the penetration velocity, be it subsonic, transonic or supersonic. We do this by considering, on the local scale near the tip of the penetrated cavity, an elastic–plastic free boundary problem that takes into account the residual stresses produced by the moving plasticized region of the target. It is the self-consistency of this elastic–plastic model that dictates predictions for the penetration velocity.
A well-posed integral equation formulation for three-dimensional rough surface scattering
Authors: Chandler-Wilde Simon N , Heinemeyer Eric , Potthast Roland
Published: July 2006

We consider the problem of scattering of time-harmonic acoustic waves by an unbounded sound-soft rough surface. Recently, a Brakhage–Werner type integral equation formulation of this problem has been proposed, based on an ansatz as a combined single- and double-layer potential, but replacing the usual fundamental solution of the Helmholtz equation with an appropriate half-space Green's function. Moreover, it has been shown in the three-dimensional case that this integral equation is uniquely solvable in the space

when the scattering surface

does not differ too much from a plane. In this paper, we show that this integral equation is uniquely solvable with no restriction on the surface elevation or slope. Moreover, we construct explicit bounds on the inverse of the associated boundary integral operator, as a function of the wave number, the parameter coupling the single- and double-layer potentials, and the maximum surface slope. These bounds show that the norm of the inverse operator is bounded uniformly in the wave number,
κ
, for
κ
>0, if the coupling parameter
η
is chosen proportional to the wave number. In the case when

is a plane, we show that the choice

is nearly optimal in terms of minimizing the condition number.
Fitness cost of incubation in great tits (
Parus major
) is related to clutch size
Authors: de Heij Maaike E , van den Hout Piet J , Tinbergen Joost M
Published: July 2006

Life-history theory predicts that parents produce the number of offspring that maximizes their fitness. In birds, natural selection on parental decisions regarding clutch size may act during egg laying, incubation or nestling phase. To study the fitness consequences of clutch size during the incubation phase, we manipulated the clutch sizes during this phase only in three breeding seasons and measured the fitness consequences on the short and the long term. Clutch enlargement did not affect the offspring fitness of the manipulated first clutches, but fledging probability of the subsequent clutch in the same season was reduced. Parents incubating enlarged first clutches provided adequate care for the offspring of their first clutches during the nestling phase, but paid the price when caring for the offspring of their second clutch. Parents that incubated enlarged first clutches had lower local survival in the 2 years when the population had a relatively high production of second clutches, but not in the third year when there was a very low production of second clutches. During these 2 years, the costs of incubation were strong enough to change positive selection, as established by brood size manipulations in this study population, into stabilizing selection through the negative effect of incubation on parental fitness.
A mixed-mating strategy in a hermaphroditic vertebrate
Authors: Mackiewicz Mark , Tatarenkov Andrey , Turner Bruce J , Avise John C
Published: July 2006

Mixed-mating systems, in which hermaphrodites can either self-fertilize or outcross, are common in many species of plants and invertebrates and have been informative models for studying the selective forces that can maintain both inbreeding and outbreeding in populations. Here, we document a remarkable instance of evolutionary convergence to an analogous mixed mating system by a vertebrate, the mangrove killifish (Kryptolebias marmoratus). In this androdioecious species, most individuals are simultaneous hermaphrodites that characteristically self-fertilize, resulting in local populations that consist of (nearly) homozygous lines. Most demes are also genetically diverse, an observation traditionally attributed to de novo mutation coupled with high levels of inter-site migration. However, data presented here, from a survey of 35 microsatellite loci in Floridian populations, show that genotypic diversity also stems proximally from occasional outcross events that release ‘explosions’ of transient recombinant variation. The result is a local population genetic pattern (of extensive genotypic variety despite low but highly heterogeneous intra-individual heterozygosities) that differs qualitatively from the genetic architectures known in any other vertebrate species. Advantages of a mixed-mating strategy inK. marmoratusprobably relate to this fish's solitary lifestyle and its ability to colonize new habitats.
Evolutionary games and population dynamics: maintenance of cooperation in public goods games
Authors: Hauert Christoph , Holmes Miranda , Doebeli Michael
Published: July 2006

The emergence and abundance of cooperation in nature poses a tenacious and challenging puzzle to evolutionary biology. Cooperative behaviour seems to contradict Darwinian evolution because altruistic individuals increase the fitness of other members of the population at a cost to themselves. Thus, in the absence of supporting mechanisms, cooperation should decrease and vanish, as predicted by classical models for cooperation in evolutionary game theory, such as the Prisoner's Dilemma and public goods games. Traditional approaches to studying the problem of cooperation assume constant population sizes and thus neglect the ecology of the interacting individuals. Here, we incorporate ecological dynamics into evolutionary games and reveal a new mechanism for maintaining cooperation. In public goods games, cooperation can gain a foothold if the population density depends on the average population payoff. Decreasing population densities, due to defection leading to small payoffs, results in smaller interaction group sizes in which cooperation can be favoured. This feedback between ecological dynamics and game dynamics can generate stable coexistence of cooperators and defectors in public goods games. However, this mechanism fails for pairwise Prisoner's Dilemma interactions and the population is driven to extinction. Our model represents natural extension of replicator dynamics to populations of varying densities.
The role of survival for the evolution of female philopatry in a solitary forager, the grey mouse lemur (Microcebus murinus)
Authors: Lutermann Heike , Schmelting Barthel , Radespiel Ute , Ehresmann Petra , Zimmermann Elke
Published: July 2006

It is widely accepted that natal philopatry is a prerequisite for the evolution of sociality. The life-history hypothesis maintains that longevity of adults results in extended territory tenure and thus limits breeding vacancies for offspring, which makes natal philopatry more likely. Here, we tested the importance of longevity for natal philopatry in females of a basal primate, the grey mouse lemur (Microcebus murinus). This species is regarded as being solitary due to its foraging habits but while males disperse, female offspring in this species forgo dispersal and form long-term sleeping groups with their mothers. We tested whether high adult survival could be a cause for natal philopatry of female offspring. In addition, we assessed costs and benefits associated with space sharing between mothers and daughters and whether mothers actively increase survival of daughters by beqeauthal of territories, information transfer about resources or thermoregulation. Contrary to our predictions, adult females had low-survival rates. Space sharing appeared to improve survival of both, mothers and daughters. This could be a result of information transfer about sleeping sites and thermoregulatory benefits. Our results cast doubt on the idea that longevity predisposes species for social traits and provide support for benefits of philopatry.
Seasonal infectious disease epidemiology
Authors: Grassly Nicholas C , Fraser Christophe
Published: July 2006

Seasonal change in the incidence of infectious diseases is a common phenomenon in both temperate and tropical climates. However, the mechanisms responsible for seasonal disease incidence, and the epidemiological consequences of seasonality, are poorly understood with rare exception. Standard epidemiological theory and concepts such as the basic reproductive numberR0no longer apply, and the implications for interventions that themselves may be periodic, such as pulse vaccination, have not been formally examined. This paper examines the causes and consequences of seasonality, and in so doing derives several new results concerning vaccination strategy and the interpretation of disease outbreak data. It begins with a brief review of published scientific studies in support of different causes of seasonality in infectious diseases of humans, identifying four principal mechanisms and their association with different routes of transmission. It then describes the consequences of seasonality forR0, disease outbreaks, endemic dynamics and persistence. Finally, a mathematical analysis of routine and pulse vaccination programmes for seasonal infections is presented. The synthesis of seasonal infectious disease epidemiology attempted by this paper highlights the need for further empirical and theoretical work.
Gametic isolation in guppies (
Poecilia reticulata
)
Authors: Ludlow A.M , Magurran A.E
Published: July 2006

Post-mating reproductive isolating mechanisms may be among the earliest reproductive barriers to emerge among incipient species. Trinidadian guppy,
Poecilia reticulata
, populations in the Caroni and Oropouche drainages in Northern Trinidad exhibit marked genetic divergence and provide an ideal system in which to search for these barriers. We inseminated virgin females with equal amounts of sperm from two males, a ‘native’ male from the female's own population and a ‘foreign’ male from the other drainage. Artificial insemination ensured that mating order and mate choice did not affect the outcome. Paternities were assigned to the resulting broods using microsatellite markers. As predicted, sperm from native males had precedence over foreign sperm. Moreover, this effect was symmetrical for both drainages. In contrast, we detected no native sperm precedence in controls, in which females received sperm from the same and another population within the same drainage. Our results show that gametic isolation can arise between geographically proximate, though genetically divergent, populations of a single species and highlight the potential role of this process in speciation.
No evidence for presence of maternal mitochondrial DNA in the sperm of
Mytilus galloprovincialis
males
Authors: Venetis Constantinos , Theologidis Ioannis , Zouros Eleftherios , Rodakis George C
Published: July 2006

Species of the mussel family Mytilidae have a special mitochondrial DNA (mtDNA) transmission system, known as doubly uniparental inheritance (DUI), which consists of a maternally inherited (F) and a paternally inherited (M) mitochondrial genome. Females are normally homoplasmic for the F genome and males are heteroplasmic mosaics, with their somatic tissues dominated by the maternal and their gonads dominated by the paternal genome. Several studies have indicated that the maternal genome may often be present in the male germ line. Here we report the results from the examination of mtDNA in pure sperm from more than 30 males of
Mytilus galloprovincialis
. In all cases, except one, we detected only the M genome. In the sperm of one male, we detected a paternal genome with an F-like primary sequence that was different from the sequence of the maternal genome in the animal's somatic tissues. We conclude that the male germ line is protected against invasion by the maternal genome. This is important because fidelity of gamete-specific transmission of the two mitochondrial genomes is a basic requirement for the stability of DUI.
Transgenerational priming of immunity: maternal exposure to a bacterial antigen enhances offspring humoral immunity
Authors: Grindstaff Jennifer L , Hasselquist Dennis , Nilsson Jan-Åke , Sandell Maria , Smith Henrik G , Stjernman Martin
Published: July 2006

Young vertebrates have limited capacity to synthesize antibodies and are dependent on the protection of maternally transmitted antibodies for humoral disease resistance early in life. However, mothers may enhance fitness by priming their offspring's immune systems to elevate disease resistance. Transgenerational induced defences have been documented in plants and invertebrates, but maternal priming of offspring immunity in vertebrates has been essentially neglected. To test the ability of mothers to stimulate the immune systems of offspring, we manipulated maternal and offspring antigen exposure in a wild population of birds, pied flycatchers (Ficedula hypoleuca). We show that immunization of the mother before egg laying apparently stimulates a transgenerational defence against pathogens by elevating endogenous offspring antibody production. If the disease environments encountered by mothers and offspring are similar, this transgenerational immune priming may allow young to better cope with the local pathogen fauna.
The impacts of different management strategies and environmental forcing in ecological communities
Authors: Enberg Katja , Fowler Mike S , Ranta Esa
Published: July 2006

Understanding the effects of population management on the community a target species belongs to is of key importance for successful management. It is known that the removal or extinction of a single species in a community may lead to extinctions of other community members. In our study, we assess the impacts of population management on competitive communities, studying the response of both locally stable and unstable communities of varying size (between four and 10 species) to three different management strategies; harvesting of a target species, harvesting with non-targeted catch, and stocking of the target species. We also studied the consequences of selecting target species with different relative abundances, as well as the effects of varying environmental conditions.

We show here how the effects of management in competitive communities extend far beyond the target population. A crucial role is played by the underlying stability properties of the community under management. In general, locally unstable communities are more vulnerable to perturbation through management. Furthermore, the community response is shown to be sensitive to the relative density of the target species. Of considerable interest is the result that even a small (2.5%) increase in the population size of the target species through stocking may lead to extinction of other community members. These results emphasize the importance of considering and understanding multi-species interactions in population management.
Disruptive coloration provides camouflage independent of background matching
Authors: Schaefer H. Martin , Stobbe Nina
Published: July 2006

Natural selection shapes the evolution of anti-predator defences, such as camouflage. It is currently contentious whether crypsis and disruptive coloration are alternative mechanisms of camouflage or whether they are interrelated anti-predator defences. Disruptively coloured prey is characterized by highly contrasting patterns to conceal the body shape, whereas cryptic prey minimizes the contrasts to background. Determining bird predation of artificial moths, we found that moths which were dissimilar from the background but sported disruptive patterns on the edge of their wings survived better in heterogeneous habitats than did moths with the same patterns inside of the wings and better than cryptic moths. Despite lower contrasts to background, crypsis did not provide fitness benefits over disruptive coloration on the body outline. We conclude that disruptive coloration on the edge camouflages its bearer independent of background matching. We suggest that this result is explainable because disruptive coloration is effective by exploiting predators' cognitive mechanisms of prey recognition and not their sensory mechanisms of signal detection. Relative to disruptive patterns on the body outline, disruptive markings on the body interior are less effective. Camouflage owing to disruptive coloration on the body interior is background-specific and is as effective as crypsis in heterogeneous habitats. Hence, we hypothesize that two proximate mechanisms explain the diversity of visual anti-predator defences. First, disruptive coloration on the body outline provides camouflage independent of the background. Second, background matching and disruptive coloration on the body interior provide camouflage, but their protection is background-specific.
Are algal communities driven toward maximum biomass?
Authors: Passy Sophia I , Legendre Pierre
Published: July 2006

In this continental-scale study, we show that in major benthic and planktonic stream habitats, algal biovolume—a proxy measure of biomass—is a unimodal function of species richness (SR). The biovolume peak is observed at intermediate to high SR in the benthos but at low richness in the phytoplankton. The unimodal nature of the biomass–diversity relationship implies that a decline in algal biomass with potential harmful effects on all higher trophic levels, from invertebrates to fish, can result from either excessive species gain or species loss, both being common consequences of human-induced habitat alterations. SR frequency distributions indicate that the most frequent richness is habitat-specific and significantly higher in the benthos than in the plankton. In all studied stream environments, the most frequent SR is lower than the SR that yields the highest biovolume, probably as a result of anthropogenic influences, but always within one standard deviation from it, i.e. they are statistically indistinguishable. This suggests that algal communities may be driven toward maximum biomass.
A new probabilistic seismic hazard assessment for greater Tokyo
Authors: Stein Ross S , Toda Shinji , Parsons Tom , Grunewald Elliot
Published: July 2006

Tokyo and its outlying cities are home to one-quarter of Japan's 127 million people. Highly destructive earthquakes struck the capital in 1703, 1855 and 1923, the last of which took 105 000 lives. Fuelled by greater Tokyo's rich seismological record, but challenged by its magnificent complexity, our joint Japanese–US group carried out a new study of the capital's earthquake hazards. We used the prehistoric record of great earthquakes preserved by uplifted marine terraces and tsunami deposits (17M∼8 shocks in the past 7000 years), a newly digitized dataset of historical shaking (10 000 observations in the past 400 years), the dense modern seismic network (300 000 earthquakes in the past 30 years), and Japan's GeoNet array (150 GPS vectors in the past 10 years) to reinterpret the tectonic structure, identify active faults and their slip rates and estimate their earthquake frequency. We propose that a dislodged fragment of the Pacific plate is jammed between the Pacific, Philippine Sea and Eurasian plates beneath the Kanto plain on which Tokyo sits. We suggest that the Kanto fragment controls much of Tokyo's seismic behaviour for large earthquakes, including the damaging 1855M∼7.3 Ansei-Edo shock. On the basis of the frequency of earthquakes beneath greater Tokyo, events with magnitude and location similar to theM∼7.3 Ansei-Edo event have aca20% likelihood in an average 30 year period. In contrast, our renewal (time-dependent) probability for the greatM≥7.9 plate boundary shocks such as struck in 1923 and 1703 is 0.5% for the next 30 years, with a time-averaged 30 year probability ofca10%. The resulting net likelihood for severe shaking (ca0.9gpeak ground acceleration (PGA)) in Tokyo, Kawasaki and Yokohama for the next 30 years isca30%. The long historical record in Kanto also affords a rare opportunity to calculate the probability of shaking in an alternative manner exclusively from intensity observations. This approach permits robust estimates for the spatial distribution of expected shaking, even for sites with few observations. The resulting probability of severe shaking isca35% in Tokyo, Kawasaki and Yokohama andca10% in Chiba for an average 30 year period, in good agreement with our independent estimate, and thus bolstering our view that Tokyo's hazard looms large. Given $1 trillion estimates for the cost of anM∼7.3 shock beneath Tokyo, our probability implies a $13 billion annual probable loss.
European Standard Series patch test results from a contact dermatitis clinic in Israel during the 7‐year period from 1998 to 2004
Authors: Lazarov Aneta
Published: July 2006

The results of a 7‐year retrospective study (1998–2004) from patch testing with the European Standard Series (ESS) establishing the frequency of sensitization in a contact dermatitis clinic in Israel are presented. 23 allergens were patch tested on 2156 patients, 1462 females (67.8%) and 694 males (32.2%). Atopy and asthma were present in 21.9% of the patients. One or more allergic reactions were observed in 937 patients (43.5%). The highest yield of patch test positives from the 1076 positive reactions were obtained from nickel sulfate (13.9%), fragrance mix (7.1%), potassium dichromate (3.8%), Balsam of Peru (3.6%), CL + Me‐isothiazolinone (3.4%) and cobalt chloride (3.4%). Allergens which produced the least amount of positive results were primin and clioquinol. Allergic contact dermatitis (ACD) was established in 32.8%, whereas occupationally related allergic (8.0) and irritant contact dermatitis (5.6%) affected a total of 13.6% of the cases studied. The most common clinical forms of dermatitis were chronic dermatitis (47.7%) followed by acute dermatitis (22.8%), and lichenification and hyperkeratosis (7.9%). The hands (30.7%), face and neck (23.9%) and extremities (11.3%) were the most frequently affected areas. Four allergens in our study differed from the top 10 allergens in Europe namely: Cl + Me‐isothiazolinone, formaldehyde, 4‐tert‐butylphenol formaldehyde resin and sesquiterpene lactone mix reflecting an existing difference in environmental exposure. Our study is the first to provide data on the frequency of sensitization and important allergens in the aetiology of ACD in Israel. In spite of the existing differences with Europe, we conclude that ESS is an appropriate screening system for the diagnosis of ACD in Israel.
Contact allergy to para‐phenylenediamine in a permanent eyelash dye
Authors: Teixeira Marta , De Wachter Liesbet , Ronsyn Elke , Goossens An
Published: July 2006

We present the case of a 30‐year‐old atopic lady with a known history of intolerance to several materials, including dark stockings, who developed a severe dermatitis on the eyelids and peri‐orbital regions, as well as a conjunctivitis after having her eyelashes tinted by a beautician with a permanent black eyelash and eyebrow dye (Combinal, Dr Temt Laboratories, Austria). Patch tests revealed positive reactions to para‐phenylenediamine (PPD), both diluted 0.01% and 1% in pet., to the eyelash dye (tested semiopen as is) and to some of the azo‐dyes tested. The permanent eyelash dye did contain PPD, the use of which is illegal but seems to be a common practice. The patient had most probably been sensitized through nylon stockings containing azo‐dyes, with PPD itself cross‐reacting to them. With the growth in popularity of tattooing and permanent make‐up, doctors should be aware of the new uses of this old allergen. Moreover, although many manufacturers have made great efforts to improve cosmetics concerning their safety, some of them remain uninformed about cosmetic legislation or do not respect it at all. Because many of these products are acquired via internet, lack of legislation about this shopping modality is also a serious problem.
Allergic contact dermatitis to plants in a Spanish dermatology department: a 7‐year review
Authors: Cabanillas Miguel , Fernández‐Redondo Virginia , Toribio Jaime
Published: July 2006

To investigate the incidence of allergic contact dermatitis (ACD) to plants in our area, we reviewed the records of the patients that were studied in the Allergic Contact Unity of our hospital in the last 7 years (2248 patients). We found 69 cases of positive patch tests to plant allergens, representing 3% of all the patients in that period. Diallyl disulfide was the most frequent allergen (47 cases), involving mainly middle‐aged housewives with chronic hand eczema. Positive tests to sesquiterpene lactone mix (SL mix) were found in 11 patients, mostly middle‐aged rural workmen with an airborne clinical pattern. Other allergens detected were lichens, primin, tulipalin A and wood. These results show a high incidence of ACD to diallyl disulfide that, in our opinion, should be tested in all housewives or cooks with chronic hand eczema. The predominance of the classical airborne pattern of allergy to SL in our study may be because the airborne way of allergen exposure in our area, with a high percentage of rural population, is the most frequent, and it makes it important to remember this possibility in the differential diagnosis of photosensitivity.
Moisturizer effect on Irritant Dermatitis: an overview
Authors: Yokota Miki , Maibach Howard I.
Published: July 2006

Moisturizers are empirically used as prevention and treatment of surfactant and irritant dermatitis. Some products state they not only improve barrier function by providing moisturization but also create an environment optimal for healing. Yet, moisturizer clinical efficacy remains a topic of controversy. We reviewed publication from 1992 to 2006 that quantitatively examines moisturizer effectiveness, as an update of our prior overview, Zhai and Maibach in 1998 (2). We intuitively (in a testimonial sense) believe that moisturizers are sometimes effective for preventing and treating irritant dermatitis. However, moisturizer may not be broadly effective (8, 12) and may be relatively specific against certain acids, bases, hydrophilics, and lipophilics. We need to develop principles of what is formulated in moisturizers to improve efficacy; for this purpose, there is a need for experimental moisturizer models for comparative studies.
Severe adverse cutaneous reaction to insulin due to cresol sensitivity
Authors: Rajpar S. F. , Foulds I. S. , Abdullah A. , Maheshwari M.
Published: July 2006

We present the case of an 80‐year‐old lady known to be sensitive to chlorocresol (4‐chloro‐3‐methyl phenol) who developed severe erythrodermic exfoliative dermatitis with atypical features 2 weeks after commencing subcutaneous insulin. All medications except insulin were stopped, without major improvement. It was noted that the insulin contained m‐cresol (m‐methyl phenol) so a parabens‐based insulin was substituted. There was a significant improvement in her clinical condition within 72 hr. Further patch and intradermal testing to the insulin and m‐cresol was planned, but she developed a nosocomial infection and died. We hypothesize that the adverse cutaneous reaction was a systemic manifestation of cresol sensitivity, given the rapid clinical resolution on changing insulins and the previously demonstrated sensitivity to chlorocresol, particularly as cross‐reactivity between different low molecular weight methyl phenols is documented. Local injection site reactions and systemic side‐effects including nausea, diarrhoea and vomiting have previously been reported with cresol‐containing insulins, although to our knowledge, this is the first reported case of a severe cutaneous reaction. It is important to be aware of m‐cresol as a potential allergen, as it is contained in most commercially available insulins.
The 5‐HT4 antagonist R216073 does not affect gastric motor and sensory function in patients with functional dyspepsia
Authors: VAN LELYVELD N. , TER LINDE J. , BARON A. , MUNDT M. , WAJS E. , SAMSOM M.
Published: July 2006

Background  Serotonin and the 5‐HT4 receptor play an important role in gastrointestinal motor and sensory functions. While 5‐HT4 agonists are known for their prokinetics properties, the effect of 5‐HT4 antagonists on upper gastrointestinal functions is largely unknown.

Aim  To assess the effect of a 5‐HT4 receptor antagonist (R216073) on gastric relaxation and visceral sensitivity in patients with functional dyspepsia. Secondly, the influence of a functional polymorphism in the gene encoding the serotonin transport protein on drug response was determined.

Methods  A double‐blind, randomized, placebo‐controlled, two‐period crossover study was performed in 20 functional dyspepsia patients. The effect of a single dose of 2000 mg R216073 on gastric relaxation and sensitivity was tested using three‐dimensional ultrasonography and a nutrient drinktest.

Results  R216073 did not affect partial gastric volumes or upper abdominal sensations scored during three‐dimensional ultrasonography (P > 0.05). The maximum tolerated volume or upper abdominal sensations induced by the drinktest were not affected by R216073 (P > 0.05). The serotonin transport protein promoter polymorphism was not associated with any of the end‐points of the study.

Conclusions  A single dose of R216073 had no effect on fundic relaxation, drinking capacity, or upper abdominal symptoms in patients with functional dyspepsia.
Nutritional status and prognosis in cirrhotic patients
Authors: GUNSAR F. , RAIMONDO M. L. , JONES S. , TERRENI N. , WONG C. , PATCH D. , SABIN C. , BURROUGHS A. K.
Published: July 2006

Background and Aim  The potential prognostic value for survival of nutritional status in cirrhotics after adjusting Child–Pugh classification and Model for End‐Stage Liver Disease has not been evaluated.

Methods  We used Kaplan–Meier and Cox proportional hazards regression models to identify factors associated with mortality in a cohort of 222 cirrhotics [M/F:145/77 median age 52 (18–68) years] with prospectively collected nutritional parameters as well as modified subjective global nutritional assessment, Royal Free Hospital‐Subjective Global Assessment index. Follow‐up was censored at the time of transplantation. Other variables were ones in Child–Pugh and Model for End‐Stage Liver Disease scores, age, aetiology of cirrhosis and renal function,

Results  Pretransplant mortality (Kaplan–Meier) was 21% by 2 years (135 patients were transplanted). Among the nutritional parameters, only Royal Free Hospital‐Subjective Global Assessment remained significantly associated with mortality in multivariable models (P = 0.0006). The final model included the following variables: urea (P = 0.0001), Royal Free Hospital‐Subjective Global Assessment (P = 0.003), age (P = 0.0001), Child–Pugh grade (P = 0.009) and prothrombin time (P = 0.003). The results were similar when the Child–Pugh grade was replaced by the Model for End‐Stage Liver Disease score in the model, and whether a competing risks model was used.

Conclusions  Nutritional indices add significantly to both Child–Pugh grade and Model for End‐Stage Liver Disease scores when assessing the patient prognosis.