bluuebunny/crossref_metadata_2025 huggingface dataset:
Theoretical studies on the role of food exploitation for the competition of scaamble type
Authors: Murai Minoru
Published: October 2006

A model was made to clarify the basic processes of competition to occur among larvae by the exploitation as defined byBakker (1969). It was found that this model is applicable to the experimental results on the food exploitation among Droshophila larvae obtained byBakker (1961). In the model the preimaginal stage is divided into two periods;Tf which is the time that a group of larvae spends in exhausting the food after hatching, and Ts which is the duration of the starvation period after Tf.Tf and then Wl (larval body weight) just after the end of Tf are decided by Fs (amount of food supplied per larva at larval hatching) and Fc (amount of food consumed per larva).Tf affects on the onset of Ts as well as Rl (rate of decrease in the individual body weight during Ts).Wa (weight of emerging adults) is gotten by a subtraction of Rl from Wl just after the end of Tf,Re is affected directly by these components of Wl and Rl. As a result, Wa and Re are expressed by functions of Fs. This model confirmed that the food exploitation lead to the competition of scramble type. Finally it was suggested that there exist some strategies which prevent ill‐effects owing to the food exploitation.
Studies on the adult polymorphism in the southern green stink bug, Nezara viridula (hemiptera: Pentatomidae)
Authors: Kiritani Keizi
Published: October 2006

Polymorphism in adult colour pattern of Nezara viridula is determined on the genetic basis. The basic colour patterns of adult are classified into four types, i. e. G, O, R and F. No appreciable differences between these types were observed in respect to various physiological traits of nymphs and adults, except that type G seems to be superior in reproductive ability but to be inferior in ability of surviving winters at least to types R and F.

Inter‐generation changes in percentage frequency of G type were examined from 1959 to 1967 covering more than 30 generations. Percentage frequencies of G types prior to the severe winter of 1962–3 fluctuated greatly around a mean of 87.9%, while they did to a lesser extent than before with a mean of 85.0% after the winter. Unexpected high percentages of G type were recorded frequently in summer generations, viz. 1st and 2nd. On the other hand, the relative frequencies of G and O types decreased after hibernation in contrast to the increases in those of F and R. This sort of changes in genetic composition related to the winter of 1962–3 was observed in several populations segregated from each other.

This seasonal alternation of selective activity in the environments is considered to be responsible for retention of the polymorphism. Alternative possible causes, i. e. difference in habitat preference, non‐random mating and selective predation by predators among polymorphs, may safely be rejected as irrelevant to the mechanism in maintaining polymorphism.

The polymorphism of this insect seems to be in a transient state rather than balanced one contributing little to population regulation, but the persistence of N. viridula in the periphery range may be assisted by retention of the polymorphism.
Measuring neighborhood context for young children in an urban area
Authors: Coulton Claudia J. , Korbin Jill E. , Su Marilyn
Published: October 2006

Awareness of worsening conditions in urban areas has led to a growing interest in how neighborhood context affects children. Although the ecological perspective within child development has acknowledged the relevance of community factors, methods of measuring the neighborhood context for children have been quite limited. An approach to measuring neighborhood environments was tested using the average perceptions of caregivers of young children sampled from high‐ and low‐risk block groups. Individual‐ and aggregate‐level reliabilities and discriminant validity were acceptable for dimensions of neighborhood quality and change, participation in block organizations, disorder and incivilities, service usage and quality, and retaliation against adults. However, for measures of neighborhood interaction and the tendency of adults to intervene with children, there was virtually no agreement among respondents within block groups, resulting in poor aggregate reliability. A model of variability may be a more promising way of characterizing neighborhoods along these dimensions.
Tests of four hypotheses on soldier production, by using wild colonies of Pheidole fervida F. Smith (Hymenoptera: Formicidae)
Authors: Ito Fuminori , Higashi Seigo
Published: October 2006

Following four hypotheses on the production of soldiers were tested in the Pheidole fervida colonies collected in the natural field:

The proportion of new soldiers is primarily dependent on the population size of old workers.

The abundance of old soldiers reduces the proportion of new soldiers.

The production of sexuals reduces the proportion of new soldiers.

The number of soldiers is correlated with the size of defense zone.

The present test suggested that the last idea was most likely to the wild colonies of P. fervida.
A laboratory study on the predatory mite, Typhlodromus pyri (Acarina: Phytoseiidae). II The effect of temperature and prey consumption on the numerical reponse of adult females
Authors: Hayes A. J.
Published: October 2006

The numerical response of adult female T. pyri feeding on different levels of ERM larvae, and at a range of temperatures was examined. The duration of the pre‐oviposition period decreased as larval consumption increased, and the rate of oviposition was linearly related to the rate of consumption of larvae. Mathematical models were used to describe these relationships in terms of temperature and consumption of ERM larvae. The results were discussed in relation to the nature of the T. pyri/ERM interaction in New Zealand apple orchards.
Stopping rule of host search by the parasitoid, Chrysocharis pentheus (Hymenoptera: Eulophidae), in host patches
Authors: Sugimoto Tuyosi , Tsujimoto Shigechika
Published: October 2006

We studied the stopping rule obeyed by the female parasitoid, Chrysocharis pentheus, in deciding when to leave the leaflet on which she is searching for larvae of Phytomyza ranunculi. She seemed not to employ some stopping rules that have been suggested; i.e., a fixed‐number rule and a fixed‐time rule and others. The stopping model formulated for Dapsilarthra rufiventris parasitic on the same host species fitted well to the results. The model assumes that the searching female will deposit a marking pheromone on the leaflet at a rate proportional to the search speed and will leave the leaflet when the amount of the pheromone that has accumulated on the leaflet reaches the threshold, L. In this model, L denotes the amount of search effort spent on the leaflet. A comparison of the observed results with the predictions from the model suggested that L increased markedly at the first encounter with the mine (host), but less at later encounters. C. pentheus appears to employ a mixed strategy of a fixed search‐effort and an area‐concentrated search. This would confer an adaptive advantage in foraging for P. ranunculi larvae, which are distributed in clumps among leaflets in the field.
Prey or host searching behavior that leads to a sigmoid functional response in invertebrate predators and parasitoids
Authors: Luck Robert F. , van Lenteren Joop C. , Twine Peter H. , Juenen Lodewyk , Unruh Thomas
Published: October 2006

Invertebrate predators and parasitoids have long been characterized as having a hyperbolic (Type 2) functional response. Modifications were made to Holling's sand paper disc experiment which consisted of limiting the initial period of search during which a host must be contacted. Failure to contact a host during this initial period causes the predator to emigrate from the search area. The modification generated a sigmoid (Type 3) functional response. This response resulted from the low probability of encountering a host during the initial period of search at low host densities in the time allotted. A limited period of search has been found in several insect parasitoids. Such a strategy would minimize the time (energy) spent per offspring produced by minimizing the time invested in searching microhabitats in which hosts are scarce or absent.
Age‐dependent loss of insulin‐like growth factor‐1 receptor immunoreactive cells in the supraoptic hypothalamus is reduced in calorically restricted mice
Authors: Yaghmaie F. , Saeed O. , Garan S.A. , Voelker M.A. , Gouw A.M. , Freitag W. , Sternberg H. , Timiras P.S.
Published: October 2006

Both life‐long caloric restriction (CR) and the suppression of insulin‐like growth factor‐1 (IGF‐1) signaling reliably extend the mammalian lifespan. The neuroendocrine system, regulated by the hypothalamus, remains the most convincing site of action for both these modes of life extension. Yet, determining whether CR actions are mediated by the modulation of neuroendocrine IGF‐1 signaling remains unclear. Of the hypothalamic nuclei that express the IGF‐1 receptor (IGF‐1R), the cells of the supraoptic nucleus (SON) display some of the most robust IGF‐1R expression. Taking IGF‐1R immunoreactivity as an index of sensitivity to IGF‐1, we counted IGF‐1R immunoreactive and non‐immunoreactive cells in the SON of young‐ad‐libitum fed (young‐Al, 6 weeks), old‐ad‐libitum fed (Old‐Al, 22 months), and old‐calorie‐restricted (Old‐CR, 22 months) female B6D2F1 mice. An automated imaging microscopy system (AIMS) was used to generate cell counts for each section of supraoptic hypothalamus. Results show that while the total number of cells in the SON of ad‐libitum fed mice does not change significantly with aging, a significant reduction in IGF‐1R immunoreactive cells does occur in ad‐libitum fed mice with aging. In contrast to this, calorie restricted mice show both a decline in the total number of cells and IGF‐1R immunoreactive cells in the SON with age, but with the decrease in the latter being notably attenuated when compared to the degree of loss seen in ad‐libitum fed mice. Thus, while CR induces greater loss in the total number of cells in the SON with age, it reduces the degree of age‐dependent loss seen in IGF‐1R expressing cells. As a result, when compared to Old‐AL mice, the SON of Old‐CR mice displays a greater proportion of IGF‐1R cells and thus possibly enhanced IGF‐1 sensitivity with aging.
Reverse Radial Artery Bone Flap Reconstruction of Segmental Metacarpal Losses
Authors: MERLINO G. , BORSETTI M. , BOLTRI M.
Published: October 2006

A vascularised bone segment of the distal radius was harvested as a distally based flap to treat segmental metacarpal bone loss in three patients. One reconstruction followed resection of a giant cell tumour excision and the other two were to replace traumatic bone loss. The bone defects were in the second metacarpal in two cases and in the second and third metacarpal in one case and included three shaft and one distal metacarpal reconstruction. The mean length of the metacarpal defects was 6 cm. All of the flaps survived and no complications occurred at the donor site. Clinical and radiological union was established in all cases after an average of 3 months.
Charles Babbage: Reclaiming an operations management pioneer
Authors: Lewis Michael A.
Published: October 2006

Charles Babbage (1791–1871) was the embodiment of a polymath: elected a Royal Society fellow, holder of the Lucasian Chair of mathematics at Cambridge, founder of the London Statistical Society, author of many papers and full‐length monographs and, most famously from a 21st century perspective, the architect of modern computing with his difference engines and designs for the analytical engine. The scale and complexity of these machines meant their realisation was dependent upon the latest industrial advances like parts standardization and machine tool technology. As a result Babbage committed large amounts of his time and money to the theoretical and empirical study of advanced production and engineering practice.

This paper argues that Charles Babbage deserves to be recognised as a pioneer in the field of operations management. His path‐breaking contributions were born of a singular intellect and degree of creativity combined with a commitment to empiricist scientific method and statistical measurement. Moreover, he was working as Britain transformed itself into the most highly industrialized country the world had ever seen. The paper draws in particular upon the various editions of his best‐selling book, ‘On the Economy of Machines and Manufactures’, first published in 1832. It reviews the many core operations principles evident in Babbage's analyses and highlights insights that remain relevant to today's theoretical and practical concerns. The paper concludes with a discussion of how a combination of contextual and biographical factors left Charles Babbage a largely unsung pioneer in the field of operations management.
Methicillin resistant Staphylococcus aureus: is it a problem for nasal surgery?
Authors: Sharma A , Philpott C , Pope L , McKiernan D
Published: October 2006

Methicillin resistant Staphylococcus aureus (MRSA) is becoming ever more prevalent in the UK, and the proportion of MRSA to methicillin sensitive Staphylococcus aureus (MSSA) seems to be increasing. New strains of MRSA are ever developing resistance to antibiotic treatment, increasing morbidity and mortality of infection.

Staphylococcus aureus is part of the normal flora of the nose, and MRSA colonizes the nose in infection. However, nasal surgery is rarely complicated by staphylococcal infections, and MRSA infection following nasal surgery is rare.

The authors present a literature review of MRSA infection, its relation to the nasal cavity, and infection following nasal surgery.
The sociolinguistic situation of ‘contemporary dialects of French’ in France today: an overview of recent contributions on the dialectalisation of Standard French
Authors: BLANCHET PHILIPPE , ARMSTRONG NIGEL
Published: October 2006

This article presents a synthesis of the sociolinguistic situation of what the authors refer to as the ‘contemporary dialects’ of French in the France of today. The introduction emphasises the methodological and conceptual problems attending any such definition and evaluation, attempting to clarify the complex situation and to identify the various kinds of ‘dialects’, ‘uses’ and ‘speakers’. We then concentrate on the regional ‘dialects’ of French in continental France, urban and rural, and summarise a series of important recent studies, concentrating on local variation. We also distinguish the sociolinguistic situations of the northern and the southern parts of the country. Even though France is known to be a highly centralised country, whose linguistic policy has been aiming at monolingualism for the past two centuries, the article offers some possibly surprising and nuanced results that show more variation than established opinion would generally admit about contemporary France.
On finding focus
Authors: Orser Charles E.
Published: October 2006

Few observers could argue with the proposition that archaeology has dramatically changed in the past couple of decades. Perhaps tacitly or even unknowingly adopting one of the central tenets of critical archaeology, archaeologists everywhere have learned to expand their audiences and to consider the contemporary meanings of their interpretations. Members of descendant communities and other stakeholders now commonly demand a role in the retelling of history. The 1930s view of ‘every man [sic] the historian’ has become ‘every person the archaeological interpreter’. Archaeology is no longer the sole purview of the ivory tower and the detached, absent-minded archaeologist. The days of sitting quietly in a well-appointed laboratory measuring potshards are largely gone. Only the best-funded, venerable of practitioners has this luxury today.
Questions, theory and concepts
Authors: Plog Stephen
Published: October 2006

I agree with the thrust of Matthew Johnson's paper; in particular, I concur with his conclusion that there is archaeological theory, but not a ‘distinctive way of thinking about the world in theoretical terms specific to archaeology’ (p. 117). As Johnson argues, I believe we currently have multiple theories of archaeology and all of these overlap with other disciplines. During a six-year period of administrative service at the University of Virginia in which it was necessary to venture outside the literature that I typically read and review the publications of faculty from a variety of departments as part of promotion and tenure decisions, I was initially often surprised by, and later reminded of, the degree of theoretical commonalities between archaeology and other disciplines that Johnson has highlighted.
Energy avalanches in the central plasma sheet
Authors: Liu W. W. , Charbonneau P. , Thibault K. , Morales L.
Published: October 2006

The central plasma sheet (CPS) is simulated as a 1D cellular automaton. The system is driven deterministically and globally by a spatially non‐uniform energy loading (convection). Each node (a flux tube) evolves until one of two local instability criteria is exceeded. The unstable node releases a small amount of energy to the ionosphere and another small amount is distributed to its neighboring nodes. The partition between the two modes of energy distribution is the only random factor in the model. The energy redistribution relaxes the node deterministically to a stable state. The simulation suggests that a central plasma sheet driven in the above manner is in a self‐organized critical state, with energy avalanches obeying a scale‐free distribution. The avalanches, however, co‐exist with quasi‐periodic intermittencies manifested in ring‐current injection, which is correlated with strong CPS avalanches, and tailward energy ejection, which shows no apparent correlation in this aspect.
Glutamate is Preferred over Glutamine for Intermediary Metabolism in Cultured Cerebellar Neurons
Authors: Olstad Elisabeth , Qu Hong , Sonnewald Ursula
Published: October 2006

The glutamate—glutamine cycle is thought to be of paramount importance in the mature brain; however, its significance is likely to vary with regional differences in distance between astrocyte and synapse. The present study is aimed at evaluating the role of this cycle in cultures of cerebellar neurons, mainly consisting of glutamatergic granule cells. Cells were incubated in medium containing [U-13C]glutamate or [U-13C]glutamine in the presence and absence of unlabeled glutamine and glutamate, respectively. Cell extracts and media were analyzed using high-performance liquid chromatography (HPLC) and gas chromatography combined with mass spectrometry (GC/MS). Both [U-13C]glutamate and [U-13C]glutamine were shown to be excellent precursors for synthesis of neuroactive amino acids and tricarboxylic acid (TCA) cycle intermediates. Labeling from [U-13C]glutamate was higher than that from [U-13C]glutamine in all metabolites measured. The presence of [U-13C]glutamate plus unlabeled glutamine in the experimental medium led to labeling very similar to that from [U-13C]glutamate alone. However, incubation in medium containing [U-13C]glutamine in the presence of unlabeled glutamate almost abolished labeling of metabolites. Thus, it could be shown that glutamate is the preferred substrate for intermediary metabolism in cerebellar neurons. Label distribution indicating TCA cycle activity showed more prominent cycling from [U-13C]glutamine than from [U-13C]glutamate. Labeling of succinate was lower than that of the other TCA cycle intermediates, indicating an active role of the γ-amino butyric acid shunt in these cultures. It can be concluded that the cerebellar neurons rely more on reuptake of glutamate than supply of glutamine from astrocytes for glutamate homeostasis.
Taxonomic revision and cladistic analysis of Teratopactus Heller (Coleoptera:Curculionidae)
Authors: Guadalupe del Río M. , Lanteri Analía A. , Guedes Jerson V. C.
Published: October 2006

Teratopactus Heller (Entiminae : Naupactini) is a broad-nosed weevil genus widespread in South America. This first taxonomic revision of the genus includes seven species: T. capucinus (Perty) (type species; syn. T. senex (Boheman)); T. elegans (Lucas), comb.nov.; T. gibbicollis (Boheman); T. nodicollis (Boheman) (syn. T. angulicollis (Lucas), T. paulanus (Fonseca & Autuori), T. serripes (Boheman), and T. perpastus (Boheman), syn. nov.); T. retusus (Boheman); T. tuberculatus (Arrow); and T. vittatus (Mannerheim), comb.nov. All species except T. tuberculatus have a strong ovipositor lacking styli, T. elegans, T. nodicollis and T. vittatus show well developed humeri bearing a strong tooth and T. retusus, T. capucinus and T. gibbicollis are characterised by a strongly gibbous pronotum and reduced humeri. Teratopactus nodicollis is the most variable and widespread species (Argentina, Brazil, Bolivia, Paraguay and Uruguay), T. tuberculatus and T. elegans range through Brazil and Paraguay and the remaining species are endemic to Brazil. The first cladistic analysis of the genus Teratopactus plus two outgroups, using 36 morphological characters, established synapomorphies and revealed relationships between the species in a single cladogram with the following topology: (T. tuberculatus ((T. elegans (T. nodicollis– T. vittatus)) (T. retusus (T. capucinus–T. gibbicollis)))).
Auger Spectroscopy and Surface Analysis
Authors: Thurgate S. M.
Published: October 2006

Abstract In 1925 Pierre Auger reported on his observations of low energy
electrons associated with core-ionised atoms in cloud chamber experiments. He
was able to correctly identify the mechanism for their production, and such
electrons are now known as Auger electrons. Typically
Auger electrons have energies in the range 10 eV to 2 keV. The short distance
that such low energy electrons travel in solids ensures that Auger electrons
come from the surface layers. The data generated by the AES technique are
complex.
There are at least three electrons involved in the process, and there are many
possible configurations for the atom. These possibilities led to spectra that
are not readily interpreted in detail. Theory lags behind experiment in this
area. In principle, it should be possible to find information about the
chemical environment of atoms from Auger spectra. While there are clear
changes in spectral lineshapes, there is no simple way to go from the spectra
to an understanding of the chemical bonding of the atom. There are a number of
experiments currently underway which aim to improve our understanding of the
Auger process. Synchrotron experiments with tunable energy x-rays are
providing new insight. Experiments that use positrons to excite Auger emission
have also produced further recent understanding. Coincidence experiments
between photoelectrons and Auger electrons have also made recent advances.
Auger photoelectron coincidence spectroscopy reduces the complexity of Auger
spectra by only counting those electrons that occur as a consequence of
selected ionisations. The effect is to reduce the complexity of the spectra,
and to isolate processes that are often clouded by the simultaneous occurrence
of other effects.
Physics and the Cosmos: The Origin of Cosmic Rays of ‘Low’ and ‘Very High’ Energies
Authors: Wolfendale Arnold W.
Published: October 2006

The subject of ‘cosmic rays’ is one that embraces a vast range of
particle and photon energies and is an ideal one for examining ‘Physics
and the Cosmos’. In the present work we examine the twin problems of the
origin of cosmic rays of both low and very high energies and find that they
are related by studies of the Magellanic Clouds. This remarkable result comes
from the hypothesis that there is a Giant Halo surrounding the Galaxy, support
coming from Magellanic Cloud observations. Also examined is the flux of
extragalactic gamma rays and its relevance to the question of the asymmetry
between matter and anti-matter in the Universe.
Interplay between PIP
3
and calmodulin regulation of olfactory cyclic nucleotide-gated channels
Authors: Brady James D. , Rich Elizabeth D. , Martens Jeffrey R. , Karpen Jeffrey W. , Varnum Michael D. , Brown R. Lane
Published: October 2006

Phosphatidylinositol-3,4,5-trisphosphate (PIP
3
) has been proposed to modulate the odorant sensitivity of olfactory sensory neurons by inhibiting activation of cyclic nucleotide-gated (CNG) channels in the cilia. When applied to the intracellular face of excised patches, PIP
3
has been shown to inhibit activation of heteromeric olfactory CNG channels, composed of CNGA2, CNGA4, and CNGB1b subunits, and homomeric CNGA2 channels. In contrast, we discovered that channels formed by CNGA3 subunits from cone photoreceptors were unaffected by PIP
3
. Using chimeric channels and a deletion mutant, we determined that residues 61–90 within the N terminus of CNGA2 are necessary for PIP
3
regulation, and a biochemical “pulldown” assay suggests that PIP
3
directly binds this region. The N terminus of CNGA2 contains a previously identified calcium–calmodulin (Ca
2+
/CaM)-binding domain (residues 68–81) that mediates Ca
2+
/CaM inhibition of homomeric CNGA2 channels but is functionally silent in heteromeric channels. We discovered, however, that this region is required for PIP
3
regulation of both homomeric and heteromeric channels. Furthermore, PIP
3
occluded the action of Ca
2+
/CaM on both homomeric and heteromeric channels, in part by blocking Ca
2+
/CaM binding. Our results establish the importance of the CNGA2 N terminus for PIP
3
inhibition of olfactory CNG channels and suggest that PIP
3
inhibits channel activation by disrupting an autoexcitatory interaction between the N and C termini of adjacent subunits. By dramatically suppressing channel currents, PIP
3
may generate a shift in odorant sensitivity that does not require prior channel activity.
Hot-spot mimicry of a cytokine receptor by a small molecule
Authors: Thanos Christopher D. , DeLano Warren L. , Wells James A.
Published: October 2006

Protein–protein complexes remain enticing, but extremely challenging, targets for small-molecule drug discovery. In a rare example described earlier, a high-affinity small molecule, SP4206 (
K
d
≈ 70 nM), was found to block binding of the IL-2α receptor (IL-2Rα) to IL-2 (
K
d
≈ 10 nM). Recently, the structure of the IL-2/IL-2Rα complex was solved [Rickert, M., Wang, X., Boulanger, M. J., Goriatcheva, N., Garcia, K. C. (2005)
Science
308:1477–1480]. Using structural and functional analysis, we compare how SP4206 mimics the 83-fold larger IL-2Rα in binding IL-2. The binding free energy per contact atom (ligand efficiency) for SP4206 is about twice that of the receptor because of a smaller, but overlapping, contact epitope that insinuates into grooves and cavities not accessed by the receptor. Despite its independent design, the small molecule has a similar, but more localized, charge distribution compared with IL-2Rα. Mutational studies show that SP4206 targets virtually the same critical “hot-spot” residues on IL-2 that drive binding of IL-2Rα. Moreover, a mutation that enhances binding to the IL-2Rα near these hot spots also enhances binding to SP4206. Although the protein and small molecule do bind the same hot spot, they trap very different conformations of IL-2 because of its flexible nature. Our studies suggest that precise structural mimics of receptors are not required for high-affinity binding of small molecules, and they show that there are multiple solutions to tight binding at shared and adaptive hot spots.
COPASI—a COmplex PAthway SImulator
Authors: Hoops Stefan , Sahle Sven , Gauges Ralph , Lee Christine , Pahle Jürgen , Simus Natalia , Singhal Mudita , Xu Liang , Mendes Pedro , Kummer Ursula
Published: October 2006

Motivation: Simulation and modeling is becoming a standard approach to understand complex biochemical processes. Therefore, there is a big need for software tools that allow access to diverse simulation and modeling methods as well as support for the usage of these methods.

Results: Here, we present COPASI, a platform-independent and user-friendly biochemical simulator that offers several unique features. We discuss numerical issues with these features; in particular, the criteria to switch between stochastic and deterministic simulation methods, hybrid deterministic–stochastic methods, and the importance of random number generator numerical resolution in stochastic simulation.

Availability: The complete software is available in binary (executable) for MS Windows, OS X, Linux (Intel) and Sun Solaris (SPARC), as well as the full source code under an open source license from .

Contact:  mendes@vbi.vt.edu
What is the extent of prokaryotic diversity?
Authors: Curtis Thomas P , Head Ian M , Lunn Mary , Woodcock Stephen , Schloss Patrick D , Sloan William T
Published: October 2006

The extent of microbial diversity is an intrinsically fascinating subject of profound practical importance. The term ‘diversity’ may allude to the number of taxa or species richness as well as their relative abundance. There is uncertainty about both, primarily because sample sizes are too small. Non-parametric diversity estimators make gross underestimates if used with small sample sizes on unevenly distributed communities. One can make richness estimates over many scales using small samples by assuming a species/taxa-abundance distribution. However, no one knows what the underlying taxa-abundance distributions are for bacterial communities. Latterly, diversity has been estimated by fitting data from gene clone libraries and extrapolating from this to taxa-abundance curves to estimate richness. However, since sample sizes are small, we cannot be sure that such samples are representative of the community from which they were drawn. It is however possible to formulate, and calibrate, models that predict the diversity of local communities and of samples drawn from that local community. The calibration of such models suggests that migration rates are small and decrease as the community gets larger. The preliminary predictions of the model are qualitatively consistent with the patterns seen in clone libraries in ‘real life’. The validation of this model is also confounded by small sample sizes. However, if such models were properly validated, they could form invaluable tools for the prediction of microbial diversity and a basis for the systematic exploration of microbial diversity on the planet.
Self‐Efficacy as a Mediator of the Relationship Between Causal Attributions and Exercise Behavior
Authors: Shields Christopher A. , Brawley Lawrence R. , Lindover Tamara I.
Published: October 2006

The primary purposes of this study were to examine whether the attribution–intention link was mediated by self‐efficacy and whether the attribution–behavior link was mediated by self‐efficacy. As a secondary purpose, we examined whether the attribution–behavior link was mediated by exercise intentions. These relationships were tested prospectively at multiple time points. Participants were 260 adult exercisers (M age=32 years) enrolled in 12 weeks of structured exercise classes. Social cognitive measures were assessed at early and midprogram; attendance was tracked for the first and second half of the program. Hierarchical multiple regression procedures indicated support for self‐efficacy as a mediator of the relationship between attributions and behavior. Secondary analyses revealed support for intention as a mediator of the attribution–behavior relationship. Finally, additive relationships in support of social cognitive theory also were detected. The attribution/self‐efficacy/behavior link is important for adherence interventions and should be investigated further in both asymptomatic and symptomatic populations.
Short‐term fasting‐induced autonomic activation and changes in catecholamine levels are not mediated by changes in leptin levels in healthy humans
Authors: Chan Jean L. , Mietus Joseph E. , Raciti Patricia M. , Goldberger Ary L. , Mantzoros Christos S.
Published: October 2006

Objective  In animal models, the adipocyte‐secreted hormone leptin increases energy expenditure by increasing sympathetic outflow but its role in humans remains to be elucidated. We evaluated whether inducing hypoleptinaemia (with and without administration of leptin at replacement doses) for 3 days would influence catecholamine levels and sympathetic and parasympathetic activity in healthy humans.

Methods  We studied six normal‐weight subjects in the General Clinical Research Center (GCRC) under three conditions: baseline fed state (control study) and two 72‐h fasting studies (to decrease leptin levels), with administration of either placebo or replacement‐dose recombinant methionyl human leptin (r‐metHuLeptin) in a randomized, double‐blind fashion. In each condition, 24‐h urinary catecholamine levels, heart rate and heart rate variability (HRV), a standard tool for assessing cardiac autonomic modulation, were measured.

Results  Study parameters remained stable during the control condition and the baseline assessment of all three studies. In response to 72‐h fasting, which decreased serum leptin levels by 80%, 24‐h urinary norepinephrine and dopamine levels and heart rate increased while cardiac vagal modulation decreased (all P < 0·05). Replacement‐dose r‐metHuLeptin to keep leptin levels within the physiological range during fasting did not alter fasting‐associated changes in heart rate, catecholamine levels or cardiac vagal tone.

Conclusions  The findings of this controlled, interventional study indicate that changes in heart rate, catecholamine levels and cardiac vagal modulation associated with 72‐h fasting are independent of regulation by leptin. Thus, changes in leptin levels within the physiological range do not seem to play a role in regulating autonomic function during short‐term starvation in healthy humans.
Impacts of fine sediment addition to tussock, pasture, dairy and deer farming streams in New Zealand
Authors: MATTHAEI CHRISTOPH D. , WELLER FLORIAN , KELLY DAVID W. , TOWNSEND COLIN R.
Published: October 2006

1. Increased fine sediment input caused by agricultural development is expected to act as a stressor for stream ecosystems. In a large‐scale field experiment, we added fine river sand to 50‐m reaches of three second‐order streams in each of four categories of catchment development (ungrazed tussock grasslands, grazed pasture, dairying and deer farming) and measured the responses of macroinvertebrates and aquatic moss.

2. Before addition, fine sediment cover differed between land uses, being lowest in tussock (7%), intermediate in pasture (30%) and dairy (47%) and highest in deer streams (88%). Sediment addition increased cover by one land‐use category (e.g. augmented sediment cover in tussock streams was similar to pre‐existing cover in pasture streams), and cover remained high in impact reaches (compared with controls) throughout the 5‐week experiment. Sediment addition did not change concentrations of phosphate, nitrate and ammonium, which were generally highest in dairy streams and lowest in tussock streams.

3. Aquatic mosses (most common in tussock, absent in dairy and deer), invertebrate density (highest in deer, lowest in tussock), taxon richness (highest in pasture, lowest in deer) and diversity (highest in pasture and tussock, lowest in dairy and deer) all differed between land uses. Sediment addition resulted in reductions of moss cover, invertebrate taxon richness and richness of Ephemeroptera, Plecoptera and Trichoptera in impact relative to control reaches.

4. The impact of sediment addition was strongest in pasture streams where pre‐existing sediment cover was moderate and richness and diversity of the invertebrate community highest. However, even in the already sediment‐rich and species‐poor deer streams, density of one common taxon was reduced significantly by sediment addition, and another two were affected in the same way in dairy streams, the second‐most intense land use.

5. Our experiment has disentangled the impact of sediment addition from other concomitant land‐use effects that could not be reliably distinguished in previous research, which has mainly consisted of correlative studies or unrealistically small‐scale experiments.
Involvement of IL‐10 in exhaustion of myeloid dendritic cells and rescue by CD40 stimulation
Authors: Kajino Kiichi , Nakamura Ichiro , Bamba Hiromichi , Sawai Toshihiro , Ogasawara Kazumasa
Published: October 2006

It has recently been shown that immature dendritic cells (DCs) stimulated by a danger signal undergo transient maturation followed by exhaustion. However, the exact mechanism for this has not been elucidated. In this study, we show that interleukin‐10 (IL‐10) secreted from transiently matured DCs stimulated by danger signals is responsible for this rapid DC exhaustion. Blocking of the autocrine IL‐10 enabled transient mature DCs to maintain the mature phenotype for several days. However, these DCs remained phenotypically unstable because the addition of IL‐10 altered the transient mature DCs to exhausted DCs. More importantly, stimulation of DCs by CD40 protected transient mature DCs from IL‐10‐dependent exhaustion, with the result that mature DCs remained stable in the presence of IL‐10. Furthermore, in vivo administration of stable mature DCs pulsed with ovalbumin protein induced antigen‐specific cytotoxic T lymphocytes (CTLs) effectively, whereas neither exhausted DCs nor transient mature DCs were able to prime a strong antigen‐specific CTL response. These results indicate that DC−T cell engagement via CD40−CD154 is required for stable DC maturation leading to effective CTL induction. Otherwise, DCs stimulated solely by a danger signal are temporarily activated, but then rapidly lose their immune‐activating capacity under the influence of autocrine IL‐10.
Multidisciplinary perceptions of the role of nurses and healthcare assistants in rehabilitation of older adults in acute health care
Authors: Atwal Anita , Tattersall Kirsty , Caldwell Kay , Craik Christine
Published: October 2006

Aim.  This paper describes the perceptions of nurses, healthcare assistants, doctors and therapists of rehabilitation and the role of nurses and healthcare assistants on an acute older adults ward in a London teaching hospital.

Background.  The role perception, education and training and attitudes towards the older adults have been identified as barriers that have an impact upon the nurses’ role within rehabilitation. However, little is known about the role of nurses and healthcare assistants in rehabilitation of older adults in acute health care.

Design.  Action research study.

Method.  Twenty‐four semi‐structured interviews were conducted and audio recorded about healthcare professionals’ understanding of rehabilitation, the type of skills needed and their perceptions of the role of nurses and healthcare assistants in rehabilitation. The interview transcripts were analysed using the thematic content analysis.

Results.  The findings suggest that the therapists relied on nurses and healthcare assistants for therapy carry‐over. Healthcare assistants were perceived as the professional group who could deliver therapy carry‐over. There was an evidence of role hierarchy as healthcare assistants perceived that they were not actively involved in decision‐making or discharge planning.

Conclusion.  This paper suggests that healthcare assistants and nurses are viewed as the professional group best placed to deliver therapy carry‐over. However, whilst there is an acknowledgement of their role, there remains a reluctance to acknowledge healthcare assistants as a professional group and to involve them within decision‐making and discharge planning

Relevance to clinical practice.  Employers must be seen to advocate, support and implement education and training programs for healthcare assistants. However, whilst nurses and healthcare assistants have an integral role in rehabilitation, there needs to be more research into the how they are supported by therapy professionals.
Prospective pilot study of living kidney donor decision‐making and outcomes
Authors: Walton‐Moss Benita , Ebony Boulware L , Cooper Matthew , Taylor Laura , Dane Kathryn , Nolan Marie T
Published: October 2006

Abstract:  In its recent report on organ donation, the Institute of Medicine has recommended rigorous studies of how living organ donors make the decision to donate. In this pilot study, 65 donor applicants were interviewed while being evaluated in the outpatient donor clinic and 20 were surveyed again three months after donation. Fifteen and six of these subjects were surveyed again in six and 12 months respectively. Several strategies for retaining donors in a prospective longitudinal study are discussed. Half of the donors indicated that the decision to donate was a shared family decision. Married donors were slightly more likely than non‐married donors to involve another family member in this decision. Several donors made practical recommendations for improved education of donors during what many perceived to be a very lengthy evaluation process. Some subjects recommended more discussion about post‐operative pain and the expected pace of recovery after discharge. Others spoke of the challenge of completing basic homemaking tasks when the donor and recipient were in the same nuclear family. We are continuing to explore these and other aspects of donor decision‐making and outcomes and have expanded our sample to include non‐donors in the post‐evaluation period.
Biologic agents in psoriasis
Authors: Lee Michael R , Cooper Alan J
Published: October 2006

This paper reviews the new biologic agents that selectively block the immunologic steps implicated in the pathogenesis of psoriasis. Four strategies have been targeted: reduction of the number of pathogenic T cells; inhibition of T‐cell activation and migration; modulation of the immune system; and blockage of the activity of inflammatory cytokines. There are three classes: monoclonal antibodies, fusion proteins and recombinant cytokines or growth factors. The actions, efficacy and side‐effect profile of the biologic agents, alefacept, efalizumab, etanercept and infliximab, are reviewed.
Retrospective 5‐year review of 131 patients with mycosis fungoides and Sézary syndrome seen at the National Skin Centre, Singapore
Authors: Tan Eugene Sern Ting , Tang Mark Boon Yang , Tan Suat Hoon
Published: October 2006

A total of 131 new cases of mycosis fungoides and Sézary syndrome were diagnosed clinically and histopathologically at our centre over a 5‐year period. There were 87 males and 44 females with a mean age of 36.3 years (range 3–87 years) and no racial predilection. Of the 62 patients (47.3%) with classical mycosis fungoides, the majority were male (male : female = 4.2:1). There was one patient with Sézary syndrome. Patients aged older than 50 years were more likely to present with a longer duration of symptoms and advanced disease. In contrast to classical mycosis fungoides, the 47 patients diagnosed with hypopigmented mycosis fungoides had early stage disease, were younger, and no gender predilection was noted. The mean duration of follow up was 19.7 months (range 0.2–54.8 months). Complete remission was achieved in 24.7% and 53.8% of patients followed up at 1 and 3 years, respectively, using skin‐directed and systemic treatment modalities appropriate for the stage of disease. There were five patients with progressive disease and three patients with advanced disease who died from disease‐related complications. The most significant prognostic factors for 1‐year and 3‐year outcomes were the patient’s duration of symptoms and stage of disease at presentation.
Allopurinol induced generalized eosinophilic pustular folliculitis
Authors: Ooi Colin G , Walker Patrick , Sidhu Shireen K , Gordon Lynette A , Marshman Gillian
Published: October 2006

A 71‐year‐old Cambodian man who was commenced on allopurinol for the treatment of gout developed a generalized papulopustular follicular eruption 8 weeks following introduction of the drug. The skin biopsy findings were consistent with that of eosinophilic pustular folliculitis. Resolution of the rash took place during the 8 weeks following cessation of allopurinol and treatment with oral and topical corticosteroids.
Interstitial mycosis fungoides initially diagnosed as interstitial granulomatous drug reaction
Authors: Fuller Karyn
Published: October 2006

A 74 year old woman presented with a 1‐month history of symmetrical erythematous annular plaques involving her groin and medial thigh 3 to 4 years post commencing simvastatin. Initial histology was consistent with the diagnosis of interstitial granulomatous drug reaction (IGDR), however 11 months post cessation of Simvastatin the plaques were expanding in size. Repeat biopsy demonstrated features of interstitial mycosis fungoides (IMF).

IMF is a rare variant of mycosis fungoides. It has been reported to resemble granuloma annulare, inflammatory morphoea and IGDR with an interstitial lymphocytic infiltrate. IGDR presents most commonly with a history of asymptomatic, erythematous to violaceous plaques in an annular pattern, mainly involving the intertriginous areas, medial thighs and inner aspects of the arms. There is a temporal association between the initiation of drug therapy and lesional onset and resolution after cessation of the drug. It has clinical and histological features that overlap with IMF. This case of a rare variant of mycosis fungoides initially diagnosed as interstitial granulomatous drug reaction is presented to highlight the importance of recognising this differential diagnosis when presumed IGDR fails to resolve.
Pulse itraconazole vs. continuous terbinafine for the treatment of dermatophyte toenail onychomycosis in patients with diabetes mellitus
Authors: Gupta AK , Gover MD , Lynde CW
Published: October 2006

Background Oral terbinafine and oral itraconazole are two of the most common agents used for the treatment of toenail dermatophyte onychomycosis. Despite the fact that diabetic patients are more likely to have onychomycosis than normal individuals are, there is little research into the efficacy of standard oral regimens of terbinafine and itraconazole for onychomycosis in the diabetic population.

Study design We present a prospective, randomized, single‐blind, parallel group, comparator‐controlled, multi‐centre study designed to assess the efficacy of the pulse itraconazole (200 mg twice daily, 1 week on, 3 weeks off, for 12 weeks) vs. continuous terbinafine (250 mg once daily for 12 weeks) oral therapies in the treatment of dermatophyte toenail distal and lateral subungual onychomycosis (DLSO) in the diabetic population.

Efficacy parameters Primary efficacy measures included mycological cure rate (negative KOH and culture) and effective cure (mycological cure plus nail plate involvement of 10% or less) at Week 48.

Results At Week 48, mycological cure was attained by 88.2% (30 of 34) and 79.3% (23 of 29) of patients in the itraconazole and terbinafine groups, respectively (Pnot significant). Effective cure (mycological cure with ≤ 10% of nail plate involvement) was attained by 52.9% (18 of 34) of the itraconazole group and 51.7% (15 of 29) of the terbinafine group (Pnot significant). Three itraconazole patients experienced side effects in the form of gastrointestinal problems. There were no serious adverse events and no interactions with concomitant medications recorded.

Discussion Both continuous terbinafine and itraconazole pulse therapy are effective and safe in the management of dermatophyte toenail onychomycosis in people with diabetes.