bluuebunny/crossref_metadata_2025 huggingface dataset:
Excess vacancies in high energy ion implanted SiGe
Authors: Kögler R. , Mücklich A. , Skorupa W. , Peeva A. , Kuznetsov A. Yu. , Christensen J. S. , Svensson B. G.
Published: February 2007

Excess vacancies generated by high energy implantation with 1.2MeV Si+ and 2MeV Ge+ ions in SiGe were investigated after rapid thermal annealing at 900°C. Excess vacancies were probed by decoration with Cu and measuring the Cu profile by secondary ion mass spectrometry. Cross section transmission electron microscopy of cleaved specimen enabled to visualize nanocavities resulting from agglomeration of excess vacancies. The ion-induced damage in SiGe increases with increasing Ge fraction of the alloy. The amorphization threshold decreases and the extension of a buried amorphous layer increases for given implantation and annealing conditions. In contrast to ballistic simulations of excess defect generation where perfect local self-annihilation is assumed the concentrations of excess vacancies and excess interstitials in SiGe increase with increasing Ge fraction. The main contribution to the high excess vacancy concentration in SiGe results from the inefficient recombination of vacancies and interstitials. The widely used +1 model describing the ion-induced damage in Si is not valid for SiGe.
Nanometer scale x-ray absorption spectroscopy and chemical states mapping of ultra thin oxides on silicon using electrostatic force microscopy
Authors: Ishii M. , Hamilton B. , Poolton N. R. J. , Rigopoulos N. , De Gendt S. , Sakurai K.
Published: February 2007

Electrostatic force microscopy (EFM) was used to obtain highly spatially resolved spectroscopic and image information of semiconductor surface region. EFM with x-ray source (X-EFM) can probe x-ray induced photoionization of near surface electron trapping. The X-EFM signal dependent on x-ray photon energy results in nanometer scale x-ray absorption spectra. Furthermore, probing tip scanning at fixed x-ray photon energy provides chemical states imaging of the trapping. The authors demonstrate characterization of substoichiometric chemical oxidation of a Si surface with less than 1nm spatial resolution.
Candlestick oven with a silica wick provides an intense collimated cesium atomic beam
Authors: Pailloux A. , Alpettaz T. , Lizon E.
Published: February 2007

This article shows that readily available glass and silica fibers and braids are suitable capillary structure for recirculating ovens, such as candlestick ovens, becoming then an alternative wick material to conventional metal based capillary structures. In order to study wettability and capillarity of metallic liquid cesium on borosilicate and silica microstructures, samples were selected, prepared, and tested experimentally. The contact angle of cesium on silica glass was roughly measured: θ=35°±10°. A commercially available silica braid was then introduced inside a candlestick oven to transfer the metallic liquid cesium from the cold reservoir to the hot emission point of the candlestick. A collimated cesium atomic beam of intensity of 2×1016at.∕ssr was obtained, stable and reproducible. Furthermore, this modified oven is easy to handle daily.
Internal magnetostatic potentials of magnetization-graded ferromagnetic materials
Authors: Sudakar C. , Naik R. , Lawes G. , Mantese J. V. , Micheli A. L. , Srinivasan G. , Alpay S. P.
Published: February 2007

The authors investigated the internal magnetic field induced by a spatially varying magnetization in a compositionally graded ferromagnet. The authors discuss results on a hexagonal ferrite sample, with a variation in saturation magnetization of 30emu∕g over a sample thickness of 2.5mm. The direct current magnetization shows a small anisotropy depending on the direction of the external magnetic field relative to the grading direction. This contribution from a grading induced magnetic field is more pronounced in alternating current susceptibility measurements. The authors find a shift in magnetic properties corresponding to an internal magnetic field of 30Oe, which is significantly lower than the predicted value of approximately 1900Oe. The authors discuss reasons for this discrepancy.
Fe-based bulk metallic glass with high plasticity
Authors: Yao K. F. , Zhang C. Q.
Published: February 2007

Fe-based bulk metallic glasses usually exhibit very poor ductility (<0.5%), which has limited their applications. Here the authors report an Fe-based bulk metallic glass which shows a plastic strain of ∼5.2%, together with high strength and distinct strain-hardening characteristics. Its yield strength is ∼2.32GPa, while the ultimate strength is ∼2.80GPa due to the strain-hardening effect. Multiple shear bands and related shear ledges are observed on the deformed specimen. The high plasticity and strain hardening are attributed to the nanoscale inhomogeneity that resulted from liquid phase separation, which can hinder the propagation of shear bands and promote multiple shearing.
High-performance, large area, deep ultraviolet to infrared polarizers based on 40 nm line/78 nm space nanowire grids
Authors: Wang Jian Jim , Walters Frank , Liu Xiaoming , Sciortino Paul , Deng Xuegong
Published: February 2007

Large-area, 100mm in diameter, aluminum nanowire grids with 40nm line/78nm space were fabricated with full-wafer immersion interference lithography. The aluminum nanowire grids with a 59nm half-pitch work as a highly efficient optical polarizer for deep ultraviolet wavelength down to ∼250nm. In addition, an extremely high contrast from 10 000:1 to 50 000:1 was achieved across the whole visible and near-infrared wavelength range, along with good transmittance (85%–90%). The broadband large-area high-performance polarizer operating down to deep ultraviolet wavelength opens up applications including semiconductor lithography and metrology applications.
Fast scanning of a pulsed terahertz signal using an oscillating optical delay line
Authors: Jin Yun-Sik , Jeon Seok-Gy , Kim Geun-Ju , Kim Jung-Il , Shon Chae-Hwa
Published: February 2007

We describe a fast measurement of a pulsed terahertz signal generated by a femtosecond laser and a photoconductive antenna using an oscillating optical delay line. The method to measure the amplitude of the retroreflector in the oscillating optical delay line is proposed and the displacement of the retroreflector is exactly calculated to acquire the optical delay time in the fast scan mode. With the different oscillation frequency and amplitude of the retroreflector, the pulsed terahertz signals are measured and analyzed. The comparison of the temporal waveform and frequency spectrum between the fast scan mode and the slow scan mode shows a good agreement with the decrease in the scanning time from 60to1s at a signal to noise ratio of 430.
Influence of spontaneous polarization on the electrical and optical properties of bulk, single crystal ZnO
Authors: Allen M. W. , Miller P. , Reeves R. J. , Durbin S. M.
Published: February 2007

Hall effect, photoluminescence, and Schottky diode measurements were made on the Zn-polar and O-polar faces of undoped, bulk, single crystal, c-axis ZnO wafers. Significant polarity related differences were observed in the PL and Schottky diode characteristics of low carrier concentration, hydrothermally grown wafers. Increased emission from free exciton recombinations and from recombinations between 3.3725 and 3.3750eV was observed on the Zn-polar face. Conversely, emission between 3.3640 and 3.3680eV was more intense on the O-polar face. The barrier heights of silver oxide Schottky diodes were approximately 130meV larger on the Zn-polar face compared to the O-polar face.
Room temperature ferromagnetism in Zn1−xCuxO thin films
Authors: Chakraborti D. , Narayan J. , Prater J. T.
Published: February 2007

Here the authors report systematic studies on the epitaxial growth and properties of Zn1−xCuxO (x=0.02–0.1) thin films deposited onto sapphire c-plane single crystals using pulsed-laser deposition. X-ray diffraction and high resolution transmission electron microscopy (HRTEM) were employed to study the epitaxial relations of Zn1−xCuxO with the substrate, and x-ray photoelectron spectroscopy was used to establish the bonding characteristics and oxidation states of copper inside the ZnO host. Room temperature ferromagnetism was observed in the Zn1−xCuxO films with magnetic moment per Cu atom decreasing with an increasing Cu content. The presence of any magnetic phase was ruled out using HRTEM. Thus, the ferromagnetism was attributed to Cu ions substituted into the ZnO lattice.
Influence of defects in n−-GaN layer on the responsivity of Schottky barrier ultraviolet photodetectors
Authors: Zhao D. G. , Jiang D. S. , Zhu J. J. , Liu Z. S. , Zhang S. M. , Liang J. W. , Yang Hui , Li X. , Li X. Y. , Gong H. M.
Published: February 2007

The influence of defects on the responsivity of GaN Schottky barrier ultraviolet photodetectors with n−-GaN∕n+-GaN layer structures is investigated. It is found that employing undoped GaN instead of Si-doped GaN as the n−-GaN layer brings about a higher responsivity due to a lower Ga vacancy concentration. On the other hand, the dislocations may increase the recombination of electron-hole pairs and enhance the surface recombination in the photodetectors. Employing undoped GaN and reducing the dislocation density in the n−-GaN layer are necessary to improve the responsivity of Schottky barrier photodetectors.
Organic nanochannel field-effect transistor with organic conductive wires
Authors: Sakai Masatoshi , Nakamura Masakazu , Kudo Kazuhiro
Published: February 2007

The authors fabricated an organic nanochannel field-effect transistor (FET) that is self-wired with highly conductive organic conductors. The advantages of the transistor are a short channel (approximately 400nm in length) and spontaneous formation of an active layer of the FET. Further, in principle, the carrier-injection barrier is absent at the interface of the organic metal and organic semiconductor. Thus, the transistor is highly conductive despite the narrow cross section of the channel. The FET characteristics of the nanochannel transistor exhibit the n-channel enhancement mode behavior.
Major erosion at the end of the Messinian Salinity Crisis: evidence from the Levant Basin, Eastern Mediterranean
Authors: Bertoni C. , Cartwright J. A.
Published: February 2007

This paper presents a detailed analysis of the top of the Messinian evaporites (Horizon M) in the Levant region, offshore Israel, based on the integration of three‐dimensional (3D)/2D seismic and well data. 3D mapping of a series of intra‐evaporite horizons and their termination against Horizon M provides new insights into the depositional setting and structural evolution of this saline giant system. New evidence of a discordant relationship between the intra‐evaporite horizons and the top of the Messinian evaporites (Horizon M) is given by the seismic stratigraphic analysis. This confirms that the top of the Messinian evaporites represents an erosional unconformity of semiregional extent in the Levant region. The truncation of the folded and faulted intra‐evaporite horizons indicates for the first time a Messinian phase of evaporite deformation, i.e. pre‐dating the well‐documented Plio‐Pleistocene thin‐skinned tectonic phase in the region. This major erosional unconformity is interpreted as subaerial in origin, documenting the exposure of the evaporitic system at the end of the Messinian Salinity Crisis. These results give new evidence for the understanding of the events occurring during the last stages of the Messinian Salinity Crisis in the region.
Potential novel hosts for the lily leaf beetle Lilioceris lilii Scopoli (Coleoptera: Chrysomelidae) in eastern North America
Authors: ERNST CRYSTAL , CAPPUCCINO NAOMI , ARNASON JOHN THOR
Published: February 2007

Abstract 1. Introduced insects often incorporate native plants into their diets and might be expected to show a predilection for novel hosts that are phylogenetically related to their normal hosts. The lily leaf beetle, Lilioceris lilii (Coleoptera: Chrysomelidae), is an introduced pest of cultivated lilies. Oviposition behaviour, larval behaviour, and development of L. lilii was examined on a range of potential host plants, as well as on the normal host, Asiatic hybrid lilies Lilium sp.

2. Neonate larval feeding behaviour was quantified on 15 food plant species: 10 from the Liliales, three from the Asparagales and two eudicots. Larvae fed plants closely related to the genus Lilium were more likely to initiate feeding, less likely to abandon their food leaf, and consumed more leaf area.

3. In no‐choice tests, females oviposited on the novel hosts Lilium philadelphicum, Medeola virginiana, Clintonia borealis, Streptopus amplexifolius, and Polygonatum biflorum; however, all but L. philadelphicum received very few eggs. Non‐Lilium novel hosts were not used for oviposition when presented along with Asiatic lilies in choice tests.

4. A single individual was reared to the adult stage on the novel host S. amplexifolius. Several larvae survived to the pupal stage on M. virginiana, although no adults emerged from those pupae. Larvae reared on the native wood lily L. philadelphicum performed equally well or better than on the Asiatic cultivar.

5. Our results indicate that the lily leaf beetle poses a threat to native Liliaceae. Several native Lilium species, including L. philadelphicum, are threatened or endangered in certain jurisdictions throughout their range; these species should be monitored closely for colonisation by the beetle.
Host‐dependent differences in prey acquisition between populations of a kleptoparasitic spider Argyrodes kumadai (Araneae: Theridiidae)
Authors: BABA YUKI G. , WALTERS RICHARD J. , MIYASHITA TADASHI
Published: February 2007

Abstract 1. A kleptoparasitic spider, Argyrodes kumadai, is known to use phylogenetically unrelated host species in different regions –Cyrtophora moluccensis (Araneidae) in south‐west Japan and Agelena silvatica (Agelenidae) in north‐east Japan. The work reported here examined whether differences in host characters affect prey acquisition of A. kumadai.

2. Field surveys showed that prey‐biomass capture rate of Argyrodes was significantly higher in populations parasitising Cyrtophora than in populations parasitising Agelena. Although Argyrodes appeared to catch fewer prey within Cyrtophora webs, they were able to feed upon substantially larger prey.

3. Differences in prey‐biomass capture rate were found to reflect differences in host traits rather than regional differences in potential prey availability. Individuals in populations parasitising Cyrtophora were observed to acquire prey via a number of foraging tactics that included stealing wrapped food bundles, feeding upon prey remains and, in the case of large prey items, feeding together with the host. In contrast, individuals in populations parasitising Agelena were only ever observed to feed upon small prey items ignored by its host.

4. This variability in prey acquisition between kleptoparasite populations reflected different opportunities for feeding within their respective host webs – opportunities that were primarily determined by the foraging behaviour of the host. One key trait associated with host foraging behaviour was host‐web structure, namely the presence/absence of a retreat.
Effects of dietary nicotine on the development of an insect herbivore, its parasitoid and secondary hyperparasitoid over four trophic levels
Authors: HARVEY JEFFREY A. , VAN DAM NICOLE M. , WITJES LEONTIEN M. A. , SOLER ROXINA , GOLS RIETA
Published: February 2007

Abstract 1. Allelochemicals in herbivore diet are known to affect the development of higher trophic levels, such as parasitoids and predators.

2. This study examines how differing levels of nicotine affects the development of a herbivore, its parasitoid and secondary hyperparasitoid over four trophic levels. Separate cohorts of the herbivore, Manduca sexta, were fed on artificial diets containing 0.0, 0.1, and 0.5% wet weights of nicotine. Some of the larvae in each cohort were separately parasitised in the first (L1) and third (L3) instars by the gregarious endoparasitoid, Cotesia congregata. Newly emerged parasitoid cocoons were, in turn, parasitised by the hyperparasitoid, Lysibia nana.

3. Pupal mass in M. sexta was negatively correlated with nicotine concentrations in the artificial diet, although larval development time was unaffected.

4. Hyperparasitoid survival was highest when there were low levels of nicotine in the diet of M. sexta. Cocoon mass in C. congregata and adult mass in L. nana were mostly affected by nicotine levels in host diet when L1 M. sexta larvae were parasitised. The effects were slightly stronger on L. nana than on C. congregata, indicating the presence of both qualitative and quantitative effects of nicotine concentration on both species.

5. The results suggest that allelochemicals in herbivore diet can have both direct and indirect effects on the performance of higher trophic levels. However, in multitrophic interactions these effects can vary with the stage of the herbivore attacked by the primary parasitoid, as well as with the strategy employed by the herbivore to deal with plant phytotoxins.
Species richness estimation and determinants of species detectability in butterfly monitoring programmes
Authors: KÉRY MARC , PLATTNER MATTHIAS
Published: February 2007

Abstract1. Species richness is the most widely used biodiversity index, but can be hard to measure. Many species remain undetected, hence raw species counts will often underestimate true species richness. In contrast, capture–recapture methods estimate true species richness and correct for imperfect and varying detectability.

2. Detectability is a crucial quantity that provides the link between a species count and true species richness. For insects, it has hardly ever been estimated, although this is required for the interpretation of species counts.

3. In the Swiss butterfly monitoring programme about 100 transect routes are surveyed seven times a year using a highly standardised protocol. In July 2003, control observers made two additional surveys on 38 transects. Data from these 38 quadrats were analysed to see whether currently available capture–recapture models can provide quadrat‐specific estimates of species richness, and to estimate species detectability in relation to transect, observer, survey, region, and abundance.

4. Species richness over the entire season cannot be estimated using current capture–recapture methods. The species pool was open, preventing use of closed population models, and detectability varied by species, preventing use of current open population models. Assuming a closed species pool during two mid‐season (July) surveys, a Jackknife capture–recapture method was used that accounts for heterogeneity to estimate mean detectability and species richness.

5. In every case, more species were present than were counted. Mean species detectability was 0.61 (SE 0.01) with significant differences between observers (range 0.37–0.83). Species‐specific detection at timet+ 1 was then modelled for those species seen attfor three mid‐season surveys. Detectability averaged 0.50 (range 0.17–0.81) for individual species and 0.65, 0.44, and 0.42 for surveys. Abundant species were detected more easily, although this relationship explained only 5% of variation in species detectability.

6. These are important, although not entirely unexpected, results for species richness estimation of short‐lived animals. Raw counts of species may be misleading species richness indicators unless many surveys are conducted. Monitoring programmes should be calibrated, i.e. the assumption of constant detectability over dimensions of interest needs to be tested. The development of capture–recapture or similar models that can cope with both open populations and heterogeneous species detectability to estimate species richness should be a research priority.
Conserved oviposition preferences in alpine leaf beetle populations despite host shifts and isolation
Authors: VERDON ALINE , MARGRAF NICOLAS , DAVISON ANTHONY C. , RAHIER MARTINE , NAISBIT RUSSELL E.
Published: February 2007

Abstract 1. Choosing the plant on which to lay their eggs is the last act of care that most female herbivorous insects bestow upon their offspring. These decisions play a pivotal role in insect–plant interactions, placing host preference under strong selection and contributing to the diversity of phytophagous insects as one of the first traits to adapt to new hosts.

2. This study presents a test of whether extreme isolation and exposure to different host plants can produce intra‐specific divergence in oviposition preference in alpine insects. Geographic variation should impose selection to fine‐tune host plant ranking and specificity to the plants normally encountered, to avoid wasting time during the very limited reproductive season experienced at high altitudes.

3. Beetles from five populations of Oreina elongata differing in host availability were offered three natural hosts: Cirsium spinosissimum, Adenostyles alliariae, and Adenostyles glabra. A novel application of a continuation ratio model (logistic regression) was made to sequential no‐choice experiments, combined with quasi‐likelihood analysis of multiple‐choice experiments.

4. The results show little geographic variation in host plant choice: all populations strongly preferred Cirsium in multiple‐choice trials, and in no‐choice experiments laid around 47% of their remaining eggs during each stage, almost regardless of the host present.

5. Enemy‐free space seems to explain the preference for Cirsium, but isolation and exposure to different plants has clearly not caused local adaptation in host plant ranking or specificity. Reasons for this conservatism despite divergence in other characteristics are discussed.
Heterospecific ovicide influences the outcome of competition between two endoparasitoids, Encarsia formosa and Encarsia luteola
Authors: COLLIER TIMOTHY R. , HUNTER MARTHA S. , KELLY SUZANNE E.
Published: February 2007

Abstract 1. Studies of inter‐specific competition in parasitoids have largely focused on the outcome of within‐host competition and the behavioural mechanisms by which female parasitoids prevent competition. Another, less well studied, possibility is oviposition preceded by ‘heterospecific ovicide’, the destruction of the other species’ egg. Heterospecific ovicide essentially eliminates within‐host competition.

2. This study investigated the mechanisms and outcome of within‐host competition in Encarsia formosa and Encarsia luteola, solitary endoparasitoids of whitefly pests. These species are known to commit ovicide of conspecific eggs.

3. Competition experiments indicated that the offspring of second‐ovipositing females had an apparent advantage in competition, regardless of whether the second female was E. formosa or E. luteola.

4. Observations of ovipositor movement through the cuticle of host whitefly nymphs showed that both species often committed heterospecific ovicide and then oviposited or host‐fed. Multiparasitism and heterospecific host discrimination were less common and absent respectively.

5. Heterospecific ovicide appears to explain the second‐female advantage in competition between these species. Second‐female advantage is contrary to the paradigmatic view of multiparasitism, where the first‐ovipositing female has an advantage in competition or one of the species consistently prevails in competition.
The adaptive nature of non‐food collection for the Florida harvester ant, Pogonomyrmex badius
Authors: SMITH CHRIS R. , TSCHINKEL WALTER R.
Published: February 2007

Abstract 1. Many animals forage for non‐food objects, such as nesting materials. In many organisms, the depots of such objects can be expansive, and are not intuitively adaptive. This study empirically explores varying theories for why these depots exist in the Florida harvester ant, Pogonomyrmex badius.

2. The Florida harvester ant, like its western congeners, collects and deposits large quantities of non‐food objects around its nest entrance. The vast majority of objects sampled from colonies in this study population were charcoal pieces whereas most western species collect pebbles.

3. Objects in these depots can number in the millions, suggesting a large cost to this behaviour and strengthening an adaptationist argument.

4. Many hypotheses have been suggested for these depots, including temperature and water modification and territoriality. No evidence was found to support the results of a previous study which found that charcoal depots deter other ant species.

5. The depots do not appear to affect soil hydrology, but do slightly increase soil temperature at the very top of the nest. In an attempt to estimate the seasonal fitness of colonies with and without charcoal depots, no statistical difference was detected in sexual investment between treatment groups.

6. These results suggest that the charcoal depots may be selectively advantageous through temperature modification, but may serve alternate functions that are species and habitat specific.
Aphid dispersal flight disseminates fungal pathogens and parasitoids as natural control agents of aphids
Authors: FENG MING‐GUANG , CHEN CHUN , SHANG SU‐WEI , YING SHENG‐HUA , SHEN ZHI‐CHENG , CHEN XUE‐XIN
Published: February 2007

Abstract 1. Dispersal flight, a well‐known strategy for aphids to locate suitable plants, was studied for its possible role in disseminating fungal pathogens and parasitoids as natural control agents of aphids by air captures in Hangzhou, China during 2001–2005. Up to 3183 migratory alates of green peach aphid Myzus persicae were captured from air using a yellow‐plus‐plant trap on the top platform of a six‐storey building in an urbanised area, and individually reared in a laboratory for ≥ 7 days.

2. Among the captured alates, 28.9% survived on average for 2.5 days and then died from mycoses attributed to 10 species of obligate or non‐obligate aphid pathogens. These were predominated by Pandora neoaphidis, which was causative of 80% of the mycosed alates. Another 4.4% survived for an average of 3.7 days, followed by mummification of Aphidius gifuensis (52.9%) and Diaeretella rapae (47.1%).

3. Numerous progeny colonies individually initiated by infected, parasitised, or healthy alates were monitored daily for 12 days, and fitted well to a logistic equation depicting the potential of their post‐flight colonisation and fecundity. Both infected and parasitised alates from air were highly capable of initiating progeny colonies independently, although their potential fecundity was greatly reduced compared with that of healthy counterparts.

4. Our results confirmed that both obligate and non‐obligate pathogens can be widespread with aphid dispersal flight, and demonstrated that parasitoids also took advantage of the host flight for their dispersal. This study provides new insights into aphid dispersal biology.
Sublethal effect of brood parasitism on the grass‐carrying wasp Isodontia mexicana
Authors: O’NEILL KEVIN M. , O’NEILL JAMES F. , O’NEILL RUTH P.
Published: February 2007

Abstract 1. The nests of solitary, nest‐provisioning wasps (Sphecidae and Crabronidae) are commonly attacked by brood parasites, including flies of the families Phoridae and Sarcophagidae. Larvae of the flies commonly kill the wasp offspring directly or starve it by consuming prey provided by the adult female wasps.

2. To determine whether brood parasitic flies can have a sublethal effect (i.e. reduced body size) on wasp offspring, nests of the wasp Isodontia mexicana were collected at two field sites in upstate New York, U.S.A. Nest diameter had no effect on the probability that a wasp cell would be inhabited by a brood parasite. Most offspring that developed in cells also containing phorids or sarcophagids managed to complete development and emerge as adults. Nevertheless, they had significantly smaller body size than conspecifics emerging from unparasitised cells in which the developing wasp did not have to compete for food (which in this species consists of tree crickets and katydids). Apparently, this is the first time that a sublethal effect of brood parasitism on offspring body size has been quantified for a solitary wasp species. Known effects of body size on the reproductive success of adult wasps suggest that sublethal consequences of the presence of brood parasites may have a significant effect on the fitness of adult I. mexicana.
The spatial pattern of soil‐dwelling termites in primary and logged forest in Sabah, Malaysia
Authors: DONOVAN SARAH E. , GRIFFITHS GEORGIANNE J. K. , HOMATHEVI RAHMAN , WINDER LINTON
Published: February 2007

Abstract 1. Primary and logged lowland dipterocarp forest sites were sampled for subterranean termites using soil pits located on a grid system in order to detect any patchiness in their distribution.

2. A spatial pattern in termite distributions was observed in the primary and logged sites, but the response differed between soil‐feeding and non‐soil‐feeding termites.

3. Spatial analysis showed that soil‐feeding termites were homogeneously distributed in the primary forest but significantly aggregated in the logged forest. This pattern was reversed for non‐soil‐feeding termites and may result from differences in resource provisioning between the two sites.

4. Gaps in termite distribution comprised a greater area than patches for both feeding groups and sites, but gaps dominated the logged site.

5. A significant association between soil‐feeding and non‐soil‐feeding termite distributions occurred at both sites. This arose from an association between patches in the primary forest and between gaps in the logged forest.

6. Termite spatial pattern was optimally observed at a minimum extent of 64 m and lag of 2 m.

7. The spatially explicit SADIE (Spatial Analysis by Distances IndicEs) analyses were more successful than (non‐spatially explicit) multivariate analysis (Canonical Correspondence Analysis) at detecting associations between termite spatial distributions and that of other biotic and abiotic variables.
The role of food and colony size in sexual offspring production in a social insect: an experiment
Authors: SORVARI JOUNI , HAKKARAINEN HARRI
Published: February 2007

Abstract1. Large colonies of ants are known to have a higher propensity for sexual offspring production, probably owing to their high capacity to exploit food resources.

2. The effects of food supplementation on the propensity for sexual offspring production, and whether it is linked with colony size, were investigated in an environment with poor resources (clear‐cut areas).

3. Large colony size was associated with a higher propensity for sexual offspring production in food‐supplemented colonies, whereas in non‐supplemented control colonies an association with colony size was not found.

4. The results demonstrate that large colonies seem to have a higher capacity to exploit supplemented food. In addition, the production of sexual offspring was apparently limited by food availability in clear‐cuts, especially for large colonies.
Reconsidering the conceptualization of nursing workload: literature review
Authors: Morris Roisin , MacNeela Padraig , Scott Anne , Treacy Pearl , Hyde Abbey
Published: February 2007

Aim.  This paper reports a literature review that aimed to analyse the way in which nursing intensity and patient dependency have been considered to be conceptually similar to nursing workload, and to propose a model to show how these concepts actually differ in both theoretical and practical terms.

Background.  The literature on nursing workload considers the concepts of patient ‘dependency’ and nursing ‘intensity’ in the realm of nursing workload. These concepts differ by definition but are used to measure the same phenomenon, i.e. nursing workload.

Method.  The literature search was undertaken in 2004 using electronic databases, reference lists and other available literature. Papers were sourced from the Medline, Psychlit, CINAHL and Cochrane databases and through the general search engine Google. The keywords focussed on nursing workload, nursing intensity and patient dependency.

Findings.  Nursing work and workload concepts and labels are defined and measured in different and often contradictory ways. It is vitally important to understand these differences when using such conceptualizations to measure nursing workload. A preliminary model is put forward to clarify the relationships between nursing workload concepts.

Conclusion.  In presenting a preliminary model of nursing workload, it is hoped that nursing workload might be better understood so that it becomes more visible and recognizable. Increasing the visibility of nursing workload should have a positive impact on nursing workload management and on the provision of patient care.
Can nurses help identify patients with depression following stroke? A pilot study using two methods of detection
Authors: Lightbody C. Elizabeth , Baldwin Robert , Connolly Martin , Gibbon Bernard , Jawaid Naila , Leathley Michael , Sutton Chris , Watkins Caroline L.
Published: February 2007

Aim.  This paper reports a study to determine the accuracy of the Geriatric Mental State examination and the Montgomery–Asberg Depression Rating Scale, when administered by a nurse, in detecting depression in patients who have recently had a stroke.

Background.  After a stroke, survivors spend considerable amounts of time in the direct care of nurses. Many show signs of depression, and this has been associated with an adverse effect on recovery and rehabilitation. Identifying those with depression when they have communication and cognitive difficulties is especially difficult. Treatments are available to assist in the management of depression, and early detection and intervention may assist in this process.

Method.  A cross‐sectional pilot study was conducted, comparing (a) clinical diagnosis of depression by a psychiatrist with (b) two clinical interviews, using the Geriatric Mental State examination and the Montgomery–Asberg Depression Rating Scale, conducted by a nurse. The data were collected in 2002.

Findings.  Twenty‐eight patients, who were still in hospital in the second week poststroke, were included. The median age was 72 (interquartile range: 61–78). There were 14 males. The psychiatrist rated seven (25%) patients as depressed. The Geriatric Mental State examination had a sensitivity of 71%, a specificity of 67%, a positive predictive value of 42%, a negative predictive value of 88% in detecting depression and an overall efficiency of 68%. The Montgomery–Asberg Depression Rating Scale had a sensitivity of 100%, a specificity of 65%, a positive predictive value of 54%, a negative predictive value of 100% and an overall efficiency of 75%.

Conclusion.  In this study, the Geriatric Mental State examination and the Montgomery–Asberg Depression Rating Scale were at least as efficient at detecting the depression in patients who have had a stroke. However, as the Montgomery–Asberg Depression Rating Scale is quicker to administer, it may prove more useful to nurses clinically.
Predictors of treatment adherence in young children with type 1 diabetes
Authors: Chisholm Vivienne , Atkinson Leslie , Donaldson Caroline , Noyes Kathryn , Payne Anne , Kelnar Chris
Published: February 2007

Aim.  This paper reports a study to investigate whether diabetes‐specific, demographic and psychosocial variables predict adherence in young children with type 1 diabetes.

Background.  Paediatric diabetes rates are increasing worldwide; however, young children are neglected in treatment adherence research, despite the importance of adherence for health. Greater understanding of adherence in this group could enhance nurses’ ability to provide care tailored to families’ needs.

Method.  A cross‐sectional study was carried out between 2001 and 2003 with 65 children aged 2–8 years and their mothers in Britain. Mothers were interviewed about children's diabetes care, nutritional analyses were conducted and mothers completed assessments of diabetes knowledge, parenting stress, family functioning and child psychological adjustment. Demographic and medical information was collected from patient records.

Findings.  Consistent with older populations, blood glucose monitoring and dietary regimens showed greater adherence variability than injection frequency and injection time consistency. Better maternal diabetes knowledge correlated with less injection time variability, more frequent blood glucose monitoring, lower percentage energy intake from extrinsic sugars, lower glycosylated haemoglobin levels and fewer relationship difficulties. Longer diabetes duration, greater injection time variability and higher percentage energy intake from extrinsic sugars predicted less frequent blood glucose monitoring. More relationship difficulties and less frequent blood glucose monitoring predicted higher percentage energy intake from extrinsic sugars.

Conclusions.  Nurses can facilitate treatment adherence through provision of educational, practical and socio‐emotional support. Nursing interventions should target blood glucose monitoring and dietary regimens in particular, and nurses should be sensitive to the various caretaking challenges presented to parents by different components of the diabetes regimen.
Patients’ preferences shed light on the murky world of guideline‐based medicine
Authors: Penston James
Published: February 2007

Concordance – that is, shared decision‐making between doctors and patients – is nowadays accepted as an integral part of good clinical practice. It is of particular importance in the case of treatments with only marginal benefits such as those recommended in guidelines for the management of common, chronic diseases. However, the implementation of guideline‐based medicine conflicts with that of concordance.

Studies indicate that patients are not adequately informed about their treatment. Clinical guidelines for conditions such as cardiovascular disease are based on large‐scale randomized trials and the complex nature of the data limits effective communication especially in an environment characterized by time constraints. But other factors may be more relevant, notably pressures to comply with guidelines and financial rewards for meeting targets: it is simply not in the interests of doctors to disclose accurate information. Studies show that patients are far from impressed by the small benefits derived from large scale trials. Indeed, faced with absolute risk reductions, patients decline treatment promoted by guidelines.

To participate in clinical decisions, patients require unbiased information concerning outcomes with and without treatment, and the absolute risk reduction; they should be told that most patients receiving long‐term medication obtain no benefit despite being exposed to adverse drug reactions; furthermore, they should be made aware of the questionable validity of large‐scale trials and that these studies may be influenced by those with a vested interest.

Genuine concordance will inevitably lead to many patients rejecting the recommendations of guidelines and encourage a more critical approach to clinical research and guideline‐based medicine.
Accessing rural populations: role of the community pharmacist in a breast and cervical cancer screening programme
Authors: McGuire Timothy R. , Leypoldt Melissa , Narducci Warren A. , Ward Kathy
Published: February 2007

Rationale Community pharmacists are one of the most frequently visited health care providers in the USA. The article describes a demonstration project which used community pharmacists to educate and enrol low to moderate income and medically under‐served women into a statewide breast and cervical cancer screening programme.

Methods The Nebraska Department of Health programme entitled, ‘Every Woman Matters’, funded through the Centers of Disease Control and Prevention, provided no cost or low cost mammography and pap smears to eligible women. Patient enrolment packets were distributed to 91 pharmacies expressing an initial interest in participating. These were reduced to 28 pharmacies based on their commitment level during the initial 3 months of the study.

Results One hundred and fourteen patient referrals were generated from the 28 network pharmacies; two from pharmacies in urban areas, and 112 referrals from rural sites. All referrals were from the 22 independently owned pharmacies in the study.

Conclusions Results suggest that the use of independent community pharmacies in the rural setting can be an effective method of recruiting women into public health programmes.
Guard‐cell apoplastic sucrose concentration – a link between leaf photosynthesis and stomatal aperture size in the apoplastic phloem loader Vicia faba L.
Authors: KANG YUN , OUTLAW WILLIAM H. , ANDERSEN PETER C. , FIORE GIORDANO B.
Published: February 2007

In broad bean (Vicia faba L.), an apoplastic phloem loader, the sucrose concentration increases up to ∼ 2 mM in the leaf apoplast and up to ∼ 150 mM in the guard‐cell apoplast during the photoperiod. This high concentration in the guard‐cell apoplast results from transpiration and is sufficient osmotically to reduce stomatal aperture size by up to 3 µm or ∼ 25% of the maximum aperture size. In this paper, we investigated a parallel and required role for high bulk‐leaf apoplastic sucrose concentration, which correlates with high photosynthesis rate. An empirically determined combination of lowered light intensity and lowered CO2 concentration reduced the photosynthesis rate to nominally one‐fifth of the control value without a significant change in transpiration. This reduction in photosynthesis caused the sucrose concentration in the leaf apoplast – the immediate source pool for guard cells – to decrease by 70% (to 0.4 mM). In turn, sucrose concentration in the guard‐cell apoplast decreased by ∼ 80% (to ∼ 40 mM). These results complete the required evidence for a non‐exclusive, transpiration‐linked, photosynthesis‐dependent passive mechanism for the modulation of stomatal aperture size. In an ancillary investigation, hexoses in the bulk‐leaf apoplast decreased when photosynthesis was lowered, but their concentrations in the guard‐cell apoplast of control plants indicated that their osmotic contribution was negligible.
The Na+ transporter AtHKT1;1 controls retrieval of Na+ from the xylem in Arabidopsis
Authors: DAVENPORT ROMOLA JANE , MUÑOZ‐MAYOR ALICIA , JHA DEEPA , ESSAH PAULINE ADOBEA , RUS ANA , TESTER MARK
Published: February 2007

HKT‐type transporters appear to play key roles in Na+ accumulation and salt sensitivity in plants. In Arabidopsis HKT1;1 has been proposed to influx Na+ into roots, recirculate Na+ in the phloem and control root : shoot allocation of Na+. We tested these hypotheses using 22Na+ flux measurements and ion accumulation assays in an hkt1;1 mutant and demonstrated that AtHKT1;1 contributes to the control of both root accumulation of Na+ and retrieval of Na+ from the xylem, but is not involved in root influx or recirculation in the phloem. Mathematical modelling indicated that the effects of the hkt1;1 mutation on root accumulation and xylem retrieval were independent. Although AtHKT1;1 has been implicated in regulation of K+ transport and the hkt1;1 mutant showed altered net K+ accumulation, 86Rb+ uptake was unaffected by the hkt1;1 mutation. The hkt1;1 mutation has been shown previously to rescue growth of the sos1 mutant on low K+; however, HKT1;1 knockout did not alter K+ or 86Rb+ accumulation in sos1.
Phylogenetic relationships and pathogenicity of Colletotrichum acutatum isolates from grape in subtropical Australia
Authors: Whitelaw‐Weckert M. A. , Curtin S. J. , Huang R. , Steel C. C. , Blanchard C. L. , Roffey P. E.
Published: February 2007

The identity of Colletotrichum acutatum as the causal pathogen of grape ripe‐rot, which causes yield loss and a bitter taint that lowers wine quality in Australian subtropical wine‐grape regions, was confirmed using species‐specific primers. Cultural, morphological and molecular methods (RAPD‐PCR and sequencing of parts of the 5·8S‐ITS regions and the β‐tubulin‐2 gene) were used to determine the phylogenetic relationships of Australian C. acutatum isolates from wine grapes and other horticultural crops. A combination of RAPD‐PCR and β‐tubulin‐2 gene data showed that all wine‐grape ripe‐rot isolates from northern regions of New South Wales (NSW) and Queensland belong to a proposed new C. acutatum group (A9), together with isolates from Australian strawberry, mango, blueberry and olive. The 5·8S‐ITS sequences for these grape pathogens were identical to published sequences for an isolate from Cyclamen (the Netherlands) and differed by 1 bp from isolates from Capsicum (Taiwan) and orange (Costa Rica). The grape ripe‐rot isolates from the Shoalhaven Valley (southern NSW) were clustered within two other C. acutatum groups: A2 and A5. In vitro infection studies showed that Australian C. acutatum isolates from almond, blueberry, chilli, grape, mango, olive, strawberry and tomato were able to infect grape and could also infect blueberry and strawberry, indicating a lack of host specificity. This lack of host specificity, the genetic similarity with non‐grape isolates, and the fact that many of the non‐grape hosts were isolated from wine‐growing regions, suggest the potential for cross‐infection between grape and other horticultural crops.
Revision of the net‐winged midge genus Horaia Tonnoir and its phylogenetic relationship to other genera within the tribe Apistomyiini (Diptera: Blephariceridae)
Authors: GIBSON JOEL F. , COURTNEY GREGORY W.
Published: February 2007

Abstract Based partly on recent collections from Nepal and northern Thailand, new data are added to the knowledge of Horaia Tonnoir. Pupal and larval stages of H. montana Tonnoir are re‐described, larval descriptions for H. manaliella (Kaul) are provided, and two new species, H. diminutiva and H. namtoki, and a new subspecies, H. montana piedmonti, are described. Dichotomous keys to adults, pupae and instar IV larvae of blepharicerid genera from south‐east Asia and of all known species of the genus Horaia are provided. Phylogenetic analysis of the tribe Apistomyiini suggests that Horaia is a monophyletic genus closely related to a clade containing Apistomyia Bigot and Parapistomyia Zwick. This clade is, in turn, sister to a weakly supported clade comprising Theischingeria Zwick +Austrocurupira Dumbleton. The New Zealand endemics Peritheates Lamb +Neocurupira Lamb are proposed as sister group to other apistomyiines, within which Nothohoraia Craig + (Curupirina Stuckenberg +Nesocurupira Stuckenberg) is sister group to the remaining genera. The proposed phylogeny supports Zwick’s Antarctic origin hypothesis for the biogeography of the Apistomyiini in Asia and Australasia.
Object Exploration of Garden and Sardinian Warblers Peaks in Spring
Authors: Mettke‐Hofmann Claudia
Published: February 2007

Seasonality of environments is a widespread phenomenon and many species show seasonal behavioural changes as an adaptation to this environmental variability. Exploratory behaviour, an important means to obtain information about the environment, varies between species depending on different costs and benefits of exploration under various environmental conditions or life styles. It can be expected that exploration also varies intraspecifically over the annual cycle according to seasonally changing costs and benefits of exploration due to seasonal environments and/or an organism's requirements. Captive garden and Sardinian warblers were confronted with five different and novel objects in their familiar aviary over the course of 1 yr. Both species showed a seasonal peak in object exploration in spring and low exploration values throughout the rest of the year indicating that knowledge about the environment is particularly important during the time of territory or nest‐site selection. Furthermore, the year‐round resident Sardinian warblers were more explorative than the migratory garden warblers. Residents have to be well informed about their environment and changes therein, whereas this is less important for migrants. This corroborates earlier findings in parrots and seems to be a general phenomenon consistent across taxa.