bluuebunny/crossref_metadata_2025 huggingface dataset:
Passive acoustic monitoring of bottlenose dolphin and harbour porpoise, in Cardigan Bay, Wales, with implications for habitat use and partitioning
Authors: Simon Malene , Nuuttila Hanna , Reyes-Zamudio Mercedes M. , Ugarte Fernando , Verfub Ursula , Evans Peter G.H.
Published: February 2010

Knowledge about harbour porpoise and bottlenose dolphin occurrence in Cardigan Bay Special Area of Conservation (SAC), Wales, is limited to daylight hours during summer, when conditions are suitable for traditional visual surveys. T-PODs are autonomous instruments programmed to log time-cues of species-specific echolocation signals for long periods of time. Here we investigated bottlenose dolphin and harbour porpoise habitat use and partitioning by deploying ten calibrated T-PODs in Cardigan Bay SAC for one year. The T-PODs detected both species all year round with a peak of detections in April–October for dolphins and in October–March for porpoise, revealing a previously unknown importance of the place to harbour porpoise during winter. Though the two species are sympatric, simultaneous detections of both species were rare and indication of temporal habitat partitioning between the two species in some parts of the SAC was observed. The one location where simultaneous detections were not as rare was close to the stretch of shoreline where stranding of porpoises killed by dolphins are most common, suggesting that the observed spatiotemporal overlap leads to inter-specific interactions, in some cases fatal for the porpoise.
Growth, hatch size and maturation in a southern population of the loliginid squidLoliolus noctiluca
Authors: Ceriola Luca , Jackson George D.
Published: February 2010

Age, growth and cost of reproduction were examined for the small near-shore loliginid squidLoliolus noctilucain Tasmanian waters, near the southern limit of its distribution. The effects of several factors on hatch size were also evaluated by comparing the statolith natal ring size (NR) from individuals collected in different locations, seasons and years. The life cycle ofL. noctilucawas less than six months. July-hatched females grew faster than their May-hatched counterparts, indicating a faster growth in winter-hatched compared with autumn-hatched individuals. There was considerable variation in NRs as function of location, season, year and sex, with females displaying NRs considerably larger than males in any location and year. Immature and maturing females displayed poorer body condition than mature counterparts, suggesting that gonad growth does not affect the mantle or fin growth. A good condition was maintained also in spent individuals indicating thatL. noctilucacontinued to invest in somatic organs throughout the spawning period. A reproductive strategy closer to ‘multiple spawning’, than to ‘single spawning’ was proposed for this species.Loliolus noctilucawas used as a model to explore the possible effects of climate change on near-shore loliginid populations.
Growth and reproduction of Munida rutllanti (Decapoda: Anomura: Galatheidae) and impact of parasitism by Pleurocrypta sp. (Isopoda: Bopyridae) in the Adriatic Sea
Authors: Petrić Mirela , Ferri Josipa , Mladineo Ivona
Published: February 2010

Relative growth and reproductive biology of Munida rutllanti were investigated for the first time in the Adriatic Sea. A total of 938 individuals were analysed. Sex-ratio differed statistically from the expected 1:1. Six individuals exhibited secondary sex characteristics of both males and females. Carapace length of males ranged from 10.5 to 21.5 mm, while in females it ranged from 11.2 to 19.4 mm. Sexual dimorphism was observed in seven morphometric characters. Ovigerous females were first observed in summer and later in autumn with higher frequency. Realized fecundity showed wide variation (273–3250 eggs) and positive correlation between the brood and female size. An epicaridean isopod Pleurocrypta sp., parasitizing the gill chamber of both sexes was isolated and its effect on the oogenesis was studied by histological examination of host reproductive system. Growth inhibition, modification of secondary sex characteristics, as well as retardation of oogenesis and failure of oviposition, are repercussions of bopyrid infestation. Given the small prevalence (7.85%) of the bopyrid in the M. rutllanti Adriatic population, we assume that for the moment there is no severe effect on the host population dynamic.
Iron metabolism in trypanosomatids, and its crucial role in infection
Authors: TAYLOR M. C. , KELLY J. M.
Published: February 2010

Iron is almost ubiquitous in living organisms due to the utility of its redox chemistry. It is also dangerous as it can catalyse the formation of reactive free radicals – a classical double-edged sword. In this review, we examine the uptake and usage of iron by trypanosomatids and discuss how modulation of host iron metabolism plays an important role in the protective response. Trypanosomatids require iron for crucial processes including DNA replication, antioxidant defence, mitochondrial respiration, synthesis of the modified base J and, in African trypanosomes, the alternative oxidase. The source of iron varies between species. Bloodstream-form African trypanosomes acquire iron from their host by uptake of transferrin, andLeishmania amazonensisexpresses a ZIP family cation transporter in the plasma membrane. In other trypanosomatids, iron uptake has been poorly characterized. Iron-withholding responses by the host can be a major determinant of disease outcome. Their role in trypanosomatid infections is becoming apparent. For example, the cytosolic sequestration properties of NRAMP1, confer resistance against leishmaniasis. Conversely, cytoplasmic sequestration of iron may be favourable rather than detrimental toTrypanosoma cruzi. The central role of iron in both parasite metabolism and the host response is attracting interest as a possible point of therapeutic intervention.
Précis ofBayesian Rationality: The Probabilistic Approach to Human Reasoning
Authors: Oaksford Mike , Chater Nick
Published: February 2010

According to Aristotle, humans are the rational animal. The borderline between rationality and irrationality is fundamental to many aspects of human life including the law, mental health, and language interpretation. But what is it to be rational? One answer, deeply embedded in the Western intellectual tradition since ancient Greece, is that rationality concerns reasoning according to the rules of logic – the formal theory that specifies the inferential connections that hold with certainty between propositions. Piaget viewed logical reasoning as defining the end-point of cognitive development; and contemporary psychology of reasoning has focussed on comparing human reasoning against logical standards.

Bayesian Rationalityargues that rationality is defined instead by the ability to reason aboutuncertainty. Although people are typically poor at numerical reasoning about probability, human thought is sensitive to subtle patterns of qualitative Bayesian, probabilistic reasoning. In Chapters 1–4 ofBayesian Rationality(Oaksford & Chater 2007), the case is made that cognition in general, and human everyday reasoning in particular, is best viewed as solving probabilistic, rather than logical, inference problems. In Chapters 5–7 the psychology of “deductive” reasoning is tackled head-on: It is argued that purportedly “logical” reasoning problems, revealing apparently irrational behaviour, are better understood from a probabilistic point of view. Data from conditional reasoning, Wason's selection task, and syllogistic inference are captured by recasting these problems probabilistically. The probabilistic approach makes a variety of novel predictions which have been experimentally confirmed. The book considers the implications of this work, and the wider “probabilistic turn” in cognitive science and artificial intelligence, for understanding human rationality.
The Impact of Symptomatic Hoarding in OCD and its Treatment
Authors: Seaman Catherine , Oldfield Victoria B. , Gordon Olivia , Forrester Elizabeth , Salkovskis Paul M.
Published: February 2010

Background: The value of defining subtypes in obsessive compulsive disorder (OCD) has become an important issue for recent debate. Probably the most robust example of subtyping is the identification of hoarding as being different both in terms of psychopathology and response to treatment. Aims: To identify differences in psychopathology and treatment response in OCD patients with and without additional hoarding symptoms. Method: Patients who had undertaken CBT for OCD were selected as falling into either a high or a low hoarding group. The high hoarding group (n = 18) was selected on the basis of a high score on the hoarding subscale of a self-report measure of OCD symptoms in addition to reaching clinician judged “threshold” on the hoarding item of the Obsessive Compulsive Personality Disorder (OCPD) SCID-II module. The low hoarding group (n = 20) was selected on the basis of a low score on the hoarding subscale and a clinician judgement that the hoarding item of the OCPD SCID-II module was “absent”. Results: On some measures of pre-treatment psychopathology, patients with OCD with hoarding symptoms were more severely affected than those without hoarding symptoms. It was found that there was no difference in eventual treatment outcome between the two groups, although there was some evidence that the hoarding group showed greater symptom decreases. Conclusions: The presence of hoarding symptoms does not negatively impact on the treatment of OCD.
Effectiveness of Group and Individual Formats of a Combined Motivational Interviewing and Cognitive Behavioral Treatment Program for Problem Gambling: A Randomized Controlled Trial
Authors: Oei Tian P. S. , Raylu Namrata , Casey Leanne M.
Published: February 2010

Background: The study aimed to assess the effectiveness of group and individual formats of a combined motivational interviewing and cognitive behavioral treatment (CBT) program for problem gamblers (PGs) using a randomized controlled design. Method: One hundred and two PGs were randomly assigned to individual or group CBT conditions. Twenty-eight of these participants were randomly allocated to a 6-week waitlist control condition prior to receiving the designated treatment. Results: At post-treatment, there were significant improvements in all dependent variables (frequency and amount gambled, gambling urges, gambling cognitions, negative psychological states, and life satisfaction) for both the treatment conditions but not for the waitlist condition. Individuals that completed the individual (compared to group) treatment condition generally had higher effect sizes for gambling correlates. Therapeutic gains for gambling correlates were generally maintained at 6-month follow-up. Conclusions: A combined motivational interviewing and CBT program applied in group or individual format can improve PG behaviors, as well as gambling correlates.
Predicting cash flows related to defined benefit plan contributions
Authors: DOWDELL THOMAS D. , KLAMM BONNIE K. , SPINDLE ROXANNE M.
Published: February 2010

Future contributions to defined benefit pension plans are a significant cash flow item that can be difficult to estimate. Funding ratios – pension assets relative to pension liabilities – have long been considered important for estimating cash flows needed for current and future pension contributions (Ballester et al., 1998). However, US GAAP or IFRS funding ratios that companies report in their financial statements may differ from funding ratios used by pension regulators. These regulatory funding ratios may be more useful for predicting future contributions.

We investigate whether US regulatory and GAAP funding ratios are different and whether regulatory funding ratios provide useful information for predicting future contributions. For 3,877 firm years from 1995 through 2002, we observe that regulatory and GAAP funding ratios differ by more than 5% for 73% of our sample. We also find that predictions of future contributions are improved by using regulatory funding ratios in addition to GAAP funding ratios. Our results are relevant to accounting standard setters' ongoing review of pension accounting rules.
Characteristics of seismic and acoustic signals produced by calving, Bering Glacier, Alaska
Authors: Richardson Joshua P. , Waite Gregory P. , FitzGerald Katelyn A. , Pennington Wayne D.
Published: February 2010

We recorded 126 calving and iceberg breakup events from the terminus of the Bering Glacier during five days in August 2008 using seismometers and three small‐aperture arrays of infrasound sensors. The seismic signals were typically emergent, narrow‐band, and lower‐frequency, similar to records at other glaciers. The acoustic records were characterized by shorter‐duration, higher‐frequency signals with more impulsive onsets. We demonstrate that triangular infrasound arrays permit improved locations of calving events over seismic arrivals that rely on a relatively complicated, poorly known, velocity model. Twenty‐six of 35 well‐located events occurred on icebergs in Vitus Lake, rather than the glacier face. While our data do not permit a complete description of the source process, the distinctive frequency contents and durations in the seismic and infrasound data suggest that the two data types record different aspects of the same process.
Spatial variation in extreme winds predicts large wildfire locations in chaparral ecosystems
Authors: Moritz Max A. , Moody Tadashi J. , Krawchuk Meg A. , Hughes Mimi , Hall Alex
Published: February 2010

Fire plays a crucial role in many ecosystems, and a better understanding of different controls on fire activity is needed. Here we analyze spatial variation in fire danger during episodic wind events in coastal southern California, a densely populated Mediterranean‐climate region. By reconstructing almost a decade of fire weather patterns through detailed simulations of Santa Ana winds, we produced the first high‐resolution map of where these hot, dry winds are consistently most severe and which areas are relatively sheltered. We also analyzed over half a century of mapped fire history in chaparral ecosystems of the region, finding that our models successfully predict where the largest wildfires are most likely to occur. There is a surprising lack of information about extreme wind patterns worldwide, and more quantitative analyses of their spatial variation will be important for effective fire management and sustainable long‐term urban development on fire‐prone landscapes.
Climate engineering by artificial ocean upwelling: Channelling the sorcerer's apprentice
Authors: Oschlies A. , Pahlow M. , Yool A. , Matear R. J.
Published: February 2010

Recent suggestions to reduce the accumulation of anthropogenic carbon dioxide in the atmosphere have included ocean fertilization by artificial upwelling. Our coupled carbon‐climate model simulations suggest that artificial upwelling may, under most optimistic assumptions, be able to sequester atmospheric CO2 at a rate of about 0.9 PgC/yr. However, the model predicts that about 80% of the carbon sequestered is stored on land, as a result of reduced respiration at lower air temperatures brought about by upwelling of cold waters. This remote and distributed carbon sequestration would make monitoring and verification particularly challenging. A second caveat predicted by our simulations is that whenever artificial upwelling is stopped, simulated surface temperatures and atmospheric CO2 concentrations rise quickly and for decades to centuries to levels even somewhat higher than experienced in a world that never engaged in artificial upwelling.
Influence of the electric field perpendicular to the current sheet on ion beamlets in the magnetotail
Authors: Dolgonosov M. S. , Zimbardo G. , Greco A.
Published: February 2010

Several studies, both experimental, analytical, and numerical, show that a substantial electrostatic field Ez perpendicular to the magnetotail current sheet can be found. This electric field has a typical bipolar structure. We propose a theoretical analysis describing the ion behavior in the vicinity of the current sheet under the influence of Ez in a two‐dimensional taillike magnetic field reversal. It is shown that for some initial parameters resonant acceleration is possible, forming beamlets (small‐scale and almost monoenergetic field‐aligned ion beams). To check the analytical results, a test particle simulation has been performed, where the dawn‐dusk electric field Ey is also present to accelerate particles. We find that for electric field Ez pointing away (or toward) the current sheet, the beamlet resonant regions are shifted toward the Earth (or away from the Earth) resulting in decreasing (or increasing) typical energy of ions leading to the modification of the universal scaling predicted by Zelenyi et al. (2007). Another effect due to the presence of Ez is an overlapping of beamlet energies to form a wide energetic beam. Implications for beamlet observations are discussed.
Magnetic pumping of whistler waves by tether current modulation
Authors: Sanchez‐Arriaga G. , Sanmartin J. R.
Published: February 2010

Magnetic excitation of whistlers by a square array of electrodynamic tethers is discussed. The array is made of perpendicular rows of tethers that carry equal, uniform, and time‐modulated currents at equal frequency with a 90° phase shift. The array would fly vertical in the orbital equatorial plane, which is perpendicular to the geomagnetic field B0 when its tilt is ignored. The array radiates a whistler wave along B0. A parametric instability due to pumping by the background magnetic field through the radiated wave gives rise to two unstable coupled whistler perturbations. The growth rate is maximum for perturbations with wave vector at angles 38.36° and 75.93° from B0. For an experiment involving a wavefront that moves with the orbiting array, which might serve to study nonlinear wave interactions and turbulence in space plasmas, characteristic values of growth rate and parameters, such as the number of tethers and their dimensions and distances in the array, are discussed for low Earth orbit ambient conditions.
Isotopic and geochemical evidence for a recent transition in mantle chemistry beneath the western Canadian Cordillera
Authors: Manthei Christian D. , Ducea Mihai N. , Girardi James D. , Patchett P. Jonathan , Gehrels George E.
Published: February 2010

New petrologic, geochemical, and isotopic data are reported from a suite of mafic dike and lava flow samples collected from sites within the western Canadian Cordillera. Samples range in age from Eocene to Quaternary and document a significant transition in mantle chemistry that occurred sometime after 10 Ma. Eocene to late Miocene basalts emplaced as dikes within the Coast Mountains Batholith contain abundant hornblende, are enriched in large ion lithophile elements (LILE) (Ba, Rb, K), have negative high field strength element (HFSE) (Nb, Ta) anomalies, and were likely derived from lithospheric mantle (87Sr/86Sr = 0.70353–0.70486; ɛNd = +2.5 to +5.7) that was stabilized after the cessation of arc magmatism in the area. By contrast, Quaternary lava flows have lower LILE concentrations, positive Nb‐Ta anomalies, and were likely generated by upwelling asthenosphere (87Sr/86Sr = 0.70266–0.70386; ɛNd = +7.4 to +8.8) or at least a mantle source with different chemical and isotopic characteristics. A regional comparison of mafic rocks from western Canada that are also Eocene to Quaternary in age indicates that the transition in mantle chemistry after 10 Ma was pervasive and widespread and was not limited to the present study area. This transition occurred ∼40 Ma after the cessation of Cordilleran arc magmatism in central British Columbia, suggesting that large‐scale transitions in mantle chemistry beneath magmatic arcs may occur on the order of tens of millions of years after the final subduction of oceanic lithosphere, in this case as a result of lithospheric thinning by continental extension.
On the generation and evolution of nonlinear internal waves in the South China Sea
Authors: Buijsman M. C. , Kanarska Y. , McWilliams J. C.
Published: February 2010

The nonhydrostatic Regional Ocean Modeling System is applied to the nonlinear internal waves, or solitons, that are generated at the Luzon ridge in the South China Sea. The Luzon ridge near the Batan islands is represented by an idealized ridge with a height of 2.6 km on a flat bottom. Model runs are performed for various ridge shapes and (a)symmetric tidal forcings. The model is in the mixed tidal lee wave regime. The barotropic tide over the ridge generates first‐mode waves through the internal tide release mechanism. Westward‐traveling solitons emerge from these first‐mode waves through nonlinear steepening. In the internal tide release mechanism, asymmetric tides with strong eastward currents can generate strong westward solitons. The eastward current creates an elevation wave with a higher energy density west of the ridge, and as soon as the current slackens, the wave is released westward. On its backslope strong solitons develop. The energy density is further enhanced by nonlinearities, such as differences in phase speeds and energy fluxes related to lee waves. A modal and harmonic decomposition shows the generation of vertical modes and higher temporal harmonics and indicates significant wave‐wave interaction (e.g., triads). In the mixed tidal lee wave regime, more energy is contained in the first mode compared to the higher modes. Hence, linear internal tide beams are less well defined and strong solitons develop.
Sediment transport under wave groups: Relative importance between nonlinear waveshape and nonlinear boundary layer streaming
Authors: Yu Xiao , Hsu Tian‐Jian , Hanes Daniel M.
Published: February 2010

Sediment transport under nonlinear waves in a predominately sheet flow condition is investigated using a two‐phase model. Specifically, we study the relative importance between the nonlinear waveshape and nonlinear boundary layer streaming on cross‐shore sand transport. Terms in the governing equations because of the nonlinear boundary layer process are included in this one‐dimensional vertical (1DV) model by simplifying the two‐dimensional vertical (2DV) ensemble‐averaged two‐phase equations with the assumption that waves propagate without changing their form. The model is first driven by measured time series of near‐bed flow velocity because of a wave group during the SISTEX99 large wave flume experiment and validated with the measured sand concentration in the sheet flow layer. Additional studies are then carried out by including and excluding the nonlinear boundary layer terms. It is found that for the grain diameter (0.24 mm) and high‐velocity skewness wave condition considered here, nonlinear waveshape (e.g., skewness) is the dominant mechanism causing net onshore transport and nonlinear boundary layer streaming effect only causes an additional 36% onshore transport. However, for conditions of relatively low‐wave skewness and a stronger offshore directed current, nonlinear boundary layer streaming plays a more critical role in determining the net transport. Numerical experiments further suggest that the nonlinear boundary layer streaming effect becomes increasingly important for finer grain. When the numerical model is driven by measured near‐bed flow velocity in a more realistic surf zone setting, model results suggest nonlinear boundary layer processes may nearly double the onshore transport purely because of nonlinear waveshape.
Transport and evolution of a pollution plume from northern China: A satellite‐based case study
Authors: Li Can , Krotkov Nickolay A. , Dickerson Russell R. , Li Zhanqing , Yang Kai , Chin Mian
Published: February 2010

On 5 April 2005, during the East Asian Study of Tropospheric Aerosols: An International Regional Experiment (EAST‐AIRE) aircraft campaign, heavy loadings of SO2 (20 ppb near ground, 1–3 ppb at ∼2 km altitude) and dust with aerosol optical depth of ∼1 were measured over Shenyang, an industrialized city ∼600 km NE of Beijing. In this study, Ozone Monitoring Instrument (OMI) and MODIS satellite sensors are employed to look into this air pollution episode at a regional scale and to track the transport and evolution of the plume from China to the NW Pacific on the following days. A method is proposed to combine in situ measurements and trajectory tracer modeling with satellite observations to quantify the change in the SO2 mass during plume transport. We demonstrate that an air mass factor correction is needed for quantitative use of the OMI SO2 data, to account for the effects of the viewing geometry, the SO2 profile shape, and the aerosol/cloud interference on retrievals. The total SO2 loading of the plume decreased from ∼1.1 × 1011 g on 5 April to ∼5.0 × 1010 g on 7 April. The overall, e‐folding lifetime of SO2 in this plume, empirically derived from the rate of SO2 decay, was ∼2 days (range of 1–4 days). SO2 to sulfate conversion increased the aerosol optical depth by ∼0.1–0.4 near the center of the plume on 6 and 7 April, while the loss of primary dust particles reduced the aerosol loading of the plume by a similar amount. Simulations with a chemical transport model suggest similar loss of dust and formation of sulfate within the plume during transport. The method established in this study can be further developed and applied to study other episodes of pollution transport and their impact on weather and climate.
Schumann resonances excitation due to positive and negative cloud‐to‐ground lightning
Authors: Surkov V. V. , Hayakawa M.
Published: February 2010

In this paper, we have applied a statistical approach to the problem of Schumann resonances excitation due to both negative and positive cloud‐to‐ground lightning (−CG and +CG, respectively). Correlation matrices and a power spectrum of natural electromagnetic variations resulted from the global lightning activity are estimated. On the basis of these estimates we have shown that the global +CG lightning activity can make a significant contribution to the low‐frequency portion of power spectrum and to the Schumann resonances. Despite their infrequent occurrence compared to the negative flashes, the global +CG lightning can be of primary importance in generating the power spectrum since their charge moment and continuing current are, on average, larger than those of the −CG lightning.
Two‐relaxation‐time lattice Boltzmann method for the anisotropic dispersive Henry problem
Authors: Servan‐Camas Borja , Tsai Frank T.‐C.
Published: February 2010

This study develops a lattice Boltzmann method (LBM) with a two‐relaxation‐time collision operator (TRT) to cope with anisotropic heterogeneous hydraulic conductivity and anisotropic velocity‐dependent hydrodynamic dispersion in the saltwater intrusion problem. The directional‐speed‐of‐sound technique is further developed to address anisotropic hydraulic conductivity and dispersion tensors. Forcing terms are introduced in the LBM to correct numerical errors that arise during the recovery procedure and to describe the sink/source terms in the flow and transport equations. In order to facilitate the LBM implementation, the forcing terms are combined with the equilibrium distribution functions (EDFs) to create pseudo‐EDFs. This study performs linear stability analysis and derives LBM stability domains to solve the anisotropic advection‐dispersion equation. The stability domains are used to select the time step at which the lattice Boltzmann method provides stable solutions to the numerical examples. The LBM was implemented for the anisotropic dispersive Henry problem with high ratios of longitudinal to transverse dispersivities, and the results compared well to the solutions in the work of Abarca et al. (2007).
Impacts of precipitation seasonality and ecosystem types on evapotranspiration in the Yukon River Basin, Alaska
Authors: Yuan Wenping , Liu Shuguang , Liu Heping , Randerson James T. , Yu Guirui , Tieszen Larry L.
Published: February 2010

Evapotranspiration (ET) is the largest component of water loss from terrestrial ecosystems; however, large uncertainties exist when estimating the temporal and spatial variations of ET because of concurrent shifts in the magnitude and seasonal distribution of precipitation as well as differences in the response of ecosystem ET to environmental variabilities. In this study, we examined the impacts of precipitation seasonality and ecosystem types on ET quantified by eddy covariance towers from 2002 to 2004 in three ecosystems (grassland, deciduous broadleaf forest, and evergreen needleleaf forest) in the Yukon River Basin, Alaska. The annual precipitation changed greatly in both magnitude and seasonal distribution through the three investigated years. Observations and model results showed that ET was more sensitive to precipitation scarcity in the early growing season than in the late growing season, which was the direct result of different responses of ET components to precipitation in different seasons. The results demonstrated the importance of seasonal variations of precipitation in regulating annual ET and overshadowing the function of annual precipitation. Comparison of ET among ecosystems over the growing season indicated that ET was largest in deciduous broadleaf, intermediate in evergreen needleleaf, and lowest in the grassland ecosystem. These ecosystem differences in ET were related to differences in successional stages and physiological responses.
Roles of Organometal(loid) Compounds in Environmental Cycles
Authors: Thayer John S.
Published: February 2010

Organo compounds form an integral part of the environmental cycles of metals and metalloids. For phosphorus, selenium, and (possibly) arsenic, they are biochemical necessities. For others, they create enhanced mobility and altered biological effects. Investigations in this area grew out of human introduction of these compounds or their precursors into the natural environment.
Organoarsenicals. Distribution and Transformation in the Environment
Authors: Reimer Kenneth J. , Koch Iris , Cullen William R.
Published: February 2010

The widespread distribution of organoarsenic compounds has been reviewed in terms of the five kingdoms of life. Over 50 organoarsenicals are described. Pathways for their formation are discussed and significant data gaps have been identified.
Alkyl Derivatives of Antimony in the Environment
Authors: Filella Montserrat
Published: February 2010

The presence of methylated antimony species has been reported in surface waters, sediments, soils, and biota, mainly detected using hydride generation techniques. Compared to other elements, relatively few studies have been published. Monomethyl-, dimethyl-, and trimethylantimony species have been found, always at very low concentrations. It is important to point out that (i) it has been proved that the identity of some of the published species might be uncertain due to possible artefacts during the analytical process; (ii) existing analytical methods do not reveal the oxidation state of the antimony in the detected species. Volatile methylated species have also been detected in landfill and sewage fermentation gases. Laboratory culture experiments have indicated that biomethylation can result from bacterial, yeast, and fungal activity, in both aerobic and anaerobic conditions. Antimony is methylated much less rapidly and less extensively than arsenic and it has been suggested that antimony biomethylation could be a fortuitous rather than a detoxification process.
Formation, Occurrence, Significance, and Analysis of Organoselenium and Organotellurium Compounds in the Environment
Authors: Wallschläger Dirk , Feldmann Jörg
Published: February 2010

Among all environmentally-relevant trace elements, selenium has one of the most diverse organic chemistries. It is also one of the few trace elements that may biomagnify in food chains under certain conditions. Yet, the exact chemical forms of selenium involved in the uptake into organisms and transfer to higher trophic levels, as well as the biochemical mechanisms that lead to their subsequent metabolism in organisms, are still not well understood. This is in part due to the analytical challenges associated with measuring the myriad of discrete Se species occurring in organisms. While there are generalized concepts of selenium metabolism, there is a lack of conclusive analytical evidence supporting the existence of many postulated intermediates. Likewise, there is a disconnect between the major selenium species encountered in abiotic compartments (waters, soils, and sediment), and those found in organisms, which renders the qualitative and quantitative description of the bioaccumulation process uncertain. Here, we summarize the knowledge on important selenium and tellurium species in all environmental compartments, and identify gaps and uncertainties in the existing body of knowledge, with emphasis on problems associated with past and current analytical methodology.
Organomercurials. Their Formation and Pathways in the Environment
Authors: Hintelmann Holger
Published: February 2010

The most important mercury species in the environment is monomethylmercury (MMHg), the topic of this chapter. This organic mercury compound is normally not released into the environment but formed by natural processes. Mercuric mercury (Hg2+) is methylated by bacteria and to a lesser extent through abiotic pathways. Highest rates of formation are found in anoxic aquatic environments. Terrestrial systems are mostly irrelevant for MMHg production and not a concern. Most productive environments are sediments, wetlands, and coastal marshes, but also the anoxic hypolimnion of lakes and anaerobic microhabitats like the rhizosphere of floating macrophytes. Prime suspects for methylation are sulfate-reducing bacteria, although also iron reducers have lately been identified as capable mercury methylators. What makes methylmercury such an insidious contaminant is its enormous biomagnification potential. Methylmercury is accumulated by more than seven orders of magnitude from sub ng/L concentrations in water to over 1,000,000 ng/kg in piscivorous fish, which are the main concern from a human health point of view. Since methylmercury is a very potent neurotoxin, particularly small children, pregnant women, and women in childbearing age are advised to either limit their fish consumption to a few meals per week or to select fish species known to have low levels of methylmercury. Formation of methylmercury is counteracted by other bacteria, which are capable of demethylating methylmercury. This process is regulated by an inducible mer operon system and serves as a detoxification mechanism in polluted environments. The other naturally occurring organic mercury species, dimethylmercury (DMHg), is only present at very low levels at great depths in the world oceans. However, it might be an important and very mobile pre-cursor for methylmercury in marine and polar ecosystems.
Prevalence of other sexually transmissible infections in patients with newly diagnosed anogenital warts in a sexual health clinic
Authors: Sturgiss Elizabeth A. , Jin Fengyi , Martin Sarah J. , Grulich Andrew , Bowden Francis J.
Published: February 2010

Background: Anogenital warts are a common initial presentation to the Canberra Sexual Health Centre. It is anticipated that the introduction of human papillomavirus vaccination will reduce the incidence of anogenital warts. The present study determines the prevalence of other sexually transmissible infections in patients newly diagnosed with warts who may not have presented for screening without the impetus of a genital lump. Methods: The prevalence of other sexually transmissible infections in new patients presenting to the Canberra Sexual Health Centre diagnosed with anogenital warts was determined from a retrospective clinical audit from 2002 to 2007. Results: A total of 1015 new patients were diagnosed with anogenital warts. Of this total cohort, 53 (5.2%) were found to be co-infected with either chlamydia and/or gonorrhoea. Only 13.2% of co-infected patients reported symptoms other than genital lumps. Of co-infected patients 11.3% reported contact with a partner with chlamydia and/or gonorrhoea. Not all patients were screened for other sexually transmissible infections: 762 (75.1%) were screened for chlamydia and 576 (56.7%) were screened for gonorrhoea. Of those tested, 6.8% of men and 6.9% of women were positive for chlamydia highlighting the importance of offering full sexually transmissible infection screening in those newly diagnosed with anogenital warts. Chlamydia was more common in younger patients who reported a higher number of sexual partners. Conclusions: It is anticipated that human papillomavirus vaccination will lead to a decline in anogenital wart incidence as well as other human papillomavirus associated disease. Although one opportunity for testing for other sexually transmissible infections may be lost in this population, the decrease in anogenital warts will leave clinicians with more time to pursue other screening programs. Education and screening campaigns should continue to focus on the asymptomatic nature of the majority of sexually transmissible infections.
A case of apparent resistance to all available antiretroviral drugs in a HIV-positive patient
Authors: Chibo Doris , Roth Norman , Birch Chris
Published: February 2010

We describe a case of multidrug and class resistant HIV in a patient with psychological issues affecting his adherence. The complexities involved in subsequent treatment decisions when resistance interpretation algorithms are discordant are discussed.
Aboriginal health worker screening for sexually transmissible infections and blood-borne viruses in a rural Australian juvenile correctional facility
Authors: Templeton David J. , Tyson Beverley A. , Meharg Joel P. , Habgood Katalin E. , Bullen Patricia M. , Malek Sharafat , McLean Rick
Published: February 2010

Introduction: In Australia, Aboriginal youth are disproportionately represented in juvenile detention centres. We assessed the prevalence of sexually transmissible infections (STIs) and blood-borne viruses (BBVs) identified by an Aboriginal Health Worker (AHW)-led screening program delivered to male detainees of a rural juvenile detention centre. Methods: A retrospective review of first screening visit data was performed. Demographic and behavioural data were collected and the prevalence of STI/BBV was assessed. Results: Over a 4-year period to November 2004, 101 screens on new medium-to-long-term detainees were performed. The median age of participants was 17 years (range 14–20) and 87% were Aboriginal. Most reported multiple lifetime sexual partners (mean 14, range 0–60) and a minority had used a condom for the last episode of vaginal intercourse. Injecting drug use and non-professional tattoos or piercings were both reported by over one-third of participants, with over 80% reporting previous incarceration. One-quarter of those screened were newly diagnosed with one or more STI/BBV. The most common infection identified was urethral chlamydia (prevalence 16.3%, 95% confidence interval 10.0–25.5%), although the prevalence of newly diagnosed syphilis, hepatitis B and hepatitis C were each over 5%. Many participants remained susceptible to hepatitis B. Conclusion: An AHW-led STI/BBV screening program identified a large number of asymptomatic and previously undiagnosed infections in this group of young male detainees. Such an education and screening program using skilled Aboriginal staff not affiliated with the correctional system could have a substantial impact on the prevalence of STI/BBV among juvenile detainees.
A cross-sectional study of reported symptoms for sexually transmissible infections among female sex workers in Papua New Guinea
Authors: Bruce Eunice , Bauai Ludwina , Masta Andrew , Rooney Poyap J. , Paniu Michael , Sapuri Mathias , Keogh Louise , Kaldor John , Fairley Christopher K.
Published: February 2010

Background: Sexually transmissible infections (STIs) are common in female sex workers (FSWs), most of which are asymptomatic and therefore under-reported. Our aim was to determine the sensitivity and specificity of reported symptoms obtained via questionnaire augmented with leukocyte esterase (LE) urine dipstick test for the detection of Chlamydia trachomatis (Ct), Neisseria gonorrhea (Ng) and Trichomonas vaginalis (Tv) detected using polymerase chain reaction (PCR). Methods: In November 2003, a cohort of FSWs was screened for STIs and completed a questionnaire. Results: We enrolled 129 FSWs (90% participation rate) of whom 48 (37%), 30 (23%) and 53 (41%) were diagnosed with Ng, Ct and Tv, respectively, by PCR. Of those diagnosed with any of these infections, 78% reported anogenital symptoms and of those without infections, 28% reported symptoms. Anogenital symptoms were present in over 50% FSWs. Genital odour (present in 26%), lower abdominal pain (present in 29%), dysuria (present in 19%) had a sensitivity around (50%), specificity (>80%) and all were significantly associated with positive PCR results for individual organisms; however, the sensitivity of these symptoms to detect the presence of any positive PCR result was low (<50%). When LE urine dipstick test result of >1 was combined with the presence of three reported symptoms the sensitivity was 86%, specificity of 73% and a positive predictive value of 72%; a better predictor of infections. Conclusions: Our finding suggest an approach that incorporates LE urine dipstick test >1 and multiple symptoms may be a feasible option for screening infections among FSWs in resource constraint settings.
Risk factors for herpes simplex virus type 2 and its association with HIV among pregnant teenagers in Zimbabwe
Authors: Munjoma Marshall W. , Mapingure Munyaradzi P. , Stray-Pedersen Babill
Published: February 2010

Herpes simplex virus type 2 (HSV-2) causes a chronic infection that is recognised as the leading cause of genital ulcer disease worldwide and is known to increase the risk of HIV infection. In a cross-sectional study we examined risk factors for HSV-2 among 176 pregnant teenagers recruited from three primary health care clinics in Zimbabwe. The prevalence of HSV-2 and HIV were 41.6% and 29.2% respectively. HIV-infected teenagers were more likely to be HSV-2 seropositive compared with the HIV uninfected teenagers, odds ratio (OR) 7.9 (95% confidence interval (CI) 3.7–16.9). In multivariate analysis having an older partner remained independently associated with HSV-2 seropositivity, OR 2.9 (95% CI 1.2–6.9) suggesting that risk factors for HSV-2 seropositivity among pregnant teenagers depend primarily on the behaviour of the male partners.
Quantum chemical treatments of metal clusters
Authors: Weigend Florian , Ahlrichs Reinhart
Published: February 2010

This work focuses on finding and rationalizing the building principles of clusters with approximately 300 atoms of different types of metals: main group elements (Al, Sn), alkaline earth metals (Mg), transition metals (Pd) and clusters consisting of two different elements (Ir and Pt). Two tools are inevitable for this purpose: (i) quantum chemical methods that are able to treat a given cluster with both sufficient accuracy and efficiency and (ii) algorithms that are able to systematically scan the (3
n
−6)-dimensional potential surface of an
n
-atomic cluster for promising isomers. Currently, the only quantum chemical method that can be applied to metal clusters is density functional theory (DFT). Other methods either do not account for the multi-reference character of metal clusters or are too expensive and thus can be applied only to clusters of very few atoms, which usually is not sufficient for studying the building principles. The accuracy of DFT is not known
a priori
, but extrapolations to bulk values from calculated series of data show satisfying agreement with experimental data. For scans of the potential surface, simulated annealing techniques or genetic algorithms were used for the smaller clusters (approx. 20–30 atoms), and for the larger clusters considerations were restricted to selected packings and shapes. For the mixed-metallic clusters, perturbation theory turned out to be efficient and successful for finding the most promising distributions of the two atom types at the different sites.
Determining the size-dependent structure of ligand-free gold-cluster ions
Authors: Schooss Detlef , Weis Patrick , Hampe Oliver , Kappes Manfred M.
Published: February 2010

Ligand-free metal clusters can be prepared over a wide size range, but only in comparatively small amounts. Determining their size-dependent properties has therefore required the development of experimental methods that allow characterization of sample sizes comprising only a few thousand mass-selected particles under well-defined collision-free conditions. In this review, we describe the application of these methods to the geometric structural determination of Au
+

n

and Au
−

n

with
n
= 3–20. Geometries were assigned by comparing experimental data, primarily from ion-mobility spectrometry and trapped ion electron diffraction, to structural models from quantum chemical calculations.
Surface modification, functionalization and bioconjugation of colloidal inorganic nanoparticles
Authors: Sperling R. A. , Parak W. J.
Published: February 2010

Inorganic colloidal nanoparticles are very small, nanoscale objects with inorganic cores that are dispersed in a solvent. Depending on the material they consist of, nanoparticles can possess a number of different properties such as high electron density and strong optical absorption (e.g. metal particles, in particular Au), photoluminescence in the form of fluorescence (semiconductor quantum dots, e.g. CdSe or CdTe) or phosphorescence (doped oxide materials, e.g. Y
2
O
3
), or magnetic moment (e.g. iron oxide or cobalt nanoparticles). Prerequisite for every possible application is the proper surface functionalization of such nanoparticles, which determines their interaction with the environment. These interactions ultimately affect the colloidal stability of the particles, and may yield to a controlled assembly or to the delivery of nanoparticles to a target, e.g. by appropriate functional molecules on the particle surface. This work aims to review different strategies of surface modification and functionalization of inorganic colloidal nanoparticles with a special focus on the material systems gold and semiconductor nanoparticles, such as CdSe/ZnS. However, the discussed strategies are often of general nature and apply in the same way to nanoparticles of other materials.
How plants manipulate the scatter-hoarding behaviour of seed-dispersing animals
Authors: Vander Wall Stephen B.
Published: February 2010

Some plants that are dispersed by scatter-hoarding animals appear to have evolved the ability to manipulate the behaviour of those animals to increase the likelihood that seeds and nuts will be stored and that a portion of those items will not be recovered. Plants have achieved this in at least four ways. First, by producing large, nutritious seeds and nuts that are attractive to animals and that stimulate hoarding behaviour. Second, by imposing handling costs that cause animals to hoard rather than to eat items immediately. These handling costs can take one of two forms: physical barriers (e.g. hard seed coats) that take time to remove and secondary chemicals (e.g. tannins) that impose metabolic costs. Third, by masting, where a population of plants synchronizes reproductive effort, producing large nut crops at intervals of several years. Mast crops not only satiate seed predators, but also increase the amount of seed dispersal because scatter-hoarding animals are not easily satiated during caching (causing animals to store more food than they can consume) but are satiated during cache recovery. And fourth, by producing seeds that do not emit strong odours so that buried seeds are less likely to be discovered. These, and perhaps other, traits have increased the relative success of plant species with seeds dispersed by scatter-hoarding animals.