bluuebunny/crossref_metadata_2025 huggingface dataset:
Commentary: The Year in Nuclear Receptor Control of Metabolism
Authors: Mangelsdorf David J.
Published: September 2010

This commentary highlights some of the most important discoveries in the field of nuclear receptor control of metabolism that occurred over the past year (2009 to 2010). As might be expected in a field that encompasses several hundred active laboratories, the task of providing a balanced look at these discoveries was daunting. Thus, to help make the selection of these discoveries, a small panel of colleagues was recruited to help. After selecting the top candidate discoveries from a Google search and a PubMed search, the panel was asked to rank them. These final selections were presented at “The Year In Basic Science Session” of the Annual Meeting of the Endocrine Society, ENDO 2010, the highlights of which are reproduced in this article.
Wake structure and wing kinematics: the flight of the lesser dog-faced fruit bat,Cynopterus brachyotis
Authors: Hubel Tatjana Y. , Riskin Daniel K. , Swartz Sharon M. , Breuer Kenneth S.
Published: October 2010

We investigated the detailed kinematics and wake structure of lesser dog-faced fruit bats (Cynopterus brachyotis) flying in a wind tunnel. High speed recordings of the kinematics were conducted to obtain three-dimensional reconstructions of wing movements. Simultaneously, the flow structure in the spanwise plane perpendicular to the flow stream was visualized using time-resolved particle image velocimetry. The flight of four individuals was investigated to reveal patterns in kinematics and wake structure typical for lower and higher speeds. The wake structure identified as typical for both speed categories was a closed-loop ring vortex consisting of the tip vortex and the limited appearance of a counter-rotating vortex near the body, as well as a small distally located vortex system at the end of the upstroke that generated negative lift. We also investigated the degree of consistency within trials and looked at individual variation in flight parameters, and found distinct differences between individuals as well as within individuals.
The shadow-induced withdrawal response, dermal photoreceptors, and their input to the higher-order interneuron RPeD11 in the pond snailLymnaea stagnalis
Authors: Sunada Hiroshi , Sakaguchi Taichi , Horikoshi Tetsuro , Lukowiak Ken , Sakakibara Manabu
Published: October 2010

The shadow-induced withdrawal response in Lymnaea stagnalis is mediated by dermal photoreceptors located on the foot, mantle cavity, and skin around the pneumostome area. Here, we determined whether we could obtain a neural correlate of the withdrawal response elicited by a shadow in a higher-order central neuron that mediates withdrawal behavior. We measured the electrophysiological properties of the higher-order interneuron Right Pedal Dorsal 11 (RPeD11), which has a major role in Lymnaea withdrawal behavior. In semi-intact preparations comprising the circumesophageal ganglia, the mantle cavity and the pneumostome, but not the foot and eyes, a light-on stimulus elicited a small short-lasting hyperpolarization and a light-off stimulus elicited a depolarization of RPeD11. We also determined that dermal photoreceptors make a monosynaptic contact with RPeD11. The dermal photoreceptor afferents course to the circumesophageal ganglia via the anal and genital nerves to the visceral ganglion, and/or via the right internal and external parietal nerves to the parietal ganglion. Finally, in addition to responding to photic stimuli, RPeD11 responds to both mechanical and chemical stimuli delivered to the pneumostome.
Sexually dimorphic sensory gating drives behavioral differences in túngara frogs
Authors: Hoke Kim L. , Ryan Michael J. , Wilczynski Walter
Published: October 2010

Males and females can differ both in the social behaviors they perform and in the contexts in which they engage in these behaviors. One possible mechanism of sex differences in behavior is a sexual dimorphism in the relay of sensory information to motor areas, but no studies have examined the role of such a relay in vertebrate sexually dimorphic behaviors. We used egr-1 expression as a marker of neural activation in frogs exposed to conspecific and heterospecific acoustic signals to compare activation patterns throughout the brains of males and females. We determined how the sexes differ in the transformation of social signals into motor responses in the context of social communication. We examined the relationships between egr-1 mRNA levels in the auditory midbrain and forebrain areas, as well as how forebrain expression related to the behavioral responses of the animals. Forebrain network activation patterns and forebrain–behavior relationships were similar in males and females. By contrast, we found a sex difference in the relationship between midbrain and forebrain activation; midbrain auditory responses predicted forebrain responses in females but not in males. This sex difference suggests that sensory inputs differentially regulate motor systems underlying social behaviors in males and females. This sensorimotor transformation may be a common locus for generating sex differences in behavior.
A novel stiffening factor inducing the stiffest state of holothurian catch connective tissue
Authors: Yamada Akira , Tamori Masaki , Iketani Tomoaki , Oiwa Kazuhiro , Motokawa Tatsuo
Published: October 2010

The dermis of sea cucumbers is a catch connective tissue or mutable collagenous tissue that shows large changes in stiffness. Extensive studies on the dermis revealed that it can adopt three different states having different mechanical properties that can be reversibly converted. These are the stiff, standard and soft states. The standard state is readily produced when a dermal piece is immersed in the sea water containing Ca2+, whereas the soft state can be produced by removal of Ca2+. A stiffening protein, tensilin, has been isolated from some sea cucumbers (Cucumaria frondosa and Holothuria leucospilota). Although tensilin converts the state of the dermis from soft to standard, it cannot convert from standard to stiff. In this study, we isolated and partially purified a novel stiffening factor from the dermis of Holothuria leucospilota. The factor stiffened the dermis in normal artificial sea water (ASW) but did not stiffen the soft dermis in Ca2+-free ASW. It also stiffened the dermis that had been converted to the standard state in Ca2+-free ASW by the action of tensilin. These results suggest that the factor produces the stiff dermis from the standard state but cannot work as a stiffener on the soft dermis. Its addition to longitudinal muscles of the sea cucumber produced no effects, suggesting that its effect is specific to the catch connective tissue. Its stiffening activity was susceptible to trypsin, meaning that it is a polypeptide, and its molecular mass estimated from gel filtration chromatography was 2.4 kDa.
Effects of immune supplementation and immune challenge on oxidative status and physiology in a model bird: implications for ecologists
Authors: van de Crommenacker Janske , Horrocks Nicholas P. C. , Versteegh Maaike A. , Komdeur Jan , Tieleman B. Irene , Matson Kevin D.
Published: October 2010

One route to gain insight into the causes and consequences of ecological differentiation is to understand the underlying physiological mechanisms. We explored the relationships between immunological and oxidative status and investigated how birds cope physiologically with the effects of immune-derived oxidative damage. We successively implemented two experimental manipulations to alter physiological status in a model bird species: the homing pigeon (Columba livia). The first manipulation, an immune supplementation, was achieved by oral administration of lysozyme, a naturally occurring and non-specific antimicrobial enzyme. The second manipulation, an immune challenge, took the form of an injection with lipopolysaccharide, a bacterial endotoxin. Between groups of lysozyme-treated and control birds, we compared lipopolysaccharide-induced changes in reactive oxygen metabolites, total antioxidant capacity, haptoglobin, oxygen consumption, body mass and cloacal temperature. Lysozyme supplementation intensified the lipopolysaccharide-induced inflammatory response and generated short-term oxidative and metabolic costs. We identified significant interactions between immune supplementation and immune challenge in terms of reactive oxygen metabolites, haptoglobin and oxygen consumption. Our study provides alternative interpretations of differences in oxidative and immunological indices and demonstrates that these indices can also fluctuate and interact across very short time scales, reflecting something akin to current ‘health status’ or ‘physiological condition’. These ephemeral effects highlight the need to broadly consider current physiological condition when drawing conclusions that relate physiology to ecology and evolution.
Evolution of supercontraction in spider silk: structure–function relationship from tarantulas to orb-weavers
Authors: Boutry Cecilia , Blackledge Todd Alan
Published: October 2010

Spider silk is a promising biomaterial with impressive performance. However, some spider silks also ‘supercontract’ when exposed to water, shrinking by up to ∼50% in length. Supercontraction may provide a critical mechanism to tailor silk properties, both for future synthetic silk production and by the spiders themselves. Several hypotheses are proposed for the mechanism and function of supercontraction, but they remain largely untested. In particular, supercontraction may result from a rearrangement of the GPGXX motif within the silk proteins, where G represents glycine, P proline and X is one of a small subset of amino acids. Supercontraction may prevent sagging in wet orb-webs or allow spiders to tailor silk properties for different ecological functions. Because both the molecular structures of silk proteins and how dragline is used in webs differ among species, we can test these hypotheses by comparing supercontraction of silk across diverse spider taxa. In this study we measured supercontraction in 28 spider taxa, ranging from tarantulas to orb-weaving spiders. We found that silk from all species supercontracted, except that of most tarantulas. This suggests that supercontraction evolved at least with the origin of the Araneomorphae, over 200 million years ago. We found differences in the pattern of evolution for two components of supercontraction. Stress generated during supercontraction of a restrained fiber is not associated with changes in silk structure and web architecture. By contrast, the shrink of unrestrained supercontracting fibers is higher for Orbiculariae spiders, whose silk contains high ratios of GPGXX motifs. These results support the hypothesis that supercontraction is caused by a rearrangement of GPGXX motifs in silk, and that it functions to tailor silk material properties.
Forelimb kinematics and motor patterns of the slider turtle (Trachemys scripta) during swimming and walking: shared and novel strategies for meeting locomotor demands of water and land
Authors: Rivera Angela R. V. , W. Blob Richard
Published: October 2010

Turtles use their limbs during both aquatic and terrestrial locomotion, but water and land impose dramatically different physical requirements. How must musculoskeletal function be adjusted to produce locomotion through such physically disparate habitats? We addressed this question by quantifying forelimb kinematics and muscle activity during aquatic and terrestrial locomotion in a generalized freshwater turtle, the red-eared slider (Trachemys scripta), using digital high-speed video and electromyography (EMG). Comparisons of our forelimb data to previously collected data from the slider hindlimb allow us to test whether limb muscles with similar functional roles show qualitatively similar modulations of activity across habitats. The different functional demands of water and air lead to a prediction that muscle activity for limb protractors (e.g. latissimus dorsi and deltoid for the forelimb) should be greater during swimming than during walking, and activity in retractors (e.g. coracobrachialis and pectoralis for the forelimb) should be greater during walking than during swimming. Differences between aquatic and terrestrial forelimb movements are reflected in temporal modulation of muscle activity bursts between environments, and in some cases the number of EMG bursts as well. Although patterns of modulation between water and land are similar between the fore- and hindlimb in T. scripta for propulsive phase muscles (retractors), we did not find support for the predicted pattern of intensity modulation, suggesting that the functional demands of the locomotor medium alone do not dictate differences in intensity of muscle activity across habitats.
Conditioning to magnetic direction in the Pekin duck (Anas platyrhynchos domestica)
Authors: Freire Rafael , Birch Tessa E.
Published: October 2010

The ability of ducks to derive magnetic direction information was tested in a conditioned procedure and the functional properties of the mechanism of magnetoreception investigated using common manipulations. Twelve ducks were trained to find a hidden imprinting stimulus behind one of three screens in a round arena. Once a criterion was reached, the directional choices of ducks were recorded in four treatments presented in a random order, separated with rewarded training trials to avoid extinction. In tests in the geomagnetic field, ducks preferred the screen in the training direction (P=0.005). In the crucial tests of magnetic orientation with the magnetic field experimentally shifted by 120 deg, ducks showed a significant difference in the choice for the correct magnetic direction between treatments (P=0.002). More specifically, they chose the correct magnetic direction more often than expected by chance (P=0.03), indicating that they were deriving directional information from the magnetic field. Ducks also chose the correct magnetic direction more often than expected by chance in tests with the shifted field after the upper bill was anaesthetised with lignocaine (P=0.05) or when the right eye was covered (P=0.005), indicating that these manipulations did not impair the ability to choose the correct magnetic direction. Thus, Pekin ducks can be conditioned to magnetic directions, and the results are consistent with the hypothesis that magnetic orientation is based on a chemical magnetoreception mechanism that is not restricted to the right eye.
Natural annual cycle of heat shock protein expression in land snails: desertversusMediterranean species ofSphincterochila
Authors: Arad Zeev , Mizrahi Tal , Goldenberg Shoshana , Heller Joseph
Published: October 2010

Land snails are subject to daily and seasonal variations in temperature and in water availability, and have evolved annual cycles of activity and aestivation as part of their survival strategy. We tested in the field whether adaptation to different habitats affects the endogenous levels of heat shock proteins (HSPs) in two closely related Sphincterochila snail species, a desiccation-resistant desert species, Sphincterochila zonata, and a Mediterranean-type, desiccation-sensitive species, S. cariosa. We examined HSP levels in various tissues of snails during aestivation and after resumption of activity. Our study shows that, during aestivation, S. cariosa had higher standing stocks of Hsp70 in the foot and the hepatopancreas, and of small HSPs (sHSPs) in all the examined tissues, whereas S. zonata had higher stocks of Hsp70 in the kidney and of Hsp90 in the kidney and in the hepatopancreas. Arousal induced a general upregulation of HSPs, except for Hsp90, the expression of which in the foot was higher during aestivation. We suggest that the stress protein machinery is upregulated during arousal in anticipation of possible oxidative stress ensuing from the accelerating metabolic rate and the exit from the deep hypometabolic state. Our findings support the concept that, in land snails, aestivation and activity represent two distinct physiological states, and suggest that land snails use HSPs as important components of the aestivation mechanism, and as part of their survival strategy during and after arousal. Our study also indicates that adaptation to different habitats results in the development of distinct strategies of HSP expression with likely consequences for the ecology and distribution of land snails.
Misperceiving the Beliefs of Others: How Pluralistic Ignorance Contributes to the Persistence of Positive Security Analyst Reactions to the Adoption of Stock Repurchase Plans
Authors: Zhu David H. , Westphal James D.
Published: October 2010

We consider how a social psychological bias referred to as pluralistic ignorance occurs among security analysts and how this bias may lead to behavioral conformity and isomorphism in analysts' reactions to the adoption of a particular organizational policy, namely, stock repurchase plans. Our theory suggests why (1) there may be a systematic tendency for analysts to underestimate the extent to which other analysts share their reservations about repurchase plans (i.e., reservations about whether plans reflect well on the performance prospects of adopting firms), such that (2) analysts conform to other analysts and issue more positive earnings forecasts and stock recommendations in response to the adoption of repurchase plans despite having private reservations about whether the plans reflect well on adopting firms. We also contend that analysts are less likely to underestimate the extent to which others share their reservations about repurchase plans to the extent that they have frequent communication ties to other analysts. Whereas prior neoinstitutional research on conformity and isomorphism has primarily adopted a cognitive perspective in which actors conform to the behavior of others based on their understandings of a particular policy or practice (i.e., they take the value of the policy for granted or infer the value of the policy from others' prior decisions), we develop a social psychological perspective on isomorphism wherein actors imitate others based on their biased perceptions of others' beliefs about the policy. We also extend perspectives on institutional persistence by explaining why constituents may continue to publicly endorse a policy despite having private reservations about the policy's efficiency benefits.
Artefact in a Panoral Radiograph: A Short Communication
Authors: Cho Shiu-yin , Chu Vanessa , Ki Yung
Published: October 2010

Artefacts in dental radiographs are not uncommon findings. In some cases, however, such film faults might lead to difficult or even wrong diagnoses. In this brief report, the authors present a case where a small piece of paper cast a foreign body-like image onto a panoral radiograph. The importance of proper techniques and film handling when taking radiographs cannot be over-emphasised.
Practice-Based Cone-Beam Computed Tomography: A Review
Authors: Gray Crawford F
Published: October 2010

Sectional imaging is a useful tool for the dental practitioner, especially in the fields of oral surgery and implant dentistry. Until recently, the most readily available way to gain three-dimensional information has been computed tomography (CT). The main drawbacks to using this technique have been the substantial dose of ionising radiation and accessibility. Cone-beam computed tomography (CBCT) allows 3D imaging to be made using bespoke equipment designed for the dental practice environment. Exposure to ionising radiation is substantially lower than that for an average x-ray CT scan, but in most cases is still greater than when other dental radiographs are taken. Various guidelines are now in the public domain and these are referenced within this review of CBCT. The concepts of appropriate selection criteria and optimisation of imaging parameters are stressed, along with compliance with the regulations relating to the use of ionising radiation—Ionising Radiation Regulations 1999 and Ionising Radiation (Medical Exposure) Regulations 2000—and training requirements.
Personal Construct Psychology: A Theory to Help Understand Professional Development, A Philosophy to Support It
Authors: Brocklehurst Paul R
Published: October 2010

Aim

The aim of this paper is to introduce the reader to personal construct psychology as a theory to help understand the process of change in facilitative and mentoring relationships.

Background

Continuing professional development is critical if practitioners are to keep up to date with new ideas, techniques, and materials. However, is it important not only to consider what is learnt, it is also important to understand the how of learning in order to develop an approach that leads to lifelong learning. Mentoring, coaching, and appraisal are all facilitative processes that aim to encourage professionals to engage with their own development. This leads to differing degrees of both behavioural and attitudinal change. As a result, it is useful to have a theory that can help an individual to understand these changes and to identify any difficulties that are associated with them.

Approach

Personal construct psychology has long been recognised as a potential framework for personal development. It has been used extensively in a broad range of domains, including clinical and educational psychology, management, and psychotherapy.

Conclusion

Personal construct psychology is a useful theory for understanding the facilitative process because it enables the facilitator to form a conceptual framework to comprehend behavioural and attitudinal change. Its underlying philosophical approach also supports lifelong learning, given its emphasis on an enquiring mind and reflection, both of which are key to continuing professional development.
The Use of the International Caries Detection and Assessment System (ICDAS) in a National Health Service General Dental Practice as Part of an Oral Health Assessment
Authors: Ormond Charles , Douglas Gail , Pitts Nigel
Published: October 2010

Introduction

The Scottish Dental Clinical Effectiveness Programme (SDCEP) is developing guidance for oral health assessment and review that is intended for use in National Health Service (NHS) general dental practice. One section of this guidance is assessment of the teeth, including their caries status. The detailed caries assessment method identified by the guidance group is the International Caries Detection and Assessment System (ICDAS).

Aim

The aim of this study was to investigate the implications of using the ICDAS in an NHS general practice and, in particular, the time taken to use the system.

Method

After online and in-practice training and calibration, 50 adult and 50 child patients were randomly allocated for assessment using the ICDAS detection codes. The ICDAS protocol states that the teeth should be clean and dry. For this study, all patients had their teeth brushed by the dentist before the assessment and the results were recorded on draft ICDAS clinical pro forma sheets. The time taken for the assessment was assessed with a stopwatch and recorded in a spreadsheet program.

Results

The results showed that the mean time for the assessment of an adult was 3.80 minutes, or 4.99 minutes if the time for pre-examination cleaning and drying was included. For a child, the mean time was 2.53 minutes, or 3.99 minutes if pre-examination brushing time was included.

Conclusions

These results indicate that with training and experience, it is possible to carry out an ICDAS assessment in a time that is practical in general dental practice.
Secondary transfer effects from imagined contact: Group similarity affects the generalization gradient
Authors: Harwood Jake , Paolini Stefania , Joyce Nick , Rubin Mark , Arroyo Analisa
Published: October 2010

An experiment examined the effects of imagining contact with an illegal immigrant on attitudes towards illegal immigrants and subsequent effects of that attitude change on feelings about other groups (secondary transfer). Compared to a condition in which participants imagined negative contact with an illegal immigrant, participants who imagined positive contact reported more positive attitudes concerning illegal immigrants. Using bootstrapped mediation models, effects of positive imagined contact on attitudes towards illegal immigrants were shown to generalize to other groups that were independently ranked as similar to illegal immigrants, but not to dissimilar groups. This generalization gradient effect was relatively large. Implications for theory and practical applications to prejudice reduction are discussed.
Resistance to Brand Switching when a Radically New Brand is Introduced: A Social Identity Theory Perspective
Authors: Lam Son K. , Ahearne Michael , Hu Ye , Schillewaert Niels
Published: October 2010

There has been little research on how market disruptions affect customer–brand relationships and how firms can sustain brand loyalty when disruptions occur. Drawing from social identity theory and the brand loyalty literature, the authors propose a conceptual framework to examine these issues in a specific market disruption, namely, the introduction of a radically new brand. The framework focuses on the time-varying effects of customers’ identification with and perceived value of the incumbent relative to the new brand on switching behavior. The authors divert from the conventional economic perspective of treating brand switching as functional utility maximization to propose that brand switching can also result from customers’ social mobility between brand identities. The results from longitudinal data of 679 customers during the launch of the iPhone in Spain show that both relative customer–brand identification and relative perceived value of the incumbent inhibit switching behavior, but their effects vary over time. Relative customer–brand identification with the incumbent apparently exerts a stronger longitudinal restraint on switching behavior than relative perceived value of the incumbent. The study has important strategic implications for devising customer relationship strategies and brand investment.
Book Reviews
Authors: Skinner Alanson
Published: October 2010

Book reviewed in this article:

Similar observations may be found in Mr. Moore's “Certain Sand Mounds of the St. Johns River

Ditto, Part II

“Certain Sand Mounds of Duval County, Florida

Professor Wm. H. Holmes writes (“Earthenware of Florida,”
Desire and Technology: An Interview with Atom Egoyan
Authors: Wilson Emma
Published: October 2010

Armenian Canadian director Atom Egoyan's recent films, Adoration (2006) and Chloe (2009), and his art installations, pursue and complicate his career-long interest in technology and its intersections with desire and fantasy. In an interview with Emma Wilson, Egoyan discusses these works and reflects more broadly on filmmaking in the digital age.
Solidarity Not Identification: Straub-Huillet's Radical Cinema
Authors: Fisher Mark
Published: October 2010

A review of work by Danièle Huillet and Jean-Marie Straub—Chronicle of Anna Magdalena Bach (1967), Class Relations (1984), Sicily! (1998), and A Visit to the Louvre (2004)—which discusses the “Straubian shot,” use of sound and music, and the films' demand for a fully attentive and “fraternal” form of spectatorship.
Getting ready for surgery through natural orifice
Authors: Lukovich Peter , Zsirka-Klein A. , Vanca T. , Szpaszkij L. , Benkő P.
Published: October 2010

The technical background of pure Natural Orifice Translumenal Endoscopic Surgery (NOTES) surgery has not been created yet, but ever more reports are being published on hybrid NOTES surgery and single-port surgical interventions, which have appeared as a result of device development inspired by NOTES. Surgery carried out through single ports only differ from pure NOTES in respect of the access orifice, which makes learning this technique extremely important for anyone whishing to implement a surgical intervention through a natural orifice. Numerous publications have appeared by now on the single port or hybrid NOTES surgery of various organs (gall bladder, kidney, large bowel). Based on these, most surgery is safely feasible through one port as well, but the surgery takes longer and it is not significantly less painful than a “traditional” laparoscopic intervention. Long-term results are still missing, primarily in what concerns the frequency of infections and post-operative hernia. We have received an answer to part of the dilemmas formulated in the White Paper. Besides specially bent laparoscopic devices robot technology and devices controlled by extracorporal magnets may both be a solution to the problem of triangulation. The transvaginal and transgastric paths do not seem to cause significant risks from the viewpoint of infections, but the closing of viscerotomy in the case of the stomach is far from being solved. In respect of learning and practicing new surgical techniques no method exists at the moment that could be considered the “gold standard”. Besides the earlier questions there are new ones as well awaiting partial solutions (e.g. necessity of drain following a NOTES surgery, oncologic principles).
Stressors in Breast Cancer Post-Treatment: a Qualitative Approach
Authors: Silva Gisele da , Santos Manoel Antônio dos
Published: September 2010

With the increasing effectiveness of breast cancer treatment, the scientific interest in investigating the quality of life of survivors has increased. However, research addressing the post-treatment period is still scarce. The aim of this study was to identify the stressors present in the lives of women in the one to five years post-diagnosis period. The sample was composed of 16 women assisted at a specialized mastectomy rehabilitation service. Data were collected through semi-structured interviews and analyzed using content analysis. The results indicate conflicts with self-image and alteration in the feeling of autonomy, fear in relation to the evolution of the condition, feelings of guilt about the disorder generated in the family, experience of disturbing social situations and a desire to return to their professional occupation. These results reveal the existence of stressors in this phase and the importance of support offered by psychosocial rehabilitation services for this population.
Testing system for hydraulic properties of unsaturated nonwoven geotextiles
Authors: McCartney J.S. , Znidarcic D.
Published: October 2010

ABSTRACT: The water retention curve (WRC) of unsaturated nonwoven geotextiles is necessary for the prediction of transient water flow in unsaturated soil–geotextile systems. A test method is introduced in this study to measure the WRC of deformable, unsaturated nonwoven geotextiles. This test method combines the axis-translation technique with water flow control using a flow pump. Specifically, a nonwoven geotextile specimen is placed within a flexible wall permeameter atop a cellulose membrane having high air entry and low impedance, and the flow pump is used to impose upward or downward water flow across the membrane. A control loop is used to reach stable suction values at the boundary of the suction in order to ensure that points on the WRC are defined for equilibrium flow conditions. A piston is used to apply a vertical load on the nonwoven geotextile specimen in order to replicate field loading conditions, and was also useful for measurement of changes in specimen volume. The combination of flow control, suction stabilization, and height measurement allow this new approach to effectively consider the impact of normal stress and matric suction on the porosity of the geotextile during measurement of the WRC. Experimental results for typical tests indicate that this approach yields drying and rewetting WRC curves for a geotextile specimen consistent with those in the technical literature.
Briefing: remanufacturing and reuse – trends and prospects
Authors: Parker David
Published: September 2010

To date, much of the effort in resource efficiency has been directed at the reduction of waste. Recent legislation, however, points to the use of actions higher in the waste management hierarchy, including a higher value of options for resource reduction or product reuse. This paper reviews the spectrum of reuse, its dimensions and potential, and the consequent impact on the carbon reduction agenda. An important element of reuse is change to the relationships between manufacturers and consumers and the implied business models. The paper concludes with a review of actions and policies that could be enacted to encourage greater product reuse.
The application of remanufacturing in sustainable manufacture
Authors: Ijomah Winifred L.
Published: September 2010

Modern society is characterised by high consumption and ownership of constantly replaced products. Typically, the discarded products are disposed in landfill or scrapped for material recovery. The resulting escalation in landfill and its associated problems has brought remanufacturing to the fore as a sustainable manufacture and waste management strategy. The significance of remanufacturing is that it would permit manufacturers to respond to competitive, environmental and legislative pressures by enabling them to meet pressing waste legislation while producing high-quality, lower-cost products with less environmentally damaging end-of-life and manufacturing modes. However, as a relatively new topic, remanufacturing has gained little attention in world economies. This paper describes the potential role of product recovery processes, in particular remanufacture, in managing products over their life cycle. It also explains the significance of remanufacture to the construction industry and describes the technical challenges of designing products for remanufacture.
Multiscale codependence analysis: an integrated approach to analyze relationships across scales
Authors: Guénard Guillaume , Legendre Pierre , Boisclair Daniel , Bilodeau Martin
Published: October 2010

The spatial and temporal organization of ecological processes and features and the scales at which they occur are central topics to landscape ecology and metapopulation dynamics, and increasingly regarded as a cornerstone paradigm for understanding ecological processes. Hence, there is need for computational approaches which allow the identification of the proper spatial or temporal scales of ecological processes and the explicit integration of that information in models. For that purpose, we propose a new method (multiscale codependence analysis, MCA) to test the statistical significance of the correlations between two variables at particular spatial or temporal scales. Validation of the method (using Monte Carlo simulations) included the study of type I error rate, under five statistical significance thresholds, and of type II error rate and statistical power. The method was found to be valid, in terms of type I error rate, and to have sufficient statistical power to be useful in practice. MCA has assumptions that are met in a wide range of circumstances. When applied to model the river habitat of juvenile Atlantic salmon, MCA revealed that variables describing substrate composition of the river bed were the most influential predictors of parr abundance at 0.4–4.1 km scales whereas mean channel depth was more influential at 200–300 m scales. When properly assessed, the spatial structuring observed in nature may be used purposefully to refine our understanding of natural processes and enhance model representativeness.
Seed availability and insect herbivory limit recruitment and adult density of native tall thistle
Authors: Russell F. Leland , Rose Karen E. , Louda Svata M.
Published: October 2010

Understanding spatial and temporal variation in factors influencing plant regeneration is critical to predicting plant population growth. We experimentally evaluated seed limitation, insect herbivory, and their interaction in the regeneration and density of tall thistle (Cirsium altissimum) across a topographic ecosystem productivity gradient in tallgrass prairie over two years. On ridges and in valleys, we used a factorial experiment manipulating seed availability and insect herbivory to quantify effects of: seed input on seedling density, insect herbivory on juvenile density, and cumulative impacts of both seed input and herbivory on reproductive adult density. Seed addition increased seedling densities at three of five sites in 2006 and all five sites in 2007. Insect herbivory reduced seedling survival across all sites in both years, as well as rosette survival from the previous year's seedlings. In both years, insecticide treatment of seed addition plots led to greater adult tall thistle densities in the following year, reflecting the increase in juvenile thistle densities in the experimental year. Seedling survival was not density dependent. Our analytical projection model predicts a significant long‐term increase in adult densities from seed input, with a greater increase under experimentally reduced insect herbivory. While plant community biomass and water stress varied significantly between ridges and valleys, the effects of seed addition and insect herbivory did not vary with gradient position. These results support conceptual models that predict seedling and adult densities of short‐lived monocarpic perennial plants should be seed limited. Further, the experiment demonstrates that even at high juvenile plant densities, at which density dependence potentially could have overridden herbivore effects on plant survival, insect herbivory strongly affected juvenile thistle performance and adult densities of this native prairie species.
Explaining long‐distance dispersal: effects of dispersal distance on survival and growth in a stream salamander
Authors: Lowe Winsor H.
Published: October 2010

Long‐distance dispersal (LDD) may contribute disproportionately to range expansions, the creation of new evolutionary lineages, and species persistence in human‐dominated landscapes. However, because data on the individual consequences of dispersal distance are extremely limited, we have little insight on how LDD is maintained in natural populations. I used six years of spatially explicit capture–mark–recapture (CMR) data to test the prediction that individual performance increases with dispersal distance in the stream salamander Gyrinophilus porphyriticus. Dispersal distance was total distance moved along the 1‐km study stream, ranging from 0 to 565 m. To quantify individual performance, I used CMR estimates of survival and individual growth rates based on change in body length. Survival and growth rates increased significantly with dispersal distance. These relationships were not confounded by pre‐dispersal body condition or by ecological gradients along the stream. Individual benefits of LDD were likely caused by an increase in the upper limit of settlement site quality with dispersal distance. My results do not support the view that the fitness consequences of LDD are unpredictable and instead suggest that consistent evolutionary mechanisms may explain the prevalence of LDD in nature. They also highlight the value of direct CMR data for understanding the individual consequences of variation in dispersal distance and how that variation is maintained in natural populations.
Diffusion about the mean drift location in a biased random walk
Authors: Codling Edward A. , Bearon Rachel N. , Thorn Graeme J.
Published: October 2010

Random walks are used to model movement in a wide variety of contexts: from the movement of cells undergoing chemotaxis to the migration of animals. In a two‐dimensional biased random walk, the diffusion about the mean drift position is entirely dependent on the moments of the angular distribution used to determine the movement direction at each step. Here we consider biased random walks using several different angular distributions and derive expressions for the diffusion coefficients in each direction based on either a fixed or variable movement speed, and we use these to generate a probability density function for the long‐time spatial distribution. We demonstrate how diffusion is typically anisotropic around the mean drift position and illustrate these theoretical results using computer simulations. We relate these results to earlier studies of swimming microorganisms and explain how the results can be generalized to other types of animal movement.
STIMULUS DISPARITY AND PUNISHER CONTROL OF HUMAN SIGNAL‐DETECTION PERFORMANCE
Authors: Lie Celia , Alsop Brent
Published: October 2010

The present experiment examined the effects of varying stimulus disparity and relative punisher frequencies on signal detection by humans. Participants were placed into one of two groups. Group 3 participants were presented with 1:3 and 3:1 punisher frequency ratios, while Group 11 participants were presented with 1:11 and 11:1 punisher frequency ratios. For both groups, stimulus disparity was varied across three levels (low, medium, high) for each punisher ratio. In all conditions, correct responses were intermittently reinforced (1:1 reinforcer frequency ratio). Participants were mostly biased away from the more punished alternative, with more extreme response biases found for Group 11 participants compared to Group 3. For both groups, estimates of discriminability increased systematically across the three disparity levels and were unaffected by the punisher ratios. Likewise, estimates of response bias and sensitivity to the punisher ratios were unaffected by changes in discriminability, supporting the assumption of parameter invariance in the Davison and Tustin (1978) model of signal detection. Overall, the present experiment found no relation between stimulus control and punisher control, and provided further evidence for similar but opposite effects of punishers to reinforcers in signal‐detection procedures.
RESPONSE ACQUISITION AND FIXED‐RATIO ESCALATION BASED ON INTERRESPONSE TIMES IN RATS
Authors: Taylor Tracy G. , Galuska Chad M. , Banna Kelly , Yahyavi‐Firouz‐abadi Noushin , See Ronald E.
Published: October 2010

The effectiveness of a fixed‐ratio (FR) escalation procedure, developed by Pinkston and Branch (2004) and based on interresponse times (IRTs), was assessed during lever‐press acquisition. Forty‐nine experimentally naïve adult male Long Evans rats were deprived of food for 24 hr prior to an extended acquisition session. Before the start of the session, three food pellets were placed in the magazine. Otherwise, no magazine training, shaping, nor autoshaping procedure was employed. The first 20 presses each resulted in the delivery of a 45‐mg food pellet. Then, the FR increased (2, 4, 8, 11, 16, 20, 25, 30) when each IRT in the ratio was less than 2 s during three consecutive ratios. Sessions lasted 13 hr or until 500 pellets were earned. On average, rats reached a terminal ratio of 11 (mean) or 16 (median) during the first session. Seven rats reached the maximum value of FR 30 and only one rat did not acquire the response. In most rats, a break‐and‐run pattern of responding characteristic of FR schedules began to develop in this acquisition session. Subsequently, the ratio‐escalation procedure continued during daily 2‐hr sessions. In these sessions, the starting ratio requirement was set at the terminal ratio reached in the previous session. Using this procedure, over half (26) of the rats reached the FR 30 requirement by the fourth session. These data demonstrate that a ratio‐escalation procedure based on IRTs provides a time‐efficient way of establishing ratio responding.
CONDITIONED REINFORCEMENT AND RESPONSE STRENGTH
Authors: Shahan Timothy A.
Published: October 2010

Stimuli associated with primary reinforcers appear themselves to acquire the capacity to strengthen behavior. This paper reviews research on the strengthening effects of conditioned reinforcers within the context of contemporary quantitative choice theories and behavioral momentum theory. Based partially on the finding that variations in parameters of conditioned reinforcement appear not to affect response strength as measured by resistance to change, long‐standing assertions that conditioned reinforcers do not strengthen behavior in a reinforcement‐like fashion are considered. A signposts or means‐to‐an‐end account is explored and appears to provide a plausible alternative interpretation of the effects of stimuli associated with primary reinforcers. Related suggestions that primary reinforcers also might not have their effects via a strengthening process are explored and found to be worthy of serious consideration.
Ancient water management techniques to counteract drought and desertification in the Mediterranean
Authors: Laureano Pietro
Published: September 2010

People always have had to confront themselves with the unforeseeable behaviour of the environment and climatic variability. However, for the first time in the history of our planet, climatic change is today caused by human activity. This situation of global crisis is caused by a series of factors that make of the present emergency a new scenario, exposing entire areas of the planet to the risk of lack of water and desertification. However, desert and desertification are two different things. The desert is characterised by a precise ecological balance established in the course of time by specific climatic conditions. These precise conditions have generated knowledge capable of facing adversities with appropriate techniques for capturing and distributing water, for preserving soil, for recycling and for the economical use of energy. The paper analyse the different solutions adopted in ancient periods in order to cope with water scarcity. In particular the study compares the Neolithic experiences in the Puglia Region and in the Sassi di Matera (Italy) with similar structures in the rest of Mediterranean. These traditional solutions are today proposed in a new innovative form to cope with environmental crises.
Looking for efficiency through integrated water management between agriculture and urban uses
Authors: Cubillo Francisco
Published: September 2010

Many urban water systems must cope with water scarcity and climate change and additionally they must be able to fulfil the objectives of environmental protection, efficiency and sustainability. At the end they must provide the expected level of service now and in the future horizons. Some new comprehensive approaches are assessing the total water footprint in a territory using the concept of virtual water and incorporating interactions between agriculture, urban and industrial uses. Besides this broader method of analysis it is important to go further and make analysis of opportunities for efficiency based on a new paradigm of integrated use of water. Investing in improvement of efficiency not only in urban distribution systems, studying the possibilities of permanent or temporal reallocation of water rights from agriculture to urban. Establishing agreements for interchange of raw water for urban regenerated water. Signing options contracts for water trading under drought conditions. Risk of shortage is the factor to complete the framework and it is a key component to review and to manage