bluuebunny/crossref_metadata_2025 huggingface dataset:
Prospective modelling of 3D hyporheic exchange based on high‐resolution topography and stream elevation
Authors: Käser Daniel H. , Binley Andrew , Krause Stefan , Heathwaite A. Louise
Published: March 2013

River managers and scientists interested in hyporheic processes need adequate tools for characterizing hyporheic exchange flow (HEF) at local sites where only poor information on subsurface properties are available. This study evaluates a three‐dimensional modelling approach, on the basis of detailed surface parameterization and a simplified subsurface structure, for comparison of potential HEF characteristics at three experimental reaches at the channel‐unit scale. First, calibration is conducted to determine the best fit‐of‐heads given the model simplification, then the structure of residuals are used to evaluate the origin of the misfit, and finally, a sensitivity analysis is conducted to identify inter‐site differences in HEF. Results show that such an approach can highlight potential magnitude differences in HEF characteristics between reaches. The sensitivity analysis is successful in delineating the small area of exchange that remains under conditions of high groundwater discharge. In this case, however, the calibrated model performs poorly in representing the exchange pattern at the sediment–water interface, thus suggesting that the approach is less adequate for a deterministic simulation of observed heads. The summary statistics are in the range of similar published models, for which the reported indicator is the root mean square error on heads normalized by the head drop over the reach. We recommend, however, that modellers use a more comparable indicator, such as a measure of the residuals normalized by a measure of observed vertical head differences. Overall, when subsurface data are unavailable or sparse, a three‐dimensional groundwater model based on high‐resolution topographic data combined with a sensitivity analysis appears as a useful tool for a preliminary characterization of HEF. Copyright © 2013 John Wiley & Sons, Ltd.
Modelling discharge through artesian springs based on a high‐resolution piezometric network
Authors: Martínez‐Santos P. , Díaz‐Alcaide S. , Castaño‐Castaño S. , Hernández‐Espriú A.
Published: March 2013

Artesian springs are localized aquifer outlets that originate when pressurized ground water is allowed to rise to the surface. Computing artesian discharge directly is often subject to practical difficulties such as restricted accessibility, abundant vegetation or slow flow rates. These circumstances call for indirect approaches to quantify flow. This paper presents a method to estimate ground water discharge through an upwelling spring by means of a three‐layer steady‐state groundwater flow model. Model inputs include on‐site measurements of vertical sediment permeability, sediment temperatures and hydraulic gradients. About 70 spring bed piezometers were used to carry out permeability tests within the spring sediments, as well as to quantify the hydraulic head at different depths below the discharge point. Sediment temperatures were measured at different depths and correlated to permeabilities in order to demonstrate the potential of temperature as a substitute for cumbersome slug tests. Results show that the spatial distribution of discharge through the spring bottom is highly heterogeneous, as sediment permeability varies by several orders of magnitude within centimetres. Sensitivity analyses imply that geostatistical interpolation is irrelevant to the results if field datasets come from a sufficiently high resolution of piezometric records. Copyright © 2013 John Wiley & Sons, Ltd.
A coupled surface resistance model to estimate crop evapotranspiration in arid region of northwest China
Authors: Li Sien , Hao Xingmei , Du Taisheng , Tong Ling , Zhang Jianhua , Kang Shaozhong
Published: March 2013

The Penman–Monteith (PM) model has been widely used to estimate crop evapotranspiration (ET), but it performs poorly with sparse vegetation. By combining the Jarvis canopy resistance model and the soil resistance model, we have developed a coupled surface resistance model to address this issue. Maize field and vineyard ET, measured by the eddy covariance method during 2007 and 2008, were used to test the estimations produced by the PM model combined with our coupled surface resistance model and Jarvis model, respectively. Results indicate that PM model combined with the coupled surface resistance model produces higher determination coefficient and lower root mean square error when compared with the PM–Jarvis method, either for maize field or for the sparse vineyard, on half‐hourly or daily time scales. Our study confirms that the coupled surface resistance model produces higher accuracy than the Jarvis model and provides a method to calculate resistance parameters for using the PM model to simulate the ET of sparse vegetation. Copyright © 2013 John Wiley & Sons, Ltd.
Rating curve uncertainty and change detection in discharge time series: case study with 44‐year historic data from the Nyangores River, Kenya
Authors: Juston John , Jansson Per‐Erik , Gustafsson David
Published: March 2013

The intersection of the developing topic of rating curve and discharge series uncertainty with the topic of hydrological change detection (e.g., in response to land cover or climatic change) has not yet been well studied. The work herein explores this intersection, with consideration of a long‐term discharge response (1964–2007) for a ~650‐km2 headwater basin of the Mara River in west Kenya, starting with stream rating and daily gauge height data. A rating model was calibrated using Bayesian methods to quantify uncertainty intervals in model parameters and predictions. There was an unknown balance of random and systemic error in rating data scatter (a scenario not likely unique to this basin), which led to an unknown balance of noise and information in the calibrated statistical error model. This had implications on testing for hydrological change. Overall, indications were that shifts in basin's discharge response were rather subtle over the 44‐year period. A null hypothesis for change using flow duration curves (FDCs) from four different 8‐year data intervals could be either accepted or rejected over much of the net flow domain depending on different applications of the statistical error model (each with precedence in the literature). The only unambiguous indication of change in FDC comparisons appeared to be a reduction in lowest baseflow in recent years (flows with >98% exceedance probability). We defined a subjective uncertainty interval based on an intermediate balance of random and systematic error in the rating model that suggested a possibility of more prevalent impacts. These results have relevance to management in the Mara basin and to future studies that might establish linkages to historic land use and climatic factors. The concern about uncertain uncertainty intervals (uncertainty2) extends beyond the Mara and is relevant to testing change where non‐random rating errors may be important and subtle responses are investigated. Copyright © 2013 John Wiley & Sons, Ltd.
Multiple Mediation of Trauma and Parenting Stress in Mothers in Home Visiting
Authors: Ammerman Robert T. , Shenk Chad E. , Teeters Angelique R. , Noll Jennie G. , Putnam Frank W. , Van Ginkel Judith B.
Published: March 2013

Parenting stress is associated with poor maternal and child outcomes. Multiple contributors to parenting stress have been proposed, but disaggregation of distinct pathways has been relatively unexplored. In addition, the contribution of maternal experience of childhood trauma has been inadequately considered. Childhood trauma and parenting stress are common in mothers in home visiting programs. Understanding the relation between childhood trauma and parenting stress holds promise for improvement of home visiting approaches. This study examined the relation between childhood trauma and parenting stress, with a focus on the mediating roles of depression and social support. Participants consisted of 208 first‐time mothers enrolled in a home visiting program who were assessed at about 5 months’ postpartum. Measures of maternal childhood trauma, depression, social support, and parenting stress were administered. A multiple mediator model revealed that childhood trauma was related to parenting stress, and the relation between childhood trauma and parenting stress was separately mediated by both depression and social support. Depression and social support uniquely and distinctly accounted for the association between childhood trauma and parenting stress. Home visiting programs may improve their impact on parenting stress by augmenting or modifying strategies to more effectively address maternal depression and social support.
Properties of spinal lamina III GABAergic neurons in naïve and in neuropathic mice
Authors: Gassner M. , Leitner J. , Gruber‐Schoffnegger D. , Forsthuber L. , Sandkühler J.
Published: March 2013

Background

Nerve injury leads to Aβ‐fibre‐mediated mechanical allodynia that is in part due to an impaired GABAergic inhibition in the spinal cord dorsal horn. The properties and function of GABAergic neurons in spinal cord lamina III, an area where low‐threshold mechanosensitive Aβ‐fibres terminate are, however, largely unknown.

Methods

We used transgenic mice, which express enhanced green fluorescent protein (EGFP) under control of the promoter GAD67. The morphology and neurochemical characteristics of GABAergic, EGFP‐expressing neurons were characterized. We assessed active and passive membrane properties of spinal lamina III GABAergic neurons in naïve animals and animals with a chronic constriction injury (CCI) of the sciatic nerve.

Results

EGFP‐expressing neurons in lamina III were predominantly islet cells (47%), whereas non‐EGFP‐expressing neurons were largely inverted stalked cells (40%). EGFP‐expressing neurons accounted for about 25% of GABAergic neurons in lamina III. Forty‐four percent co‐expressed glycine, 10% neuronal nitric oxide synthase and 3% co‐expressed parvalbumin. We found costaining with protein kinase CβII in 42% of EGFP‐expressing neurons but no expression of protein kinase Cγ. Membrane properties and excitability of EGFP‐and non‐EGFP‐expressing neurons from naïve and neuropathic animals were indistinguishable. The most frequent firing pattern was tonic firing (naïve: 35%, neuropathic: 37%) followed by gap firing (naïve: 33%, neuropathic: 25%). Delayed, initial burst and single‐spike firing patterns made up the remainder in both groups.

Conclusion

A change in membrane excitability or discharge pattern of this group of lamina III GABAergic neurons is unlikely the cause for mechanical allodynia in animals with CCI.
Transforming pain medicine: Adapting to science and society
Authors: Borsook D. , Kalso E.
Published: March 2013

The field of chronic pain medicine is currently facing enormous challenges. The incidence of chronic pain is increasing worldwide, particularly in the developed world. As a result, chronic pain is imposing a growing burden on Western societies in terms of cost of medical care and lost productivity. This burden is exacerbated by the fact that despite research efforts and a huge expenditure on treatment for chronic pain, clinicians have no highly effective treatments or definitive diagnostic measures for patients. The lack of an objective measure for pain impedes basic research into the biological and psychological mechanisms of chronic pain and clinical research into treatment efficacy. The development of objective measurements of pain and ability to predict treatment responses in the individual patient is critical to improving pain management. Finally, pain medicine must embrace the development of a new evidence‐based therapeutic model that recognizes the highly individual nature of responsiveness to pain treatments, integrates bio‐psycho‐behavioural approaches, and requires proof of clinical effectiveness for the various treatments we offer our patients. In the long‐term these approaches will contribute to providing better diagnoses and more effective treatments to lessen the current challenges in pain medicine.
Temporal filtering with fast ICCD cameras in Raman studies
Authors: Ehn A. , Levenius M. , Jonsson M. , Aldén M. , Bood J.
Published: March 2013

A common problem when applying Raman scattering in applied research is spectral interference from laser‐induced fluorescence. Extensive work has been invested in developing spectral and polarization filters as well as modulation schemes to refine spontaneous Raman signals. This current work, however, focuses on utilizing the temporal domain using a picosecond laser system and ICCD cameras with relatively short decay of the camera gate to prevent the fluorescence tail from being captured in Raman experiments. Further, the approach of using an ICCD camera to perform temporal filtering is compared to earlier proposed detection schemes using streak cameras or Kerr gates. The temporal‐filtering scheme is evaluated in a spectroscopic investigation where a background subtraction algorithm is presented. The temporal‐filtering scheme was also evaluated for Raman imaging of a levitated water droplet surrounded by fluorescing toluene vapor. Furthermore, the temporal‐filter detection scheme was simulated in order to provide straight forward evaluation tools to estimate the potential of performing temporal filtering with a laser/camera system considering: laser‐pulse duration, time jitter, camera‐gate characteristics, gate delay times, fluorescence lifetimes, and relative signal strength between the Raman and fluorescence signal. The fluorescence signal was modeled with a closed two‐level system, and the simulated results were compared to results from an investigation of the rising slope of toluene fluorescence. These evaluation tools and experimental investigations may serve as guidelines for planning and performing Raman measurements in situations where traditional filter‐rejection schemes are insufficient. Copyright © 2013 John Wiley & Sons, Ltd.
Physiotherapy and Lumbar Facet Joint Injections as a Combination Treatment for Chronic Low Back Pain. A Narrative Review of Lumbar Facet Joint Injections, Lumbar Spinal Mobilizations, Soft Tissue Massage and Lower Back Mobility Exercises
Authors: Chambers Hannah
Published: March 2013

Objectives

The aim of this study was to summarize the available evidence on lumbar facet joint injections and the physiotherapy treatments, land‐based lower back mobility exercise, soft tissue massage and lumbar spinal mobilizations for chronic low back pain (CLBP). The plausibility of physiotherapy and lumbar facet joint injections as a combination treatment is discussed.

Methods

Using a systematic process, an online electronic search was performed using key words utilizing all available databases and hand searching reference lists. Using a critical appraisal tool from the Critical Appraisal Skills Programme (CASP), the literature was screened to include primary research. The main aspects of the research were summarized.

Results

The evidence for lumbar facet joint injections suggests an overall short‐term positive effect on CLBP. Land‐based lower back mobility exercise and soft tissue massage appear to have a positive effect on CLBP in the short term and possibly in the longer term. There is insufficient evidence to draw conclusions for lumbar spinal mobilizations.

Conclusion

The review indicates that lumbar facet joint injections create a short period when pain is reduced. Physiotherapy treatments including land‐based lower back mobility exercise and soft tissue massage may be of benefit during this time to improve the longer‐term outcomes of patients with CLBP. It is not possible to make generalizations or firm conclusions. The current review highlights the need for further research. A randomized controlled trial is recommended to assess the impact of physiotherapy in combination with lumbar facet joint injections on CLBP. Copyright © 2013 John Wiley & Sons, Ltd. Copyright © 2013 John Wiley & Sons, Ltd.
Recent Progress (2007–2012) in Permafrost Isotope Geochemistry
Authors: Lacelle Denis , Vasil'chuk Yurij K.
Published: March 2013

This paper reviews contributions to permafrost isotope geochemistry published between 2007 and 2012 and proposes future research directions. It focuses on: (1) the origin and age of ground ice; (2) geochemistry and water movement in the active and transient layers; and (3) geochemistry and water movement in deep permafrost. The use of isotope geochemistry to study permafrost‐related processes has grown significantly over the last few years. These processes have been elucidated by combining geochemical and isotope measurements from different components of permafrost. Such combination has yielded new insights, for example, into the water source and transfer processes that lead to the formation of ground ice, as well as groundwater movement and residence time in permafrost. Permafrost isotope geochemistry has a promising future and should provide valuable tools for the study of a rapidly changing permafrost environment. Copyright © 2013 John Wiley & Sons, Ltd.
Effect of MoO3‐doped PTCDA as buffer layer on the performance of CuPc/C60 solar cells
Authors: Guan Min , Cao Guohua , Chu Xinbo , Zhang Yang , Liu Xingfang , Zeng Yiping
Published: March 2013

The long‐term performance stability of organic solar cells (OSCs), as well as their high power‐conversion efficiency, is necessary for their practical use. A stable OSC with the structure of ITO/buffer/donor/acceptor/cathode is presented. A thin layer of MoO3‐doped PTCDA (molar ratio 1:1) is adopted as the buffer in CuPc/C60 organic heterojunction photovoltaic (PV) solar cells, resulting in four to five times longer lifetime. The CT complex of buffer layer plays a decisive role in improving the stability and abnormal efficiency changes.
Systematic Engineering of Uniform, Highly Efficient, Targeted and Shielded Viral‐Mimetic Nanoparticles
Authors: Karjoo Zahra , McCarthy Helen O. , Patel Parin , Nouri Faranak Salman , Hatefi Arash
Published: March 2013

In the past decades, numerous types of nanomedicines have been developed for the efficient and safe delivery of nucleic acid‐based drugs for cancer therapy. Given that the destination sites for nucleic acid‐based drugs are inside cancer cells, delivery systems need to be both targeted and shielded in order to overcome the extracellular and intracellular barriers. One of the major obstacles that has hindered the translation of nanotechnology‐based gene‐delivery systems into the clinic has been the complexity of the design and assembly processes, resulting in non‐uniform nanocarriers with unpredictable surface properties and efficiencies. Consequently, no product has reached the clinic yet. In order to address this shortcoming, a multifunctional targeted biopolymer is genetically engineered in one step, eliminating the need for multiple chemical conjugations. Then, by systematic modulation of the ratios of the targeted recombinant vector to PEGylated peptides of different sizes, a library of targeted–shielded viral‐mimetic nanoparticles (VMNs) with diverse surface properties are assembled. Through the use of physicochemical and biological assays, targeted–shielded VMNs with remarkably high transfection efficiencies (>95%) are screened. In addition, the batch‐to‐batch variability of the assembled targeted–shielded VMNs in terms of uniformity and efficiency is examined and, in both cases, the coefficient of variation is calculated to be below 20%, indicating a highly reproducible and uniform system. These results provide design parameters for engineering uniform, targeted–shielded VMNs with very high cell transfection rates that exhibit the important characteristics for in vivo translation. These design parameters and principles could be used to tailor‐make and assemble targeted–shielded VMNs that could deliver any nucleic acid payload to any mammalian cell type.
An Assessment of the Impact of SiO2 Nanoparticles of Different Sizes on the Rest/Wake Behavior and the Developmental Profile of Zebrafish Larvae
Authors: Xue Ji‐Yang , Li Xiang , Sun Ming‐Zhu , Wang Ya‐Ping , Wu Ming , Zhang Chun‐Yang , Wang Ya‐Nan , Liu Bo , Zhang Yao‐Shu , Zhao Xin , Feng Xi‐Zeng
Published: March 2013

In this study, zebrafish larvae are introduced as an in vivo platform to examine the neurotoxicity and developmental toxicity associated with continuous exposure to a concentration gradient of different sizes of SiO2 nanoparticles (15 nm and 50 nm diameter) to determine the dose effect and size effect of SiO2 nanoparticle (NP)‐induced toxicity. Bovine serum albumin (BSA‐V) is utilized as a stabilizing agent to prevent coagulation of the SiO2 nanoparticles. To the best of our knowledge, this study is the first to describe locomotor activity assays linking rest/wake behavioral profiles for the purpose of investigating the neurotoxicity of NPs. In addition, developmental toxicological endpoints including mortality, LC50, malformation, and cartilaginous deformity are assessed. The results show a concentration‐dependent increase in behavioral neurotoxicity, mortality, and malformation among larvae treated with the SiO2 nanoparticles of 15 nm and 50 nm. A comparison of the 15 nm and 50 nm NPs by K‐means clustering analysis demonstrates that the 15 nm NPs have a greater neurotoxic effect than the 50 nm NPs, with the 50 nm NPs exhibiting greater developmental toxicity on the zebrafish larvae than the 15 nm NPs.
Exploring the Association Between Well-Being and Psychopathology in Adolescents
Authors: Bartels Meike , Cacioppo John T. , van Beijsterveldt Toos C. E. M. , Boomsma Dorret I.
Published: March 2013

Promotion of mental well-being and prevention of emotional and behavioral problems are suggested to go hand in hand. The present study examined the association between subjective well-being (SWB) and psychopathology and investigated the etiology of this association in a large population-based cohort study of adolescent twins (n = 9,136) and their non-twin siblings (n = 1,474) aged 12–20 years. Phenotypic, genetic, and environmental correlations between SWB and psychopathology were obtained from multivariate genetic modeling conditional on sex. An SWB factor score was used based on measures of subjective happiness, satisfaction with life, and quality of life. Psychopathology was obtained from all syndrome and broad-band scales of the Dutch version of the ASEBA Youth Self Report. Males reported significantly higher levels of SWB than females. Females reported significantly more internalizing problems while males report significantly higher levels of externalizing behavior. In both sexes, significant negative associations were found between SWB and psychopathology, with the strongest associations seen for SWB and the YSR syndrome scale anxious/depression behavior. The observed associations were primarily explained by genetic correlations while non-shared environmental influences were mainly domain specific. The genetic liability to lower levels of SWB are indicative of a genetic liability to higher levels of psychopathology, suggesting that it might be feasible to screen for emotional and behavioral problems before clear signs are present by screening on indices of subjective well-being.
Characterizing mild cognitive disorders in the young‐old over 8 years: Prevalence, estimated incidence, stability of diagnosis, and impact on IADLs
Authors: Anstey Kaarin J. , Cherbuin Nicolas , Eramudugolla Ranmalee , Sargent‐Cox Kerry , Easteal Simon , Kumar Rajeev , Sachdev Perminder
Published: March 2013

Objectives

Few studies report incidence of mild cognitive impairment (MCI) and other mild cognitive disorders (MCD) in cohorts in their 60s, at an age when diagnoses are less stable. The authors' goal was to estimate the incidence and prevalence of MCI and MCD, characterize subgroups with stable vs nonstable diagnoses, and evaluate the impact of diagnosis on daily life in a young‐old cohort.

Methods

A community‐based cohort age 60 to 64 years in 1999 (n = 2551) was monitored for 8 years and assessed every 4 years. A two‐stage sampling design was used to identify MCI and MCD through a neuropsychological and neurological assessment. A panel of physicians blind to previous diagnoses reviewed each case using published criteria.

Results

The prevalence of MCDs in the cohort aged 68 to 72 years at the last follow‐up was approximately 10%. An estimated 141 subjects (7.7%) progressed to MCI and 183 subjects (10.0%) progressed to MCD between years 4 and 8. Only eight participants received a dementia diagnosis at any wave, five of whom progressed from MCDs. More than 45% of diagnoses were unstable during the 8 years of follow‐up. Stable diagnoses were associated with lower Mini‐Mental State Examination scores, history of neurological disorder, higher cardiovascular risk, and depression at baseline. MCDs were associated with impairments in instrumental activities of daily living and higher rates of reporting memory problems prior to diagnosis.

Conclusions

MCDs in individuals in their 60s occur in at least 10% of the population and are likely to be heterogeneous in terms of their etiology and long‐term prognosis, but may cause a significant impact in everyday life.
Dementia severity and weight loss: A comparison across eight cohorts. The 10/66 study
Authors: Albanese Emiliano , Taylor Clare , Siervo Mario , Stewart Robert , Prince Martin J. , Acosta Daisy
Published: March 2013

Background

We aimed to investigate the association between dementia severity and weight loss in countries with low and middle incomes, where most prevalent cases reside.

Methods

Cross‐sectional catchment area surveys were performed in Cuba, Mexico, Venezuela, Peru, Dominican Republic, Puerto Rico, China, and India. In 16,538 older adults (≥65 years of age), significant weight loss was self‐reported and confirmed by an informant. We conducted neuropsychological testing and clinical and neurological assessments. Dementia severity was determined by applying a validated algorithm and was quantified by the Clinical Dementia Rating Scale.

Results

The characteristics of those who reported weight loss varied across countries. In Poisson models, after controlling for relevant covariates and for waist and arm circumferences, dementia severity was associated with reported weight loss (pooled prevalence ratios [95% confidence intervals {CI}] 2.19 [1.98, 2.41]; 3.81 [3.35, 4.33]; and 5.18 [4.41, 6.10] for CDR 0.5, 1, and 2/3, respectively, compared with CDR 0). The association increased linearly through stages of dementia severity in all countries (P for trend < .001), and between‐country heterogeneity was minimal.

Conclusions

We found a strong gradient effect in the direct association between dementia severity and reported weight loss, homogeneous across sites from eight countries, consistent with mechanistic data on the role of neurodegenerative processes on energy balance and with dietary changes due to disease severity. Considering the well‐recognized effect of weight loss on morbidity and mortality and the large number affected by dementia in less resourced countries, amelioration of weight loss in dementia patients should be considered with priority in these settings.
Algebraic Graph Theory
Authors: Biggs Norman
Published: March 2013

This is a substantial revision of a much-quoted monograph, first published in 1974. The structure is unchanged, but the text has been clarified and the notation brought into line with current practice. A large number of 'Additional Results' are included at the end of each chapter, thereby covering most of the major advances in the last twenty years. Professor Biggs' basic aim remains to express properties of graphs in algebraic terms, then to deduce theorems about them. In the first part, he tackles the applications of linear algebra and matrix theory to the study of graphs; algebraic constructions such as adjacency matrix and the incidence matrix and their applications are discussed in depth. There follows an extensive account of the theory of chromatic polynomials, a subject which has strong links with the 'interaction models' studied in theoretical physics, and the theory of knots. The last part deals with symmetry and regularity properties. Here there are important connections with other branches of algebraic combinatorics and group theory. This new and enlarged edition this will be essential reading for a wide range of mathematicians, computer scientists and theoretical physicists.
Tent caterpillars are robust to variation in leaf phenology and quality in two thermal environments
Authors: Sarfraz Rana M. , Kharouba Heather M. , Myers Judith H.
Published: March 2013

The synchrony between emergence of spring-active, insect herbivores and the budburst of their host plants could be affected by warming temperatures with influences on the availability and quality of foliage as it undergoes physical and chemical changes. This can affect the growth and survival of insects. Here, we used sun-exposed and shaded trees to determine whether the synchrony between egg hatch of western tent caterpillar,Malacosoma californicum pluviale Dyar(Lepidoptera: Lasiocampidae) and budburst of its host red alder,Alnus rubraBongard (Betulaceae) changes with different thermal environments (temperature and light together). To explore the potential outcome of a shift in phenological synchrony, we used laboratory assays of larval growth and survival to determine the effect of variation in young, youthful and mature leaves from sun-exposed and shaded trees. While the average higher temperature of sun-exposed trees advanced the timing of budburst and egg hatch, synchrony was not disrupted. Leaf quality had no significant influence on growth or survival in the laboratory for early instars reared as family groups. Later instar larvae, however, performed best on mature leaves from sun-exposed trees. The robust relationship between leaf and larval development of western tent caterpillars suggests that warming climates may not have a strong negative impact on their success through shifts in phenological synchrony, but might influence other aspects of leaf quality and larval condition.
III - The Odyssey
Authors: Rutherford Richard
Published: March 2013

Although it is theoretically possible (and has been asserted) that the Iliad followed the Odyssey, or that the two poems were composed quite independently, with no influence from one to the other, majority opinion ancient and modern puts the Odyssey later, and assumes it to be in important respects a successor, even a sequel, to the Iliad. This position can be maintained in two main forms: those who believe in a single master-poet as the creator of both epics may assign the Iliad to Homer's youth, the Odyssey to his riper years (a position memorably expressed by Longinus); those who follow the ancient separatists can regard the Odyssey as a rival work, composed by a poet who immensely admired the Iliad but whose own poetic and moral concerns lay elsewhere. This view is now much more common. It may be difficult, however, in a tradition which involved so much use of conventional themes and formulaic material, to decide firmly in favour of common or separate authorship. Whichever view one prefers, the important point seems to be that the Odyssey is later, and that it is conceived as a poem on the same scale as the Iliad, but differing strikingly in content and ethos.
Bile composition, plasma lipids and oxidative hepatic damage induced by calcium supplementation; effects of goat or cow milk consumption
Authors: Díaz-Castro Javier , Alférez María JM , López-Aliaga Inmaculada , Nestares Teresa , Sánchez-Alcover Ana , Campos Margarita S
Published: March 2013

Calcium-fortified foods, especially milk and dairy products are recommended to be consumed daily for groups in risk of nutritional deficiency, including children, young adults, menopausal women, pregnant women and the elderly, however Ca-supplementation promotes gallstone formation because Ca is a nucleating factor. The objective of the current study was to assess the influence of cow or goat milk-based diets, either normal or Ca-supplemented, on bile composition, biochemical parameters and hepatic antioxidant status. Weanling male rats were randomly divided into six groups, fed standard, goat or cow milk-based diets, either with normal Ca content (5·0 g/kg), or Ca-supplemented (10·0 g/kg), for 2 weeks. Bile cholesterol concentration and output was higher in rats fed goat milk in comparison with those fed with standard and cow-milk-based diet. Ca-supplementation increased lithogenic index with the standard and cow-milk based diets, this change was not observed with the goat milk diet. Activities of plasma transaminases were also lower in the animals fed Ca-supplemented goat milk, in comparison with the other diets assayed. In general, Ca-supplement in the diet led to an increase in the hepatic oxidative damage, with an increase in the activities of all the antioxidant enzymes studied in the standard and cow milk diet, but not with goat milk. The habitual consumption of goat milk has positive effects on the plasma lipid profile, biliary composition and hepatic antioxidant defence. In addition, under our experimental conditions, Ca-supplementation of this type of milk does not increase the lithogenic index, or hepatic oxidative damage.
Rethinking echolalia: repetition as interactional resource in the communication of a child with autism
Authors: STERPONI LAURA , SHANKEY JENNIFER
Published: March 2013

Echolalia is a pervasive phenomenon in verbal children with autism, traditionally conceived of as an automatic behavior with no communicative function. However, recently it has been shown that echoes may serve interactional goals. This article, which presents a case study of a six-year-old child with autism, examines how social interaction organizes autism echolalia and how repetitive speech responds to discernible interactional trajectories. Using linguistic, discourse, and acoustic analyses, we demonstrate that the child is able to mobilize echolalia to mark different stances, through the segmental and suprasegmental modulation of echoes. We offer an interpretive framework that deepens our understanding of the complex interactions that children with autism can engage in by using echoes, and discuss the implications of this perspective for current views of atypical language development in autism.
SKILL BIAS IN AN ENDOGENOUS GROWTH MODEL: EVALUATING THE CASE FOR MARKET SIZE AND ACCELERATION EFFECTS
Authors: Sanders Mark
Published: March 2013

Skill-biased technical change occupied empirical economists for much of the 1990s. The empirical literature firmly established a positive correlation between technology indicators and demand shifts. In the minds of many, that has established a causal relationship. This leap of faith, however, is at odds with Hicks's conventional wisdom that endogenous technological change will be biased toward using cheap and abundant resources. In addition, if the rate of technical change is considered to be endogenous, the assumption of an exogenous bias toward skilled labor should at least be questioned. Two hypotheses explaining endogenous skill bias in technical change have been suggested in the theoretical literature: the acceleration effect and the market size effect. In this paper these are studied in a single endogenous-growth model to derive the sufficient and necessary conditions for both hypotheses. After confronting these conditions with the evidence, the paper concludes that it strongly favors the acceleration hypothesis.
CAN CAPACITY CONSTRAINTS EXPLAIN ASYMMETRIES OF THE BUSINESS CYCLE?
Authors: Knüppel Malte
Published: March 2013

In this paper, we investigate the ability of a modified real business cycle (RBC) model to reproduce asymmetries observed for macroeconomic variables over the business cycle. To replicate the empirical skewness of major U.S. macroeconomic variables, we introduce a capacity constraint into an otherwise prototypical RBC model. This constraint emerges because of the assumption of kinked marginal costs of utilization, where the kink is located at a utilization rate of 100%. We find that a model with a suitably calibrated cost function reproduces the empirical coefficients of skewness remarkably well.
Computational modeling of bilingualism: How can models tell us more about the bilingual mind?
Authors: LI PING
Published: March 2013

Models are no new beasts to scholars of bilingualism. During the last several decades we have seen many interesting and important models that postulate how the bilingual mind works. But specific, computationally implemented, models are far less common than general, verbal, models of bilingualism. This is because the former require efforts on the part of the researcher to conduct algorithmic and representational implementations, whereas the latter do not. The central question is: What good does implementation do in telling us about the bilingual mind beyond what the verbal models do? This Special Issue is an attempt to address this question with seven computational models of bilingualism from different research labs.
Predictors of vitamin D deficiency and insufficiency in adult Bahrainis: a cross-sectional study
Authors: Golbahar Jamal , Al-Saffar Nida , Altayab Diab Diab , Al-Othman Sara , Darwish Abdullah , Al-Kafaji Ghada
Published: March 2013

Objective

High prevalence of hypovitaminosis D has been reported to be common in different regions of the Middle East. The objective of the present study was to examine the predictors of vitamin D deficiency and insufficiency in Bahrainis.

Design

A cross-sectional study.

Setting

Blood transfusion volunteers at a blood bank.

Subjects

Serum levels of total 25-hydroxyvitamin D, bone markers and other parameters such age, sex, season and clothing style in the 500 healthy Bahrainis were investigated.

Results

In the entire cohort the prevalence of vitamin D deficiency was 49·4 % and the relative risk of vitamin D deficiency increased significantly by 1·1, 1·2, 1·5, 1·7 and 1·2 fold with younger age group (P = 0·03), hyperparathyroidism (P = 0·01), low serum Ca (P < 0·001), warm and hot months of the year (P < 0·0001) and female sex (P = 0·002), respectively. In females the prevalence of vitamin D deficiency was 67·6 % and the relative risk of vitamin D deficiency increased significantly by 1·1, 1·2, 1·2, 1·2 and 1·4 fold with younger age group (P = 0·04), hyperparathyroidism (P = 0·03), low serum Ca (P = 0·001), warm and hot months of the year (P = 0·001) and conservative clothing style (P = 0·04), respectively. In contrast, in males the prevalence of vitamin D deficiency was 31·2 % and the relative risk of vitamin D deficiency was increased by 1·6 fold in warm and hot months of the year (P < 0·0001).

Conclusions

High prevalence of low circulating levels of vitamin D and the relative risk factors associated with vitamin D deficiency and insufficiency observed in the present study suggest an urgent need for public health interventions including vitamin D food fortification in Bahrain.
Plasma zinc, vitamin B12 and α-tocopherol are positively and plasma γ-tocopherol is negatively associated with Hb concentration in early pregnancy in north-west Bangladesh
Authors: Shamim Abu Ahmed , Kabir Alamgir , Merrill Rebecca D , Ali Hasmot , Rashid Mahbubur , Schulze Kerry , Labrique Alain , West Keith P , Christian Parul
Published: March 2013

Objective

The objective of the current analysis was to explore the association of multiple micronutrients with Hb concentration among pregnant women in a South Asian setting, a topic that has not been adequately explored.

Design

Sociodemographic, anthropometric and micronutrient status (plasma ferritin, transferrin receptor, retinol, α- and γ-tocopherol, folate, vitamin B12, Zn) and Hb concentration were assessed at early pregnancy.

Setting

The biochemical sub-study was nested within a double-blind, placebo-controlled, community-based vitamin A and β-carotene supplementation trial in rural north-western Bangladesh (JiVitA). All assessments were conducted before trial supplementation was initiated.

Subjects

A systematic sample of 285 women was selected from those enrolled in the biochemical sub-study.

Results

Seventeen per cent of women were mildly anaemic; moderate and severe anaemia was uncommon (2·1 %). α-Tocopherol, vitamin B12 and Zn deficiencies were common (43·5 %, 19·7 % and 14·7 %, respectively); however, vitamin A, folate and Fe deficiencies were comparatively rare (7·4 %, 2·8 % and <1 %, respectively). Plasma Zn, vitamin B12 and α-tocopherol were positively associated and plasma γ-tocopherol was negatively associated with Hb (P < 0·05) after adjustment for gestational age, inflammation status, season and nutritional status measured by mid-upper arm circumference.

Conclusions

Among pregnant women in rural Bangladesh with minimal Fe deficiency, plasma Zn, vitamin B12, and α- and γ-tocopherol concentrations were associated with Hb concentration. Appreciating the influence on Hb of micronutrients in addition to those with known associations with anaemia, such as Fe, folate, and vitamin A, is important when addressing anaemia in similar settings.
ON FREE SPECTRA OF A CLASS OF FINITE INVERSE MONOIDS
Authors: DOLINKA IGOR
Published: March 2013

For a finite Clifford inverse algebra $A$, with natural order meet-semilattice ${Y}_{A} $ and group of units ${G}_{A} $, we show that the inverse monoid obtained as the semidirect product ${ Y}_{A}^{1} {\mathop{\ast }\nolimits}_{\rho } {G}_{A} $ has a log-polynomial free spectrum whenever $\rho $ is a term-expressible left action of ${G}_{A} $ on ${Y}_{A} $ and all subgroups of $A$ are nilpotent. This yields a number of examples of finite inverse monoids satisfying the Seif conjecture on finite monoids whose free spectra are not doubly exponential.
An Application of Configural Frequency Analysis
Authors: Zhang Li , Xin Ziqiang , Ding Cody , Lin Chongde
Published: March 2013

Development of class reasoning was investigated using configural frequency analysis (CFA). We administered class inclusion, vicariant inclusion, and law of duality tasks to a sample of 540 Chinese second through fifth graders. In each task, children were asked to compare two classes and make a choice from four alternative answers while the number of classes was not given. Results showed that (1) children’s performance on both class inclusion and vicariant inclusion tasks improved significantly from Grade 2 to Grade 3 and from Grade 3 to Grade 4, but children did not tend to give correct answers to class inclusion items until Grade 4 and to vicariant inclusion items until Grade 5; (2) children from Grades 2 to 5 performed poorly on the law of duality task, but fifth graders were more likely to respond correctly than the general population; and (3) second graders tended to give wrong answers such as “equal number” and “not sure.” A discussion of the development of class reasoning followed.
Appropriation des Savoirs et Mémoire Collective
Authors: Richardot Sophie
Published: March 2013

The aim of this study is to understand to what extent soliciting collective memory facilitates the appropriation of knowledge. After being informed about Milgram’s experiment on obedience to authority, students were asked to mention historical or contemporary events that came to mind while thinking about submission to authority. Main results of the factorial analysis show that the students who do not believe in the reproducibility of the experimental results oppose dramatic past events to a peaceful present, whereas those who do believe in the reproducibility of the results also mention dramatic contemporary events, thus linking past and present. Moreover, the students who do not accept the results for today personify historical events, whereas those who fully accept them generalize their impact. Therefore, according to their attitude toward this objet of knowledge, the students refer to two kinds of memory: a “closed memory,” which tends to relegate Milgram’s results to ancient history; and an “open memory,” which, on the contrary, transforms past events into a concept that helps them understand the present. Soliciting collective memory may contribute to the appropriation of knowledge provided the memory activated is an “open” one, linking past to present and going beyond the singularity of the event.
The Impact of Feedback on Goal Setting and Task Performance
Authors: Krenn Björn , Würth Sabine , Hergovich Andreas
Published: March 2013

This research project was undertaken in response to Kluger and DeNisi’s (1996 ) call for more primary studies to investigate specific propositions of the feedback intervention theory (FIT). To study the assumptions of FIT on the level of task-motivation processes, we analyzed the impact of combined positive and negative feedback. Participants (N = 413) performed a series of tasks in which they were to indicate the number of athletes appearing in short video sequences of different sports. After each task performance the participants received manipulated feedback and were to choose between predetermined options (e.g., raise the level of difficulty, maintain the level of difficulty). We found that the participants most frequently raised the difficulty level after receiving positive feedback and maintained the level after receiving negative feedback. There were no significant differences in the performance of participants who raised and those who maintained the difficulty level after receiving positive or negative feedback. However, the performance of participants who raised the difficulty level after receiving positive feedback increased more than that of those who maintained the difficulty level after receiving negative feedback. In addition, we observed an increase in participants’ avoidance behavior in response to repeated negative feedback. The results partially confirmed the assumptions of the FIT.
How Nonexperts Understand Conflicting Information on Social Science Issues
Authors: Maier Johanna , Richter Tobias
Published: March 2013

When people read Web-based science-related journalistic articles, they usually read more than one text. As a consequence, they face the task of constructing a coherent mental model of the issue on the basis of conflicting information. We assume that recipients handle this task by evaluating the plausibility of information against their current understanding and prior knowledge (epistemic validation). On the one hand, information judged as implausible is often not processed further, yielding a bias toward plausible information in the mental model (plausibility bias). On the other hand, recipients can also engage in elaborative processing when they are motivated to develop a justified point of view (epistemic reading goal), which should lead to a rich mental model in contrast to the goal of memorizing facts (receptive reading goal). The present study investigated the relationships of perceived plausibility and comprehension of multiple articles related to a social science topic (the OECD’s Programme for International Student Assessment [PISA] study) and effects of a recipient’s reading goal, using multilevel models (items nested within recipients) on a trial-by-trial basis. As predicted, information judged as plausible was more likely to be integrated into the recipient’s mental model. This plausibility bias was independent of the recipient’s reading goal. However, an epistemic reading goal led to an overall stronger mental model than did a receptive reading goal. Moreover, we found a positive relationship between perceived plausibility and memory for text. The present results demonstrate that recipients make sense of science communication about controversial issues by actively monitoring the plausibility of information and regulating comprehension processes according to their reading goals.