bluuebunny/crossref_metadata_2025 huggingface dataset:
Vertical profiling of precipitation using passive microwave observations: The main impediment and a proposed solution
Authors: Haddad Ziad S. , Park Kyung‐Won
Published: March 2009

Several methods have been proposed to train microwave radiometers to retrieve precipitation rates estimated by a radar that observed the same location at the same time. These radar‐trained passive microwave algorithms differ in the quantities that are estimated; some estimate the vertically integrated liquid water, whereas others estimate the near‐surface precipitation. Since it is no more or less credible to estimate the rain rate at the surface than it is to estimate the rain rate at any discrete altitude, it is particularly interesting to quantify to what extent it is indeed feasible to estimate vertical profiles of precipitation from a passive microwave radiometer, what the obstacles are, and what vertical resolution would be achievable. To that end, we selected five study regions and started by quantifying the vertical variability of rainfall as derived from the Tropical Rainfall Measuring Mission (TRMM) radar. Two cases emerged: a monsoon‐like case where the first principal component of the vertical precipitation accounts for about 90% of the variability and a Mediterranean‐like case where the first principal component accounts for about 80% of the variability. A Bayesian approach was applied to the TRMM Microwave Imager measurements colocated with the radar profiles. For the monsoon‐like regions, it produced estimates of rain rates at 250‐meter vertical increments, which compared well with the TRMM radar estimates. For the Mediterranean‐like regions, the retrieval errors were very large. We therefore proceeded to identify the main reason for the failure of the straightforward training method. It turns out to be the unknown signature of the sea surface in the portion of the beam that does not contain precipitation. In the problematic Mediterranean case, our original straightforward approach can still be applied to measurements that do not suffer from this identifiable partial beam filling. For measurements that do, we derive a filtering approach to neutralize the variability of the partial surface signature and thus overcome the problem.
Parameterization of surface kinetic effects for bulk microphysical models: Influences on simulated cirrus dynamics and structure
Authors: Harrington Jerry Y. , Lamb Dennis , Carver Robert
Published: March 2009

A parameterization for the influences of the deposition coefficient (αd) and, therefore, surface kinetics on ice crystal vapor growth in bulk microphysical models is derived. The parameterization is developed by considering three distinct growth regimes, each of which depends on the mean size of the ice crystals: inefficient growth in which surface kinetics dominate vapor growth, efficient growth in which diffusion dominates vapor growth, and an intermediate regime in which both surface kinetics and diffusion are important. Analytical solutions to the distribution‐integrated vapor growth equations are derived for the inefficient and efficient growth regimes, whereas a plausible approximation is suggested for the intermediate growth regime. Use in a numerical cloud model requires a method to choose between the growth regimes, and we show that the kinetic length scale can be used for this purpose. The parameterization is used in eddy‐resolving simulations of a warm and unstable cirrus case. Simulation results tend to match prior microphysical studies: cirrus microphysics are insensitive to αd if αd > 0.1, whereas lower values of αd produce relatively high ice concentrations and ice supersaturations. Our simulations suggest that large changes in cirrus structure and dynamics occur when αd becomes lower than ∼0.05. When growth is this inefficient, ice concentrations are high and precipitation rates are low, which leads to a cirrocumulus‐like structure over time. The dynamic motions in these clouds are driven primarily by infrared cloud top cooling and cloud base warming. At larger values of αd (>0.05), the more efficient vapor growth leads to lower ice concentrations and larger precipitation rates. This causes the initially layered cirrus to transition into cirrus uncinus with precipitation tails. The cloud fraction in this case is low, with lifetimes almost 6 hours less than in the cases with inefficient growth (αd < 0.05).
Metallothioneins in Yeast and Fungi
Authors: Dolderer Benedikt , Hartmann Hans-Jürgen , Weser Ulrich
Published: March 2009

Small cysteine-rich proteins sharing most if not all of the general features used to define the metallothionein (MT) superfamily are found in yeast and fungi. Unlike MTs from mammalian sources, most of the known yeast and fungal MTs are Cu(I) rather than Zn(II) or Cd(II) binding proteins. The sequences of fungal MTs reported so far are quite diverse, in such a way that fungal MTs are assigned to six different families. Family 8 contains the MTs with the highest similarity to the N-terminal domains of mammalian MTs. The best characterized member of this family is isolated from the ascomycete Neurospora crassa. It represents a copper-induced polypeptide of only about 25 amino acid residues and harbors a single cluster made up of six Cu(I) that are bound to its seven cysteine residues. The MTs assigned to families 9 and 10 are MT-1 and MT-2 found in the human pathogenic yeast Candida glabrata. The regulation of these proteins employing a copper sensitive transcription factor shares the same principle as were described for the MTs found in Saccharomyces cerevisiae, Cu-MT and Crs5, that are assigned to families 12 and 13. S. cerevisiae Cu-MT is the only MT, of which the structure including its Cu(I)8-thiolate core has been revealed. It should be emphasized that this is the largest known Cu cluster in biological systems. Besides the presentation of these well studied aspects, the open questions of Cd(II) and Zn(II) binding in yeasts and fungi are addressed and future directions of the MT research are discussed.
Fast determination of phases in LixFePO4 using low losses in electron energy-loss spectroscopy
Authors: Moreau P. , Mauchamp V. , Pailloux F. , Boucher F.
Published: March 2009

Experimental valence electron energy-loss spectra, obtained on different phases of LixFePO4, are analyzed with first principles calculations based on density functional theory. In the 4–7 eV range, a large peak is identified in the FePO4 spectrum but is absent in LiFePO4, which allows the easy formation of energy filtered images. The intensity of this peak, nonsensitive to the precise orientation of the crystal, is large enough to rapidly determine existing phases in the sample and permit future dynamical studies.
Micro-organic single crystalline phototransistors of 7,7,8,8-tetracyanoquinodimethane and tetrathiafulvalene
Authors: Jiang Hui , Yang Xianjin , Cui Zhenduo , Liu Yongchang , Li Hongxiang , Hu Wenping
Published: March 2009

Classical p-type and n-type organic single crystals, tetrathiafulvalene (TTF) and 7,7,8,8-tetracyanoquinodimethane (TCNQ), are introduced to investigate photoswitch and phototransistor. High photoresponsivity, low persistent conductivity, and response reversibility can be found in single crystalline TCNQ, while TTF has large persistent conductivity when the light is switched on and off. It is probably attributed to different band gaps and the compactness of molecular packing. Single crystalline TCNQ combines light detection, switching, signal amplification in a single device and realization of multiple functions which exhibit a very promising potential for the fabrication of organic photoelectric devices.
Vacancy phonon scattering in thermoelectric In2Te3–InSb solid solutions
Authors: Pei Yanzhong , Morelli Donald T.
Published: March 2009

Solid solution formation is a common and effective approach to reduce the lattice thermal conductivity for thermoelectric materials because of additional phonon scattering by point defects due to mass and strain fluctuations. This scattering is maximal for vacancies. In this paper we present an example of the strong effect of phonon-vacancy scattering for the InSb–In2Te3 system. The measured transport properties show a reduction by more than an order of magnitude of the lattice thermal conductivity. Further efforts are also made on optimization for thermoelectric applications through doping. Our results indicate that these solid solutions are a prospective new-type thermoelectric material.
MRAP and MRAP2 are bidirectional regulators of the melanocortin receptor family
Authors: Chan Li F. , Webb Tom R. , Chung Teng-Teng , Meimaridou Eirini , Cooray Sadani N. , Guasti Leonardo , Chapple J. Paul , Egertová Michaela , Elphick Maurice R. , Cheetham Michael E. , Metherell Louise A. , Clark Adrian J. L.
Published: March 2009

The melanocortin receptor (MCR) family consists of 5 G protein-coupled receptors (MC1R–MC5R) with diverse physiologic roles. MC2R is a critical component of the hypothalamic–pituitary–adrenal axis, whereas MC3R and MC4R have an essential role in energy homeostasis. Mutations in MC4R are the single most common cause of monogenic obesity. Investigating the way in which these receptors signal and traffic to the cell membrane is vital in understanding disease processes related to MCR dysfunction. MRAP is an MC2R accessory protein, responsible for adrenal MC2R trafficking and function. Here we identify MRAP2 as a unique homologue of MRAP, expressed in brain and the adrenal gland. We report that MRAP and MRAP2 can interact with all 5 MCRs. This interaction results in MC2R surface expression and signaling. In contrast, MRAP and MRAP2 can reduce MC1R, MC3R, MC4R, and MC5R responsiveness to [Nle4,D-Phe7]alpha-melanocyte-stimulating hormone (NDP-MSH). Collectively, our data identify MRAP and MRAP2 as unique bidirectional regulators of the MCR family.
A unique virulence factor for proliferation and dwarfism in plants identified from a phytopathogenic bacterium
Authors: Hoshi Ayaka , Oshima Kenro , Kakizawa Shigeyuki , Ishii Yoshiko , Ozeki Johji , Hashimoto Masayoshi , Komatsu Ken , Kagiwada Satoshi , Yamaji Yasuyuki , Namba Shigetou
Published: March 2009

One of the most important themes in agricultural science is the identification of virulence factors involved in plant disease. Here, we show that a single virulence factor, tengu-su inducer (TENGU), induces witches' broom and dwarfism and is a small secreted protein of the plant-pathogenic bacterium, phytoplasma. When
tengu
was expressed in
Nicotiana benthamiana
plants, these plants showed symptoms of witches' broom and dwarfism, which are typical of phytoplasma infection. Transgenic
Arabidopsis thaliana
lines expressing
tengu
exhibited similar symptoms, confirming the effects of
tengu
expression on plants. Although the localization of phytoplasma was restricted to the phloem, TENGU protein was detected in apical buds by immunohistochemical analysis, suggesting that TENGU was transported from the phloem to other cells. Microarray analyses showed that auxin-responsive genes were significantly down-regulated in the
tengu
-transgenic plants compared with
GUS
-transgenic control plants. These results suggest that TENGU inhibits auxin-related pathways, thereby affecting plant development.
Functions and genres of ESL children’s English writing at home and at school
Authors: Sze Celine , Chapman Marilyn , Shi Ling
Published: March 2009

Drawing on a sociocultural perspective of genre as a social action situated in a particular context, this study examined the functions and genres of four second-grade ESL (English as a Second Language) children’s English writing at home and at school. The two boys and two girls were born and raised in Canada, speaking English at school and with their siblings, and Cantonese at home with their parents. A total of 67 pieces of school writing and 54 pieces of home writing were collected over a five-week period. Findings show that home writing exhibit a wider range of functions and genres than school writing. The study suggests that teachers should be aware of the value of the writing opportunities and contexts bicultural children have at home and, therefore, incorporate such home experiences into classroom teaching to enrich the process of literacy development.
Asian English language learners’ identity construction in an after school literacy site
Authors: Choi Jayoung
Published: March 2009

The importance of students’ identity development has increasingly been acknowledged in the fields of second language acquisition and literacy research. In the cases of two populations receiving growing attention in the research literature, English Language Learners (immigrant students learning English in school settings) and Heritage Language Learners (students attempting, informally or formally, to learn or further develop a language other than English that is spoken in the home environment), identity construction is an especially complicated process. These students move between two environments, one where the native language and culture are represented and another where a second or target language and its culture are engaged. Determining where and with whom they affiliate academically, culturally, linguistically, and socially is an ongoing process. This article describes a qualitative study of four Asian adolescent English Language Learners who participated in an after school literacy club where, through reading multicultural literature and responding to the literature and each other through face to face discussions and electronically via a Wiki site within a Read, Talk, and Wiki (RTW) format, they also engaged in a process of identity construction. The article examines how the RTW club created an important space in which this process occurred and how the students made use of this setting.
Epidemiology and Control of Pertussis Outbreaks in a Tertiary Care Center and the Resource Consumption Associated With These Outbreaks
Authors: Leekha Surbhi , Thompson Rodney L. , Sampathkumar Priya
Published: March 2009

Objective.

To describe the epidemiology and control of 2 separate outbreaks of pertussis at a large tertiary care center and the resource consumption associated with these outbreaks.

Design.

Descriptive study.

Setting.

The Mayo Clinic in Rochester, Minnesota, a tertiary care center catering to both referral patients and patients from the community.

Methods.

We reviewed routine and enhanced surveillance data collected by infection prevention and control practitioners during the outbreaks. Pertussis was diagnosed either on the basis of a nasopharyngeal specimen positive for Bordetella pertussis by use of polymerase chain reaction (PCR) or on the basis of a compatible clinical syndrome along with an epidemiologic link to PCR-confirmed cases.

Results.

Two pertussis outbreaks, the first community based and the second hospital based (ie, due to transmission among healthcare personnel), occurred during the period from October 2004 through October 2005. In the first outbreak from November 2004 through March 2005, there were 109 cases diagnosed; 105 (96%) of these cases were diagnosed on the basis of a nasopharyngeal specimen positive for B. pertussis by use of PCR. Adolescents 10-19 years of age were most affected (77 cases [71%]). Only 13 cases (12%) occurred among healthcare personnel; however, many healthcare personnel required postexposure prophylaxis. A second outbreak of 122 cases occurred during the period from July through October 2005; of these 122 cases, 96 (79%) were diagnosed on the basis of a nasopharyngeal specimen positive for B. pertussis by use of PCR, and 64 (52%) involved healthcare personnel. There were many instances of transmission among healthcare personnel and from patients to healthcare personnel, but no documented transmission from healthcare personnel to Patients. The outbreaks were controlled by aggressive case finding, treatment of those infected, prophylaxis of all healthcare personnel and patients who had contact with both probable and confirmed cases, implementation of educational efforts, and compliance with respiratory etiquette. Vaccination of healthcare personnel against pertussis began in October 2005.

Conclusion.

Pertussis remains a public health problem. Outbreaks in healthcare facilities consume the resources of those facilities in terms of personnel, testing, treatment of cases, and prophylaxis of those individuals who were in contact with those cases. Adult vaccination may reduce the disease burden.
A Statewide System for Improving Influenza Vaccination Rates in Hospital Employees
Authors: Polgreen Philip M. , Polgreen Linnea A. , Evans Thomas , Helms Charles
Published: March 2009

Objective.

To describe and report the progress of a provider-initiated approach to increase influenza immunization rates for healthcare workers.

Design.

Observational study.

Setting.

The State of Iowa.

Subjects.

Acute care hospitals in Iowa.

Methods.

Hospitals reported rates of employee influenza vaccination to a provider-based collaborative during 2 influenza seasons (2006-2007 and 2007-2008). Hospital characteristics related to higher vaccination rates were examined.

Results.

One hundred (87.0%) of 115 Iowa hospitals and/or health systems participated in season 1; individual hospital vaccination rates ranged from 43.5% to 99.2% (mean, 72.4%; median, 73.1%). In season 2, 115 (100%) of 115 Iowa hospitals and/or health systems participated. Individual hospital vaccination rates ranged from 53.6% to 100% (mean, 79.5%; median, 82.0%). In both seasons, urban and large hospitals had vaccination rates that were 6.3% to 7.6% lower than those of hospitals in other locations. Hospitals that used declination statements had influenza vaccination rates 12.6% higher than hospitals that did not use declination statements in season 2.

Conclusion.

The initial vaccination rates were high for healthcare workers in Iowa, especially in smaller rural hospitals, and rates increased during season 2. The successful voluntary approach for reporting influenza vaccination rates that we describe provides an efficient platform for collecting and disseminating other statewide measures of healthcare quality.
Global change and eutrophication of coastal waters
Authors: Rabalais Nancy N. , Turner R. Eugene , Díaz Robert J. , Justić Dubravko
Published: March 2009

Rabalais, N. N., Turner, R. E., Díaz, R. J., and Justić, D. 2009. Global change and eutrophication of coastal waters. – ICES Journal of Marine Science, 66: 1528–1537. The cumulative effects of global change, including climate change, increased population, and more intense industrialization and agribusiness, will likely continue and intensify the course of eutrophication in estuarine and coastal waters. As a result, the symptoms of eutrophication, such as noxious and harmful algal blooms, reduced water quality, loss of habitat and natural resources, and severity of hypoxia (oxygen depletion) and its extent in estuaries and coastal waters will increase. Global climate changes will likely result in higher water temperatures, stronger stratification, and increased inflows of freshwater and nutrients to coastal waters in many areas of the globe. Both past experience and model forecasts suggest that these changes will result in enhanced primary production, higher phytoplankton and macroalgal standing stocks, and more frequent or severe hypoxia. The negative consequences of increased nutrient loading and stratification may be partly, but only temporarily, compensated by stronger or more frequent tropical storm activity in low and mid-latitudes. In anticipation of the negative effects of global change, nutrient loadings to coastal waters need to be reduced now, so that further water quality degradation is prevented.
What drove tuna catches between 1525 and 1756 in southern Europe?
Authors: Ganzedo U. , Zorita E. , Solari A. P. , Chust G. , del Pino A. Santana , Polanco J. , Castro J. J.
Published: March 2009

Ganzedo, U., Zorita, E., Solari, A. P., Chust, G., Santana del Pino, A., Polanco, J., and Castro, J. J. 2009. What drove tuna catches between 1525 and 1756 in southern Europe? – ICES Journal of Marine Science, 66: 1595–1604. From 1525 to 1756, catches of tuna in almadrabas (trapnets) fluctuated greatly, but the overall trend was a downwards one. The aim of this study is to assess the potential influence of climatic factors on tuna fishing. We performed time-series analysis of the climate over the years 1525–1756 and determined whether such events can be related to historical data on bluefin tuna catches in the almadrabas of Medina Sidonia. We used a generalized linear model to relate the tuna catches to climatic parameters. We carried out variance partitioning analysis of tuna catches to assess the relative contribution of climate from temporal autocorrelation. The temporal autocorrelation in tuna catches was used as a surrogate for the contribution of the population dynamics to variation in the catch series. The results indicated that climate accounted for up to 12.3% of the total variance, the temporal effects (autocorrelation) accounted for up to 38.8% of the total variance, and up to 35.7% of the catch was accounted for by the joint effect of the two components. The significant variance accounted for by climate suggests that low temperatures during the Maunder minimum (the so-called “The Little Ice Age”, years 1640–1715) may have reduced both recruitment and abundance of tuna in the North Atlantic and the Mediterranean. Our findings suggest that both environmental and population dynamic components played an important role in regulating the almadraba catches in Medina Sidonia.
Micro-, nano- and hierarchical structures for superhydrophobicity, self-cleaning and low adhesion
Authors: Bhushan Bharat , Jung Yong Chae , Koch Kerstin
Published: March 2009

Superhydrophobic surfaces exhibit extreme water-repellent properties. These surfaces with high contact angle and low contact angle hysteresis also exhibit a self-cleaning effect and low drag for fluid flow. Certain plant leaves, such as lotus leaves, are known to be superhydrophobic and self-cleaning due to the hierarchical roughness of their leaf surfaces. The self-cleaning phenomenon is widely known as the ‘lotus effect’. Superhydrophobic and self-cleaning surfaces can be produced by using roughness combined with hydrophobic coatings. In this paper, the effect of micro- and nanopatterned polymers on hydrophobicity is reviewed. Silicon surfaces patterned with pillars and deposited with a hydrophobic coating were studied to demonstrate how the effects of pitch value, droplet size and impact velocity influence the transition from a composite state to a wetted state. In order to fabricate hierarchical structures, a low-cost and flexible technique that involves replication of microstructures and self-assembly of hydrophobic waxes is described. The influence of micro-, nano- and hierarchical structures on superhydrophobicity is discussed by the investigation of static contact angle, contact angle hysteresis, droplet evaporation and propensity for air pocket formation. In addition, their influence on adhesive force as well as efficiency of self-cleaning is discussed.
Predictive coding under the free-energy principle
Authors: Friston Karl , Kiebel Stefan
Published: March 2009

This paper considers prediction and perceptual categorization as an inference problem that is solved by the brain. We assume that the brain models the world as a hierarchy or cascade of dynamical systems that encode causal structure in the sensorium. Perception is equated with the optimization or inversion of these internal models, to explain sensory data. Given a model of how sensory data are generated, we can invoke a generic approach to model inversion, based on a free energy bound on the model's evidence. The ensuing free-energy formulation furnishes equations that prescribe the process of recognition, i.e. the dynamics of neuronal activity that represent the causes of sensory input. Here, we focus on a very general model, whose hierarchical and dynamical structure enables simulated brains to recognize and predict trajectories or sequences of sensory states. We first review hierarchical dynamical models and their inversion. We then show that the brain has the necessary infrastructure to implement this inversion and illustrate this point using synthetic birds that can recognize and categorize birdsongs.
Light Regulation of Gibberellin Biosynthesis in Pea Is Mediated through the COP1/HY5 Pathway
Authors: Weller James L. , Hecht Valérie , Vander Schoor Jacqueline K. , Davidson Sandra E. , Ross John J.
Published: March 2009

Light regulation of gibberellin (GA) biosynthesis occurs in several species, but the signaling pathway through which this occurs has not been clearly established. We have isolated a new pea (Pisum sativum) mutant, long1, with a light-dependent elongated phenotype that is particularly pronounced in the epicotyl and first internode. The long1 mutation impairs signaling from phytochrome and cryptochrome photoreceptors and interacts genetically with a mutation in LIP1, the pea ortholog of Arabidopsis thaliana COP1. Mutant long1 seedlings show a dramatic impairment in the light regulation of active GA levels and the expression of several GA biosynthetic genes, most notably the GA catabolism gene GA2ox2. The long1 mutant carries a nonsense mutation in a gene orthologous to the ASTRAY gene from Lotus japonicus, a divergent ortholog of the Arabidopsis bZIP transcription factor gene HY5. Our results show that LONG1 has a central role in mediating the effects of light on GA biosynthesis in pea and demonstrate the importance of this regulation for appropriate photomorphogenic development. By contrast, LONG1 has no effect on GA responsiveness, implying that interactions between LONG1 and GA signaling are not a significant component of the molecular framework for light–GA interactions in pea.
Cancer stem cells and their niche
Authors: Iwasaki Hiroko , Suda Toshio
Published: March 2009

The unique characteristics of stem cells, specifically pluripotency and self‐renewal, are critical for sustaining the lifelong functionality of organs. Stem cells reside in a special microenvironment called the niche. Stem cells interact with the niche via adhesion molecules and exchange molecular signals that maintain the specific features of stem cells. A better understanding of the nature of stem cells and their niches is expected to provide an alternative approach to the treatment of various serious diseases, including cancer, in clinical practice. It has been suggested that tumor tissue contains a type of stem cell referred to as a cancer stem cell. Interestingly, there are a number of molecules that are commonly expressed in normal and cancer stem cells that lead to different phenomena depending on the local conditions. In this review, the hematopoietic system is used as an example to show how stem cells interact with different niches. The regulatory mechanisms of two kinds of bone marrow niche, osteoblastic and vascular, are covered in this review. Furthermore, the involvement of the niche in cancer stem cell regulation, tumor invasion and metastasis, and its response to oxidative stress is described, and novel therapeutic approaches involving the interactions between cancer stem cells and their niches are addressed. (Cancer Sci 2009; 100: 1166–1172)
Cigarette smoking is an independent risk factor for type 2 diabetes: a four‐year community‐based prospective study
Authors: Cho Nam H. , Chan Juliana C. N. , Jang Hak Chul , Lim Soo , Kim Hyung L. , Choi Sung Hee
Published: March 2009

Objectives  We investigated the association between smoking and its additive effects with insulin resistance and β‐cell function on the incidence of type 2 diabetes in a prospective population‐based cohort study.

Design and method  A total of 10 038 subjects were recruited from rural and urban areas. All subjects underwent 75 g oral glucose tolerance tests and full biochemical assessments at baseline and during 4‐year follow‐up period. The final analysis was limited to 4041 men due to the low smoking rates in women.

Results  The ex‐ and heavy current smokers had the highest incidence of diabetes of 12·5% and 11·1% respectively, compared with never‐smokers (7·9%) during 4 years. After multivariate adjustment by Cox‐proportional hazard model, ex‐ and current smokers reveal a relative risk of 1·60 (95% CI: 1·07–2·39), 2·06 (1·35–3·16, for <20 cigarettes/day) and 2·41 (1·48–3·93, for ≥20 cigarettes/day) respectively compared with never smokers. The risk of new onset diabetes was the highest in those with low homeostasis model assessment for beta cell function (HOMA‐β) and high homeostasis model assessment for insulin resistance (HOMA‐IR) group in both smokers and never smokers.

Conclusions  Smoking is an independent risk factor for type 2 diabetes mellitus and showed synergistic interaction with the status of low insulin secretion and high insulin resistance for developing diabetes. Given the high rates of smoking and growing burden of diabetes in the world, cessation of smoking should be considered as one of the key factors for diabetes prevention and treatment programmes.
What steps should be considered in the patient who has had a negative cervical exploration for primary hyperparathyroidism?
Authors: Harrison Barney
Published: March 2009

The key to cure of the patient with persistent primary hyperparathyroidism is a clear understanding of the investigations, operative procedure and pathology related to the initial procedure. Reinvestigation and subsequent surgery should be performed in a specialist unit. A logical pathway of increasingly sophisticated localization studies (MIBI, ultrasound, CT/MRI, selective venous catheterization for PTH) will usually guide the surgeon to the missing parathyroid gland/s. Improved preoperative localization can facilitate the use of a minimally invasive small incision approach. The surgeon must have a detailed knowledge of the nuances of parathyroid embryology and a meticulous surgical technique, not only to identify and safely remove the retained gland/s but also do so without causing unnecessary morbidity. Results of re‐operation (84–98% cure) from centres of excellence are highly commendable, yet the use of ‘new’ technology (that includes intra‐operative PTH) has not translated into improved outcomes in all cases. Some parathyroid glands are extremely difficult to find! Re‐operative parathyroid surgery is a challenge, sometimes easy, and on other occasions extremely difficult.
Depletion of soil organic carbon and nitrogen under Pinus taeda plantations in Southern Brazilian grasslands (Campos)
Authors: Wiesmeier M. , Dick D. P. , Rumpel C. , Dalmolin R. S. D. , Hilscher A. , Knicker H.
Published: March 2009

Establishment of pine (Pinus spp.) plantations on grasslands could increase carbon (C) sequestration to counteract increased atmospheric carbon dioxide concentrations. In the grasslands of the southern Brazilian highland (Campos), large areas have been converted to Pinus plantations over the last 30 years. In order to assess the impact of this land‐use change on the amount and composition of soil organic matter (SOM), we investigated a grassland pasture site (G), and both an 8‐year‐old (P8) and a 30‐year‐old (P30) plantation with Pinus taeda. Soil samples down to 45 cm were analysed for texture, pH, soil organic carbon (SOC) and total nitrogen (Ntot) concentrations. Chemical composition of SOM was determined by using cross‐polarization magic angle spinning (CPMAS) 13C NMR spectroscopy. We analysed for stable C isotope (δ13C) and assessed the lignin composition by CuO oxidation. Additionally, contents of pyrogenic organic material (PyOM) were determined because the Campos is regularly burnt. Both pine plantations revealed relatively small SOC concentrations in the mineral soil of 72.6 mg g−1 (P8) and 56.8 mg g−1 (P30) and Ntot concentrations of 4.0 mg g−1 (P8) and 2.9 mg g−1 (P30) for the A horizon, while grassland showed significantly (P < 0.01) larger contents of 100.2 mg g−1 for SOC and 5.9 mg g−1 for Ntot. Accumulation of litter layers suggests decreased input of organic material into the mineral soil under pine, which was confirmed by the δ13C values and lignin composition. Smaller contents of vanillyl‐ (V), syringyl‐ (S), and cinnamyl (C)‐phenols, smaller ratios of S/V and C/V, and smaller ratios of acidic to aldehydic forms of V and S phenols indicated a high degree of decomposition of residual grass‐derived SOM in the upper part of the mineral soil (0–10 cm) under pine plantations. This was confirmed by CPMAS 13C NMR spectroscopy, showing an increasing Alkyl C/O‐Alkyl C ratio at the same depth. No significant changes in the contents of PyOM could be detected, but all sites tended to show the greatest concentrations at deeper soil depths > 15 cm, indicating a vertical relocation of PyOM. The results suggest that decomposition of residual SOM originating from grassland species contributes to the decrease of SOC and Ntot and to an acidification in the topsoil under pine plantations. We also suggest that slow litter decomposition and incorporation and the absence of fires at the plantations are additional reasons for the reduced amount of SOM. Depletion of SOM and the acidification of the topsoil may reduce the availability and supply of nutrients and diminish the C sequestration potential of the mineral soil.
Seeking feedback in blended learning: competitive versus cooperative student attitudes and their links to learning outcome
Authors: Hwang A. , Arbaugh J.B.
Published: March 2009

Emerging research has revealed the impact of electronic media usage on student outcomes, such as satisfaction and reported learning efficacy. However, little is known of its impact on measurable knowledge acquisition. Results from this study showed that participation on discussion topics through Blackboard, an electronic discussion forum, predicted multiple‐choice test performance. In contrast, none of the traditional face‐to‐face feedback‐seeking behaviours, neither with professors in class or out of class, nor among fellow students, had significant influence on test results. An examination of underlying attitudes driving both electronic and face‐to‐face feedback‐seeking behaviours showed that competitiveness rather than cooperation drove average intensity of electronic board participation, which in turn, was related to participation across the number of electronic topical forums. The influencing role of competitiveness in this undergraduate student sample may indicate undergraduate students' lack of workplace experience, where cooperation rather than competition is often needed for workplace effectiveness. This and implications of other findings are discussed in the paper.
From bar diagrams to letter‐symbolic algebra: a technology‐enabled bridging
Authors: Looi C.‐K. , Lim K.‐S.
Published: March 2009

In the Singapore primary school Mathematics curriculum, students are taught the model method that uses bar diagrams to visualize the problem structure in a given word problem. When these students progress to secondary school, they learn the algebraic way of solving word problems. Studies (e.g. Ng et al.) have shown that poor bridging of students from the use of bar diagrams to the use of letter‐symbolic algebraic methods can hinder their learning of algebra. We design a software tool ‘AlgeBAR’ to scaffold the learning of the algebraic process, especially the formulation of equations to support a pedagogy that seeks to help students transit from bar diagrams to algebraic methods. In this paper, we report a cycle of evaluation of the intervention pedagogy by examining a class that uses the software tool as part of a holistic intervention package. This evaluation is in the context of an overall design research approach that sought to address complex problems in real classroom contexts in collaboration with practitioners and to integrate design principles with technological affordances to render plausible solutions. Our findings show that the software tool can be an important enabler of the bridging process.
Water and nutrients alter herbaceous competitive effects on tree seedlings in a semi‐arid savanna
Authors: Van Der Waal Cornelis , De Kroon Hans , De Boer Willem F. , Heitkönig Ignas M. A. , Skidmore Andrew K. , De Knegt Henrik J. , Van Langevelde Frank , Van Wieren Sipke E. , Grant Rina C. , Page Bruce R. , Slotow Rob , Kohi Edward M. , Mwakiwa Emmanuel , Prins Herbert H. T.
Published: March 2009

Globally, both climatic patterns and nitrogen deposition rates show directional changes over time. It is uncertain how woody seedlings, which coexist with herbaceous plants in savannas, respond to concurrent changes in water and nutrient availability.

We investigated competition effects between herbaceous vegetation and tree seedlings (Colophospermum mopane) under changed water and nutrient (fertilized) conditions in a garden experiment situated in a semi‐arid savanna.

Herbaceous competition significantly suppressed woody seedling growth. The effect of herbaceous competition on woody seedling growth remained constant with both increasing water and nutrient availability. However, during a wet‐season drought, herbaceous competition apparently caused premature leaf senescence in non‐irrigated treatments. Fertilization exacerbated negative competition effects during the drought, while irrigation prevented leaf loss of tree seedlings in spite of herbaceous competition and fertilization.

Based on a conceptual model, we propose that the vigorous response of herbaceous plants to increased nutrient availability leads to faster depletion of soil water, which increasingly causes water stress in woody seedlings if the interval between watering events is prolonged, e.g. during wet‐season droughts.

Synthesis. Our data support the notion that changes in drought frequency are of greater importance to woody recruitment success than changes in annual rainfall amount. Based on the water and nutrient interactions observed in our experiment, we suggest that the effect of increased nitrogen deposition on woody seedling recruitment is contingent on water availability.
Molecular basis of the RHD gene in blood donors with DEL phenotypes in Shanghai
Authors: Li Q. , Hou L. , Guo Z.‐H. , Ye L‐Y. , Yue D‐Q. , Zhu Z‐Y.
Published: March 2009

Background and Objectives  The purpose of the work was to analyse the genotype of D‐elute (DEL) samples and to elucidate whether there were novel DEL alleles in Chinese population.

Materials and Methods  D‐negative samples were identified by an indirect antiglobulin test (IAT), and absorption∖elution tests to screen weak D, partial D and DEL phenotypes. DELs were further analysed by multiplex PCR, PCR‐sequence‐specific primers (PCR‐SSP) and sequencing. Some of the DEL samples were determined to show RHD zygosity by PCR‐restriction fragment length polymorphism or real‐time quantitative PCR.

Results  Of 400 253 samples from individual donations, 1585 (0·40%) were typed as D negative. Among these D‐negative samples, 279 DELs were observed. Two hundred and sixty‐eight DELs were confirmed to have the RHD (K409 K) allele. Three DELs seemed to have RHD‐CE‐D hybrid alleles, including one RHD‐CE(4–9)‐D, one RHD‐CE(2–5)‐D and one suspected RHD(1–9)‐CE. Five novel RHD alleles were found among the rest of the DEL samples, including four RHD 3 g > a, one RHD (R10W), one RHD (L18P), one RHD (L84P) and one RHD (A137E). Eighty‐four DELs were analysed for Rhesus box zygosity, there were 77 RHD+/RHD–and seven RHD+/RHD+.

Conclusion  About 4·35% apparent D negative Chinese individuals were weak D or partial D, while 17·60% were DEL. Novel DEL alleles are rare, and all but 11 of the 279 DELs were due to the most common DEL allele, RHD (K409 K). The RHD 3G > A might be the second most frequent DEL allele in Chinese. Exploration of a complete molecular basis for DEL in Chinese ethnic groups is a long‐term endeavour.
Orthopedic disability and socioemotional functioning
Authors: Yagmurlu M. Firat , Yagmurlu Bilge , Yilmaz Muberra
Published: March 2009

Background:  The major aim of the study was to examine self‐concept, emotional stability, and sociability of Turkish adolescents with orthopedic disability, and the links between these domains and sport participation.

Method:  Participants of the study were 95 students in grades 5–12 (mean age, 15.44 ± 2.40 years). They were recruited from two boarding schools established for youth with orthopedic disabilities. Parents of the adolescents participated in the study by completing a form to provide information about the child, his/her condition (e.g. first appearance, severity, treatment), and the household in general. Adolescents filled in self‐report scales that were developed to measure self‐concept, emotional stability, and sociability.

Results:  Hierarchical multiple regression indicated that regular engagement in sports significantly predicted self‐concept of adolescents with orthopedic disability, and the predictive value of playing sport was significant even after differences in participant age, sex, and severity of the disability were taken into account. Emotional stability and sociability of adolescents with disability were predicted by sports playing but to a low degree.

Conclusion:  Study findings underline the importance of understanding social aspects of disability, and the positive association between playing sports and an individuals positive beliefs about oneself.
FACTORS OF INTERREGIONAL INCOME INEQUALITY IN POSTWAR JAPAN: THEIL DECOMPOSITION AND GAP ACCOUNTING ANALYSES
Authors: Kataoka Mitsuhiko
Published: March 2009

This study empirically identifies some factors of interregional income inequality in postwar Japan during the period 1955–2005 using a decomposition analysis with a Theil L index and a gap accounting analysis. One major empirical finding was that interregional inequality in per capita GDP during the period 1955–2005 showed a double peaked M‐shaped curve, which was predominantly attributed to interregional inequality in labor productivity. The sectoral decomposition analysis revealed that the factors that caused fluctuations in interregional inequality in labor productivity differed from year to year. The fluctuations during the period 1960–1980 were caused by an intersectoral equilibrating process between the tertiary sector and other sectors, whereas that the fluctuations that occurred in the late 1980s and early 1990s resulted from interregional disequilibrating and equilibrating processes within the tertiary sector.
Rioting as a Political Tool: the 2005 Riots in France
Authors: JOBARD FABIEN
Published: March 2009

Abstract: Riots that occurred in October and November 2005 in France, as a result of a police chase resulting in the death of two young boys from a deprived area of the Parisian outskirts, force us to shed new light on the political dimension of breakdowns labelled as ‘riots’. To achieve this aim, we examine the accuracy of the notion of ‘race riots’ often used, in England and in the United States, to characterise such violent outbursts. And, with the help of actual political data, we examine how far the riots have led to changes in the politics of France.
Abnormal iron metabolism and oxidative stress in mice expressing a mutant form of the ferritin light polypeptide gene
Authors: Barbeito Ana G. , Garringer Holly J. , Baraibar Martin A. , Gao Xiaoying , Arredondo Miguel , Núñez Marco T. , Smith Mark A. , Ghetti Bernardino , Vidal Ruben
Published: March 2009

Insertional mutations in exon 4 of the ferritin light chain (FTL) gene are associated with hereditary ferritinopathy (HF) or neuroferritinopathy, an autosomal dominant neurodegenerative disease characterized by progressive impairment of motor and cognitive functions. To determine the pathogenic mechanisms by which mutations in FTL lead to neurodegeneration, we investigated iron metabolism and markers of oxidative stress in the brain of transgenic (Tg) mice that express the mutant human FTL498‐499InsTC cDNA. Compared with wild‐type mice, brain extracts from Tg (FTL‐Tg) mice showed an increase in the cytoplasmic levels of both FTL and ferritin heavy chain polypeptides, a decrease in the protein and mRNA levels of transferrin receptor‐1, and a significant increase in iron levels. Transgenic mice also showed the presence of markers for lipid peroxidation, protein carbonyls, and nitrone–protein adducts in the brain. However, gene expression analysis of iron management proteins in the liver of Tg mice indicates that the FTL‐Tg mouse liver is iron deficient. Our data suggest that disruption of iron metabolism in the brain has a primary role in the process of neurodegeneration in HF and that the pathogenesis of HF is likely to result from a combination of reduction in iron storage function and enhanced toxicity associated with iron‐induced ferritin aggregates in the brain.
α‐Synuclein induces migration of BV‐2 microglial cells by up‐regulation of CD44 and MT1‐MMP
Authors: Kim Seonghan , Cho Seo‐Hyun , Kim Ka Young , Shin Ki Young , Kim Hye‐Sun , Park Cheol‐Hyoung , Chang Keun‐A , Lee Sang Hyung , Cho Daeho , Suh Yoo‐Hun
Published: March 2009

Although there is known to be a marked concentration of reactive microglia in the substantia nigra pars compacta (SNpc) of patients with Parkinson’s disease (PD), a disorder in which α‐synuclein plays a key pathogenic role, the specific roles of α‐synuclein and microglia remains poorly understood. In this study, we investigated the effects of α‐synuclein and the mechanisms of invasive microglial migration into the SNpc. We show that α‐synuclein up‐regulates the expressions of the cell adhesion molecule CD44 and the cell surface protease membrane‐type 1 matrix metalloproteinase through the extracellular regulated kinases 1/2 pathway. These concurrent inductions increased the generation of soluble CD44 to liberate microglia from the surrounding extracellular matrix for migration. The effects of α‐synuclein were identical in BV‐2 murine microglial cells subjected to cDNA transfection and extracellular treatment. These inductions in primary microglial cultures of C57Bl/6 mice were identical to those in BV‐2 cells. α‐Synuclein‐induced microglial migration into the SNpc was confirmed in vivo using a 6‐hydroxydopamine mouse model of PD. Our data demonstrate a correlation between α‐synuclein‐induced phenotypic changes and microglial migration. With the recruitment of the microglial population into the SNpc during dopaminergic neurodegeneration, α‐synuclein may play a role in accelerating the pathogenesis of PD.
The Failure Mechanisms of Micro‐Scale Cantilevers Under Shock and Vibration Stimuli
Authors: Sheehy M. , Punch J. , Goyal S. , Reid M. , Lishchynska M. , Kelly G.
Published: March 2009

Abstract:  Recent advances in micro‐electro‐mechanical system (MEMS) fabrication technology have resulted in proliferation of micro‐scale mechanical devices, some of which are applied in environments with severe levels of shock. The objective of this paper was to investigate the use of experimental and numerical methods in quantifying the behaviour of representative MEMS devices subject to high‐g impact stimuli. Micro‐cantilevers were analysed under vibration and shock on a modified Hopkinson pressure bar and vibration table to determine the mechanical properties of single crystal silicon (SCS). The characteristic dimensions of the beams were of 100 μm in height/width with beam lengths ranging from 5 to 7 mm. The experimental approach allowed non‐invasive in situ monitoring of the micro‐cantilevers upon impact through accelerometry and high‐speed imaging. An investigation of the shock response of micro‐cantilever beams indicates that orientation plays a significant role in their sensitivity to shock because of the planarity of the fabrication technique. Scanning electron microscopy identified octahedral cleavage of SCS as the dominant failure mechanism of the micro‐cantilevers. Finite element analysis in conjunction with in situ high‐speed imaging proved to be a viable non‐invasive inverse technique to determine the loci and amplitude of tensile stress within generic micro‐scale devices.