bluuebunny/crossref_metadata_2025 huggingface dataset:
Teachers' Support Strategies for Lower Achievers in Basic School in Ghana
Authors: Hayford Samuel , Avoke Selete
Published: July 2011

Students in Basic schools in Ghana manifest diverse learning needs, which require innovative approaches to enable them to succeed in learning activities. The paper is part of a larger study conducted in Ghana, which used a range of data collecting methods including questionnaires, interviews with teachers and focus groups of below average students. This report focuses on data from semi-structured interviews with 12 basic (elementary-secondary) school teachers from two districts in the central region of Ghana. This paper explores strategies basic school teachers adopt to enhance successful participation of students who score below average and achieve lower attainments in regular classrooms in the country.
Practical Considerations for Working with Latino and Asian American Students and Families
Authors: Moreno Gerardo , Wong-Lo Mickie
Published: July 2011

Preparing educators to work with students from culturally and linguistically diverse (CLD) background is increasingly valued as the demographics of todays classrooms continue to evolve. Embracing cultural differences and recognizing the distinctive factors associated within the composition of CLD families are critical elements as educators become more proficient in working with students from diverse backgrounds. Recommended practices discussed within this article provide a glimpse into two enriched cultures, Latino and Asian American, which are among the minority categories found to be most prevalent within the American education system. Furthermore, recognition of the contributing factors associated with cultural differences can be instrumental in cultivating the meaning of diversity as well as working with students of CLD background effectively.
Eighth Grade Mathematics Achievement Gaps across Race, Ethnicity, and Gender
Authors: Pinar Colleen
Published: July 2011

This study examined differences in mathematics performance of female and male students by race/ethnicity at national levels drawing from a sample of 8th grade public school students obtained from the National Assessment of Educational Progress 8th Grade Mathematics Assessment for 2003-2007. Results of this study will demonstrate how 8th grade mathematics performance is distributed across race/ethnicity and gender factors and will help explain disparities in 8th grade mathematics achievement by race/ethnicity and gender. With the passing of No Child Left Behind, increasing pressures are felt at all levels to close achievement gaps in mathematics. Implications of these findings are important for improving mathematics achievement outcomes for all students.
X-ray investigation of melt flow behavior under magnetic stirring regime in laser beam welding of aluminum
Authors: Gatzen M. , Tang Z. , Vollertsen F. , Mizutani M. , Katayama S.
Published: July 2011

The use of magnetic fields to influence weld bead shape and dilution in laser welding of aluminum alloys was recently suggested. It was already demonstrated for the case of laser welding of hot-cracking sensitive aluminum alloys with silicon-containing filler wire that applying alternating magnetic fields has an impact on the dilution of silicon in the melt pool, yielding a sufficient silicon content throughout the weld and allowing to suppress hot-cracking. However, the interaction mechanisms between the aluminum melt and the magnetic field are still subject of current investigations and are not fully revealed yet. The behavior of the melt flow under influence of an external magnetic field can be visualized by microfocused high-speed x-ray transmission imaging. To do so, high density tracer materials such as tin (Sn) and tungsten (W) particles that follow the melt flow are introduced into the base material. It can be seen that the additionally induced forces of the magnetic field cause higher velocities in the melt pool. Moreover, the flow of molten liquid perpendicular to the magnetic field is modified. The experimental results are discussed in light of general theoretical assumptions concerning a liquid metal flow under the influence of an external magnetic field. It is established that the effect of the alternating magnetic field can be explained as an anisotropic pulsating electromagnetic force brake that causes a specific deflection of the liquid metal flow.
Hydrogen gas sensors based on nanocrystalline TiO2 thin films
Authors: Haidry Azhar , Schlosser Peter , Durina Pavol , Mikula Marian , Tomasek Milan , Plecenik Tomas , Roch Tomaš , Pidik Andrej , Stefecka Miloslav , Noskovic Jaroslav , Zahoran Miroslav , Kus Peter , Plecenik Andrej
Published: July 2011

Titanium dioxide thin films are extensively studied for applications in solid state gas sensor devices. Their gas sensing properties are strongly dependent on deposition technique, annealing temperature, film thickness and consequent properties like crystalline structure, grain size or amount of defects and impurities. In this work we report the gas sensing properties of TiO2 thin films prepared by reactive magnetron sputtering technique and subsequently annealed at temperatures 600°C and 900°C. The films were exposed to different concentrations of H2 gas up to 10 000 ppm. Their sensitivity to gas at various operating temperatures, ranging from 250°C to 450°C, was obtained by measuring their resistance.
The Association Between Submaximal Quadriceps Force Steadiness and the Knee Adduction Moment During Walking in Patients With Knee Osteoarthritis
Authors: Sørensen Tina Juul , Langberg Henning , Aaboe Jens , Bandholm Thomas , Bliddal Henning , Henriksen Marius
Published: July 2011

Study Design

Cross-sectional study.

Objectives

To investigate the relationship between quadriceps force steadiness and knee adduction moment during walking in patients with knee osteoarthritis (OA).

Background

Studies have shown that quadriceps force steadiness is impaired in patients with knee OA. Furthermore, patients with knee OA, compared to healthy controls, have also demonstrated a significantly higher external knee adduction moment during walking. However, no studies have examined the relationship between quadriceps force steadiness and the peak knee adduction moment during walking in this population.

Methods

Forty-one patients with knee OA (34 females and 7 males) were included in the study. Submaximal isometric quadriceps force steadiness was measured during a force target-tracking task. Peak knee adduction moments during ambulation were measured using a 3-dimensional gait analysis system, and knee pain was assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) pain subscale and a visual analog scale.

Results

Regression analyses showed that quadriceps force steadiness did not predict the peak knee adduction moment (adjusted R2 = 0.05, P = .41). Inclusion of covariates did not change the outcome.

Conclusion

No statistically significant association between submaximal isometric quadriceps force steadiness and peak knee external adduction moments during walking was found. It could be speculated that submaximal isometric quadriceps muscle force steadiness and knee joint loads during walking represent 2 distinctive pathways and may have independent influences on knee OA pathogenesis. J Orthop Sports Phys Ther 2011;41(8):592–599, Epub 12 July 2011. doi:10.2519/jospt.2011.3481
Investigation of Abdominal Muscle Thickness Changes After Spinal Manipulation in Patients Who Meet a Clinical Prediction Rule for Lumbar Stabilization
Authors: Konitzer Lisa N. , Gill Norman W. , Koppenhaver Shane L.
Published: July 2011

Study Design

Prospective case series.

Objectives

To investigate changes in abdominal muscle thickness with ultrasound imaging, after spinal manipulative therapy (SMT), in a subgroup of patients with low back pain (LBP) who meet a proposed clinical prediction rule for lumbar stabilization exercise (LSE).

Background

The characteristics of a subgroup of patients with LBP who respond clinically to LSE has been proposed. Although the pathoanatomical characteristics of this subgroup have not been determined, clinicians often assume that this type of LBP is related, in part, to neuromuscular deficits of the lateral abdominal muscles. Recent evidence suggests that SMT may facilitate abdominal muscle activity and, therefore, enhance exercises targeting these deficits.

Methods

Nineteen patients (mean age ± SD, 32.5 ± 7.8 years; 11 female) with LBP, who met the criteria for LSE, underwent ultrasound imaging of the transversus abdominis (TrA) and internal oblique (IO) muscles before, immediately after, and 3 to 4 days after lumbopelvic SMT. Measurements of resting thickness, contracted thickness during the abdominal drawing-in maneuver, and percent thickness change from rest to contraction of the TrA and IO muscles were analyzed with repeated-measures analysis of variance. Numeric pain rating scale and Oswestry Disability Index data were also collected.

Results

No significant differences in resting, contracted, or percent thickness change in the TrA or IO were found over the 3 time periods. There were statistically significant reductions in numeric pain rating scale and Oswestry Disability Index scores, but mean differences failed to meet the minimal clinically important difference.

Conclusion

The results provide preliminary evidence that TrA and IO muscle resting and contracted thicknesses do not change post-SMT in patients with LBP in the LSE subgroup. In addition, while reductions in pain and disability were noted, they were not clinically meaningful. J Orthop Sports Phys Ther 2011;41(9):666–674, Epub 12 July 2011. doi:10.2519/jospt.2011.3685
Morphological and anatomical investigations on three Allium L. (Liliaceae) species of east Anatolia, Turkey
Authors: Özdemir Canan , Akta? Kâmuran , Altan Yasin
Published: July 2011

Three East Anatolia species of Allium namely, A. karsianum Fomin, A. kunthianum Vved., A. rupestre Steven are compared morphologically and anatomically. The results showed that all the species investigated can be distinguished by their morphological and anatomical characters. Key words: Allium; Anatomy; Morphology DOI: http://dx.doi.org/10.3329/bjb.v40i1.7990 Bangladesh J. Bot. 40(1): 9-15, 2011 (June)
Differential chromosome banding and isozyme assay in Corchorus aestuans L.
Authors: Alam Sheikh Shamimul , Khatun Masuda , Sultana Syeda Sharmeen
Published: July 2011

Karyotype of Corchorus aestuans L. was investigated with differential staining, viz. orcein, CMA and DAPI. In addition, activities of three isozyme system namely, esterase, acid phosphatase and peroxidase were studied to obtain specific molecular markers. This species was found to possess 2n = 14 metacentric chromosomes. In this species, three terminal CMA-bands appeared of which two in chromosome pairs I and the rest in a member of chromosome pair VI. Two thick DAPI-positive terminal bands were found in pair II and III. These two chromosomes showed deep CMA-negative bands at the terminal regions where DAPIpositive bands were found. Moreover, one member of pair VII fluoresced entirely with DAPI whereas an interstitial DAPI band occurred in its homologue. Five esterase, one peroxidase and two acid phosphatase bands were observed in this species. These isozyme bands were very stable and species specific. Therefore, differential fluorescent chromosome banding and isozyme assay were found to produce characteristic cytogenetical and molecular markers in C. aestuans. Key words: Fluorascent banding; Isozyme assay; Corchorus aestuans   DOI: http://dx.doi.org/10.3329/bjb.v40i1.7997 Bangladesh J. Bot. 40(1): 47-52, 2011 (June)
Pollen tube growth of Paeonia tenuifolia L. (Paeoniaceae) in vitro and in vivo
Authors: Dane Feruzan , Ekici Nuran
Published: July 2011

In vitro and in vivo studies on pollen germination of Paeonia tenuifolia L. (Paeoniaceae) revealed that pollen grains are shed at two-celled stage. Normal and abnormal pollens were observed. Pollen viability was recorded between 55 and 75%. In vitro studies revealed 85% germination and usually the germination was monosphonic. Some pollen tubes with swollen tube tip and undulations were found. Styles and stigma were found to contain many pollen tubes 24 hrs after pollination. Key words: Paeonia tenuifolia; Pollen tube; In vitro growth; In vivo growth  DOI: http://dx.doi.org/10.3329/bjb.v40i1.8003 Bangladesh J. Bot. 40(1): 93-95, 2011 (June)
Effects of naphthalene acetic acid on yield attributes and yield of two varieties of rice (Oryza sativa L.)
Authors: Adam AMM Golam , Jahan Nargis
Published: July 2011

Effects of 100 and 200 ppm of naphthalene acetic acid (NAA) on yield attributes and yield of two varieties of rice during 2009 - 2010 Boro season were evaluated. The highest plant height was observed due to 200 ppm in both BRRI dhan-29 (V1) and BRRI dhan-50 (V2). Number of tillers per plant were found to increase due to 100 ppm NAA only in BRRI dhan-29 and varied non-significantly. Yield attributes, viz. number of branches per panicle, number of grains per panicle and filled grains per panicle increased in BRRI dhan-29, following both 100 and 200 ppm NAA, whereas, most of the yield parameters decreased in BRRI dhan-50. Due to 100 and 200 ppm NAA, grain yield per plant increased by 27.67 and 6.85%, respectively in BRRI dhan-29 though not statistically significant. However, in BRRI dhan-50 grain yield per plant decreased by 26.54% due to 100 ppm and 27.67% due to 200 ppm. Out of the two concentrations 100 ppm NAA produced better stimulation. Key words: Rice; Naphthalene acetic acid; Foliar application; Yield DOI: http://dx.doi.org/10.3329/bjb.v40i1.8004 Bangladesh J. Bot. 40(1): 97-100, 2011 (June)
Current Concepts of Metastasis Formation
Authors: Haier Jörg , Gassman Peter
Published: July 2011

The development of secondary distant organ and lymph node metastasis has an extraordinary impact on the prognosis of patients with solid cancer. In most cases the advent of metastatic growth represents the turning point from a local, potentially curable, disease to a systemic non-curable situation. As a highly regulated process, metastasis formation follows a distinct, non-random pattern characteristic for each tumor entity. Metastasis formation and strategies to prevent this lethal event in the progression of cancer is of fundamental interest for cancer science and patient care. In this special issue of Cancers, papers highlighting cellular mechanisms of metastasis formation, genetic and epigenetic aspects associated with organ and tumor specific metastasis formation, as well as papers outlining experimental and clinical therapeutic concepts for anti-metastatic treatment are included. [...]
Prevalence of Low-Level HIV-1 Variants with Reverse Transcriptase Mutation K65R and the Effect of Antiretroviral Drug Exposure on Variant Levels
Authors: Kozal Michael J , Chiarella Jennifer , John Elizabeth P St , Moreno Elizabeth A , Simen Birgitte B , Arnold Todd E , Lataillade Max
Published: July 2011

Background

It has been reported that treatment-naive individuals infected with HIV-1 subtype C may be more likely to harbour viral variants possessing a K65R reverse transcriptase gene mutation. The objectives of this study were to determine the prevalence of low-level K65R variants within different HIV-1 subtypes and to assess the effects of antiretroviral exposure on K65R variant levels.

Methods

Treatment-naive individuals infected with different HIV-1 subtypes were genotyped by ultra-deep sequencing. Samples were evaluated for low-level variants to 0.4% or 1% levels depending upon viral load. Estimated mutational load was calculated by multiplying the percentage of the variant by the plasma viral load.

Results

A total of 411 treatment-naive individuals were evaluated by ultra-deep sequencing to 1% levels; 4 subjects (0.97%) had K65R variants at ≥1% or had a very high mutation load. All four subjects had variants with linked drug resistance mutations suggesting transmitted resistant variants. 147 ARV-naive subjects were sequenced to 0.4% levels; 8.8% (13/147) had K65R low-level variants identified: 2.2% (2/92) in subtype B, 35.7% (10/28) in subtype C ( P<0.001 for B versus C) and 3.7% (1/27) in non-B/C subtypes. The 13 ARV-naive subjects with K65R variants at <1% received tenofovir plus emtricitabine plus a ritonavir-boosted protease inhibitor (TDF+FTC+PI/r) and 5 subsequently experienced virological failure. There was no enhancement in K65R levels by percentage or mutational load compared to pre-therapy levels.

Conclusions

Low-level K65R variants were more frequently identified in subtype C. K65R variants at >1% levels likely represent transmitted resistant variants. The clinical implication of low-level K65R variants below 1% in treatment-naive subjects who receive TDF+FTC+PI/r remains to be determined as the majority are very low-level and did not increase after antiretroviral exposure.
Convergence internationale des normes de fonds propres
Authors: Saadaoui Zied
Published: July 2011

Résumé Cette étude analyse empiriquement l’effet de l’application du ratio Cooke sur le profil de risque et le comportement des banques commerciales dans les pays non membres du Comité de Bâle. En utilisant d’abord un test non paramétrique, ensuite un modèle d’équations simultanées, on constate l’effet quasi inexistant des fonds propres réglementaires sur la prise de risque des banques. Dans ces pays, la capitalisation et la prise de risque des banques sont sensibles à l’environnement macroéconomique et réglementaire, ainsi qu’à l’interférence politique et la qualité des instruments de fonds propres. Dans la perspective de l’adoption de l’accord de Bâle III, il est donc important pour les pays non membres du Comité de Bâle que les instances de régulation prennent en considération les spécificités de leurs systèmes bancaires.
Cross-linking in Progressive Keratoconus Using an Epithelial Debridement or Intrastromal Pocket Technique After Previous Corneal Ring Segment Implantation
Authors: Alió Jorge L. , Toffaha Bader T. , Piñero David P. , Klonowski Pawel , Javaloy Jaime
Published: July 2011

PURPOSE:

To evaluate and compare the clinical and confocal microscopic outcomes achieved with two different procedures for cross-linking (CXL) in eyes with keratoconus: CXL with epithelial debridement and CXL with intrastromal pocket.

METHODS:

This retrospective study included 27 eyes of 21 patients (age range: 18 to 53 years) diagnosed with keratoconus who underwent implantation of intracorneal ring segments and CXL with two different techniques: CXL with previous epithelial debridement (classic group, 16 eyes) and CXL with intrastromal pocket for riboflavin infusion (pocket group, 11 eyes). Visual, refractive, topographic, aberrometric, and pachymetric data were evaluated during 12-month follow-up.

RESULTS:

No statistically significant differences between the classic and pocket groups were found in postoperative visual acuity (
P
≥.71), refraction (
P
≥.15), keratometry (
P
≥.28), corneal aberrations (
P
≥.13), or central pachymetry (
P
≥.21). A statistically significant improvement in uncorrected visual acuity found at 3 months postoperatively in both groups (
P
<.03) was consistent with a change in manifest sphere. Mean keratometric reduction at 12 months was 0.03 diopters (D) in the classic group (
P
=.55) and 0.40 D in the pocket group (
P
=.05). No significant changes in corneal higher order aberrations or central corneal thickness were found in either group (
P
≥.14).

CONCLUSIONS:

Cross-linking surgery with creation of an intrastromal pocket seems to provide similar clinical outcomes compared to the classic CXL technique.
Genetic diversity analysis of 119 Canadian maize inbred lines based on pedigree and simple sequence repeat markers
Authors: Reid L. M. , Xiang K. , Zhu X. , Baum B. R. , Molnar S. J.
Published: July 2011

Reid, L. M., Xiang, K., Zhu, X., Baum, B. R. and Molnar, S. J. 2011. Genetic diversity analysis of 119 Canadian maize inbred lines based on pedigree and simple sequence repeat markers. Can. J. Plant Sci. 91: 651–661. Since the early 1920s Agriculture and Agri-Food Canada (AAFC) has been developing maize varieties and inbred lines adapted to the early maize growing regions. These inbreds represent a large group of genetically diverse genotypes; however, many of the inbreds are of unknown heterotic backgrounds. The purpose of this study was to classify 119 elite maize inbred lines released from AAFC into heterotic groups using both pedigree data and simple sequence repeat (SSR) markers and also to explore the consistency among different classification analyses. Pedigree analysis placed the inbred lines into eight groups, six of which corresponded to known major heterotic groups representing Iowa Stiff Stalk Synthetic (BSSS), European flint, Lancaster, Minnesota 13, Early Butler, and Iodent; the two remaining groups consisted of germplasm derived mostly from Pioneer 3990 or Pioneer 3994 sources. Simple sequence repeat analysis of 105 loci resulted in a clustering of the inbreds into 10 groups. In comparison with the grouping based on pedigree, the SSR clustering groups had some discrepancies and groups of genetically similar germplasm, based on pedigree, could not always be confirmed with molecular markers. The results of this study will allow researchers and maize breeders to make more informed decisions on the use of these inbreds in breeding programs.
Soil controls of phosphorus in runoff: Management barriers and opportunities
Authors: Kleinman Peter , Sharpley Andrew , Buda Anthony , McDowell Richard , Allen Arthur
Published: July 2011

Kleinman, P. J. A., Sharpley, A. N., Budda, A. R., McDowell, R. W. and Allen, A. L. 2011. Soil controls of phosphorus in runoff: Management barriers and opportunities. Can. J. Soil Sci. 91: 329–338. The persistent problem of eutrophication, the biological enrichment of surface waters, has produced a vast literature on soil phosphorus (P) effects on runoff water quality. This paper considers the mechanisms controlling soil P transfers from agricultural soils to runoff waters, and the management of these transfers. Historical emphases on soil conservation and control of sediment delivery to surface waters have demonstrated that comprehensive strategies to mitigate sediment-bound P transfer can produce long-term water quality improvements at a watershed scale. Less responsive are dissolved P releases from soils that have historically received P applications in excess of crop requirements. While halting further P applications to such soils may prevent dissolved P losses from growing, the desorption of P from soils that is derived from historical inputs, termed here as “legacy P”, can persist for long periods of time. Articulating the role of legacy P in delaying the response of watersheds to remedial programs requires more work, delivering the difficult message that yesterday's sinks of P may be today's sources. Even legacy sources of P that occur in low concentration relative to agronomic requirement can support significant loads of P in runoff under the right hydrologic conditions. Strategies that take advantage of the capacity of soils to buffer dissolved P losses, such as periodic tillage to diminish severe vertical stratification of P in no-till soils, offer short-term solutions to mitigating P losses. In some cases, more aggressive strategies are required to mitigate both short-term and legacy P losses.
The gradient flow of Higgs pairs
Authors: Li Jiayu , Zhang Xi
Published: July 2011

In this paper, we consider the gradient flow of the Yang-Mills-Higgs functional of Higgs pairs on a Hermitian vector bundle

(E , H_{0})

over a Kähler surface

(M , \omega )

, and study the asymptotic behavior of the heat flow for Higgs pairs at infinity. The main result is that the gradient flow with initial condition

(A_{0} , \phi_{0})

converges, in an appropriate sense which takes into account bubbling phenomena, to a critical points

(A_{\infty } , \phi_{\infty})

of this functional. We also prove that the limiting Higgs pair

(A_{\infty }, \phi_{\infty})

can be extended smoothly to a vector bundle

E_{\infty }

over

(M , \omega )

, and the isomorphism class of the limiting Higgs bundle

(E_{\infty } , A_{\infty } , \phi_{\infty})

is given by the double dual of the graded Higgs sheaves associate to Harder-Narasimhan-Seshadri filtration of the initial Higgs bundle

(E , A_{0} , \phi_{0})

.
Homogenization in polygonal domains
Authors: Gérard-Varet David , Masmoudi Nader
Published: July 2011

We consider the homogenization of elliptic systems with

\varepsilon

-periodic coefficients. Classical two-scale approximation yields a

O(\varepsilon)

error inside the domain. We discuss here the existence of higher order corrections, in the case of general polygonal domains. The corrector depends in a non-trivial way on the boundary. Our analysis extends substantially previous results obtained for polygonal domains with sides of rational slopes.
To Determine the Influence of the Complete Denture Prosthesis on Masticatory Muscle Activity in Elderly Patients: An in vivo Study
Authors: Ashraf Haifa
Published: July 2011

Introduction

Mastication is a highly coordinated neuromuscular function involving fast effective movements of the jaw and continuous modulation of force. In older subjects these mechanisms act with marked differences. They have a reduced capacity in various functions of stomatognathic system.

Objectives

To evaluate the elevator and depressor muscle activity with and without complete denture prosthesis.

Materials and methods

For the purpose of the study 12 patients between the age of 40 and 70 years were selected. Surface electrodes from the electromyographic unit were placed in the region of right and left anterior temporal muscles, Masseter muscle and depressor muscle at the region of anterior belly of digastric and the electromyographic activity was recorded.

Results and discussion

The obtained values were subjected to statistical analysis. A paired t- test was performed to determine the difference between the subjects with and without denture prosthesis.

Conclusion

The elevator muscles showed higher activity in subjects wearing the denture prosthesis when compared to those without denture prosthesis. No significant change in muscle activity was seen on maximal opening of the depressor muscle between the subjects with and without denture prosthesis.
Rehabilitation of a Severely Worn Dentition using Fixed and Removable Partial Overdenture Prostheses
Authors: Jain Veena , Agnihotri Hema
Published: July 2011

Planning and executing the restorative rehabilitation of a severely worn dentition is probably one of the most intellectually and technically demanding tasks faced by the restorative dentist. This article describes the rehabilitation of a 55-year-old male patient with severe loss of tooth structure. The maxillary arch was restored using fixed restorations and the mandibular arch using the integration of fixed and removable prosthodontics. The integration of fixed and removable prosthodontics in a partially dentate patient poses a challenge as well as an opportunity for the use of a partial overdenture.
Relative effects of precipitation variability and warming on grassland ecosystem function
Authors: Fay P. A. , Blair J. M. , Smith M. D. , Nippert J. B. , Carlisle J. D. , Knapp A. K.
Published: July 2011

Abstract. Precipitation and temperature drive many aspects of terrestrial ecosystem function. Climate change scenarios predict increasing precipitation variability and temperature, and long term experiments are required to evaluate the ecosystem consequences of interannual climate variation, increased growing season (intra-annual) rainfall variability, and warming. We present results from an experiment applying increased growing season rainfall variability and year round warming in native perennial grassland. During ten years of study, total growing season rainfall varied 2-fold, and we found ~50–200 % interannual variability in plant growth and aboveground net primary productivity, leaf carbon assimilation (ACO2), and soil CO2 efflux (JCO2) despite only ∼40 % variation in mean volumetric soil water content (0–15 cm, Θ15). Interannual variation in soil moisture was thus amplified in most measures of ecosystem response. Differences between years in Θ15 explained the greatest portion (14–52 %) of the variation in these processes. Experimentally increased intra-annual rainfall variability doubled the amplitude of intra-annual soil moisture variation and reduced Θ15 by 15 %, causing most ecosystem processes to decrease 8–40 % in some or all years with increased rainfall variability compared to ambient rainfall timing, suggesting reduced ecosystem rainfall use efficiency. Warming treatments increased 5 cm soil temperature, particularly during spring, fall, and winter. Warming advanced canopy green up in spring, increased winter JCO2, and reduced summer JCO2 and forb ANPP, suggesting that the effects of warming differed in cooler versus warmer parts of the year. We conclude that (1) major ecosystem processes in this grassland may be substantially altered by predicted changes in interannual climate variability, intra-annual rainfall variability, and temperature, (2) interannual climate variation was a larger source of variation in ecosystem function than intra-annual rainfall variability and warming, and (3) effects of increased growing season rainfall variability and warming were small, but ecologically important. The relative effects of these climate drivers are likely to vary for different ecosystem processes and in wetter or drier ecosystems.
A survey of key distribution in wireless sensor networks
Authors: Chen Chi‐Yuan , Chao Han‐Chieh
Published: July 2011

Key establishment is the most fundamental cryptographic primitive in all kinds of applications where security is a concern. However, the nature of limited resources on sensor nodes restricts the use of conventional key management techniques in wireless sensor networks. Many researchers have conducted different techniques to propose different types of key distribution schemes. In this paper, we survey the existing solutions and describe the state‐of‐the‐art techniques. We not only classify these proposals into location‐independent key distribution schemes and location‐dependent key distribution schemes but also provide a comparison table. We hope to attract more research attentions on this direction. Copyright © 2011 John Wiley & Sons, Ltd.
Biorder-preserving coextensions of fundamental semigroups
Authors: Easdown David
Published: July 2011

In any extension theory for semigroups one must determine the basic building blocks and then discover how they fit together to create more complicated semigroups. For example, in group theory the basic building blocks are simple groups. In semigroup theory however there are several natural choices. One that has received considerable attention, particularly since the seminal work on inverse semigroups by Munn ([14, 15]), is the notion of a fundamental semigroup. A semigroup is called fundamental if it cannot be [shrunk] homomorphically without collapsing some of its idempotents (see below for a precise definition).
Production and Properties of Fuels from Domestic and Industrial Waste
Authors: John Ejae , Singh Kamel
Published: July 2011

Waste is a byproduct of life and civilisation; it is the material that remains after a useful component has been consumed. From an economic perspective, waste is a material involved in life or technology whose value today is less than the cost of its utilisation. From a regulatory viewpoint, waste is anything discarded or can no longer be used for its original purpose. The term solid waste includes not only solid materials but also liquid and gases. If one reuses something, it may not be considered waste.

Domestic waste (also known as rubbish, garbage, trash, or junk) is unwanted or undesired material (although the old adage one man's waste is another man's treasure sometimes applies). Waste is the general term; though the other terms are used loosely as synonyms, they have more specific meanings: rubbish or trash are mixed household waste including paper and packaging; food waste or garbage (North America) is kitchen and table waste; and junk or scrap is metallic or industrial material. There are other categories of waste as well: sewage, manure, ash, and plant materials from garden operations, including grass cuttings, fallen leaves, and pruned branches.

Industrial waste is waste produced by factories, mills, and mines. Chemical waste and toxic waste (usually a subcategory of chemical waste) are two more specific designations of industrial waste.

Municipal solid waste (MSW) is a waste that includes predominantly household waste (domestic waste) with sometimes the addition of commercial waste collected by a municipality within a given area. They are in either solid or semisolid form and generally exclude industrial hazardous waste. The term residual waste relates to waste left from household sources containing materials that have not been separated out or sent for reprocessing.

In this chapter, the components of waste is be described. Then, the processes to generate fuels derived from various domestic, urban, forestry, farm, crop and agricultural wastes will be explained, and the associated fuels characterized.
Green Sample Preparation Methods
Authors: Bendicho Carlos , Lavilla Isela , Pena Francisco , Costas Marta
Published: July 2011

Sample preparation is the stage of the analytical process where greenness-related issues can likely play the most important role. With the exception of direct methods for solid sample analysis, for most analytical methods it is necessary to carry out a certain number of operations to make the sample amenable to the instrument. These operations, which may include digestion, extraction, dissolution, preconcentration and clean-up, typically require the use of large amounts of acids, organic solvents, and in general, chemicals that can often be persistent, bioaccumulative and toxic (PBT) as well as operating conditions that can become unsafe and energy-consuming. Therefore, sample preparation stages should be targeted as a priority when green chemistry principles are to be adapted to analytical activities. This chapter is devoted to the discussion of most relevant sample preparation strategies that approach the fulfilment of the green chemistry principles. Thus, digestion and extraction strategies from solid samples for both inorganic and organic analysis are approached using microwaves and ultrasound, followed by a discussion of modern extraction techniques, such as microwave-assisted extraction, supercritical fluid extraction, pressurized liquid extraction and solid-phase extraction for trace organic analysis. Microextraction techniques also deserve a place here, since a high degree of greenness is achieved when they are implemented in analytical methodology. Finally, application of surfactants in techniques such as cloud point extraction or membranes that allow minimizing the use of organic solvents for analysis of liquid samples are discussed.
Miniaturization of Analytical Methods
Authors: Pena-Abaurrea Miren , Ramos Lourdes
Published: July 2011

This chapter highlights miniaturization in sample preparation as a valuable alternative for green analytical chemistry. The current state of the art is discussed on the basis of examples selected from representative application areas, including biomedical, environmental and food analysis, and involving conventional instrumental techniques for final determination of the target compounds. The emphasis is on those techniques and approaches that have already demonstrated their practicality by the analysis of real-life samples, and in particular on those dealing with the accurate determination of minor organic components. The potential of recent developments in this field for sample treatment simplification and complete hyphenation of analytical processes are discussed and the most pressing remaining limitations evaluated.
Generalized analytic functions in magnetohydrodynamics
Authors: Zabarankin Michael
Published: July 2011

An approach of generalized analytic functions to the magnetohydrodynamic (MHD) problem of an electrically conducting viscous incompressible flow past a solid non-magnetic body of revolution is presented. In this problem, the magnetic field and the body’s axis of revolution are aligned with the flow at infinity, and the fluid and body are assumed to have the same magnetic permeability. For the linearized MHD equations with non-zero Hartmann, Reynolds and magnetic Reynolds numbers (
M
,
Re
and
Re
m
, respectively), the fluid velocity, pressure and magnetic fields in the fluid and body are represented by four generalized analytic functions from two classes:
r
-analytic and
H
-analytic. The number of the involved functions from each class depends on whether the Cowling number S=
M
2
/(
Re
m
 
Re
) is 1 or is not 1. This corresponds to the well-known peculiarity of the case S=1. The MHD problem is proved to have a unique solution and is reduced to boundary integral equations based on the Cauchy integral formula for generalized analytic functions. The approach is tested in the MHD problem for a sphere and is demonstrated in finding the minimum-drag spheroids subject to a volume constraint for S<1, S=1 and S>1. The analysis shows that as a function of S, the drag of the minimum-drag spheroids has a minimum at S=1, but with respect to the equal-volume sphere, drag reduction is smallest for S=1 and becomes more significant for S≫1.
JAG1 mutations are found in approximately one third of patients presenting with only one or two clinical features of Alagille syndrome
Authors: Guegan K , Stals K , Day M , Turnpenny P , Ellard S
Published: July 2011

Guegan K, Stals K, Day M, Turnpenny P, Ellard S. JAG1 mutations are found in approximately one third of patients presenting with only one or two clinical features of Alagille syndrome.

Alagille syndrome is a multisystem disorder characterized by highly variable expressivity, most frequently caused by heterozygous JAG1 gene mutations. Classic diagnostic criteria combine the presence of bile duct paucity on liver biopsy with three of five systems affected; liver, heart, skeleton, eye and dysmorphic facies. The aim of this study was to determine the prevalence and distribution of JAG1 mutations in patients referred for routine clinical diagnostic testing. Clinical data were available for 241 patients from 135 families. The index cases were grouped according to the number of systems affected (heart, liver, skeletal, eye and facies) and the mutation frequency calculated for each group. JAG1 mutations were identified in 59/135 (44%) probands. The highest mutation detection rates were observed in patients with the most frequent presenting features of Alagille syndrome; ranging from 20% (one system) to 86% (five systems). The overall mutation pick‐up rate in a clinical diagnostic setting was lower than in previous research studies. Identification of a JAG1 gene mutation is particularly useful for those patients with atypical or mild Alagille syndrome who do not meet classic diagnostic criteria as it provides a definite molecular diagnosis and allows accurate genetic counselling for the family.
Drug Effectiveness Explained: The Mathematics of Antiviral Agents for HIV
Authors: Perelson Alan S. , Deeks Steven G.
Published: July 2011

A critical subset model explains the high potency of antiviral therapy for HIV.
QUANTUM PHASE SHIFT AND NEUTRINO OSCILLATIONS IN A STATIONARY, WEAK GRAVITATIONAL FIELD
Authors: LINET B. , TEYSSANDIER P.
Published: July 2011

A new method based on Synge's world function is developed for determining within the WKB approximation the gravitationally induced quantum phase shift of a particle propagating in a stationary spacetime. This method avoids any calculation of geodesics. A detailed treatment is given for relativistic particles within the weak field, linear approximation of any metric theory. The method is applied to the calculation of the oscillation terms governing the interference of neutrinos considered as the superposition of two eigenstates having different masses. It is shown that the neutrino oscillations are not sensitive to the gravitomagnetic components of the metric as long as the spin contributions can be ignored. Explicit calculations are performed when the source of the field is a spherical, homogeneous body. A comparison is made with previous results obtained in Schwarzschild spacetime.
miR-22 Promotes HBV-Related Hepatocellular Carcinoma Development in Males
Authors: Jiang Runqiu , Deng Lei , Zhao Liang , Li Xiangcheng , Zhang Feng , Xia Yongxiang , Gao Yun , Wang Xuehao , Sun Beicheng
Published: July 2011

Purpose: Previous reports have shown that IL-1α–MyD88–IL-6 signaling is essential in promoting hepatocellular carcinoma (HCC) development in a diethylnitrosamine (DEN)-induced mouse model. We aimed to determine whether interleukin (IL)-1α regulates HCC development in humans.

Methods: HBV-associated HCC tissue, corresponding adjacent tissue, and normal tissue samples were obtained from 80 male and 36 female patients. IL-1α, ERα, IL-6, and MyD88 were quantified by using real-time PCR and Western blot. Stem-loop PCR was used to quantify miR-22 expression. Luciferase reporter assays were used to study transcriptional regulation.

Results: IL-1α was highly expressed in male tumor adjacent tissue compared with normal tissue (P = 0.025); however, this was not the case for female subjects. A linear relationship was observed between increased IL-1α and decreased ERα expression in male tumor adjacent tissue (r = −0.616, P = 0.004). Our results also indicated that estrogen (E2) was suppressed upon IL-1α secretion in ERα-overexpressed HCC cells. We detected high expression of miR-22 in male tumor adjacent tissue compared with controls (P = 0.027); furthermore, we showed that miR-22 downregulates ERα transcription by targeting the 3′-untranslated region. In the DEN-induced model, IL-1α was highly expressed in sprouting tumors and gradually decreased in conjunction with HCC development.

Conclusion: Overexpression of miR-22 in male tumor adjacent tissue was associated with downregulated ERα expression, potentially by attenuating the protective effect of estrogen and causing increased IL-1α expression. These results may explain the high incidence of HBV-associated HCC in the male population. Clin Cancer Res; 17(17); 5593–603. ©2011 AACR.
Declining β-Cell Function Relative to Insulin Sensitivity With Escalating OGTT 2-h Glucose Concentrations in the Nondiabetic Through the Diabetic Range in Overweight Youth
Authors: Burns Stephen F. , Bacha Fida , Lee So Jung , Tfayli Hala , Gungor Neslihan , Arslanian Silva A.
Published: July 2011

OBJECTIVE

Overweight in youth is associated with the risk of developing type 2 diabetes. We hypothesized that β-cell function relative to insulin sensitivity decreases with increasing 2-h glucose levels based on an oral glucose tolerance test (OGTT) in overweight youth.

RESEARCH DESIGN AND METHODS

A total of 147 overweight (BMI ≥85th percentile for age and sex) youth, aged 8 to <20 years, undertook three tests: 1) a 3-h hyperinsulinemic-euglycemic clamp; 2) a 2-h hyperglycemic clamp; and 3) a 2-h OGTT. Participants were categorically assigned to five groups according to their OGTT 2-h plasma glucose level, ranging from <120 to ≥200 mg/dL. β-Cell function relative to insulin sensitivity, assessed by clamp disposition index (DI) and oral disposition index (DIO), were compared among groups.

RESULTS

Insulin sensitivity, first-phase insulin, and DI declined significantly as 2-h glucose concentrations increased. The highest DI was found in youth with 2-h plasma glucose concentrations <120 mg/dL, with a significant decline of ~40% in those with glucose concentrations between 120 and <140 mg/dL, and an ~75% decline, the lowest DI, in youth with glucose concentrations ≥200 mg/dL. Data were similar with regard to the OGTT DIO.

CONCLUSIONS

These data in overweight youth demonstrate that impairment in insulin secretion relative to insulin sensitivity is apparent even with normal glucose tolerance. Below the current cutoff of 140 mg/dL for impaired glucose tolerance, there is a >30% decline in β-cell function relative to insulin sensitivity. Against this back drop of metabolically heightened risk for type 2 diabetes, preventive measures should target the β-cell alongside insulin sensitization.
Open Versus Closed Forms of Knowledge Assessment in a Blended Learning Ecosystem
Authors: Purg Peter
Published: July 2011

Open Versus Closed Forms of Knowledge Assessment in a Blended Learning Ecosystem

The article investigates whether two opposite assessment methods, open wiki (online text-and-media collaboration) and closed multiple-choice test, can together assure a balanced addressing of the learner both as an information processor and a social entity. Comparing students' experience and satisfaction with collective knowledge construction in a moderated wiki on the one hand and knowledge testing in an online multiple choice test on the other hand, the research differentiates full-time and part-time students of a blended course. This is presented upon broader data on comparable students' populations who were assessed with open-ended oral exam questions, regular homework tasks and seminar work papers. An updated notion of media ecology conceives knowledge testing and instructional feedback as parts of an informational ecosystem: only a coherent yet internally differentiated learning environment can accurately define significant educational trends and recommendations - such that question assessment methods and signpost the development of education towards sustainability.
Crossing Divides
Authors: Hartman Deborah
Published: July 2011

This article describes a study of a sample of submissions to an Australian government Inquiry into the Education of Boys, using a relatively new methodology for reviewing literature, called an argument catalogue. The study examines the usefulness of the methodology to an analysis of the complex field of boys’ education. The author argues that the argument catalogue approach offers a way of including and analysing all voices within the field, particularly the previously under-represented views of parents and practitioners and that despite complexities, there are commonalities that can be built on, which are critical to any positive change in this field.
Discrete spectrum of quantum Hall effect Hamiltonians I. Monotone edge potentials
Authors: Bruneau Vincent , Miranda Pablo L. , Raikov Georgi
Published: July 2011

We consider the unperturbed operator

H_0 : = (-i \nabla - A)^2 + W

, self-adjoint in

L^2(\mathbb{R}^2)

. Here

A

is a magnetic potential which generates a constant magnetic field

b>0

, and the edge potential

W

is a non-decreasing non constant bounded function depending only on the first coordinate

x \in \mathbb{R}

of

(x,y) \in \mathbb{R}^2

. Then the spectrum of

H_0

has a band structure and is absolutely continuous; moreover, the assumption

\lim_{x \to \infty}(W(x) - W(-x)) < 2b

implies the existence of infinitely many spectral gaps for

H_0

. We consider the perturbed operators

H_{\pm} = H_0 \pm V

where the electric potential

V \in L^{\infty}(\mathbb{R}^2)

is non-negative and decays at infinity. We investigate the asymptotic distribution of the discrete spectrum of

H_\pm

in the spectral gaps of

H_0

. We introduce an effective Hamiltonian which governs the main asymptotic term; this Hamiltonian involves a pseudo-differential operator with generalized anti-Wick symbol equal to

V

. Further, we restrict our attention on perturbations

V

of compact support and constant sign. We establish a geometric condition on the support of

V

which guarantees the finiteness of the eigenvalues of

H_{\pm}

in any spectral gap of

H_0

. In the case where this condition is violated, we show that, generically, the convergence of the infinite series of eigenvalues of

H_+

(resp.

H_-

) to the left (resp. right) edge of a given spectral gap, is Gaussian.