bluuebunny/crossref_metadata_2025 huggingface dataset:
10‐Year Survival and Success Rates of 511 Titanium Implants with a Sandblasted and Acid‐Etched Surface: A Retrospective Study in 303 Partially Edentulous Patients
Authors: Buser Daniel , Janner Simone F. M. , Wittneben Julia‐Gabriela , Brägger Urs , Ramseier Christoph A. , Salvi Giovanni E.
Published: April 2012

Purpose: This retrospective study assessed the 10‐year outcomes of titanium implants with a sandblasted and acid‐etched (SLA) surface in a large cohort of partially edentulous patients.

Materials and Methods: Records of patients treated with SLA implants between May 1997 and January 2001 were screened. Eligible patients were contacted and invited to undergo a clinical and radiologic examination. Each implant was classified according to strict success criteria.

Results: Three hundred three patients with 511 SLA implants were available for the examination. The mean age of the patients at implant surgery was 48 years. Over the 10‐year period, no implant fracture was noted, whereas six implants (1.2%) were lost. Two implants (0.4%) showed signs of suppuration at the 10‐year examination, whereas seven implants had a history of peri‐implantitis (1.4%) during the 10‐year period, but presented with healthy peri‐implant soft tissues at examination. The remaining 496 implants fulfilled the success criteria. The mean Plaque Index was 0.65 (±0.64), the mean Sulcus Bleeding Index 1.32 (±0.57), the mean Probing Depth 3.27 mm (±1.06), and the mean distance from the implant shoulder to the mucosal margin value −0.42 mm (±1.27). The radiologic mean distance from the implant shoulder to the first bone‐to‐implant contact was 3.32 mm (±0.73).

Conclusion: The present retrospective analysis resulted in a 10‐year implant survival rate of 98.8% and a success rate of 97.0%. In addition, the prevalence of peri‐implantitis in this large cohort of orally healthy patients was low with 1.8% during the 10‐year period.
Health care professionals’ perspectives on oral care for long‐term care residents: Nursing staff, speech–language pathologists and dental hygienists
Authors: Yoon Minn N. , Steele Catriona M.
Published: April 2012

doi: 10.1111/j.1741‐2358.2011.00513.x

Health care professionals’ perspectives on oral care for long‐term care residents: Nursing staff, speech–language pathologists and dental hygienists

Background:  Oral health has been identified as a key factor in general health and systemic disease in long‐term care populations. To optimise oral health of this population, it is important to understand the oral care perspectives held by health care professionals involved in oral care provision.

Objectives:  To explore perspectives regarding oral care held by nursing staff, speech–language pathologists (SLPs) and dental hygienists (DHs) in long‐term care institutions and to understand how their perspectives impact activities and processes involved in the delivery of oral care.

Methods:  A focus group methodology was utilised. Separate focus groups for each targeted profession were held. Transcribed data were analysed using constant comparative analysis.

Results:  Daily oral health maintenance and monitoring was considered a role of nursing staff. SLPs and DHs have roles focusing on advocacy, education and supplemental care. Social factors motivate nursing staff to provide oral care, whereas factors related to the general health consequences of poor oral health underlined the motivations of SLPs and DHs.

Conclusions:  Education and training initiatives incorporating social aspects of oral health may be more effective for motivating nursing staff than approaches emphasising physical risk factors. Organisations can foster environments that support collaboration and communication amongst the members of multidisciplinary teams in order to promote oral health as a priority.
‘Like Penelope, always employed’: Reading, Life‐Writing, and the Early Modern Female Self in Katherine Austen’s Book M
Authors: Ross Sarah C. E.
Published: April 2012

Ever since Virginia Woolf evocatively imagined the frustrated existence and tragic demise of Shakespeare’s sister, the search for the literary texts of early modern women has been bound up with the search for traces of their lives. Women’s life‐writings in the early modern period, however, are often impersonal and rarely present a unified sense of self, instead occurring most frequently in generically fluid forms, and producing fragmentary subjectivities. I argue in this article that the generic eclecticism of early modern women’s life‐writings is closely related to the question of what and how early modern women read. Focusing on the example of Katherine Austen’s Book M, this article explores the relationship between early modern women’s reading and life‐writing practices. I seek to bring together scholarship in both fields, and to explore both reading and writing as activities mutually constitutive of early modern women’s textual selves.
Representing the Duke of Buckingham: Libel, Counter‐Libel and the Example of The Emperor’s Favourite
Authors: Keenan Siobhan
Published: April 2012

George Villiers, first Duke of Buckingham, enjoyed a spectacular rise to power at the Stuart court as the favourite of James I, and his son and heir, Charles I. But the Stuart monarchs’ admiration of Villiers was not shared by all. By the 1620s there was growing anxiety about the extent of his power, and Buckingham faced increasing opposition in parliament and beyond, as is reflected in parliament’s attempt to impeach him (1626), the issuing of a parliamentary remonstrance against him (1628), a massive proliferation of libellous works satirising him, including poems and plays, and his eventual assassination on 23 August 1628. This essay explores one contemporary Buckingham libel that has yet to receive sustained attention, but which sheds fascinating new light on competing contemporary perceptions of Buckingham, court favourites, and the Stuart political scene: The Emperor’s Favourite (published for the first time in 2010). Probably written by Warwickshire gentleman John Newdigate III (1600–42), The Emperor’s Favourite is a tragedy which superficially tells the story of the rise and fall of Crispinus, corrupt favourite of Roman emperor Nero, but a series of topical parallels makes clear that the play uses classical history to offer an oblique satire of Buckingham and the Stuart court.
Bioinspired synthesis of multifunctional inorganic and bio‐organic hybrid materials
Authors: Andre Rute , Tahir Muhammad N. , Natalio Filipe , Tremel Wolfgang
Published: April 2012

Owing to their physical and chemical properties, inorganic functional materials have tremendous impacts on key technologies such as energy generation and storage, information, medicine, and automotive engineering. Nature, on the other hand, provides evolution‐optimized processes, which lead to multifunctional inorganic–bio‐organic materials with complex structures. Their formation occurs under physiological conditions, and is goverened by a combination of highly regulated biological processes and intrinsic chemical properties. Nevertheless, insights into the molecular mechanisms of biomineralization open up promising perspectives for bioinspired and biomimetic design and the development of inorganic–bio‐organic multifunctional hybrids. Therefore, biomimetic approaches may disclose new synthetic routes under ambient conditions by integrating the concept of gene‐regulated biomineralization principles. The skeletal structures of marine sponges provide an interesting example of biosilicification via enzymatically controlled and gene‐regulated silica metabolism. Spicule formation is initiated intracellularly by a fine‐tuned genetic mechanism, which involves silica deposition in vesicles (silicassomes) under the control of the enzyme silicatein, which has both catalytic and templating functions. In this review, we place an emphasis on the fabrication of biologically inspired materials with silicatein as a biocatalyst.
Structural role of the active‐site metal in the conformation of Trypanosoma brucei phosphoglycerate mutase
Authors: Mercaldi Gustavo F. , Pereira Humberto M. , Cordeiro Artur T. , Michels Paul A. M. , Thiemann Otavio H.
Published: April 2012

Phosphoglycerate mutases (PGAMs) participate in both the glycolytic and the gluconeogenic pathways in reversible isomerization of 3‐phosphoglycerate and 2‐phosphoglycerate. PGAMs are members of two distinct protein families: enzymes that are dependent on or independent of the 2,3‐bisphosphoglycerate cofactor. We determined the X‐ray structure of the monomeric Trypanosoma brucei independent PGAM (TbiPGAM) in its apoenzyme form, and confirmed this observation by small angle X‐ray scattering data. Comparing the TbiPGAM structure with the Leishmania mexicana independent PGAM structure, previously reported with a phosphoglycerate molecule bound to the active site, revealed the domain movement resulting from active site occupation. The structure reported here shows the interaction between Asp319 and the metal bound to the active site, and its contribution to the domain movement. Substitution of the metal‐binding residue Asp319 by Ala resulted in complete loss of independent PGAM activity, and showed for the first time its involvement in the enzyme’s function. As TbiPGAM is an attractive molecular target for drug development, the apoenzyme conformation described here provides opportunities for its use in structure‐based drug design approaches.

Database
 Structural data for the Trypanosoma brucei 2,3‐bisphosphoglycerate‐independent phosphoglycerate mutase (iPGAM) has been deposited with the Research Collaboratory for Structural Bioinformatics (RCSB) Protein Data Bank under code 3NVL.

Structured digital abstract

 TbiPGAM and TbiPGAM bind by x‐raycrystallography (View interaction)
Urinary Biopyrrins: Potential Biomarker for Monitoring of the Response to Treatment with Anxiolytics
Authors: Novío Silvia , Núñez María Jesús , Ponte Carmen María , Freire‐Garabal Manuel
Published: April 2012

During periods of psychological stress, excess amounts of free radicals are produced. Bilirubin oxidative metabolites (biopyrrins; BOM) are generated from bilirubin as a result of its scavenging action against free radicals. We investigated whether the urinary excretion of biopyrrins is altered by anxiolytics. In the present study, mice were immobilized for a period of 6 hr. Alprazolam (0.1–1 mg/kg of body‐weight) was administered 30 min. before subjecting the animals to acute stress. The BOM concentrations in urine and the corticosterone levels in serum were measured by ELISA with an anti‐bilirubin antibody and EIA, respectively. We observed an increase in urinary biopyrrins in stressed mice in comparison with non‐stressed mice and a decrease after the treatment of stressed animals with alprazolam. A correlation between urinary BOM and serum corticosterone levels was found. Urinary levels of biopyrrins might be used to assess the response to anxiolytics prescribed during acute stress periods.
Plasminogen Activation and Thrombolysis for Ischemic Stroke
Authors: Medcalf Robert L. , Davis Stephen M.
Published: April 2012

The plasminogen-activating enzyme system has been exploited and harnessed for therapeutic thrombolysis for nearly three decades. Tissue-type plasminogen activator is still the only thrombolytic agent approved for patients with ischemic stroke. While tissue-type plasminogen activator-induced thrombolysis is proven to be of clear benefit in these patients if administered within 4.5 h poststroke onset, it is surprisingly underused in clinics despite international guidelines and improved acute stroke systems, a situation that requires urgent attention. While tissue-type plasminogen activator has also been shown to have unforeseen roles in the brain that have presented new challenges, tissue-type plasminogen activator and related fibrinolytic agents are currently being assessed over extended time frames. This review will focus on the therapeutic experience and controversies of tissue-type plasminogen activator. Furthermore, we will also provide an overview of recent and current trials assessing tissue-type plasminogen activator and related thrombolytic agents as well as novel approaches for the treatment of ischemic stroke.
Response inhibition in children with and without ADHD after traumatic brain injury
Authors: Ornstein Tisha J. , Max Jeffrey E. , Schachar Russell , Dennis Maureen , Barnes Marcia , Ewing‐Cobbs Linda , Levin Harvey S.
Published: April 2012

Children with attention‐deficit hyperactivity disorder (ADHD) and traumatic brain injury (TBI) show deficient response inhibition. ADHD itself is a common consequence of TBI, known as secondary ADHD (S‐ADHD). Similarity in inhibitory control in children with TBI, S‐ADHD, and ADHD would implicate impaired frontal‐striatal systems; however, it is first necessary to delineate similarities and differences in inhibitory control in these conditions. We compared performance of children with ADHD and those with TBI without pre‐injury ADHD on a stop signal, response inhibition task. Participants were 274 children aged 6–14 years. There were 92 children with ADHD, 103 children with TBI, and 79 typically developing children who served as controls. Among the TBI participants, injury severity ranged from mild to severe. Children with ADHD and TBI showed deficient inhibition. The deficit in children with ADHD was as great as or greater than that in children with TBI, regardless of degree of TBI severity or the presence of S‐ADHD. The finding indicates that TBI results in deficient inhibition regardless of the development of S‐ADHD.
Photosynthetic and Biochemical Effects of Cold Storage on Marine Benthic Diatoms of the Mexican Pacific Coast
Authors: Sánchez‐Saavedra M. Del Pilar , Núñez‐Zarco Estrella
Published: April 2012

We determined the effects of 16 wk of storage at low temperature (4 C) in darkness on the viability, growth, photosynthetic parameters, and biochemical composition of four diatom cultures. Significant differences in cell density and proximal composition were observed for all diatoms throughout storage. Cell density increased with time of storage for all diatoms. Protein content increased for Navicula incerta, Nitzschia laevis, and Navicula sp., whereas lipid content increased during storage in only N. incerta. When the stored diatoms were used as inocula in fresh medium, they increased their viability, generating a lag phase for Nitzschia thermalis var. minor, N. incerta, and Navicula sp. cultures. There were noted species‐specific modifications in proximal composition, ash‐free dry weight, and photosynthetic parameters in response to storage. We conclude that N. thermalis, N. incerta, N. laevis, and Navicula sp. can be stored at 4 C for 16 wk and are viable in new cultures.
Anaerobic Treatment of Brackishwater Aquaculture Sludge: An Alternative to Waste Stabilization Ponds
Authors: Mirzoyan Natella , McDonald Ryan Christopher , Gross Amit
Published: April 2012

Environmental pressure, land utilization, and economic feasibility have resulted in the development of recirculating aquaculture systems (RAS). For many RAS, sludge is collected and washed from the system to waste stabilization ponds (WSPs). However, disposal of brackishwater aquaculture sludge into WSP is often prohibited because the high salinity can interfere with treatment. Moreover, there are problems associated with WSPs because of elevated salt content, such as the common practice of reusing treated water and land application of stabilized sludge. We tested and compared the treatment of brackishwater aquaculture sludge in an upflow anaerobic sludge blanket (UASB) reactor as an alternative to a WSP. In UASB, wastewater flows upward through a blanket of granular sludge and is treated by anaerobic micro‐organisms. Reduction in organic matter and 5‐d biochemical oxygen demand by 97 and 91%, respectively, was achieved in a UASB as compared to corresponding reductions of 22 and 41% in a WSP. During the UASB digestion process, methane is produced and recovered. Overall, a reduction in potential environmentally harmful factors such as salinization, land requirements, greenhouse gas emissions, as well as transportation costs are achieved, making the UASB reactor an attractive possible alternative for saline aquaculture sludge management.
Efficacy of Liriope platyphylla on Hematology and Immune Response in Olive Flounder, Paralichthys olivaceus, Against Flexibacter maritimus Infection
Authors: Harikrishnan Ramasamy , Kim Ju‐Sang , Kim Man‐Chul , Heo Moon‐Soo , Balasundaram Chellam
Published: April 2012

The effect of different solvent‐based (methanol, ethanol, and aqueous) extracts of Liriope platyphylla at 0, 0.1, 1.0, and 2.0 mg doses on hematology and innate immune response in olive flounder, Paralichthys olivaceus, against Flexibacter maritimus is reported. The red blood cells and white blood cells significantly increased with ethanol and aqueous extracts with any dose against F. maritimus while the hematocrit level significantly increased with methanol or ethanol extracts. However, the hemoglobin content significantly increased irrespective of the doses and type of extracts, whereas the mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration significantly decreased. The lymphocytes and monocytes significantly increased in all doses and extracts, whereas neutrophils increased in ethanol or aqueous extracts. However, the thrombocytes level neither the doses nor extracts did not significant changes to the control against pathogen. Total protein and globulin levels significantly increased with all the doses of ethanol extract while does not significant change in methanol extract. The phagocytic activity and complement activity were significantly enhanced with any dose of ethanol extract while with aqueous extract it was only at 1.0 and 2.0 mg doses. At all the doses of each extract significantly enhanced the leucocytes activity against F. maritimus. The results confirm that the ethanolic and aqueous extracts of L. platyphylla stimulate the immune response against F. maritimus in P. olivaceus.
Eosin Y Triplet State as a Probe of Spatial Heterogeneity in Microcrystalline Cellulose
Authors: Rodríguez Hernán B. , Román Enrique San , Duarte Paulo , Machado Isabel Ferreira , Vieira Ferreira Luis F.
Published: April 2012

The photophysical behavior of eosin Y adsorbed onto microcrystalline cellulose was evaluated by reflectance spectroscopy, steady‐state fluorescence spectroscopy and laser induced time‐resolved luminescence. On increasing the concentration of the dye, small changes in absorption spectra, fluorescence redshifts and fluorescence quenching are observed. Changes in absorption spectra point to the occurrence of weak exciton interactions among close‐lying dye molecules, whereas fluorescence is affected by reabsorption and excitation energy trapping. Phosphorescence decays are concentration independent as a result of the negligible exciton interaction of dye pairs in the triplet state. Lifetime distribution and bilinear regression analyses of time‐resolved phosphorescence and delayed fluorescence spectra reveal the existence of two different environments: long‐lived, more energetic triplet states arise from dyes tightly entrapped within the cellulose chains, while short‐lived, less‐energetic states result from dyes in more flexible environments. Stronger hydrogen bond interactions between the dye and cellulose hydroxyl groups lead in the latter case to a lower triplet energy and faster radiationless decay. These effects, observed also at low temperatures, are similar to those encountered in several amorphous systems, but rather than being originated in changes in the environment during the triplet lifetime, they are ascribed in this case to spatial heterogeneity.
Ideology and Social Psychology
Authors: Nafstad Hilde Eileen , Blakar Rolv Mikkel
Published: April 2012

This article takes as critical point of departure the currently individualized nature of mainstream social psychology. It is argued that by using the concept of ideology, social psychology may be transformed into a more societal social psychology and thereby a discipline more relevant to individual, society and social life. Based on the interplay between language usage and ideology, moreover, a methodology for assessing ideological changes in society by identifying shifts in language usage in the public discourse (newspapers) is presented. Research conducted by this methodology, including comparative studies of how the globalized neoliberalism with its strong individualism merges with local ideologies in various societies around the world is then reviewed. Finally, analyses of a society’s ideological reactions upon terrorism, is presented.
iREDD hedges against avoided deforestation's unholy trinity of leakage, permanence and additionality
Authors: van Oosterzee Penny , Blignaut James , Bradshaw Corey J. A.
Published: April 2012

Workable financial mechanisms are essential to abate greenhouse gas emissions. Deforestation, which contributes a large proportion of total global emissions, must be avoided as an effective emissions‐reduction tactic, and to alleviate biodiversity loss and poverty. However, incentives to reduce emissions from deforestation and forest degradation (REDD) have had mixed and suboptimal success because of opportunity costs and administrative and technical issues, in particular, leakage, permanence, and additionality. We show that these latter concepts can be ambiguous, potentially contrived and in some cases, generate perverse outcomes. Encumbering avoided‐deforestation projects with these administrative shackles risks massive increases in global deforestation and a concomitant loss of biodiversity, ecosystem services and emissions‐reduction opportunities. We offer a solution built on a proven insurance‐based hedging principle, a concept we call iREDD, that could indirectly address specific technical and administrative challenges, whether real or contrived. Project‐specific iREDD insurance policies and premiums would be negotiated upfront using a simple assessment of risk based on governance quality, the integrity of management plans, liquidity, monitoring and evaluation frameworks, and political acceptability. iREDD acts as both an incentive for prudent forest management given the seller's potential financial windfall if forests are diligently managed, and guarantees not to disenfranchise the buyer.
Large‐scale bioenergy from additional harvest of forest biomass is neither sustainable nor greenhouse gas neutral
Authors: Schulze Ernst‐Detlef , Körner Christian , Law Beverly E. , Haberl Helmut , Luyssaert Sebastiaan
Published: April 2012

Owing to the peculiarities of forest net primary production humans would appropriate ca. 60% of the global increment of woody biomass if forest biomass were to produce 20% of current global primary energy supply. We argue that such an increase in biomass harvest would result in younger forests, lower biomass pools, depleted soil nutrient stocks and a loss of other ecosystem functions. The proposed strategy is likely to miss its main objective, i.e. to reduce greenhouse gas (GHG) emissions, because it would result in a reduction of biomass pools that may take decades to centuries to be paid back by fossil fuel substitution, if paid back at all. Eventually, depleted soil fertility will make the production unsustainable and require fertilization, which in turn increases GHG emissions due to N2O emissions. Hence, large‐scale production of bioenergy from forest biomass is neither sustainable nor GHG neutral.
Accounting Restatements and External Financing Choices*
Authors: Chen Xia , Cheng Qiang , Lo Alvis K.
Published: April 2012

There is little research on how accounting information quality affects a firm’s external financing choices. In this paper, we use the occurrence of accounting restatements as a proxy for the reduced credibility of accounting information and investigate how restatements affect a firm’s external financing choices. We find that for firms that obtain external financing after restatements, they rely more on debt financing, especially private debt financing, and less on equity financing. The increase in debt financing is more pronounced for firms with more severe information problems and less pronounced for firms with prompt CEO or CFO turnover and auditor dismissal. Our evidence indicates that accounting information quality affects capital providers’ resource allocation and that debt holders help alleviate information problems after accounting restatements.
Efficacy and Adverse Effects of the Antiviral Compound Plerixafor in Feline Immunodeficiency Virus‐Infected Cats
Authors: Hartmann K. , Stengel C. , Klein D. , Egberink H. , Balzarini J.
Published: April 2012

Background

Bicyclam derivatives inhibit feline immunodeficiency virus (FIV) replication through selective blockage of chemokine receptor CXCR4.

Hypothesis/Objectives

CXCR4 antagonist plerixafor (AMD3100, 1,1′‐bis‐1,4,8,11‐tetraazacyclotetradekan) alone or combination with adefovir (PMEA, 9‐(2‐phosphonylmethoxyethyl)adenine) safe and effective for treating FIV‐infected cats.

Animals

Forty naturally FIV‐infected, privately owned cats.

Materials and Methods

Prospective, placebo‐controlled, double‐blind clinical trial. Cats randomly classified into 4 treatment groups. Received AMD3100, PMEA, AMD3100 in combination with PMEA, or placebo for 6 weeks. Clinical and laboratory parameters, including CD4+ and CD8+ cell counts, FIV proviral and viral load measured by quantitative polymerase chain reaction (qPCR) evaluated. Additionally, FIV isolates from cats treated with AMD3100 tested for drug resistance.

Results

FIV‐infected cats treated with AMD3100 caused significant decrease in proviral load compared to placebo group (2.3 ± 3.8% to 1.9 ± 3.1%, of blood lymphocytes P < .05), but did not lead to improvement of clinical or immunological variables; it caused a decrease in serum magnesium concentration without clinical signs. No development of resistance of FIV isolates to AMD3100 found during treatment period. PMEA administration improved stomatitis (stomatitis score [degree 1 – 100] PMEA group: 23 ± 19 to 11 ± 10, P < .001; AMD3100 + PMEA group: 12 ± 17 to 3 ± 5, P < .05), but did not decrease proviral or viral load and caused anemia (RBC [×106/μL] PMEA group: 9.07 ± 1.60 to 6.22 ± 2.16, P < .05; AMD3100 ± PMEA group: 8.80 ± 1.23 to 5.84 ± 1.58, P < .001).

Conclusions and Clinical Importance

Administration of CXCR4 antagonists, as AMD3100, can induce reduction of proviral load and may represent viable treatment of FIV‐infected cats. Combination treatment with PMEA not recommended.
Factors Influencing Elementary Teachers' Positioning of African American Girls as Science and Mathematics Learners
Authors: Pringle Rose M. , Brkich Katie Milton , Adams Thomasenia Lott , West‐Olatunii Cirecie , Archer‐Banks Diane A.
Published: April 2012

Despite recent progress toward gender equity in science and mathematics education, the underachievement of low‐income African American girls remains a challenge when compared with their white counterparts. Furthermore, the causes of this persistent underachievement have not been explored thoroughly. We have initiated a three‐year longitudinal study of how African American girls position themselves in relation to science and mathematics learning from fifth to seventh grade, including the impact, if any, of the positioning of teachers, counselors, and parents on this process. In this article, we share findings examining science and mathematics teachers' actions and perceptions and their positioning of African American girls. This qualitative study used an interpretive design with multiple data sources including classroom observations, interviews, and field notes. Findings reveal that school‐wide policies and teachers' autonomous decisions impact the regularity of science and mathematics instruction, and that teachers do not always conceptualize the girls as science and mathematics achievers, positioning them in negative ways.
Constructing Graphical Representations: Middle Schoolers' Intuitions and Developing Knowledge About Slope and Y‐intercept
Authors: Hattikudur Shanta , Prather Richard W. , Asquith Pamela , Alibali Martha W. , Knuth Eric J. , Nathan Mitchell
Published: April 2012

Middle‐school students are expected to understand key components of graphs, such as slope and y‐intercept. However, constructing graphs is a skill that has received relatively little research attention. This study examined students' construction of graphs of linear functions, focusing specifically on the relative difficulties of graphing slope and y‐intercept. Sixth‐graders' responses prior to formal instruction in graphing reveal their intuitions about slope and y‐intercept, and seventh‐ and eighth‐graders' performance indicates how instruction shapes understanding. Students' performance in graphing slope and y‐intercept from verbally presented linear functions was assessed both for graphs with quantitative features and graphs with qualitative features. Students had more difficulty graphing y‐intercept than slope, particularly in graphs with qualitative features. Errors also differed between contexts. The findings suggest that it would be valuable for additional instructional time to be devoted to y‐intercept and to qualitative contexts.
Beneficial effects of pioglitazone against cardiovascular injury are enhanced by combination with aliskiren in a rat model of diabetic nephropathy
Authors: Elrashidy Rania A , Asker Mervat E , Mohamed Hoda E
Published: April 2012

Objectives

Aliskiren is the first in a new class of orally active direct renin inhibitors, approved for the treatment of hypertension. However, the efficacy of aliskiren in diabetic cardiovascular complications remains to be defined. This study aimed to test the hypothesis that aliskiren may enhance the beneficial effects of pioglitazone against cardiovascular injury associated with diabetic nephropathy.

Methods

Diabetic nephropathy was induced in rats by unilateral nephrectomy followed by streptozotocin injection. Diabetic nephropathic rats were orally given vehicle, pioglitazone, aliskiren, or combined pioglitazone and aliskiren for four weeks to compare their effects on cardiovascular injury, particularly myocardial fibrosis.

Key findings

Pioglitazone treatment significantly attenuated cardiac lipid peroxidation, oxidative injury and myocardial fibrosis in diabetic nephropathic rats. This was associated with up-regulation of transforming growth factor-β1 and matrix metalloproteinase-2 genes, along with down-regulation of tissue inhibitor of metalloproteinase-2 gene in cardiac tissue. The combination of aliskiren with pioglitazone exerted greater beneficial effect than monotherapy with either drug, on all the aforementioned parameters.

Conclusions

Our findings suggested that aliskiren enhanced the protective effects of pioglitazone against myocardial fibrosis, in experimental diabetic nephropathy. Thus, the combination of aliskiren and pioglitazone may be a potential therapeutic strategy for cardiovascular injury associated with diabetic nephropathy.
Human spermatozoa possess a calcium‐dependent chloride channel that may participate in the acrosomal reaction
Authors: Orta Gerardo , Ferreira Gonzalo , José Omar , Treviño Claudia L. , Beltrán Carmen , Darszon Alberto
Published: April 2012

Key points

Ion channels participate in crucial sperm functions such as motility, capacitation and the acrosome reaction.

Chloride, the main anion in physiological solutions, is deeply involved in sperm physiology.

We implemented a modified perforated patch‐clamp strategy to obtain whole cell recordings sealing on the head of mature human spermatozoa to investigate their ion channels.

This work presents the first evidence for the presence of calcium‐dependent chloride channels (CaCCs) in human spermatozoa; they could be constituted by TMEM16.

The CaCCs play an important role in the physiology of human spermatozoa and participate in the acrosome reaction.
Evaluation of a Mouse Model of Necrotic Granuloma Formation Using C3HeB/FeJ Mice for Testing of Drugs against Mycobacterium tuberculosis
Authors: Driver Emily R. , Ryan Gavin J. , Hoff Donald R. , Irwin Scott M. , Basaraba Randall J. , Kramnik Igor , Lenaerts Anne J.
Published: April 2012

Persistence of
Mycobacterium tuberculosis
remains a significant challenge for the effective treatment of tuberculosis in humans. In animals that develop necrotic lung lesions following infection with
M. tuberculosis
, drug-tolerant bacilli are present and persist in an extracellular microenvironment within the necrotic cores. In this study, we examined the efficacy of drug treatment in C3HeB/FeJ (Kramnik) mice that develop lesions with liquefactive necrosis, in comparison to BALB/c mice that develop nonnecrotic lesions following aerosol challenge. To accomplish this, Kramnik and BALB/c mice were infected by aerosol with
M. tuberculosis
and treated for 7 to 8 weeks with monotherapy using drugs with different modes of action. The efficacy of drug therapy was quantified by enumeration of bacterial load. The progression of disease and location and distribution of bacilli within lesions were visualized using various staining techniques. In the late stages of infection, Kramnik mice developed fibrous encapsulated lung lesions with central liquefactive necrosis containing abundant extracellular bacilli, whereas BALB/c mice formed nonnecrotic lesions with primarily intracellular bacilli. Necrotic lesions in Kramnik mice showed evidence of hypoxia by pimonidazole staining. Kramnik mice were significantly more refractory to drug therapy, especially for pyrazinamide. Metronidazole showed no bactericidal activity in either model. There were significantly higher numbers of drug-resistant colonies isolated from the Kramnik mice compared to BALB/c mice. These results suggest that the Kramnik mouse model will be a valuable model to test antituberculosis drugs, especially against bacilli that persist within necrotic lesions.
Evaluation of Standard- and High-Dose Daptomycin versus Linezolid against Vancomycin-Resistant Enterococcus Isolates in an
In Vitro
Pharmacokinetic/Pharmacodynamic Model with Simulated Endocardial Vegetations
Authors: Hall Ashley D. , Steed Molly E. , Arias Cesar A. , Murray Barbara E. , Rybak Michael J.
Published: April 2012

Daptomycin MICs for enterococci are typically 1- to 2-fold higher than those for
Staphylococcus aureus
, and there is an imminent need to establish the optimal dose for appropriate treatment of enterococcal infections. We investigated the bactericidal activity of daptomycin at various dose exposures compared to that of linezolid against vancomycin-resistant enterococcus (VRE) in an
in vitro
pharmacokinetic/pharmacodynamic model utilizing simulated endocardial vegetations over 96 h. Daptomycin at doses of 6, 8, 10, and 12 mg/kg of body weight/day and linezolid at a dose of 600 mg every 12 h were evaluated against two clinical vancomycin-resistant
Enterococcus faecium
strains (EFm11499 and 09-184D1051), one of which was linezolid resistant (09-184D1051), and one clinical vancomycin-resistant
Enterococcus faecalis
strain (EFs11496). Daptomycin MICs were 4, 2, and 0.5 μg/ml for EFm11499, 09-184D1051, and EFs11496, respectively. Bactericidal activity, defined as a ≥3 log
10
CFU/g reduction from the initial colony count, was demonstrated against all three isolates with all doses of daptomycin; however, bactericidal activity was not sustained with the daptomycin 6- and 8-mg/kg/day regimens. Linezolid was bacteriostatic against EFm11499 and displayed no appreciable activity against 09-184D1051 or EFs11496. Concentration-dependent killing was displayed with more sustained reduction in colony count (3.58 to 6.46 and 5.89 to 6.56 log
10
CFU/g) at 96 h for the simulated regimen of daptomycin at doses of 10 and 12 mg/kg/day, respectively (
P
≤ 0.012). No
E. faecium
mutants with reduced susceptibility were recovered at any dosage regimen; however, the
E. faecalis
strain developed reduced daptomycin susceptibility with daptomycin at 6, 8, and 10 but not at 12 mg/kg/day. Daptomycin displayed a dose-dependent response against three VRE isolates, with high-dose daptomycin producing sustained bactericidal activity. Further research is warranted.
Burkholderia pseudomallei Triggers Altered Inflammatory Profiles in a Whole-Blood Model of Type 2 Diabetes-Melioidosis Comorbidity
Authors: Morris Jodie , Williams Natasha , Rush Catherine , Govan Brenda , Sangla Kunwarjit , Norton Robert , Ketheesan Natkunam
Published: April 2012

Melioidosis is a potentially fatal disease caused by the bacteriumBurkholderia pseudomallei. Type 2 diabetes (T2D) is the most common comorbidity associated with melioidosis.B. pseudomalleiisolates from melioidosis patients with T2D are less virulent in animal models than those from patients with melioidosis and no identifiable risk factors. We developed anex vivowhole-blood assay as a tool for comparison of early inflammatory profiles generated by T2D and nondiabetic (ND) individuals in response to aB. pseudomalleistrain of low virulence. Peripheral blood from individuals with T2D, with either poorly controlled glycemia (PC-T2D [n= 6]) or well-controlled glycemia (WC-T2D [n= 8]), and healthy ND (n= 13) individuals was stimulated withB. pseudomallei. Oxidative burst, myeloperoxidase (MPO) release, expression of pathogen recognition receptors (TLR2, TLR4, and CD14), and activation markers (CD11b and HLA-DR) were measured on polymorphonuclear (PMN) leukocytes and monocytes. Concentrations of plasma inflammatory cytokine (interleukin-6 [IL-6], IL-12p70, tumor necrosis factor alpha [TNF-α], monocyte chemoattractant protein 1 [MCP-1], IL-8, IL-1β, and IL-10) were also determined. Following stimulation, oxidative burst and MPO levels were significantly elevated in blood from PC-T2D subjects compared to controls. Differences were also observed in expression of Toll-like receptor 2 (TLR2), CD14, and CD11b on phagocytes from T2D and ND individuals. Levels of IL-12p70, MCP-1, and IL-8 were significantly elevated in blood from PC-T2D subjects compared to ND individuals. Notably, differential inflammatory responses of PC-T2D, WC-T2D, and ND individuals toB. pseudomalleioccur independently of bacterial load and confirm the efficacy of this model of T2D-melioidosis comorbidity as a tool for investigation of dysregulated PMN and monocyte responses toB. pseudomalleiunderlying susceptibility of T2D individuals to melioidosis.
Changing trends in incidence and aetiology of childhood acute non-traumatic coma over a period of changing malaria transmission in rural coastal Kenya: a retrospective analysis
Authors: Gwer Samson , Thuo Nahashon , Idro Richard , Ndiritu Moses , Boga Mwanamvua , Newton Charles , Kirkham Fenella
Published: April 2012

Objectives

Recent changes in malaria transmission have likely altered the aetiology and outcome of childhood coma in sub-Saharan Africa. The authors conducted this study to examine change in incidence, aetiology, clinical presentation, mortality and risk factors for death in childhood non-traumatic coma over a 6-year period.

Design

Retrospective analysis of prospectively collected data.

Setting

Secondary level health facility: Kilifi, Coast, Kenya.

Participants

Children aged 9 months to 13 years admitted with acute non-traumatic coma (Blantyre Coma Score =2) between January 2004 and December 2009 to Kilifi District Hospital, Kenya. Exclusion criteria: delayed development, epilepsy and sickle cell disease.

Results

During the study period, 665 children (median age 32 (IQR 20–46) months; 46% were girls) were admitted in coma. The incidence of childhood coma declined from 93/100 000 children in 2004 to 44/100 000 children in 2009. There was a 64% overall drop in annual malaria-positive coma admissions and a 272% overall increase in annual admissions with encephalopathies of undetermined cause over the study period. There was no change in case death of coma. Vomiting, breathing difficulties, bradycardia, profound coma (Blantyre Coma Score=0), bacteraemia and clinical signs of meningitis were associated with increased risk of death. Seizures within 24 h prior to admission, and malaria parasitaemia, were independently associated with survival, unchanging during the study period.

Conclusion

The decline in the incidence and number of admissions of childhood acute non-traumatic coma is due to decreased malaria transmission. The relative and absolute increase in admissions of encephalopathy of undetermined aetiology could represent aetiologies previously masked by malaria or new aetiologies.
Does antiretroviral therapy initiation increase sexual risk taking in Kenyan female sex workers? A retrospective case–control study
Authors: Mawji Elysha , McKinnon Lyle , Wachihi Charles , Chege Duncan , Thottingal Paul , Kariri Anthony , Plummer Francis , Ball T Blake , Jaoko Walter , Ngugi Elizabeth , Kimani Joshua , Gelmon Lawrence , Nagelkerke Nico , Kaul Rupert
Published: April 2012

Objectives

Although antiretroviral therapy (ART) prolongs life and reduces infectiousness, in some contexts, it has been associated with increased sexual risk taking.

Design

Retrospective case–control study.

Setting

Nairobi-based dedicated female sex worker (FSW) clinic.

Participants

HIV-infected FSWs before and after ART initiation (n=62); HIV-infected and -uninfected control FSWs not starting ART during the same follow-up period (n=40).

Intervention

Initiation of ART.

Primary outcome measures

Self-reported condom use, client numbers and sexually transmitted infection incidence over the study period (before and after ART initiation in cases).

Results

Sexual risk-taking behaviour with casual clients did not increase after ART initiation; condom use increased and sexually transmitted infection incidence decreased in both cases and controls, likely due to successful cohort-wide HIV prevention efforts.

Conclusions

ART provision was not associated with increases in unsafe sex in this FSW population.
Comparability Graph Coloring for Optimizing Utilization of Software-Managed Stream Register Files for Stream Processors
Authors: Yang Xuejun , Wang Li , Xue Jingling , Wu Qingbo
Published: April 2012

The stream processors represent a promising alternative to traditional cache-based general-purpose processors in achieving high performance in stream applications (media and some scientific applications). In a stream programming model for stream processors, an application is decomposed into a sequence of kernels operating on streams of data. During the execution of a kernel on a stream processor, all streams accessed must be communicated through a nonbypassing software-managed on-chip memory, the SRF (Stream Register File). Optimizing utilization of the scarce on-chip memory is crucial for good performance. The key insight is that the interference graphs (IGs) formed by the streams in stream applications tend to be comparability graphs or decomposable into a set of comparability graphs. We present a compiler algorithm for finding optimal or near-optimal colorings, that is, SRF allocations in stream IGs, by computing a maximum spanning forest of the sub-IG formed by long live ranges, if necessary. Our experimental results validate the optimality and near-optimality of our algorithm by comparing it with an ILP solver, and show that our algorithm yields improved SRF utilization over the First-Fit bin-packing algorithm, the best in the literature.
A dynamic programming approach to maximizing a statistical measure of the lifetime of sensor networks
Authors: Ilyas Muhammad U. , Radha Hayder
Published: April 2012

The inherent many-to-one flow of traffic in wireless sensor networks (WSNs) produces a skewed distribution of energy consumption rates, leading to the early demise of those sensors that are critical to the ability of surviving nodes to communicate their measurements to the base station. Numerous previous approaches aimed at balancing the consumption of energy in wireless networks are either too complex or do not address problems unique to the flow of traffic in WSNs. In this article, we propose the use of a dynamic programming algorithm (DPA), an operational, low-complexity algorithm, used in conjunction with four different route discovery algorithms. We perform complexity analysis, statistical evaluation of changes in power consumption rates effected, and verify spatial redistribution of energy consumption of sensors in the network. Our results on multihop networks of 100 randomly placed nodes show that, on average, the two best performing variants of DPA yield a reduction of up to 28% and 36% in power consumption rate variance at the cost of raising average power consumption by 15% and 21%, respectively. Computational complexities of DPA variants range from
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), which is significantly lower than linear search of the solution space of
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). Analysis by diffusion plots shows that DPA reduces power consumption of sensors that experience the highest power consumption under the shortest path routes.
An adaptive file-system-oriented FTL mechanism for flash-memory storage systems
Authors: Chang Yuan-Hao , Wu Po-Liang , Kuo Tei-Wei , Hung Shih-Hao
Published: April 2012

As flash memory becomes popular over various platforms, there is a strong demand regarding the performance degradation problem, due to the special characteristics of flash memory. This research proposes the design of a file-system-oriented flash translation layer, in which a filter mechanism is designed to separate the access requests of file-system metadata and file contents for better performance. A recovery scheme is then proposed for maintaining the integrity of a file system. The proposed flash translation layer is implemented as a Linux device driver and evaluated with respect to ext2 and ext3 file systems. Experiments were also done over NTFS by a series of realistic traces. The experimental results show significant performance improvement over ext2, ext3, and NTFS file systems with limited system overheads.
Fortran Legacy software
Authors: Tinetti Fernando G. , Méndez Mariano
Published: April 2012

We are working on a process for carrying out a set of transformations on Fortran legacy projects. We started our work for parallelization and reduction of runtime at least on multiprocessing systems, but we found necessary to update several old Fortran features and/or legacy software issues as a previous task. We present how to define and implement several source code transformations in order to enhance readability and, also, provide a source code that we think is more likely to be parallelized in subsequent work. Furthermore, we propose that some parallelization (e.g. for shared memory parallel computers) can be made at least as a tool-guided process, i.e. as
other
source code transformations. In the most simple cases, some transformations from sequential to parallel processing could be made automatically by a source code software analysis and transformation tool, which could provide the user (programmer/developer) a suggested way of Parallelisation. Source code transformations are initially approached as restructurings, and implemented by changing the abstract syntax tree (AST) program representation. We provide some comments on our preliminary work on the source code transformations directly focussed on parallelization that we expect to implement almost automatically.