bluuebunny/crossref_metadata_2025 huggingface dataset:
The results of a randomized trial looking at 24 weeks vs 48 weeks of treatment with peginterferon α‐2a (40 kDa) and ribavirin combination therapy in patients with chronic hepatitis C genotype 1
Authors: Brandão C. , Barone A. , Carrilho F. , Silva A. , Patelli M. , Caramori C. , Focaccia R. , Pereira L. , Pedroso M. , Tatsch F. , Pessoa M. ,   the Pegasys Brazilian Study Group
Published: July 2006

Summary.  Peginterferon‐α plus ribavirin is the most effective therapy for chronic hepatitis C. This study was designed to evaluate the effect of peginterferon α‐2a (40 kDa) plus ribavirin on sustained virological response (SVR) when administered for 24 vs 48 weeks in genotype 1 naïve patients. One hundred and seventeen patients were enrolled in this controlled trial. Genotype 1 patients were randomized to 24 weeks treatment vs 48 weeks treatment. Genotype non‐1 patients received 24 weeks treatment as an observational group. Outcomes were SVR (defined by hepatitis C virus‐RNA‐negative at week 24 of follow‐up) and tolerability across the study period. The end‐of‐treatment response was 59% for genotype 1 (24 weeks treatment), 80% for genotype 1 (48 weeks treatment) and 92% for genotype non‐1 (24 weeks treatment). The end‐of‐follow‐up response was 19% (95% confidence interval (CI): 7.2–36.4) (genotype 1, 24 weeks) and 48% (95% CI: 30.2–66.9; P = 0.0175) (genotype 1, 48 weeks). Among genotype non‐1, SVR was 76% (95% CI: 62.3–86.5). There were no unexpected adverse events.Almost half of the genotype 1 patients achieved an SVR after 48 weeks treatment with peginterferon α‐2a (40 kDa) and low‐dose ribavirin and confirmed that they should be treated for 48 weeks. Safety profile was acceptable.
Lethal and behavioural effects of three synthetic repellents (DEET, IR3535 and KBR 3023) on Aedes aegypti mosquitoes in laboratory assays
Authors: LICCIARDI S. , HERVE J. P. , DARRIET F. , HOUGARD J.‐M. , CORBEL V.
Published: July 2006

Abstract The knock‐down, mortality and ‘irritancy’ effects of three synthetic repellents (DEET, IR3535 and KBR 3023) on Aedes aegypti (L) (Diptera: Culicidae) were evaluated in the laboratory in the absence of animal bait. Filter paper tests were carried out to assess the knock‐down effect (KDt50 and KDt95) and mortality (LC50 and LC95) induced by each repellent. ‘Irritancy’ tests were carried out to compare the flight response (time to first take‐off, or FT) to increasing concentrations of repellents (2–7%) and at five distances from the treated surface (0–40 mm). DEET had an insecticidal effect (KDt50= 9.7 min at 7%; CL50= 1165 mg/m2), whereas IR3535 and KBR 3023 did not. Relative to an untreated control, IR3535 was an irritant (relative irritancy or RI > 1) at doses of 5% and 7% (RI = 17.7 and 9.9, respectively), whereas DEET was an irritant at lower concentrations (RI = 12.3 at 2% DEET). KBR 3023 was the weakest irritant over the same range of concentrations (RImax= 3.6 at 6%). DEET was more of an irritant (RI20= 9.4) than IR3535 (RI20= 2.9) over a range of distances (0–20 mm), and KBR 3023 was not an irritant unless mosquitoes made contact with the treated surface. All three repellents had a significant effect on mosquitoes, but DEET exhibited a more complex mode of action than the others due to its insecticidal properties. The repellents do not behave as a single class of compounds with a common mode of action, but most probably affect different physiological systems in insects. The physiological and molecular mechanisms of repellents, especially DEET, should be investigated to ensure a better use of these molecules for skin applications and/or for treating materials against mosquitoes.
First description of the endogenous life cycle of Hypoderma sinense affecting yaks and cattle in China
Authors: OTRANTO D. , PARADIES P. , TESTINI G. , LIA R. P. , GIANGASPERO A. , TRAVERSA D. , COLWELL D. D.
Published: July 2006

Abstract Larvae belonging to five species of Hypoderma spp. (Diptera, Oestridae) cause myiasis in wild and domestic ruminants that is characterized by migrations within deep tissues. In China hypodermosis is one of the most important arthropod diseases affecting ruminants and, moreover, represents a significant zoonosis, with numerous reports of Hypoderma spp. affecting farmers. Recently, a sixth species, Hypoderma sinense Pleske, has been rediscovered but the endogenous migration pathway within the host body is completely unknown and it represents a major constraint for the control of larval infection. In December 2003 a total of 165 larval stages of Hypoderma spp. were collected from different anatomical sites of 40 yaks slaughtered at an abattoir in the province of Gansu, China. The morphological characters and size of the recovered larvae were used to infer migratory routes and 45 specimens were also subjected to a polymerase chain reaction (PCR) assay of cox1 mtDNA and amplicons sequenced. All the larvae molecularly processed were identified as H. sinense and sequence identity was confirmed by a PCR‐restriction fragment length polymorphism (PCR‐RFLP) tool carried out using BfaI and HinfI endonucleases. The finding of H. sinense larvae only in the oesophagus or both in oesophagus and subcutaneous tissue of 12 and 15 animals, respectively, indicates that H. sinense larvae migrate through the oesophagus similarly to Hypoderma lineatum (De Villers). The description of the endogenous life cycle of H. sinense will help to determine the timing of specific treatment programmes to guarantee the improvement of animal welfare and health, thus resulting in an increase in livestock production in China.
Apparent ‘sympatric’ speciation in ecologically similar herbivorous beetles facilitated by multiple colonizations of an island
Authors: JORDAL BJARTE H. , EMERSON BRENT C. , HEWITT GODFREY M.
Published: July 2006

Coexistence of recently diverged and ecologically similar sister species in complete sympatry represents a particularly compelling case for sympatric speciation. This study investigates the possible sympatric origin of two coexisting bark beetle taxa that utilize the same host plant on the island of La Palma in the Canary Islands. Aphanarthrum subglabrum and Aphanarthrum glabrum ssp. nudum breed inside dead twigs of Euphorbia lamarckii plants and are closely related to the allopatric A. glabrum ssp. glabrum in Tenerife, El Hierro and La Gomera. We tested the various speciation hypotheses in a genealogical context, using mitochondrial gene fragments from Cytochrome Oxidase I and 16S, and nuclear gene fragments from Enolase, Elongation Factor 1α and Histone H3. Phylogenetic analyses of the combined nuclear DNA data strongly supported a sister relationship between two sympatric and reproductively isolated taxa in La Palma. However, network analyses of subdivided nonrecombinant segments of the Enolase locus indicated a closer relationship between the two allopatric A. glabrum subspecies, suggesting multiple colonizations of this island. A bimodal distribution of mtDNA haplotypes in La Palma further documented the independent colonization of this island, with asymmetric introgression of mtDNA between two lineages. Consequently, the sympatric origin of the La Palma species is concluded to have involved allopatric phases before the parallel colonization of this island and subsequent introgression at some loci. The clear genetic and morphological evidence for reproductive isolation between these species suggests that the sympatric completion of divergence was either due to initial genetic incompatibility, morphological character displacement in male genitalia, or a combination of these factors.
Phosphoenolpyruvate synthase plays an essential role for glycolysis in the modified Embden‐Meyerhof pathway in Thermococcus kodakarensis
Authors: Imanaka Hiroyuki , Yamatsu Atsushi , Fukui Toshiaki , Atomi Haruyuki , Imanaka Tadayuki
Published: July 2006

We have carried out a genetic analysis on pyruvate kinase (PykTk) and phosphoenolpyruvate synthase (PpsTk) in the hyperthermophilic archaeon, Thermococcus kodakarensis. In principle, both enzymes can catalyse the final step of the modified Embden‐Meyerhof (EM) pathway found in Thermococcales, the conversion of phosphoenolpyruvate (PEP) to pyruvate, with the former utilizing ADP, while the latter is dependent on AMP and phosphate. Enzyme activities and transcript levels of both PykTk and PpsTk increased in T. kodakarensis under glycolytic conditions when compared with cells grown on pyruvate or amino acids. Using KW128, a tryptophan auxotrophic mutant with a trpE gene disruption, as a host strain, we obtained mutant strains with single gene disruptions in either the pykTk (Δpyk strain) or ppsTk (Δpps strain) gene. Specific growth rates and cell yields were examined in various media and compared with the host KW128 strain. The results indicated that both enzymes participated in pyruvate metabolism, but were not essential. In the presence of maltooligosaccharides, the Δpyk strain displayed a 15% decrease in growth rate compared with the host strain, indicating that PykTk does participate in glycolysis. However an even more dramatic effect was observed in the Δpps strain in that the strain could not grow at all on maltooligosaccharides. The results clearly indicate that, in contrast to the conventional EM pathway dependent on pyruvate kinase, PEP synthase is the essential enzyme for the glycolytic conversion of PEP to pyruvate in T. kodakarensis. The physiological roles of the two enzymes under various growth conditions are discussed.
Distinct white collar‐1 genes control specific light responses in Mucor circinelloides
Authors: Silva Fátima , Torres‐Martínez Santiago , Garre Victoriano
Published: July 2006

Light regulates many developmental and physiological processes in a large number of organisms. The best‐known light response in the fungus Mucor circinelloides is the biosynthesis of β‐carotene. Here, we show that M. circinelloides sporangiophores also respond to light, exhibiting a positive phototropism. Analysis of both responses to different light wavelengths within the visible spectrum demonstrated that phototropism is induced by green and blue light, whereas carotenogenesis is only induced by blue light. The blue regulation of both responses suggests the existence of blue‐light photoreceptors in M. circinelloides. Three white collar‐1 genes (mcwc‐1a, mcwc‐1b and mcwc‐1c) coding for proteins showing similarity with the WC‐1 photoreceptor of Neurospora crassa have been identified. All three contain a LOV (light, oxygen or voltage) domain, similar to that present in fungal and plant blue‐light receptors. When knockout mutants for each mcwc‐1 gene were generated to characterize gene functions, only mcwc‐1c mutants were defective in light induction of carotene biosynthesis, indicating that mcwc‐1c is involved in the light transduction pathway that control carotenogenesis. We have also shown that positive phototropism is controlled by the mcwc‐1a gene. It seems therefore that mcwc‐1a and mcwc‐1c genes control different light transduction pathways, although cross‐talk between both pathways probably exists because mcwc‐1a is involved in the light regulation of mcwc‐1c expression.
The diverse antioxidant systems of Helicobacter pylori
Authors: Wang Ge , Alamuri Praveen , Maier Robert J.
Published: July 2006

The gastric pathogen Helicobacter pylori induces a strong inflammatory host response, yet the bacterium maintains long‐term persistence in the host. H. pylori combats oxidative stress via a battery of diverse activities, some of which are unique or newly described. In addition to using the well‐studied bacterial oxidative stress resistance enzymes superoxide dismutase and catalase, H. pylori depends on a family of peroxiredoxins (alkylhydroperoxide reductase, bacterioferritin co‐migratory protein and a thiol‐peroxidase) that function to detoxify organic peroxides. Newly described antioxidant proteins include a soluble NADPH quinone reductase (MdaB) and an iron sequestering protein (NapA) that has dual roles – host inflammation stimulation and minimizing reactive oxygen species production within H. pylori. An H. pylori arginase attenuates host inflammation, a thioredoxin required as a reductant for many oxidative stress enzymes is also a chaperon, and some novel properties of KatA and AhpC were discovered. To repair oxidative DNA damage, H. pylori uses an endonuclease (Nth), DNA recombination pathways and a newly described type of bacterial MutS2 that specifically recognizes 8‐oxoguanine. A methionine sulphoxide reductase (Msr) plays a role in reducing the overall oxidized protein content of the cell, although it specifically targets oxidized Met residues. H. pylori possess few stress regulator proteins, but the key roles of a ferric uptake regulator (Fur) and a post‐transcriptional regulator CsrA in antioxidant protein expression are described. The roles of all of these antioxidant systems have been addressed by a targeted mutant analysis approach and almost all are shown to be important in host colonization. The described antioxidant systems in H. pylori are expected to be relevant to many bacterial‐associated diseases, as genes for most of the enzymes carrying out the newly described roles are present in a number of pathogenic bacteria.
Lactating Females Do Not Discriminate Between Their Own Young and Unrelated Pups in the Communally Breeding Rodent, Octodon degus
Authors: Ebensperger Luis A. , Hurtado María José , Valdivia Isabel
Published: July 2006

Females in numerous rodent species engage in communal nesting and breeding, in which they share one or more nests to rear their young. A potential cost of communal nesting and breeding is that mothers divert resources to unrelated offspring. One way mothers could avoid this cost is to recognize and favour their own young over unrelated offspring when allocating maternal effort. We assessed whether female degus (Octodon degus), a communally nesting and breeding caviomorph rodent, discriminate between their own and unrelated offspring during lactation. Female degus previously have been shown to distinguish between their own and unrelated pups when exposed to odours from both. We measured pup discrimination based on differences in the retrieval behaviour of females that were in early or intermediate lactation directed towards their own and unrelated offspring; offspring presented were of similar or different age. Before any event of pup retrieval, lactating females spent similar amounts of time and interacted to a similar extent with their own and unrelated pups. During pup retrieval, all lactating females transported both pups to the nest. Neither relatedness to pups, nor pup‐age differences, influenced the order in which pups were retrieved to the nest. Dams waited similar amounts of time before retrieving the first pup when the first transported young was their own or unrelated. Likewise, females waited similar amounts of time before retrieving the second pup when the pup transported first was their own or unrelated. The time between first and second pup transport events was longer when dams were in early when compared with intermediate lactation, but only when pups were of similar age. All experimental subjects nursed unrelated pups after they were retrieved. Collectively, our results do not support the hypothesis that communally breeding female degus use their recognition ability to discriminate against unrelated offspring in favour of their own young.
Ovarian Activity and Oestrous Signs among Group‐Housed, Lactating Sows: Influence of Behaviour, Environment and Production
Authors: Hultén F , Wallenbeck A , Rydhmer L
Published: July 2006

Contents

Animal welfare concerns require the development of housing systems that allow the animals to express their natural behaviour. One example of this is the group‐housing system for lactating sows. The present study aimed at exploring ovarian activity in such a system. Thirty‐eight sows farrowing individually outdoors during spring and summer, and indoors during autumn and winter, and group‐housed in groups of four during weeks 3–7 of the lactation period, were monitored regarding reproductive functions, behaviour and production during their first to fourth lactation period. Average ovulation frequency during lactation was 47%. Only 50% of these ovulating cases were accompanied by a standing oestrus. Lactational ovulation frequency was higher in later parities (p < 0.001). Ovulation frequency was higher (p < 0.05) during winter (74%) and spring (69%), than during summer (10%) and autumn (23%). Occurrence of lactational ovulation was associated with some aspects of suckling behaviour and also with litter weight gain (p < 0.05). Forty‐nine per cent of the lactational ovulations occurred during the seventh week of lactation. Timing of ovulation seemed positively (p = 0.08) associated with weight loss during lactation. Compared with the sows that were anoestrus during lactation, oestradiol‐17β values were higher (p < 0.05) only in the week before occurrence of lactational ovulation. Weaning‐to‐oestrous interval was prolonged (p < 0.05) among the sows that ovulated during lactation. The present study identifies several factors influencing ovarian activity among group‐housed sows, thereby providing tools for the control of lactational ovulation in group‐housing systems.
Gout in renal transplant recipients
Authors: STAMP LISA , HA LEAH , SEARLE MARTIN , O’DONNELL JOHN , FRAMPTON CHRIS , CHAPMAN PETER
Published: July 2006

Aims:  The aims of the present audit were to determine the prevalence of gout in renal transplant recipients in Canterbury, New Zealand, to identify risk factors for gout, and to assess the range of treatments used, their efficacy and complications. In addition, the authors wished to assess the impact of post‐renal transplant gout on the patient.

Methods:  Patients with post‐transplantation gout were identified from the Christchurch Hospital Nephrology database. For each patient with gout a post‐renal transplantation recipient without gout post transplant was found matched for age, sex and date of transplant. Case notes were audited and patients interviewed.

Results:  In total, 47/202 (23%) living renal transplant recipients had gout post transplant. Those patients with gout were more likely to be taking a loop diuretic (68%vs 34%, P < 0.001), to have a higher serum urate and impaired renal function and to have had gout prior to the transplant. Of those patients who developed gout post transplant 70% had an attack at least every 3 months. Of those who returned to work post transplant 48% required time off work because of gout.

Conclusion:  Gout is an important problem in the post‐transplant population causing significant morbidity and time off work. Diuretics, impaired renal function, gout prior to transplantation and hyperuricaemia are important risk factors. The need for diuretic therapy should be kept under review in these patients. Hypouricaemic therapy should be considered early in those who develop gout post renal transplantation. Further studies are required to determine whether treatment for asymptomatic hyperuricaemia is justified.
Prevalence and risk factors of undetected proteinuria in an elderly South‐East Asian population
Authors: JOSHI VEENA D , MOOPPIL NANDKUMAR , LIM JEREMY
Published: July 2006

Background:  Urinalysis is not a standard component of health screening in the elderly population.

Objective:  We investigated the prevalence and risk factors of undetected renal disease as defined by proteinuria (PR) in an elderly South‐East Asian population.

Method:  There were 19 848 participants of age ≥65 years in National Kidney Foundation’s Nationwide Screening programme at Singapore. Mean age was 70.6 ± 5.3 years. After excluding the 1.1% who had pre‐existing renal disease, 8.5% were identified to have previously undetected PR defined as ≥1+ protein on urine dipstick analysis. Multivariate regression revealed that male gender (OR = 1.2, reference category (Ref): female), known diabetes (odds ratio (OR) = 2.28; P < 0.0001), hypertension (OR = 1.62; P = 0.0001), presence of elevated blood pressure (BP) (≥120/90 mmHg) on screening (OR = 1.38, 1.89, 3.45 for mild, moderate and severe BP, respectively, all P < 0.0001), elevated body mass index (BMI) (OR = 1.3 for BMI ≥23 vs BMI < 23 kg/m2), and smoking (OR = 1.2, ref: non‐smokers) were significantly associated with PR. Finally, a progressive increase in OR for PR was observed with stepwise increase in age (years) (OR for 67–68.9: 1.2, P = 0.025; 69–72.9, 1.49, P = 0.49; ≥73: 1.56, P < 0.0001, Ref: 65–66.9 years).

Conclusion:  We conclude that there is high prevalence of previously undetected proteinuria in elderly South‐East Asians. Because proteinuria is a risk factor for cardiovascular disease, our findings support inclusion of urinalysis in routine health screening for this population.
Understanding biodiversity effects on prey in multi‐enemy systems
Authors: Casula Paolo , Wilby Andrew , Thomas Matthew B.
Published: July 2006

Biodiversity–ecosystem functioning theory would predict that increasing natural enemy richness should enhance prey consumption rate due to functional complementarity of enemy species. However, several studies show that ecological interactions among natural enemies may result in complex effects of enemy diversity on prey consumption. Therefore, the challenge in understanding natural enemy diversity effects is to predict consumption rates of multiple enemies taking into account effects arising from patterns of prey use together with species interactions. Here, we show how complementary and redundant prey use patterns result in additive and saturating effects, respectively, and how ecological interactions such as phenotypic niche shifts, synergy and intraguild predation enlarge the range of outcomes to include null, synergistic and antagonistic effects. This study provides a simple theoretical framework that can be applied to experimental studies to infer the biological mechanisms underlying natural enemy diversity effects on prey.
Human Development and Service Delivery in Asia
Authors: Chaudhury Nazmul , Devarajan Shantayanan
Published: July 2006

This article offers a common framework for addressing Asia's varied human‐development challenges by observing that, for the most part, they stem from a systematic failure in the delivery of basic services, especially to poor people, caused by a failure of accountability at different points in the service‐delivery chain. It describes various efforts by Asian countries to remedy this situation. While there are some encouraging early results, these efforts have also turned up some new challenges to Asia's human‐development problems, three of which ‐ politics, decentralisation, and the role of learning from impact evaluation ‐ are highlighted by the study.
Preschool Children's Attention to Environmental Messages About Groups: Social Categorization and the Origins of Intergroup Bias
Authors: Patterson Meagan M. , Bigler Rebecca S.
Published: July 2006

This study was designed to examine the effects of adults' labeling and use of social groups on preschool children's intergroup attitudes. Children (N=87, aged 3–5) attending day care were given measures of classification skill and self‐esteem and assigned to membership in a novel (“red” or “blue”) social group. In experimental classrooms, teachers used the color groups to label children and organize the classroom. In control classrooms, teachers ignored the color groups. After 3 weeks, children completed multiple measures of intergroup attitudes. Results indicated that children in both types of classrooms developed ingroup‐biased attitudes. As expected, children in experimental classrooms showed greater ingroup bias on some measures than children in control classrooms.
The Early Childhood Aggression Curve: Development of Physical Aggression in 10‐ to 50‐Month‐Old Children
Authors: Alink Lenneke R. A. , Mesman Judi , Van Zeijl Jantien , Stolk Mirjam N. , Juffer Femmie , Koot Hans M. , Bakermans‐Kranenburg Marian J. , Van IJzendoorn Marinus H.
Published: July 2006

This study examines the prevalence, stability, and development of physical aggression, as reported by mothers and fathers, in a sample of children initially recruited at 12, 24, and 36 months (N=2,253) and in a subsample followed up 1 year later (n=271) in a cross‐sequential design. Physical aggression occurred in 12‐month‐olds, but significantly more often in 24‐ and 36‐month‐olds. The rates of physically aggressive behaviors increased in the 2nd year of life, and declined from the 3rd birthday onward. Stabilities were moderate for 12‐month‐olds and high for 24‐ and 36‐month‐olds. At the ages of 24 and 36 months, boys were more aggressive than girls. The results confirm and extendR.E. Tremblay's (2004)hypothesis about the early development of physical aggression.
Qualitative Differences in the Exploration of Upright and Upside‐Down Faces in Four‐Month‐Old Infants: An Eye‐Movement Study
Authors: Gallay Mathieu , Baudouin Jean‐Yves , Durand Karine , Lemoine Christelle , Lécuyer Roger
Published: July 2006

Four‐month‐old infants were habituated with an upright or an upside‐down face. Eye‐movement recordings showed that the upright and upside‐down faces were not explored the same way. Infants spent more time exploring internal features, mainly in the region of the nose and mouth, when the face was upright. They also alternated as frequently between the face's internal features (eyes vs. nose/mouth) as between external and internal features. When the face was upside down, the infants spent half of their time exploring external features, and preferentially alternated between external features and internal features. The main effect of inversion was a decrease of the looking time to the nose/mouth region and of the number of shifts between the eye region and the nose/mouth region.
What Leads Children to Adopt New Strategies? A Microgenetic/Cross‐Sectional Study of Class Inclusion
Authors: Siegler Robert S. , Svetina Matija
Published: July 2006

Learning of class inclusion by 5‐year‐olds in response to empirical and logical explanations of an adult's answers was examined. Contrary to the view that young children possess an empirical bias, 5‐year‐olds learned more, and continued learning for longer, when given logical explanations of correct answers than when given empirical explanations. Once children discovered how to solve the problems, they showed few regressions. Many children in the microgenetic experiment followed the path of change anticipated from previous cross‐sectional studies, but children in the cross‐sectional part of the study seemed to follow a different path. Reasons for the superior effectiveness of the logical explanations were discussed.
The Effects of a Creative Dance and Movement Program on the Social Competence of Head Start Preschoolers
Authors: Lobo Yovanka B. , Winsler Adam
Published: July 2006

The effects of an eight‐week instructional program in creative dance/movement on the social competence of low‐income preschool children were assessed in this study utilizing a scientifically rigorous design. Forty preschool children from a large Head Start program were randomly assigned to participate in either an experimental dance program or an attention control group. Teachers and parents, blind to the children's group membership, rated children's social competence both before and after the program, using English and Spanish versions of the Social Competence Behavior Evaluation: Preschool Edition. The results revealed significantly greater positive gains over time in the children's social competence and both internalizing and externalizing behavior problems for the experimental group compared with the control group. Small‐group creative dance instruction for at‐risk preschoolers appears to be an excellent mechanism for enhancing social competence and improving behavior. The implications for early childhood education and intervention are discussed.
Industrial statistics: a discipline with opportunities and challenges
Authors: De Mast Jeroen , Does Ronald J. M. M.
Published: July 2006

The development of industrial statistics as a scientific discipline, as well as its contributions to improving quality and efficiency in modern industry are discussed. Furthermore, the nature, purpose, and research paradigm of scientific research in industrial statistics are profiled. These accounts form the basis for a discussion of the discipline's future and key elements therein.
Optimal versus orthogonal and equivalent‐estimation design of blocked and split‐plot experiments
Authors: Goos Peter
Published: July 2006

This article provides an overview of the recent literature on the design of blocked and split‐plot experiments with quantitative experimental variables. A detailed literature study introduces the ongoing debate between an optimal design approach to constructing blocked and split‐plot designs and approaches where the equivalence of ordinary least squares and generalized least squares estimates are envisaged. Examples where the competing design strategies lead to totally different designs are given, as well as examples in which the optimal experimental designs are orthogonally blocked or equivalent‐estimation split‐plot designs.
Model‐based control charts in phase 1 statistical process control
Authors: Koning Alex J.
Published: July 2006

In this paper, a general method of constructing control charts for preliminary analysis of individual observations is presented, which is based on recursive score residuals. A simulation study shows that certain implementations of these charts are highly effective in detecting assignable causes.
Investigation of the Ability of Haplotype Association and Logistic Regression to Identify Associated Susceptibility Loci
Authors: North B. V. , Sham P. C. , Knight J. , Martin E. R. , Curtis D.
Published: July 2006

While finely spaced markers are increasingly being used in case‐control association studies in attempts to identify susceptibility loci, not enough is yet known as to the optimal spacing of such markers, their likely power to detect association, the relative merits of single marker versus multimarker analysis, or which methods of analysis may be optimal. Some investigations of these issues have used markers simulated under different theoretical models of population evolution. However the HapMap project and other sources provide real datasets which can be used to obtain a more realistic view of the performance of these approaches.

SNPs around APOE and from two HapMap regions were used to obtain information regarding linkage disequilibrium (LD) relationships between polymorphisms, and these real patterns of LD were used to simulate datasets such as would be obtained in case‐control studies were these SNPs to influence susceptibility to disease. The datasets obtained were analysed using tests for heterogeneity of estimated haplotype frequencies and using logistic regression analyses in which only main effects from each marker were considered. All markers surrounding the putative susceptibility locus were analysed, using sets of either 1, 2, 3 or 4 markers at a time.

Some markers within 150 kb of the susceptibility locus were able to detect association. At distances less than 100 kb there was no correlation between the distance from the susceptibility locus and the strength of evidence for association. When the average inter‐locus spacing is 25 kb many loci would not be detected, while when the spacing is as low as 2 kb one can be fairly confident that at least one marker will be in strong enough LD with the susceptibility locus to enable association to be detected, if the susceptibility locus has a strong enough effect relative to the sample size. With an inter‐locus spacing of 4 kb some susceptibility loci did not have a marker locus in strong LD, potentially undermining the ability to detect association. There was little difference in the performance of haplotype‐based analysis compared with logistic regression considering effects of each marker as separate. Multimarker analysis on occasion produced results which were much more highly significant than single marker analysis, but only very rarely.

Our results support the view that if markers are randomly selected then a spacing as low as 2 kb is desirable. Multimarker analysis can sometimes be more powerful than single marker analysis so both should be performed. However, because it is rare for multimarker analysis to be much more highly significant than single marker analysis one should strongly suspect that when such results occur they may be due to mistakes in genotyping or through some other artefact. Haplotype analysis may be more prone to such problems than logistic regression, suggesting that the latter method might be preferred.
LOG‐RATIO COMPOSITIONAL DATA ANALYSIS IN ARCHAEOMETRY*
Authors: BAXTER M. J. , FREESTONE I. C.
Published: July 2006

Compositional data arise commonly in archaeometry, in the study of artefact compositions where the variables measured either sum to 100%, or can be viewed as a subset of such a set of variables. There has been debate in Archaeometry about the appropriate way to analyse such data statistically, which amounts to argument about how the data should be transformed prior to statistical analysis. This paper reviews aspects of the debate and illustrates, using both simulated and real data, that what has been proposed as the ‘correct’ theoretical approach—log‐ratio analysis—does not always work well. The reasons for this are discussed.
Competing Presynaptic and Postsynaptic Effects of Ethanol on Cerebellar Purkinje Neurons
Authors: Ming Zhen , Criswell Hugh E. , Yu Guozhong , Breese George R.
Published: July 2006

Background:Ethanol has actions on cerebellar Purkinje neurons that can result either in a net excitation or in inhibition of neuronal activity. The present study examines the interplay of presynaptic and postsynaptic mechanisms to determine the net effect of ethanol on the neuronal firing rate of cerebellar Purkinje neurons.

Methods:Whole‐cell voltage‐clamp recording of miniature inhibitory postsynaptic currents (mIPSCs) from Purkinje neurons in cerebellar slices was used to examine the effect of ethanol on presynapticsynaptic release ofγ‐aminobutyric acid (GABA) and glutamate. Extracellular recording was used to examine the net action of both presynaptic and postsynaptic effects of ethanol on the firing rate of Purkinje neurons.

Results:Under whole‐cell voltage clamp, the frequency of bicuculline‐sensitive miniature postsynaptic currents (mIPSCs) was increased dose‐dependently by 25, 50, and 100 mM ethanol without any change in amplitude or decay time. Despite this evidence of increased release of GABA by ethanol, application of 50 mM ethanol caused an increase in firing in some neurons and a decrease in firing in others with a nonrandom distribution. When both glutamatergic and GABAergic influences were removed by simultaneous application of 6‐cyano‐7‐nitroquinoxaline‐2,3‐dione and picrotoxin, respectively, ethanol caused only an increase in firing rate.

Conclusions:These data are consistent with a dual action of ethanol on cerebellar Purkinje neuron activity. Specifically, ethanol acts presynaptically to increase inhibition by release of GABA, while simultaneously acting postsynaptically to increase intrinsic excitatory drive.
Bone tissue formation adjacent to implants placed in fresh extraction sockets: an experimental study in dogs
Authors: Botticelli Daniele , Persson Leif G. , Lindhe Jan , Berglundh Tord
Published: July 2006

Objective: To study the healing of marginal defects that occurred at implants placed in a healed ridge or in fresh extraction sockets.

Material and methods: Six dogs were used. The right side of the mandible was used in the first part of the study. The first, second premolars and first molars were extracted. After 3 months of healing the bone was prepared for implant installation in these premolar and molar sites. The marginal 5 mm of each recipient site was widened with a conical drill. Following implant installation a gap of varying dimension occurred around the titanium rod (artificial defect (A) sites). At this interval the third and fourth premolars were extracted and implants were installed in the distal socket of the two teeth (natural defect (N) sites). The flaps were sutured to allow non‐submerged healing. After 2 months, the procedures were repeated in the left side. Two months later the animals were euthanized, and biopsies were obtained and prepared for histological examination.

Results: The length of the zone of de novo‘bone‐to‐implant contact’ in the defect region was longer at the A sites than at the N sites both at the 2‐ and the 4‐month interval. Further, while after 4 months of healing the marginal bone crest at the A sites was located close to the abutment/fixture junction, at the N sites a marked reduction of the height of the bone crest was documented. Hence, most A site defects became completely resolved whereas healing of the N site defects was incomplete.

Conclusion: The process of bone modeling and remodeling at an implant placed in a fresh extraction socket differs from the resolution of marginal defects that may occur following implant installation in a healed ridge.
Melatonin reduces ischemia/reperfusion‐induced superoxide generation in arterial wall and cell death in skeletal muscle
Authors: Wang Wei Z. , Fang Xin‐Hua , Stephenson Linda L. , Khiabani Kayvan T. , Zamboni William A.
Published: July 2006

Abstract:  The purpose of this study was to determine the effect of melatonin on superoxide generation in arterial wall at an early phase of reperfusion and on endothelial dysfunction of microvasculature and cell viability of cremaster muscle at late phase of reperfusion (24 hr) after prolonged ischemia. Bilateral vascular pedicles which supply blood flow to the cremaster muscle were exposed. After surgical preparation, microvascular clamps were applied on the right iliac, femoral and spermatic arteries to create 4 hr of ischemia in both feeding vessels and the unexposed cremaster muscle. The vascular clamping was omitted on the left iliac, femoral and spermatic arteries and served as an internal control. Melatonin or Vehicle was via by intravenous injection at 10 min prior to reperfusion and 10 min after reperfusion. In the first experiment, the vascular pedicle was harvested after reperfusion to measure superoxide generation in real time by lucigenin‐derived chemiluminescence. In the second experiment, endothelial‐dependent and ‐independent vasodilatation was examined in the terminal arteriole of cremaster muscle which was then harvested to examine cell viability by WST‐1 assay on day 2. Superoxide generation in arterial wall peaked at first 5‐min of reperfusion and declined to near baseline after 60 min of reperfusion. Melatonin treatment significantly reduced superoxide generation in arterial walls and improved cell viability in cremaster muscles. Melatonin treatment also significantly reduced microvascular endothelial dysfunction which was still observable in the microcirculation of cremaster muscle after 24 hr of reperfusion. Melatonin reduces superoxide generation in the early phase of reperfusion resulting in attenuating endothelial dysfunction and muscle cell death in the late phase of reperfusion.
BEFORE RECOGNITION, AND AFTER: THE EDUCATIONAL CRITIQUE
Authors: Bingham Charles
Published: July 2006

Abstract Social struggles that turn on race, gender, and sexuality are struggles for recognition. At least, this has been a widespread assumption for decades. Yet this assumption has come under critique of late. In this essay, Charles Bingham looks into the debate that surrounds the recognitive paradigm. He looks both at the general (noneducational) debate, and then at the more specific educational debate around recognition. He concludes by highlighting the practical contributions that educators bring to recognitive discourse. Such practical contributions are missing from the more general debate as it has been articulated by cultural theorists. Educational thought adds a significant, and particularly useful, dimension to discussions surrounding the recognitive assumption.
RACE IGNORE‐ANCE, COLORTALK, AND WHITE COMPLICITY: WHITE IS…WHITE ISN’T1
Authors: Applebaum Barbara
Published: July 2006

Abstract In this review essay, Barbara Applebaum uses white complicity as a framework for discussing three books: Mica Pollock’s Colormute: Race Talk Dilemmas in an American School, Debra Van Ausdale and Joe R. Feagin’s The First R: How Children Learn Race and Racist, and Virginia Lea and Judy Helfand’s Identifying Race and Transforming Whiteness in the Classroom. She explains the notion of white complicity and discusses some of the deep philosophical questions involving moral responsibility and agency that arise when one acknowledges white complicity. In particular, she examines the question of whether complicity is best described as grounded in individual intention or as an outcome of collective action, as well as whether “complicity” as a word displaces the strong sense of harm implied by the term “racist.” Finally, Applebaum explores how some of these philosophical questions crisscross through the discussions highlighted in the three books.
THEORIZING THE UNIVERSITY AS A CULTURAL SYSTEM: DISTINCTIONS, IDENTITIES, EMERGENCIES
Authors: Considine Mark
Published: July 2006

Abstract Universities currently face new environmental demands and significant internal complexities that appear to challenge their traditional modes of work and organization — and thus their very identities. In this essay, Mark Considine argues that the prospect of such changes requires us to reflect carefully upon the theoretical and normative underpinnings of universities and to delineate the structures and processes through which they might seek to negotiate their identities. Considine re‐theorizes the university as a higher education system composed by distinctions and networks acting through an important class of boundary objects. He moves beyond an environmental analysis, asserting that systems are best theorized as cultural practices based upon actors making and protecting important kinds of distinctions. Thus, the university system must be investigated as a knowledge‐based binary for dividing knowledge from other things. This approach, in turn, produces an identity‐centering (cultural) model of the system that assumes universities must perform two different acts of distinction to exist: first, they must distinguish themselves from other systems (such as the economy, organized religion, and the labor market), and, second, they must operate successfully in a chosen resource environment. Ultimately, Considine argues that while environmental problems (such as cuts in government grants) may generate periodic crises, threats within identities produce emergencies generating a radical kind of problematic for actor networks.
Effects of Ultrasound, Irradiation, and Acidic Electrolyzed Water on Germination of Alfalfa and Broccoli Seeds and Escherichia coli O157:H7
Authors: Kim Hyun Jung , Feng Hao , Kushad Mosbah M. , Fan Xuetong
Published: July 2006

ABSTRACT:  The ability of power ultrasound, acidic electrolyzed water (AEW), and gamma irradiation to inactivate Escherichia coli O157:H7 inoculated onto alfalfa and broccoli seeds was examined. The treatment conditions under which the alfalfa and broccoli seeds treated with sterile deionized water (SW), AEW, ultrasound cleaning tank (UST), ultrasound probe (USP), and irradiation (IR) would retain a germination percentage of >85% were first determined for each disinfection hurdle. E. coli O157:H7 inactivation tests were then conducted with the experimental conditions determined in the germination tests to find out the maximum inactivation ability of each disinfection hurdle. AEW treatment at 55 oC for 10 min reduced E. coli O157:H7 population by 3.4 and 3.3 log CFU/g for the alfalfa and broccoli seeds, respectively. IR at 8 kGy resulted in a 5‐log reduction with seed germination of >85% for both seed types, but a reduction in the length and thickness of the sprouts was observed. None of the ultrasound treatments achieved over a 2‐log reduction in E. coli O157:H7 population without lowering the germination to below 85%. The results of this study demonstrated that AEW and ultrasound, when applied individually or in combination with thermal treatment at 55 oC, were not able to deliver a satisfactory inactivation of E. coli O157:H7. A combination of several hurdles must be used to achieve a complete elimination of E. coli O157:H7 cells on alfalfa and broccoli seeds.
Ca2+ activation of diffusible and bound pools of μ‐calpain in rat skeletal muscle
Authors: Murphy Robyn M. , Verburg Esther , Lamb Graham D.
Published: July 2006

Skeletal muscle fibres contain ubiquitous and muscle‐specific calcium‐dependent proteases known as calpains. During normal activity, intracellular [Ca2+] in muscle fibres increases to high levels (∼2–20 μm), and it is not apparent how this can be reconciled with the activation properties of the calpains. Calpains evidently do not cause widespread proteolytic damage within muscle fibres under normal circumstances, but do have a role in necrosis in dystrophic muscle fibres. In this study, we examined the in situ localization and regulation of calpains in muscle fibres in order to identify how they are attuned to normal function. The sarcolemma of individual muscle fibres of the rat was removed by microdissection (fibre ‘skinning’) in order to determine the compartmentalization and diffusibility of the two most Ca2+‐sensitive calpains, μ‐calpain and calpain‐3, and to permit precise manipulation of cytoplasmic [Ca2+] under physiological in situ conditions. Passive force production in stretched fibres, which indicates the patency of the important elastic structural protein titin, was used as a sensitive assay of the amount of diffusible proteolytic activity in individual fibre segments and in muscle homogenates at set [Ca2+]. All calpain‐3 is bound tightly within a fibre, whereas most μ‐calpain (∼0.2 μm) is initially freely diffusible in the cytoplasm at resting [Ca2+] but binds within seconds at high [Ca2+]. [Ca2+] has to be raised to ≥ 2 μm for ≥ 1 min to initiate detectable autolysis of μ‐calpain and to activate appreciable proteolytic activity. If the [Ca2+] is raised sufficiently for long enough to initiate substantial autolysis of μ‐calpain, the Ca2+ sensitivity of the proteolytic activity is greatly increased, and it remains active even at 300 nm Ca2+, with activity only ceasing if the [Ca2+] is decreased to ∼50 nm Ca2+, close to the normal resting [Ca2+]. These findings on the Ca2+‐ and time‐dependent binding, autolytic and proteolytic properties of μ‐calpain under physiological conditions demonstrate how it is precisely attuned to avoid uncontrolled proteolytic activity under normal circumstances, and indicate why it could lead to substantial proteolytic damage if resting or localized [Ca2+] is elevated, as is likely to occur after eccentric contraction and in dystrophic muscle.
Plant and fungal cytomechanics: quantifying and modeling cellular architectureThis review is one of a selection of papers published in the Special Issue on Plant Cell Biology.
Authors: Geitmann Anja
Published: July 2006

Biomechanical studies aim at understanding the relationship between the mechanical properties of biological structures and their function. In cytomechanical investigations, this approach is brought down to the scale of cells and subcellular structures. In plant cells and the hyphae of fungi and water molds, interactions between turgor pressure, the cell wall, and the cytoskeleton are considered of primary importance. This review is an overview of how the mechanical properties of these individual features and their interactions have been measured and how the experimental data are used to produce theoretical mechanical models of cellular architecture and dynamics. Several models are discussed, and focusing on the example of tip-growing cells, various approaches to understanding the mechanical aspects of cellular morphogenesis are analyzed.