bluuebunny/crossref_metadata_2025 huggingface dataset:
Central and Peripheral RAG Protein Re‐expression: Underestimate Mechanisms of Tolerance?
Authors: Hillion S. , Rochas C. , Devauchelle V. , Youinou P. , Jamin C.
Published: August 2006

The generation of developing B cells in the bone marrow is regulated by recombination activating genes RAG1 and RAG2 proteins. They contribute to the synthesis of functional antibodies (Abs) that can present self‐reactivities following V(D)J (V, variable; D, diversity and J, joining) recombination. The emergence of autoreactive B cells is prevented by deletion through apoptosis, by stimulation blockade through anergy, or by synthesis of a new B‐cell receptor through receptor edition. In the periphery, somatic hypermutation during the course of germinal centre (GC) responses can lead to the appearance of autoreactive and low‐affinity Ab‐producing B cells. Apoptotic deletion and receptor revision regulate these autoreactive and inappropriate B cells. Moreover, the presence of RAG‐positive B cells outside GCs suggest that still uncharacterized regulation checkpoint, associated with secondary V(D)J recombination, also contribute to the regulation of autoreactivities. Failure in central and/or peripheral tolerance mechanisms associated with RAG expression could contribute to the terminal differentiation of autoreactive B cells leading to autoimmune states.
Tissue Homeostasis and Immunity – More on Models
Authors: Cunliffe J.
Published: August 2006

This article continues the ongoing debate around models of the immune system. Earlier contributors have paid much attention to the various processes that lead to adaptive immune system aggression or tolerance. They have often based their discussions around facts that have been established by experimental investigation. However, both the observation and interpretation of these facts have been influenced by the function – or system goal – that is believed to have generated them. The perception of this function (of all or part of the immune system) is influenced by long established theories in immunology (e.g. horror autotoxicus, clonal deletion in utero, pathogen elimination, clonal selection, auto‐immunity and so on) which, for many, have become enshrined as facts. One function that has had less consideration and has not been extensively investigated is the maintenance of tissue homeostasis. When the immune system is viewed from this perspective, the facts invite alternative interpretations. Whilst this perspective may not necessarily be the only valid one, let alone a correct one, viewing things this way – at least briefly – might help to expose hidden assumptions. It also emphasizes that the immune system is a system and, as such, it can by analysed through the principles of general systems theory.
Vaccine Approaches to Prevent Tuberculosis
Authors: Wiker H. G. , Mustafa T. , Målen H. , Riise A. M. D.
Published: August 2006

Mycobacterium tuberculosis, the causative agent of tuberculosis (TB), is one of the main killers among infectious pathogens in the world and represents an important factor that sustain poverty in developing countries. Failure of the BCG vaccine to protect in endemic regions, and increasing problems with multi‐drug‐resistant TB calls for development of better vaccines to prevent reactivation of tuberculosis. It has been estimated that an effective post‐exposure vaccine will prevent 30–40% of the TB cases. New vaccines should also prevent development of TB in HIV‐infected individuals. Recent characterization of M. tuberculosis H37Rv by proteomic methods has revealed a large number of novel secreted proteins that should be investigated in mouse models for latent and slowly progressive TB. There is an important balance between control of infection and tissue destruction in TB, and M. tuberculosis has developed strategies to prevent immune‐mediated sterilization. Central to this strategy is inhibition of apoptosis of macrophages. Development of novel vaccines should therefore take into consideration the effects on central markers to obtain a better picture of regulation of immunity, including FasL and Bcl‐2 which are essential in regulation of apoptosis.
Antibody‐Mediated Regulation of the Immune Response
Authors: Hjelm F. , Carlsson F. , Getahun A. , Heyman B.
Published: August 2006

Antibodies administered in vivo together with the antigen they are specific for can regulate the immune response to that antigen. This phenomenon is called antibody‐mediated feedback regulation and has been known for over 100 years. Both passively administered and actively produced antibodies exert immunoregulatory functions. Feedback regulation can be either positive or negative, resulting in >1000‐fold enhancement or >99% suppression of the specific antibody response. Usually, the response to the entire antigen is up‐ or downregulated, regardless of which epitope the regulating antibody recognizes. IgG of all isotypes can suppress responses to large particulate antigens like erythrocytes, a phenomenon used clinically in Rhesus prophylaxis. IgG suppression works in mice lacking the known Fc‐γ receptors (FcγR) and a likely mechanism of action is epitope masking. IgG1, IgG2a and IgG2b administered together with soluble protein antigens will enhance antibody and CD4+ T‐cell responses via activating FcγR, probably via increased antigen presentation by dendritic cells. IgG3 as well as IgM also enhance antibody responses but their effects are dependent on their ability to activate complement. A possible mechanism is increased B‐cell activation caused by immune complexes co‐crosslinking the B‐cell receptor with the complement‐receptor 2/CD19 receptor complex, known to lower the threshold for B‐cell activation. IgE‐antibodies enhance antibody and CD4+ T‐cell responses to small soluble proteins. This effect is entirely dependent on the low‐affinity receptor for IgE, CD23, the mechanism probably being increased antigen presentation by CD23+ B cells.
Detection of Autoantibodies to the BTB‐kelch Protein KLHL7 in Cancer Sera
Authors: Bredholt G. , Storstein A. , Haugen M. , Krossnes B. K. , Husebye E. , Knappskog P. , Vedeler C. A.
Published: August 2006

The aim of the study was to search for novel targets of autoantibodies in patients with paraneoplastic neurological syndromes (PNS). PNS are mediated by immune reactions against autoantigen(s) shared by the cancer cells and the nervous system. By serological screening of a rat cerebellum cDNA expression library using anti‐Hu‐positive sera from three patients with paraneoplastic encephalomyelitis (PEM), we identified an open reading frame encoding an isoform of the BTB‐kelch protein KLHL7. Immunohistochemical studies demonstrated that the KLHL7 protein is expressed in the nuclei of neurones, but not in other tissues including various cancers. However, the KLHL7 protein was detected in the nuclei of cancer cell lines. Antibodies to KLHL7 were detected by an immunoprecipitation assay in sera from 12 of 254 (4.7%) patients with various cancers and 2 of 170 blood donors (1.2%). None of 50 sera from patients with multiple sclerosis were positive for KLHL7 antibodies. Sixteen patients with classical PNS and anti‐Hu or anti‐Yo antibodies were also negative for KLHL7 antibodies. Seven cancer patients with KLHL7 antibodies had various signs of neurological disease that could be related to cancer, whereas the remaining five seropositive cancer patients had no clinical signs of possible PNS. The present results indicate that KLHL7 antibodies are associated with various cancers, and in some patients also with neurological disease. Whether KLHL7 antibodies can be used as paraneoplastic markers for PNS remains to be determined.
The diversity and origin of exotic ants arriving in New Zealand via human‐mediated dispersal
Authors: Ward Darren F. , Beggs Jacqueline R. , Clout Mick N. , Harris Richard J. , O’Connor Simon
Published: August 2006

The number of exotic ant species being dispersed to new regions by human transportation and the trade pathways responsible for this are poorly understood. In this study, the taxonomic diversity, trade pathways, and origin of exotic ants intercepted at the New Zealand border were examined for the period 1955–2005. Overall, there were a total 4355 interception records, with 115 species from 52 genera. The 10 most frequently intercepted genera, and the 20 most frequently intercepted species contributed > 90% of all records. Many of the species frequently intercepted are regarded as invasive species, and several are established in New Zealand. The most intercepted species was Pheidole megacephala. Despite a relatively low trade relationship, a high proportion (> 64%) of the exotic ants which were intercepted originated from the Pacific region. However, the majority of species intercepted from the Pacific was exotic to the region (71%), or to a lesser extent, wide‐ranging Pacific native species. No endemic species from the Pacific were intercepted. The effectiveness of detecting exotic ant species at the New Zealand border ranged from 48–78% for different trade pathways, indicating a number of species remain undetected. Trade routes associated with specific geographical regions represent a major filter for the arrival of exotic ant species. Despite the importance of the Pacific as a frequent pathway, we suggest that the future establishment of exotic ant species in New Zealand is likely to be mitigated by a renewed focus on trade routes with cool temperate regions, particularly Australia.
Invasion by the amphipod Gammarus pulex alters community composition of native freshwater macroinvertebrates
Authors: Kelly David W. , Bailey Roberta J. , MacNeil Calum , Dick Jaimie T. A. , McDonald Robbie A.
Published: August 2006

Assessing the effects of invading species on native community structure is often confounded by environmental factors and weakened by lack of replicated, long‐term pre‐ and post‐invasion monitoring. Here, we uncouple the community effects of a freshwater amphipod invader from environmental differences. In Irish rivers, the introduced Gammarus pulex replaces the native Gammarus duebeni celticus. However, the River Lissan in Northern Ireland is dissected by a weir that has slowed the upstream invasion by G. pulex. This allowed us in 2000 to sample three contiguous 150‐m reaches that were (1) G. pulex dominated; (2) mixed Gammarus spp.; and (3) G. duebeni celticus only. In 2003, we resampled these reaches and one additional of mixed Gammarus species and one with only G. duebeni celticus further upstream. In temperature, conductivity, and pH, there were statistically significant but no biologically relevant differences among the five reaches of 2003, and between the three reaches surveyed in both years. Although there was evidence of recovery in macroinvertebrate diversity and richness in invaded reaches between years, continued upstream invasion was associated with sustained reductions in these community metrics as compared to un‐invaded sites. Community ordination indicated (1) different associations of community composition attributed to the distribution, abundance, and biomass of the invader; and (2) increasing similarity of invaded communities over time. The impact mechanisms of G. pulex on macroinvertebrate community composition may include predation and competition. The consequences of the observed community changes for ecosystem functioning require further investigation.
Transplantation of ocular tissue from a donor with sporadic Creutzfeldt–Jakob disease
Authors: Tullo Andrew B , Buckley Roger J , Kelly Tom , Head Mark W , Bennett Peter , Armitage W John , Ironside James W
Published: August 2006

Abstract

Background:  One definite, one probable and several possible transmissions of sporadic Creutzfeldt–Jakob disease (sCJD) have followed corneal transplantation. We report an incident in the UK in 1997 in which both corneas and scleras from a donor, subsequently confirmed to have had sCJD, were transplanted. The final clinical outcome for two surviving recipients is still not yet known.

Case report:  In 1997, a 56‐year‐old woman died from biopsy‐proven carcinoma of the bronchus. Both eyes were donated for transplantation. Shortly before she died, she had developed neurological symptoms thought to be due to brain metastases. However, the final result of a neurological post‐mortem examination revealed evidence of sCJD. By this time the corneas had been transplanted, one 3 months previously into a 40‐year‐old man for keratoconus and the other 4 months previously into an 85‐year‐old woman for Fuchs’ dystrophy. In addition, both scleras had been transplanted into a 36‐year‐old man undergoing oculoplastic reconstructive surgery. The surgeons and patients were informed and removal of tissue was advised but undertaken in only two of the patients. Immunohistochemistry failed to demonstrate the presence of the abnormal form of the prion protein in explanted tissue.

Conclusions:  Eight years after the event, two patients remain free of symptoms suggestive of iatrogenic CJD (http://www.cjd.ed.ac.uk/criteria.htm). The third having died aged 92 years, some 7 years after surgery, showing signs of dementia not considered indicative of iatrogenic CJD. Nevertheless this adverse incident attracted substantial publicity. Coupled with continuing concerns in the UK about person‐to‐person transmission of variant CJD, this has lead to a number of important consequences in donor eye retrieval, ocular tissue banking and transplantation.
Iris colour, optic disc dimensions, degree and progression of glaucomatous optic nerve damage
Authors: Jonas Jost B , Budde Wido M , Stroux Andrea , Oberacher‐Velten Isabel M
Published: August 2006

Abstract

Purpose:  To evaluate whether iris colour influences size and shape of the optic nerve head and risk for glaucoma progression.

Methods:  The hospital‐based observational study included 1973 eyes of 1012 Caucasian subjects with ocular hypertension or chronic open‐angle glaucoma. For all patients, colour stereo optic disc photographs were evaluated, and corneal pachymetry and achromatic perimetry were performed. Main outcome measures were optic nerve head parameters, the development or progression of visual field defects and iris colour.

Results:  In most of the study groups, size of the optic disc, neuroretinal rim, alpha zone and beta zone of parapapillary atrophy, retinal vessel diameter and central corneal thickness did not differ significantly between eyes with blue, green, brown and mixed iris colour. In the normal‐pressure glaucoma group, neuroretinal rim area was smallest in the population with mixed‐coloured eyes and largest in the group of eyes with brown irides (P = 0.001 after correction for inter‐eye dependency and multiple testing). For the ocular hypertensive subjects and glaucoma patients with follow‐up examinations, the rate of development or progression of glaucomatous visual field loss was not significantly associated with iris colour (P = 0.060).

Conclusions:  In Caucasian subjects, iris colour does not have a major association with the size of the optic nerve head structures, central corneal thickness and retinal arterial diameter. In Caucasian patients with ocular hypertension or chronic open‐angle glaucoma, an influence of iris colour on the risk for development or progression of glaucomatous visual field defects could not be confirmed.
Study of osteoporosis awareness, investigation and treatment of patients discharged from a tertiary public teaching hospital
Authors: Inderjeeth C. A. , Glennon D. , Petta A.
Published: August 2006

Background: Patients with fragility fractures secondary to osteoporosis are at risk of recurrent fracture. Osteoporosis is often underrecognized and undertreated. We looked at the levels of awareness, investigation and treatment of patients with fracture.

Methods: The study group included patients admitted to a tertiary teaching hospital. Postal surveys were sent to female patients over 60 years of age who had been identified in the hospital database as having International Classification of Diseases‐10 codes for fracture and discharged between June 1997 and January 2002. The questionnaire had specific questions on the histories of the fractures, the risk factors, the awareness of osteoporosis, bone mineral density testing and the treatment for osteoporosis.

Results: Of 1584 surveys posted, 366 valid questionnaires were returned. The median age of respondents was 81 years with a range of 60–99 years. Fifty‐nine per cent reported one fracture, 41% two or more fractures and 65% reported a hip fracture. Forty‐eight per cent of patients were aware that they had osteoporosis and 35% reported having a bone density performed. Thirty‐seven per cent reported being on treatment for osteoporosis on discharge, with the majority being on treatment with calcium (34%).

Conclusion: This postal survey of a high‐risk patient group discharged from a tertiary hospital confirm the findings from other population‐based and hospital‐based studies that a significant proportion of patients at risk of further fracture are not investigated or offered specific treatment for osteoporosis. Lack of awareness of underlying osteoporosis by both treating clinicians and patients is likely to be a major contributing factor.
Cumulus cells affect distribution and function of the cytoskeleton and organelles in porcine oocytes
Authors: SUZUKI HIROYUKI , SAITO YOSUKE
Published: August 2006

Mammalian oocytes grow and undergo meiosis within ovarian follicles. Oocytes are arrested at the first meiotic prophase, being controlled or influenced by follicular somatic cells. Under the influence of gonadotropins, immature oocytes resume meiosis. During meiotic progression, some cytoplasmic changes occur, so‐called cytoplasmic maturation. However, porcine follicular oocytes vary greatly in developmental competence. The present review summarizes recent studies highlighting the importance of cumulus cells in maintaining the developmental ability and in reorganizing the cytoskeleton and organelles of porcine oocytes. Factors affecting wide variation of the nuclear and cytoplasmic maturation observed in the porcine oocytes are discussed. (Reprod Med Biol 2006; 5: 183–194)
Exact Bayesian Inference and Model Selection for Stochastic Models of Epidemics Among a Community of Households
Authors: CLANCY DAMIAN , O'NEILL PHILIP D.
Published: August 2006

Abstract.  Much recent methodological progress in the analysis of infectious disease data has been due to Markov chain Monte Carlo (MCMC) methodology. In this paper, it is illustrated that rejection sampling can also be applied to a family of inference problems in the context of epidemic models, avoiding the issues of convergence associated with MCMC methods. Specifically, we consider models for epidemic data arising from a population divided into households. The models allow individuals to be potentially infected both from outside and from within the household. We develop methodology for selection between competing models via the computation of Bayes factors. We also demonstrate how an initial sample can be used to adjust the algorithm and improve efficiency. The data are assumed to consist of the final numbers ultimately infected within a sample of households in some community. The methods are applied to data taken from outbreaks of influenza.
Mobilising modern facts: health technology assessment and the politics of evidence
Authors: May Carl
Published: August 2006

Conventional models of ‘evidence’ for clinical practice focus on the role of randomised controlled clinical trials and systematic reviews as technologies that promote a specific model of rigour and analytic accountability. The assumption that runs through the disciplinary field of health technology assessment (HTA), for example, is that the quantification of evidence about cost and clinical effectiveness is central to rational policy‐making and healthcare provision. But what are the conditions in which such knowledge is mediated into decision‐making contexts, and how is it understood and used when it gets there? This paper addresses these questions by examining a series of meetings and seminars attended by senior clinical researchers, social care and health service managers in the UK between 1998–2004, and sessions of the House of Commons Health Committee held in 2001 and 2005. These provide contexts in which questions about the value and utility of evidence produced within the frame of HTA were explored in relation to parallel questions about the design, evaluation and implementation of telemedicine and telecare systems. The paper points to the ways that evidence generated in the normative frame of HTA was increasingly seen as one‐dimensional and medicalised knowledge that failed to respond to the contingencies of everyday practice in health and social care settings.
In search of fair trade: ethical consumer decision making in France
Authors: Ozcaglar‐Toulouse Nil , Shiu Edward , Shaw Deirdre
Published: August 2006

While the market for fair trade products has been growing in many countries, this paper examines the French market where fair trade remains marginal but is experiencing growth. Using a modified Theory of Planned Behaviour framework the research examines consumer intention to purchase fair trade grocery products in order to explain the pertinent decision‐making criteria of both consumers of and potential consumers of fair trade. Results reveal that concerned consumers should not be treated as one homogeneous group, rather, the distinct variations in the factors that influence their decision making must be considered when promoting, labelling and distributing fair trade products. Implications for both sustaining and developing the market for fair trade products in the future are highlighted and discussed.
What organic and Fair Trade labels do not tell us: towards a place‐based understanding of certification
Authors: Getz Christy , Shreck Aimee
Published: August 2006

Certified organic and Fair Trade food products are making their way into the mainstream among Western consumers and, as such, are increasingly viewed as sustainable and preferable alternatives to the conventional food system, with its many negative social and environmental externalities. Two case studies discussed in this paper indicate, however, that operationalizing the goals for organic and Fair Trade food via certification can be a complex and difficult process. Specifically, the implementation of certification creates a disconnect between expectations raised by labels and the ‘lived experience’ of small farmers. In the case of small farmers in Mexico growing certified organic tomatoes and herbs, certification exacerbated socio‐economic inequality and disrupted local social norms by creating a hyperfocus on surveillance. In the case of small farmers in the Dominican Republic growing Fair Trade bananas, the certification process prioritized the demands of the market to such a degree that the farmers were largely unaware that they were participating in anything ‘alternative’, and it simultaneously reinforced socio‐economic inequalities within the communities. These findings suggest that if the appeal of certified labels rests on the integrity of what the label represents to consumers, then such consumer movements would benefit from a more robust analysis of how certification intersects with and affects local spaces, cultures and communities at the point of production.
Creating markets for eco‐labelling: are consumers insignificant?
Authors: Gulbrandsen Lars H.
Published: August 2006

The proliferation of voluntary certification and labelling schemes for environmentally and socially responsible production is often seen as driven by companies and consumer demand. Through a careful examination of the initiation and spread of such initiatives in the fishery and forestry sectors, this paper challenges a rational–economic perspective that sees the spread of nonstate governance schemes primarily as a market‐driven phenomenon. Drawing on a political consumerism perspective, the paper argues that transnational environmental group networks and their targeting of firms were key to the emergence of nonstate eco‐labelling schemes, and that most firms decided to support or participate in such schemes only after intensive environmental group pressure. The paper opposes the view that nonstate governance challenges traditional state authority, by showing that states, through public procurement policies and support, contributed to create markets for forestry and fishery labelling in many countries. Although some states have been more sceptical of fishery labelling, largely because of the way fishery resources are managed, they have come to accept it as a helpful supplement to public rules and regulations.
Beyond organic: consumer interest in new labelling schemes in the Central Coast of California
Authors: Howard Philip H. , Allen Patricia
Published: August 2006

Producers are interested in developing labelling schemes that go ‘beyond organic’ to address ethical criteria not included the US Department of Agriculture organic standards. However, consumer interests in labels that are not as widely available as organic in the market are poorly understood. This study reports results of focus‐group research and a survey of 1000 households in the Central Coast region of California to determine which standards consumers are most interested in supporting through their purchases. The results indicate that standards for the humane treatment of animals have the highest level of support, followed by a standard for local origin, and for a living wage for workers involved in producing food. Logistic regression analysis suggests that humane is more likely to be chosen by women, European‐Americans, younger people and frequent organic purchasers. Locally grown was preferred by older people and households with children. A living wage for workers involved in food production was selected more often by Latinos. Although a characterization of trends is not possible due to a cross‐sectional design, the results suggest some potential directions for producers in this region who are willing to supply unmet consumer demands for ethical criteria. There are three basic directions that new and emerging labels may take with respect to US national organic standards: (1) separate from organic; (2) institutionally separate, but tightly integrated with organic; and (3) intended to supplant organic. The success of each of these strategies will depend on how much trust consumers continue to place in government oversight of organic food. The study results also suggest that the movement for a more sustainable food system would benefit from devoting more attention to issues of animal rights and social justice.
Potential role of hepatic progenitor cells expression in cases of chronic hepatitis C and their relation to response to therapy: a clinicopathologic study
Authors: Tsamandas Athanassios C. , Syrokosta Ioulia , Thomopoulos Konstantinos , Zolota Vassiliki , Dimitropoulou Dimitra , Liava Anna , Coupoulou Anna Antona , Siagris Dimitrios , Petsas Theodore , Karatza Chrisoula , Gogos Charalambos A
Published: August 2006

Abstract: Background: This study investigates the correlation of hepatic progenitor cells (HPC) expression with treatment response in patients with chronic hepatitis C.

Design: The study comprised 77 liver biopsies with chronic hepatitis C (HCV). All patients were PCR‐HCV (+) and received antiviral therapy with interferon or pegylated interferon α‐2b and ribavirin. Twenty‐nine patients were assigned as responders (group A), 29 as nonresponders (group B) and 19 as relapsers (group C). Ten normal liver biopsies were used as controls. Liver paraffin sections were subjected (a) to immunohistochemistry using antibodies for cytokeratins 19 (CK19) and 7 (CK7), α‐fetoprotein (AFP), leukocyte common antigen (LCA) and CD34 antigen (b) to in situ hybridization for AFP mRNA and (c) to immunohistochemistry+in situ hybridization. Results were expressed as % of positive cells following morphometric analysis.

Results: HPC expression was present in all 87 specimens. In the control biopsies, rare HPC were detected. In the CH cases and according to AFP mRNA expression, the grade for % HPC expression was: group B: 53.2±2.6> group C: 48.37±1.8> group A: 31.4±1.6 (group A vs B P<0.01, group A vs C P<0.01, group B vs C P>0.05. Double stain revealed that HPC coexpressed CK19/AFP mRNA, CK7/AFP mRNa and AFP protein/AFP mRNA. HPC‐percentages were directly correlated with total HAI score (P<0.01), fibrosis stage (P<0.01), and transaminase values (P<0.05).

Conclusions: This study demonstrates that in cases of chronic hepatitis C, the significant association of HPC expression with the severity of disease and more specifically with the response to treatment implies that HPC development and proliferation may provide additional prognostic information and predict prognosis in such cases.
Foramen Ovale Electrodes Can Identify a Focal Seizure Onset When Surface EEG Fails in Mesial Temporal Lobe Epilepsy
Authors: Velasco Tonicarlo R. , Sakamoto Américo C. , Alexandre Veriano , Walz Roger , Dalmagro Charles L. , Bianchin Marino M. , Araújo David , Santos Antônio C. , Leite João P. , Assirati João A. , Carlotti Carlos
Published: August 2006

Summary:  Purpose: We analyze a series of patients with mesial temporal lobe epilepsy (MTLE) associated with hippocampal sclerosis (HS) submitted to presurgical investigation with scalp sphenoidal, followed by foramen ovale electrodes (FO), and, when necessary, with depth temporal electrodes. We sought to evaluate the clinical utility of FO in patients with MTLE‐HS.

Methods: We included patients who had phase I investigation with bitemporal independent seizures, nonlateralized ictal onsets, or ictal onset initiating in the side contralateral to the side of hippocampal sclerosis. Patients whose implanted FO failed to demonstrate an unambiguous unilateral ictal onset were later evaluated with depth hippocampal electrodes.

Results: Between May 1994 and December 2004, 64 patients met our inclusion criteria: 33 female (51.5%) and 31 male subjects (48.5%). The mean age at enrollment was 37.66 ± 10.6 years (range, 12–56 years). The groups with nonlateralized surface ictal EEG onsets and contralateral EEG onsets had a greater chance of lateralization with FO when compared with the group with bilateral independent seizures on surface EEG (p < 0.01). Foramen ovale electrodes lateralized the seizures in 60% of patients. Seventy percent of patients became seizure free after temporal lobectomy. Five patients were implanted with depth temporal electrodes after FO video‐EEG monitoring. The depth‐electrode EEG onsets confirmed the results of FO video‐EEG monitoring in all patients, and the surgery was refused.

Conclusions: In MTLE‐HS, FO is a reliable method for lateralization of seizures that are not clearly recorded by surface EEGs.
Experimental and Clinical Evidence for Loss of Effect (Tolerance) during Prolonged Treatment with Antiepileptic Drugs
Authors: Löscher Wolfgang , Schmidt Dieter
Published: August 2006

Summary:  Development of tolerance (i.e., the reduction in response to a drug after repeated administration) is an adaptive response of the body to prolonged exposure to the drug, and tolerance to antiepileptic drugs (AEDs) is no exception. Tolerance develops to some drug effects much more rapidly than to others. The extent of tolerance depends on the drug and individual (genetic?) factors. Tolerance may lead to attenuation of side effects but also to loss of efficacy of AEDs and is reversible after discontinuation of drug treatment. Different experimental approaches are used to study tolerance in laboratory animals. Development of tolerance depends on the experimental model, drug, drug dosage, and duration of treatment, so that a battery of experimental protocols is needed to evaluate fully whether tolerance to effect occurs. Two major types of tolerance are known. Pharmacokinetic (metabolic) tolerance, due to induction of AED‐metabolizing enzymes has been shown for most first‐generation AEDs, and is easy to overcome by increasing dosage. Pharmacodynamic (functional) tolerance is due to “adaptation” of AED targets (e.g., by loss of receptor sensitivity) and has been shown experimentally for all AEDs that lose activity during prolonged treatment. Functional tolerance may lead to complete loss of AED activity and cross‐tolerance to other AEDs. Convincing experimental evidence indicates that almost all first‐, second‐, and third‐generation AEDs lose their antiepileptic activity during prolonged treatment, although to a different extent. Because of diverse confounding factors, detecting tolerance in patients with epilepsy is more difficult but can be done with careful assessment of decline during long‐term individual patient response. After excluding confounding factors, tolerance to antiepileptic effect for most modern and old AEDs can be shown in small subgroups of responders by assessing individual or group response. Development of tolerance to the antiepileptic activity of an AED may be an important reason for failure of drug treatment. Knowledge of tolerance to AED effects as a mechanism of drug resistance in previous responders is important for patients, physicians, and scientists.
LIGHT ABSORPTION AND QUANTUM YIELD FOR GROWTH IN FIVE SPECIES OF MARINE MACROALGA1
Authors: Markager Stiig
Published: August 2006

Light utilization efficiency in five species of marine macroalgae was measured in laboratory growth experiments (13–41 days duration) at different irradiances at 7°C. All species acclimated to irradiance by changing their light absorption, resulting in a peak in light absorption between 2 and 15 μmol·m−2.s−1. Light absorption increased with thallus‐specific chlorophyll and carbon content according to linear inverse relationships between chlorophyll content (chlarea−1) and log[transmission] and between log[carbon content, Carea−1] and log[transmission]. Quantum yields for light‐limited growth and estimated gross photosynthesis were calculated based on incident and absorbed light. Quantum yield for photosynthesis based on light absorbed by pigments was high (mean = 114 mmol C·mol−1 photons) and similar among the species. Quantum yield for net growth based on incident light was also high but more variable, between 22 and 75 mmol C·mol−1 photons. Differences among species were mainly due to differences in light absorption. In conclusion, all species acclimated to low light by increasing light absorption to the maximum attainable, and growth efficiencies based on absorbed light were close to the maximum theoretically possible.
GENETIC VARIABILITY OF GELIDIUM CANARIENSIS (RHODOPHYTA) DETERMINED BY ISOZYME ELECTROPHORESIS1
Authors: Sosa Pedro A. , Garcia‐Reina Guillermo
Published: August 2006

The populations of Gelidium canariensis (Grunow) Seoane‐Camba from the Canary Islands were analyzed for genetic variability by isozyme electrophoresis in 1989 and 1990. Each population was divided into sporophytic and gametophytic subpopulations. Twenty‐three to 27 putative alleles corresponding to 22 gene loci were analyzed. Sev‐enteen loci were monomorphic in all six subpopulations, and five were polymorphic in at least one subpopulation. Significant deviations from Hardy‐Weinberg equilibrium were found. The amount of genetic variability (percentage of polymorphic loci, mean number of alleles per locus, and average gene diversity) of haploid subpopulations was lower than that of diploid subpopulations. No correlation between genetic distance and geographical distance was found. Low genetic differentiation between sporophytic and gametophytic subpopulations of the same locality was obsewed in two populations. The low genetic diversity and genetic differentiation suggest that the genetic structure of the populations of G. canariensis from the Canary Islands is due to a combination of founder effects and the predominance of asexual reproduction. Initial differences in gene frequencies may have persisted because of insufficient time to reach a higher level of differentiation.
Interarticulator cohesion within coronal consonant production
Authors: Mooshammer Christine , Hoole Philip , Geumann Anja
Published: August 2006

If more than one articulator is involved in the execution of a phonetic task, then the individual articulators have to be temporally coordinated with each other in a lawful manner. The present study aims at analyzing tongue-jaw cohesion in the temporal domain for the German coronal consonants /s, ʃ, t, d, n, l/, i.e., consonants produced with the same set of articulators—the tongue blade and the jaw—but differing in manner of articulation. The stability of obtained interaction patterns is evaluated by varying the degree of vocal effort: comfortable and loud. Tongue and jaw movements of five speakers of German were recorded by means of electromagnetic midsagittal articulography (EMMA) during /aCa/ sequences. The results indicate that (1) tongue-jaw coordination varies with manner of articulation, i.e., a later onset and offset of the jaw target for the stops compared to the fricatives, the nasal and the lateral; (2) the obtained patterns are stable across vocal effort conditions; (3) the sibilants are produced with smaller standard deviations for latencies and target positions; and (4) adjustments to the lower jaw positions during the surrounding vowels in loud speech occur during the closing and opening movement intervals and not the consonantal target phases.
Comment on paper entitled, “An inversion of Freedman’s ‘image pulse’ model in air” [J. Acoust. Soc. Am. 119(2), 965–975 (2006)]
Authors: Hickling Robert , Gaunaurd Guillermo C.
Published: August 2006

Echolocation (i.e., perceiving objects using acoustic echoes) is well-known in underwater detection and to a lesser extent in robot guidance and machine perception. The paper by Tsakiris and McKerrow is concerned with machine perception in air using Freedman’s asymptotic model, which was originally developed to predict the backscattering multiple-echo effect observed in sonar detection. This effect was subsequently shown to be due to the elastic response of underwater targets. Freedman’s model can be used in air because the acoustic target is assumed to be rigid. Also, the model’s prediction of multiple echoes can be used to obtain information about the shape of the target. This is the so-called inversion of the Freedman model by Tsakiris and McKerrow. In their paper, various simple bodies are tested in air using ultrasound and it is shown that the model provides relatively poor information about body shape. Several explanations are given. However, one explanation is not considered, namely that the model itself is not satisfactory. First, there is poor agreement with exact backscattering theory. Second, deriving information about target shape from the multiple echoes predicted by the model is a highly questionable procedure. Both these aspects are examined here.
Model-based classification of nonstationary vocal fold vibrations
Authors: Wurzbacher Tobias , Schwarz Raphael , Döllinger Michael , Hoppe Ulrich , Eysholdt Ulrich , Lohscheller Jörg
Published: August 2006

Classification of vocal fold vibrations is an essential task of the objective assessment of voice disorders. For historical reasons, the conventional clinical examination of vocal fold vibrations is done during stationary, sustained phonation. However, the conclusions drawn from a stationary phonation are restricted to the observed steady-state vocal fold vibrations and cannot be generalized to voice mechanisms during running speech. This study addresses the approach of classifying real-time recordings of vocal fold oscillations during a nonstationary phonation paradigm in the form of a pitch raise. The classification is based on asymmetry measures derived from a time-dependent biomechanical two-mass model of the vocal folds which is adapted to observed vocal fold motion curves with an optimization procedure. After verification of the algorithm performance the method was applied to clinical problems. Recordings of ten subjects with normal voice and ten dysphonic subjects have been evaluated during stationary as well as nonstationary phonation. In the case of nonstationary phonation the model-based classification into “normal” and “dysphonic” succeeds in all cases, while it fails in the case of sustained phonation. The nonstationary vocal fold vibrations contain additional information about vocal fold irregularities, which are needed for an objective interpretation and classification of voice disorders.
Effects of language experience and stimulus complexity on the categorical perception of pitch direction
Authors: Xu Yisheng , Gandour Jackson T. , Francis Alexander L.
Published: August 2006

Whether or not categorical perception results from the operation of a special, language-specific, speech mode remains controversial. In this cross-language (Mandarin Chinese, English) study of the categorical nature of tone perception, we compared native Mandarin and English speakers’ perception of a physical continuum of fundamental frequency contours ranging from a level to rising tone in both Mandarin speech and a homologous (nonspeech) harmonic tone. This design permits us to evaluate the effect of language experience by comparing Chinese and English groups; to determine whether categorical perception is speech-specific or domain-general by comparing speech to nonspeech stimuli for both groups; and to examine whether categorical perception involves a separate categorical process, distinct from regions of sensory discontinuity, by comparing speech to nonspeech stimuli for English listeners. Results show evidence of strong categorical perception of speech stimuli for Chinese but not English listeners. Categorical perception of nonspeech stimuli was comparable to that for speech stimuli for Chinese but weaker for English listeners, and perception of nonspeech stimuli was more categorical for English listeners than was perception of speech stimuli. These findings lead us to adopt a memory-based, multistore model of perception in which categorization is domain-general but influenced by long-term categorical representations.
Measurement of high intensity focused ultrasound fields by a fiber optic probe hydrophone
Authors: Zhou Yufeng , Zhai Liang , Simmons Rebecca , Zhong Pei
Published: August 2006

The acoustic fields of a high intensity focused ultrasound (HIFU) transducer operating either at its fundamental (1.1MHz) or third harmonic (3.3MHz) frequency were measured by a fiber optic probe hydrophone (FOPH). At 1.1MHz when the electric power applied to the transducer was increased from 1.6to125W, the peak positive∕negative pressures at the focus were measured to be p+=1.7–23.3MPa and p−=−1.2–−10.0MPa. The corresponding spatial-peak pulse-average (ISPPA) and spatial-average pulse-average (ISAPA) intensities were ISPPA=77–6000W∕cm2 and ISAPA=35–4365W∕cm2. Nonlinear propagation with harmonics generation was dominant at high intensities, leading to a reduced −6dB beam size (L×W) of the compressional wave (11.5×1.8–8.8×1.04mm) but an increased beam size of the rarefactional wave (12.5×1.6–13.2×2.0mm). Enhancement ratio of absorbed power density in water increased from 1.0 to 3.0. In comparison, the HIFU transducer working at 3.3MHz produced higher peak pressures (p+=3.0–35.1MPa and p−=−2.5–−13.8MPa) with smaller beam size (0.5×4mm). Overall, FOPH was found to be a convenient and reliable tool for HIFU exposimetry measurement.
Use of stimulus-frequency otoacoustic emission latency and level to investigate cochlear mechanics in human ears
Authors: Schairer Kim S. , Ellison John C. , Fitzpatrick Denis , Keefe Douglas H.
Published: August 2006

Stimulus frequency otoacoustic emission (SFOAE) sound pressure level (SPL) and latency were measured at probe frequencies from 500 to 4000Hz and probe levels from 40 to 70dB SPL in 16 normal-hearing adult ears. The main goal was to use SFOAE latency estimates to better understand possible source mechanisms such as linear coherent reflection, nonlinear distortion, and reverse transmission via the cochlear fluid, and how those sources might change as a function of stimulus level. Another goal was to use SFOAE latencies to noninvasively estimate cochlear tuning. SFOAEs were dominated by the reflection source at low stimulus levels, consistent with previous research, but neither nonlinear distortion nor fluid compression become the dominant source even at the highest stimulus level. At each stimulus level, the SFOAE latency was an approximately constant number of periods from 1000 to 4000Hz, consistent with cochlear scaling symmetry. SFOAE latency decreased with increasing stimulus level in an approximately frequency-independent manner. Tuning estimates were constant above 1000Hz, consistent with simultaneous masking data, but in contrast to previous estimates from SFOAEs.
Prediction of absolute thresholds and equal-loudness contours using a modified loudness model
Authors: Glasberg Brian R. , Moore Brian C. J.
Published: August 2006

The loudness model described by Moore et al. [J. Audio Eng. Soc. 45, 224–240 (1997)] forms the basis for a recent ANSI standard for the calculation of the loudness of steady sounds. However, the model does not give accurate predictions of the absolute thresholds published in a recent ISO standard. Here it is described how the assumed middle-ear transfer function in the model can be modified to give more accurate absolute threshold predictions. The modified model also gives reasonably accurate predictions of the equal-loudness contours published in a recent ISO standard.
Measurement of the frequency dependence of the ultrasonic parametric threshold amplitude for a fluid-filled cavity
Authors: Teklu A. , McPherson Michael S. , Breazeale M. A. , Hasse Roger D. , Declercq Nico F.
Published: August 2006

By driving a transducer at one end of a fluid-filled cavity parallel to a rigid plane reflector at the other end, standing ultrasonic waves can be generated. Variations in the cavity length resulting from transducer motion lead to the generation of resonant frequencies lower than the drive frequency (known as fractional harmonics). This excitation of fractional harmonics in a liquid-filled cavity by ultrasonic waves was described previously as a parametric phenomenon [Laszlo Adler and M. A. Breazeale, J. Acoust. Soc. Am. 48, 1077–1083 (1970)]. This system was modeled by using a modified Mathieu’s equation whose solution resulted in the prediction of critical threshold drive amplitude for the excitation of parametric oscillation. The apparatus used by Adler and Breazeale was recently refined for accurate measurements of the threshold amplitude for parametric excitation at frequencies ranging from 2 to 7MHz. The measurements showed that in this range the threshold amplitude increases with increasing drive frequency in apparent discrepancy with the results of Adler and Breazeale. Analysis of the theory indicates, however, that both past and current results lie in two different stability zones and each is in agreement with the existing theory.
Spatio-temporal dynamics of an encapsulated gas bubble in an ultrasound field
Authors: Doinikov Alexander A. , Dayton Paul A.
Published: August 2006

Coupled equations describing the radial and translational dynamics of an encapsulated gas bubble in an ultrasound field are derived by using the Lagrangian formalism. The equations generalize Church’s theory [J. Acoust. Soc. Am. 97, 1510 (1995)] by allowing for the translation motion of the bubble and radiation losses due to the compressibility of the surrounding liquid. The expression given by Church for the inner bubble radius corresponding to the unstrained state of the bubble shell is also refined, assuming that the shell can be of arbitrary thickness and impermeable to gas. Comparative linear analysis of the radial equation is carried out relative to Church’s theory. It is shown that there are substantial departures from predictions of Church’s theory. The proposed model is applied to evaluate radiation forces exerted on encapsulated bubbles and their translational displacements. It is shown that in the range of relatively high frequencies encapsulated bubbles are able to translate more efficiently than free bubbles of the equivalent size.