bluuebunny/crossref_metadata_2025 huggingface dataset:
Cognitive Predictors of Donepezil Therapy Response in Alzheimer Disease
Authors: Saumier Daniel , Murtha Susan , Bergman Howard , Phillips Natalie , Whitehead Victor , Chertkow Howard
Published: May 2007

Objectives: To examine whether the presence of domain-specific cognitive impairments would predict a response to donepezil medication in patients with mild-to-moderate Alzheimer disease (AD). Methods: The protocol was an open-label study of 30 AD subjects (mean age 74 years; education 11 years; Mini-Mental State Exam (MMSE) 23 of 30) beginning a 6-month course of treatment with donepezil. Global response to treatment was determined using a combination algorithm based on changes over 6 months in the ADAS-cog, MMSE and CIBIC. In addition, a set of neuropsychological and experimental cognitive tests designed to test five domains of cognition were administered before beginning therapy in order to determine which domain of testing would be predictive to response to treatment. The tests examined attention, short-term and working memory, learning and memory, visuo-spatial motor skills, and lexical-semantic knowledge. Results: Eighteen of the thirty subjects were rated as having responded (stable or improved scores on the combination algorithm) to the therapy. Responders were significantly less impaired prior to treatment on the following tests: the Clock Drawing Test, a Visual-Spatial Motor Tracking Test, and the Boston Picture Naming Test. No significant initial group differences were noted on the other neuropsychological or experimental cognitive measures. Conclusion: The tests that most reliably predicted response to donepezil in AD subjects were in the domains of visual-spatial motor abilities and lexical-semantic functioning.
Psychological Momentum: Intuitive Physics and Naive Beliefs
Authors: Markman Keith D. , Guenther Corey L.
Published: May 2007

The present research examines psychological momentum (PM), a perceived force that lay intuition suggests influences performance. PM theory is proposed to account for how momentum perceptions arise, and four studies demonstrate the influence of lay intuitions about PM on expectations regarding performance outcomes. Study 1 establishes that individuals share intuitions about the types of events that precipitate PM, and Study 2 finds that defeating a rival increases momentum perceptions. Study 3 provides evidence for the lay belief that as more PM accumulates during a prior task, there should be more residual momentum left to carry over to a subsequent task, and Study 4 finds that an individual whose PM is interrupted is expected to have greater difficulty completing a task than is an individual whose steady progress is interrupted. Discussion focuses on linkages between PM and related constructs.
Professionals' Beliefs About Nursing Home Regulations in Missouri
Authors: Putnam Michelle , Fengyan Tang  , Brooks-Danso Ashley , Pickard Joseph , Morrow-Howell Nancy
Published: May 2007

The process of nursing home regulation continues to need improvement to ensure the best possible quality of care. This study uses mixed methods to explore opinions of nursing home professionals and state nursing home regulation inspection team members about the regulation process and ideas for changing it in the State of Missouri. Data come from a survey of nursing home professionals (n = 334) and state regulation inspectors (n = 123) conducted in early 2004. Findings show disagreement about who is responsible for facilitating nursing home compliance; nursing home professionals desire state assistance in interpreting and applying regulations, whereas inspectors do not believe this will improve quality of care. Greater focus on resident needs may provide common ground for bridging this divide and developing interventions to ensure regulatory success.
Welfare Policy as Social Control
Authors: Chamlin Mitchell B. , Burek Melissa W. , Cochran John K.
Published: May 2007

Most macrolevel analyses of governmental aid to the poor focus on the relationship between indicators of social threat and the expansion of welfare programs. In this article, the authors' investigation extends that research by exploring the consequences of welfare contraction. Taking advantage of Wisconsin's ongoing natural experiment with welfare reform, the authors examine the extent to which the codification of more restrictive eligibility requirements functions to enhance the labor supply. The interrupted time series autoregressive integrated moving average (ARIMA) analyses of monthly welfare caseloads and labor force size fail to support previous contentions that restrictive eligibility requirements are designed to enforce work norms. The authors interpret those findings, raising serious doubts about the efficacy of the conflict perspective's contention that non-legal institutions, like welfare, serve as vehicles for the macrosocial control of subordinate groups or strata.
`Islamic Headscarves' and the European Convention On Human Rights: an Intersectional Perspective
Authors: Vakulenko Anastasia
Published: May 2007

In this article, I analyse the legal construction of `Islamic headscarves' from the perspective of intersectionality, concentrating on the relevant jurisprudence under the European Convention on Human Rights (ECHR). First, I explain the (updated) concept of intersectionality which provides my perspective for analysing the case-law. Second, I outline trends salient in earlier decisions ( Karaduman and Dahlab). Third, I examine how these trends were developed in Şahin v Turkey, the most elaborate Strasbourg authority on the issue of headscarves so far. My analysis suggests that intersectionality was fragmented in the Şahin judgment, which is to a great extent due to the choice of Article 9 ECHR (right to freedom of religion) as the primary legal basis. I argue that this fragmentation is unsatisfactory. Finally, I suggest alternative, more `intersectionality-friendly', legal bases for a headscarf claim in the framework of the ECHR, and offer some thoughts as to how such an alternative argument might proceed.
Constructing the `Right To the City' in Brazil
Authors: Fernandes Edésio
Published: May 2007

While there has been a growing utilization of Henri Lefebvre's concept of the `right to the city', not much has been said about the legal implications of such a concept. This article discusses the main aspects of the legal construction of the `right to the city' in Brazil. Following a discussion of Lefebvre's contribution to the debate on urban politics, the article analyses the role played by the legal order in the determination of the exclusionary pattern of urban development in Brazil, as well as the role a redefined legal order can have in the processes of urban reform, socio-spatial inclusion, and sustainable development. Emphasis is placed on the main dimensions of the 2001 City Statute, the legal framework governing urban development and management, which recognized the `right to the city' as a collective right, followed by an introduction to the proposed `World Charter of the Right to the City'. As a conclusion, it is argued that, while a great deal has already been done to promote the materialization of the `right to the city' in Brazil, there are still serious obstacles to be overcome, and renewed socio-political mobilization is required for the new legal-urban order to be fully implemented.
Mediator Neutrality: Making Sense of Theory and Practice
Authors: Astor Hilary
Published: May 2007

The neutrality of a third party who decides or mediates disputes is central to our ideas of fairness and justice in western liberal democracies. The focus of this article is on neutrality in mediation. It argues that neutrality is even more important to the legitimacy of mediation than it is to the legitimacy of adjudication. But feminist and critical theories have demonstrated the impossibility of neutrality. Further, it is demonstrably absent in mediation practice and it conceals the operation of power in mediation. These flaws and contradictions of neutrality open mediation to constant destabilizing internal dissent and external critique. Mediators face a conundrum — they cannot `do' neutrality, nor can they do without it. This article suggests a new approach to neutrality in mediation, which makes sense in practice and in theory. It provides for the inevitable situatedness of mediators and suggests principles to regulate their input into mediation. It suggests a method of practice that requires (rather than outlaws) attention to power relationships. These recommendations have implications for mediator practice, training, ethics, supervision and continuing education. Although directed to mediation, many of the arguments might fruitfully also be applied to adjudication.
Demobilization and Reintegration of Ex-Combatants: the Irish Case in International Perspective
Authors: Rolston Bill
Published: May 2007

This article surveys the literature on the global experience of demobilization and reintegration of combatants after wars end. It examines the factors that contribute to successful programmes. Among these, the two most frequently emphasized are the political will of all concerned to ensure the programmes work, and the active participation of ex-combatants in their own programmes of reintegration. The article then examines the situation in Ireland. In ways reintegration has failed, and for the same reasons as elsewhere. At the same time, the Irish case shows elements of success to match the best of reintegration programmes worldwide — not least the contribution of highly politicized ex-prisoners to their own reintegration and to conflict transformation more generally. These similarities have emerged in the relative absence of any involvement of the international community in demobilization and reintegration in Ireland, and indeed without direct comparisons made to good practice elsewhere.
The Inevitability and Importance of Genres in Narrative Research on Teaching Practice
Authors: Rosiek Jerry , Atkinson Becky
Published: May 2007

The authors examine the field of contemporary teacher knowledge research. Specifically, they examine the use of narrative representations by researchers in this field. They make a general argument for the development of distinct narrative genres in teacher knowledge research because considerations of distinct genre styles can help researchers refine their craft and can inform the development of appropriate standards by which different forms of narrative research might be judged. Building on this argument, they offer an outline of the features of some genres that seem to be currently emerging in teacher knowledge writings. The article closes with an examination of the implications the emergence of narratives genres would have for teacher education research.
Homicide Bereavement
Authors: Campesino Maureen
Published: May 2007

This critical narrative ethnography focused on the aftermath of gang-related homicide of two Latino teenage boys, as articulated from the perspectives of their mothers. Grounded in critical race theory, this study situates the phenomenon of Latino youth violence within contexts of local oppressive political and historical conditions. This article explores therapeutic aspects of the researcher's relationship with the bereaved mothers, ethical issues involved in trauma research, and the role of reflexivity. The bereavement narratives represent the subjugated voices of women living with violence in marginalized communities and reveal multiple layers of dehumanization. The therapeutic relationship that developed between the participants and researcher became an effective strategy for rehumanization. The traumatic nature of the women's bereavement produced a deep vulnerability, requiring a complex negotiation of roles and responsibilities of the researcher. The self-reflective experiences of the researcher in this negotiation process with the women are also explored and described.
Emergent Issues When Researching Trauma
Authors: Connolly Kate , Reilly Rosemary C.
Published: May 2007

This article examines the impact of conducting narrative research focusing on trauma and healing. It is told through three voices: the study participants who experienced the trauma, the researcher who shared her personal experiences conducting this research, and an academic colleague who acted as a reflective echo making sense of and normalizing the researcher's experience. Issues explored in the article include: harmonic resonance between the story of the participant and the life experiences of the researcher, emotional reflexivity, complex researcher roles and identities, acts of reciprocity that redress the balance of power in the research relationship, the need for compassion for the participants, and self-care for the researcher when researching trauma. The authors conclude that when researching trauma, the researcher is a member of a scholarly community and a human community, and that maintaining the stance as a member of the human community is an essential element of conducting trauma research.
Rooms With a View
Authors: Kearney Kerri S. , Mathers Judith K.
Published: May 2007

This case, based on actual events, was developed for a course in educational leadership or media management. Students will test their own processes for ethical leadership through this complex crisis in which a superintendent must decide whether to take public responsibility for questionable decisions made by his staff. This case highlights the media's ability to “spin the facts,” to reach a large number of stakeholders quickly, and to become a major player in a political agenda. Decisions made by the superintendent have potential long-range repercussions on his continued leadership of the school district and on the statewide school system.
Scott O'Neill and Lincoln Elementary School
Authors: Salmonowicz Michael J.
Published: May 2007

This case was developed for use in courses on the study of organizations, with a focus on school administration and supervision. It focuses on the challenges—most notably, changing demographics and a resistant faculty—faced by a new principal whose school has a record of success but is in danger of sliding into mediocrity. Varied data are presented about the school and its students, the district, and the community. Students must analyze the data and begin to develop a plan for working in a new leadership role to improve instruction, student performance, and school culture.
The Ten Commandments
Authors: Garver Eugene
Published: May 2007

Cases concerning posting the Ten Commandments in public places raise issues about how a culture and its legal organs can confront powerful symbols which convey different meanings to different people. Courts cannot do very well in facing issues of plural meaning. One sign of the inevitable failure of their attempts is the way everyone involved in adjudication, from the legislature to the Supreme Court, makes assertions that are simply conclusory because they tried to talk about meaning in terms of effects and both sides assume that the meaning of posting the Ten Commandments is simply derivative from the meaning of the Ten Commandments themselves. Cases such as these raise three problems: whether such a state action as posting the Ten Commandments is a unifying or divisive act, whether the sacred nature of a symbol such as the Ten Commandments disqualifies it from political uses, and whether the presence of a copy of the Ten Commandments can have practical effects, such as reducing juvenile delinquency or crime, or is the only practical consequence of either posting or not posting the Ten Commandments giving a victory to the wrong side? Law, Culture and the Humanities 2007; 3: 205—224
The Rule of Law and its Shadow: Ambivalence, Procedure, and the Justice Beyond Legality
Authors: Stauffer Jill
Published: May 2007

The subject capable of liberal legality ought to be revised such that the self-sufficient autonomous individual cohabits with a passive self always already burdened with responsibilities she did not choose. This essay uses the philosophy of Emmanuel Levinas to delineate the relationship of this new subjectivity to liberal theories of justice, and reveals a productive ambivalence with regard to justice residing within rule of law scholarship: why is it that we sometimes have to transgress the rule of law in order to do justice to what it stands for? Emerging debates about the rule of law in calls for international humanitarian intervention help us think through this question in its concrete urgency. The linkage then demonstrates that law's justice exists only as a delicate and never-concluded balancing process between the demands of ethics and those of politics — a process of balancing that is mirrored in the new account of a subject who aspires to justice and therefore makes justice beyond strict legality possible. Ambivalence is inevitable, but its effects are not limited to nihilistic resignation. Rather, ambivalence can point out for us mani-fest responsibilities too often overlooked by liberalism's autonomous individualized subject. Law, Culture and the Humanities 2007; 3: 225—243
Proposals and rationale for revision of the World Health Organization diagnostic criteria for polycythemia vera, essential thrombocythemia, and primary myelofibrosis: recommendations from an ad hoc international expert panel
Authors: Tefferi Ayalew , Thiele Juergen , Orazi Attilio , Kvasnicka Hans Michael , Barbui Tiziano , Hanson Curtis A. , Barosi Giovanni , Verstovsek Srdan , Birgegard Gunnar , Mesa Ruben , Reilly John T. , Gisslinger Heinz , Vannucchi Alessandro M. , Cervantes Francisco , Finazzi Guido , Hoffman Ronald , Gilliland D. Gary , Bloomfield Clara D. , Vardiman James W.
Published: May 2007

The Janus kinase 2 mutation, JAK2617V>F, is myeloid neoplasm-specific; its presence excludes secondary polycythemia, thrombocytosis, or bone marrow fibrosis from other causes. Furthermore, JAK2617V>F or a JAK2 exon 12 mutation is present in virtually all patients with polycythemia vera (PV), whereas JAK2617V>F also occurs in approximately half of patients with essential thrombocythemia (ET) or primary myelofibrosis (PMF). Therefore, JAK2 mutation screening holds the promise of a decisive diagnostic test in PV while being complementary to histology for the diagnosis of ET and PMF; the combination of molecular testing and histologic review should also facilitate diagnosis of ET associated with borderline thrombocytosis. Accordingly, revision of the current World Health Organization (WHO) diagnostic criteria for PV, ET, and PMF is warranted; JAK2 mutation analysis should be listed as a major criterion for PV diagnosis, and the platelet count threshold for ET diagnosis can be lowered from 600 to 450 × 109/L. The current document was prepared by an international expert panel of pathologists and clinical investigators in myeloproliferative disorders; it was subsequently presented to members of the Clinical Advisory Committee for the revision of the WHO Classification of Myeloid Neoplasms, who endorsed the document and recommended its adoption by the WHO.
Evaluation of high-throughput functional categorization of human disease genes
Authors: Chen James L , Liu Yang , Sam Lee T , Li Jianrong , Lussier Yves A
Published: May 2007

Background

Biological data that are well-organized by an ontology, such as Gene Ontology, enables high-throughput availability of the semantic web. It can also be used to facilitate high throughput classification of biomedical information. However, to our knowledge, no evaluation has been published on automating classifications of human diseases genes using Gene Ontology. In this study, we evaluate automated classifications of well-defined human disease genes using their Gene Ontology annotations and compared them to a gold standard. This gold standard was independently conceived by Valle's research group, and contains 923 human disease genes organized in 14 categories of protein function.

Results

Two automated methods were applied to investigate the classification of human disease genes into independently pre-defined categories of protein function. One method used the structure of Gene Ontology by pre-selecting 74 Gene Ontology terms assigned to 11 protein function categories. The second method was based on the similarity of human disease genes clustered according to the information-theoretic distance of their Gene Ontology annotations. Compared to the categorization of human disease genes found in the gold standard, our automated methods can achieve an overall 56% and 47% precision with 62% and 71% recall respectively. However, approximately 15% of the studied human disease genes remain without GO annotations.

Conclusion

Automated methods can recapitulate a significant portion of classification of the human disease genes. The method using information-theoretic distance performs slightly better on the precision with some loss in recall. For some protein function categories, such as 'hormone' and 'transcription factor', the automated methods perform particularly well, achieving precision and recall levels above 75%. In summary, this study demonstrates that for semantic webs, methods to automatically classify or analyze a majority of human disease genes require significant progress in both the Gene Ontology annotations and particularly in the utilization of these annotations.
Genomics of glycopeptidolipid biosynthesis in Mycobacterium abscessus and M. chelonae
Authors: Ripoll Fabienne , Deshayes Caroline , Pasek Sophie , Laval Françoise , Beretti Jean-Luc , Biet Franck , Risler Jean-Loup , Daffé Mamadou , Etienne Gilles , Gaillard Jean-Louis , Reyrat Jean-Marc
Published: May 2007

Background

The outermost layer of the bacterial surface is of crucial importance because it is in constant interaction with the host. Glycopeptidolipids (GPLs) are major surface glycolipids present on various mycobacterial species. In the fast-grower model organism Mycobacterium smegmatis, GPL biosynthesis involves approximately 30 genes all mapping to a single region of 65 kb.

Results

We have recently sequenced the complete genomes of two fast-growers causing human infections, Mycobacterium abscessus (CIP 104536T) and M. chelonae (CIP 104535T). We show here that these two species contain genes corresponding to all those of the M. smegmatis "GPL locus", with extensive conservation of the predicted protein sequences consistent with the production of GPL molecules indistinguishable by biochemical analysis. However, the GPL locus appears to be split into several parts in M. chelonae and M. abscessus. One large cluster (19 genes) comprises all genes involved in the synthesis of the tripeptide-aminoalcohol moiety, the glycosylation of the lipopeptide and methylation/acetylation modifications. We provide evidence that a duplicated acetyltransferase (atf1 and atf2) in M. abscessus and M. chelonae has evolved through specialization, being able to transfer one acetyl at once in a sequential manner. There is a second smaller and distant (M. chelonae, 900 kb; M. abscessus, 3 Mb) cluster of six genes involved in the synthesis of the fatty acyl moiety and its attachment to the tripeptide-aminoalcohol moiety. The other genes are scattered throughout the genome, including two genes encoding putative regulatory proteins.

Conclusion

Although these three species produce identical GPL molecules, the organization of GPL genes differ between them, thus constituting species-specific signatures. An hypothesis is that the compact organization of the GPL locus in M. smegmatis represents the ancestral form and that evolution has scattered various pieces throughout the genome in M. abscessus and M. chelonae.
N-glycan alterations are associated with drug resistance in human hepatocellular carcinoma
Authors: Kudo Takeaki , Nakagawa Hiroaki , Takahashi Masato , Hamaguchi Jun , Kamiyama Naoya , Yokoo Hideki , Nakanishi Kazuaki , Nakagawa Takahito , Kamiyama Toshiya , Deguchi Kisaburo , Nishimura Shin-Ichiro , Todo Satoru
Published: May 2007

Background

Correlations of disease phenotypes with glycosylation changes have been analysed intensively in the tumor biology field. Glycoforms potentially associated with carcinogenesis, tumor progression and cancer metastasis have been identified. In cancer therapy, drug resistance is a severe problem, reducing therapeutic effect of drugs and adding to patient suffering. Although multiple mechanisms likely underlie resistance of cancer cells to anticancer drugs, including overexpression of transporters, the relationship of glycans to drug resistance is not well understood.

Results

We established epirubicin (EPI) – and mitoxantrone (MIT) – resistant cell lines (HLE-EPI and HLE-MIT) from the human hepatocellular carcinoma cell line (HLE). HLE-EPI and HLE-MIT overexpressed transporters MDR1/ABCB1 and BCRP/ABCG2, respectively. Here we compared the glycomics of HLE-EPI and HLE-MIT cells with the parental HLE line. Core fucosylated triantennary oligosaccharides were increased in the two resistant lines. We investigated mRNA levels of glycosyltransferases synthesizing this oligosaccharide, namely, N-acetylglucosaminyltransferase (GnT)-IVa, GnT-IVb and α1,6-fucosyltransferase (α1,6-FucT), and found that α1,6-FucT was particularly overexpressed in HLE-MIT cells. In HLE-EPI cells, GnT-IVa expression was decreased, while GnT-IVb was increased. Both GnT-IVs were downregulated in HLE-MIT cells. HLE-MIT cells also showed decreases in fucosylated tetraantennary oligosaccharide, the product of GnT-V. GnT-V expression was decreased in both lines, but particularly so in HLE-MIT cells. Thus both N-glycan and glycosyltransferase expression was altered as cells acquired tolerance, suggesting novel mechanisms of drug resistance.

Conclusion

N-glycan and glycosyltransferase expression in HLE-EPI and HLE-MIT were analysed and presented that glycans altered according with acquired tolerance. These results suggested novel mechanisms of drug resistance.
p27kip1: a target for tumor therapies?
Authors: Nickeleit Irina , Zender Steffen , Kossatz Uta , Malek Nisar P
Published: May 2007

The cyclin kinase inhibitor p27kip1 acts as a potent tumor supressor protein in a variety of human cancers. Its expression levels correlate closely with the overall prognosis of the affected patient and often predict the outcome to different treatment modalities. In contrast to other tumor suppressor proteins p27 expression levels in tumor cells are frequently regulated by ubiquitin dependent proteolysis. Re-expression of p27 in cancer cells therefore does not require gene therapy but can be achieved by interfering with the protein turnover machinery. In this review we will summarize experimental results which highlight the potential use of p27 as a target for oncological therapies.
cis-Decoder discovers constellations of conserved DNA sequences shared among tissue-specific enhancers
Authors: Brody Thomas , Rasband Wayne , Baler Kevin , Kuzin Alexander , Kundu Mukta , Odenwald Ward F
Published: May 2007

A systematic approach is described for analysis of evolutionarily conserved cis-regulatory DNA using cis-Decoder, a tool for discovery of conserved sequence elements that are shared between similarly regulated enhancers. Analysis of 2,086 conserved sequence blocks (CSBs), identified from 135 characterized enhancers, reveals most CSBs consist of shorter overlapping/adjacent elements that are either enhancer type-specific or common to enhancers with divergent regulatory behaviors. Our findings suggest that enhancers employ overlapping repertoires of highly conserved core elements.
Seismic critical-angle reflectometry: A method to characterize azimuthal anisotropy?
Authors: Landrø Martin , Tsvankin Ilya
Published: May 2007

Existing anisotropic parameter-estimation algorithms that operate with long-offset data are based on the inversion of either nonhyperbolic moveout or wide-angle amplitude-variation-with-offset (AVO) response. We show that valuable information about anisotropic reservoirs can also be obtained from the critical angle of reflected waves. To explain the behavior of the critical angle, we develop weak-anisotropy approximations for vertical transverse isotropy and then use Tsvankin’s notation to extend them to azimuthally anisotropic models of orthorhombic symmetry. The P-wave critical-angle reflection in orthorhombic media is particularly sensitive to the parameters [Formula: see text] and [Formula: see text] responsible for the symmetry-plane horizontal velocity in the high-velocity layer. The azimuthal variation of the critical angle for typical orthorhombic models can reach [Formula: see text], which translates into substantial changes in the critical offset of the reflected P-wave. The main diagnostic features of the critical-angle reflection employed in our method include the rapid amplitude increase at the critical angle and the subsequent separation of the head wave. Analysis of exact synthetic seismograms, generated with the reflectivity method, confirms that the azimuthal variation of the critical offset is detectable on wide-azimuth, long-spread data and can be qualitatively described by our linearized equations. Estimation of the critical offset from the amplitude curve of the reflected wave, however, is not straightforward. Additional complications may be caused by the overburden noise train and by the influence of errors in the overburden velocity model on the computation of the critical angle. Still, critical-angle reflectometry should help to constrain the dominant fracture directions and can be combined with other methods to reduce the uncertainty in the estimated anisotropy parameters.
Target-oriented interferometric tomography for GPR data
Authors: Hanafy Sherif M. , Schuster Gerard T.
Published: May 2007

An interferometric form of Fermat’s principle and traveltime tomography is used to invert ground-penetrating radar (GPR) data for the subsurface velocity distribution. The input data consist of GPR traveltimes of reflections from two buried interfaces, [Formula: see text] (reference) and [Formula: see text] (target), where the data are excited and recorded by GPR antennas at the surface. Fermat’s interferometric principle is then used to redatum the surface transmitters and receivers to interface [Formula: see text] so the associated reflection traveltimes correspond to localized transit times between interfaces [Formula: see text] and [Formula: see text]. The overburden velocity model above interface [Formula: see text] is not required. The result after tomographic inversion is a high-resolution estimate of the velocity between interfaces [Formula: see text] and [Formula: see text] that does not depend on the velocity model above interface [Formula: see text]. A motivation for introducing interferometric traveltime tomography is that typical layer-stripping approaches will see the slowness error increase with depth as the layers are inverted. This suggests that near-surface statics errors are propagated and amplified with depth. In contrast, the interferometric traveltime tomography method largely eliminates statics errors by taking the difference between reflection events that emanate from neighboring layer interfaces. Slowness errors are not amplified with depth. However, the method is sensitive to the estimation accuracy for the geometry of the reference interface. Both synthetic and real field data are used successfully to validate the effectiveness of this interferometric technique.
Hydrogeologic assessment of the Amchitka Island nuclear test site (Alaska) with magnetotellurics
Authors: Unsworth Martyn , Soyer Wolfgang , Tuncer Volkan , Wagner Anna , Barnes David
Published: May 2007

Amchitka Island, in Alaska, was used for underground nuclear testing from 1965 to 1971. Since the test program concluded, there have been concerns about the possible release of radionuclides into the marine environment of the Aleutian Islands. The hydrogeology of islands such as Amchitka is characterized by a layer of freshwater overlying a saltwater layer, with the salinity increasing across a transition zone (TZ). Hydrogeologic modeling can provide an estimate of the timing and amount of radionuclide release from the explosions beneath Amchitka Island. This modeling is inconclusive because of a lack of information regarding subsurface structure. To address this problem, magnetotelluric (MT) data were collected on Amchitka Island in 2004. Broadband MT data were recorded on profiles passing through three explosion sites to give information about subsurface porosity and salinity. A 2D MT inversion produced models of sub-surface electrical resistivity and showed a pattern of increasing, decreasing, and increasing resistivity with depth at each test site. The depth at which resistivity begins to decrease defines the top of the TZ. The deeper increase in resistivity approximates the base of the TZ. The depths of the top and bottom of the TZ were determined as follows: Cannikin 900–2500 m; Long Shot 600–1700 m; Milrow 900–1700 m. Uncertainties were estimated for these depths. Effective porosities were also estimated and ranged from 10%–20% at the surface to 1%–3% at 3-km depth. These porosities are higher than those assumed in several hydrogeologic models, and give longer transit times from the explosion to the marine environment. Subject to the limits of the analysis, it appears that each of the cavities resulting from underground nuclear explosions is located in the TZ from fresh to saltwater. This implies shorter transit times to the marine environment than if the detonations had been located in the saltwater layer.
Amplitude analysis with an optimal model-based linear AVO approximation: Part I — Theory
Authors: Causse E. , Riede M. , van Wijngaarden A. J. , Buland A. , Dutzer J. F. , Fillon R.
Published: May 2007

Linear equations used to approximate reflection coefficient-versus-angle curves are usually valid only for small seismic parameter changes across reflectors, and they are rather inaccurate close to the critical angle. These inaccuracies affect the quality of AVO analysis and cause systematic errors when estimating relative seismic-parameter variations at reflectors, especially for density. We present an optimal model-based approach to build more accurate linear AVO approximations. Their basis functions are calculated by applying singular value decomposition to realistic modeled AVO curves. By extending the validity range of linear approximations to larger angles, this approach helps when using information contained at near-critical offsets. It alsooffers several advantages in other situations. The basis functions of the new approximations are orthogonal. Their coefficients represent new AVO attributes that can be used either to classify AVO responses directly, or to obtain more accurate estimates of usual AVO attributes (intercept, gradient, and possibly a third coefficient). This leads to a better estimation of seismic-parameter contrasts at reflecting interfaces. These coefficients are naturally sorted in decreasing order of importance. Therefore, the proper number of terms in the proposed equations can be chosen easily to offer an optimal compromise between noise and the information carried by each coefficient. Synthetic tests confirm the robustness of the method. This flexible and robust approach will be particularly well adapted for three-parameter AVO analysis.
Frequency-dependent attenuation analysis of ground-penetrating radar data
Authors: Bradford John H.
Published: May 2007

In the early 1990s, it was established empirically that, in many materials, ground-penetrating radar (GPR) attenuation is approximately linear with frequency over the bandwidth of a typical pulse. Further, a frequency-independent [Formula: see text] parameter characterizes the slope of the band-limited attenuation versus frequency curve. Here, I derive the band-limited [Formula: see text] function from a first-order Taylor expansion of the attenuation coefficient. This approach provides a basis for computing [Formula: see text] from any arbitrary dielectric permittivity model. For Cole-Cole relaxation, I find good correlation between the first-order [Formula: see text] approximation and [Formula: see text] computed from linear fits to the attenuation coefficient curve over two-octave bands. The correlation holds over the primary relaxation frequency. For some materials, this relaxation occurs between 10 and [Formula: see text], a typical frequency range for many GPR applications. Frequency-dependent losses caused by scattering and by the commonly overlooked problem of frequency-dependent reflection make it difficult or impossible to measure [Formula: see text] from reflection data without a priori understanding of the materials. Despite these complications, frequency-dependent attenuation analysis of reflection data can provide valuable subsurface information. At two field sites, I find well-defined frequency-dependent attenuation anomalies associated with nonaqueous-phase liquid contaminants.
Conic velocity model
Authors: Ravve Igor , Koren Zvi
Published: May 2007

The effect of gradually increasing velocity with depth in compacted sedimentary layers is described by asymptotically bounded velocity models. These models are defined by three intuitive parameters: the velocity, its vertical gradient at an initial depth level, and a bounded velocity value. Recently, we have introduced the exponential asymptotically bounded (EAB) model, which belongs to this family of velocity models. We introduce another monotonically increasing and asymptotically bounded model, which approaches the asymptotic value in a slower and smoother fashion. Its main attractiveness is the simplicity of ray tracing. The ray trajectories in this model are elliptic, hyperbolic, or parabolic curves, depending on the ray parameter (horizontal slowness). The linear velocity model with a circular trajectory is a particular case of the proposed model. Because the shapes of the ray trajectories correspond to the three types of conic sections, we call the model Conic. We derive the relationships for lateral propagation distance, traveltime, and arc length of the raypath for arbitrary nonvertical rays, and we develop procedures for initial value and boundary-value ray tracing. Both ray-tracing problems have an analytical closed-form solution.
Effects of incomplete parameterization on full-wavefield viscoelastic seismic data for petrophysical reservoir properties
Authors: Tiwari Upendra K. , McMechan George A.
Published: May 2007

In inversion of viscoelastic full-wavefield seismic data, the choice of model parameterization influences the uncertainties and biases in estimating seismic and petrophysical parameters. Using an incomplete model parameterization results in solutions in which the effects of missing parameters are attributed erroneously to the parameters that are included. Incompleteness in this context means assuming the earth is elastic rather than viscoelastic. The inclusion of compressional and shear-wave quality factors [Formula: see text] and [Formula: see text] in inversion gives better estimates of reservoir properties than the less complete (elastic) model parameterization. [Formula: see text] and [Formula: see text] are sensitive primarily to fluid types and saturations. The parameter correlations are sensitive also to the model parameterization. As noise increases in the viscoelastic input data, the resolution of the estimated parameters decreases, but the parameter correlations are relatively unaffected by modest noise levels.
Roles of Epidermal Growth Factor Family in the Regulation of Postnatal Somatic Growth
Authors: Xian Cory J.
Published: May 2007

Ligands of the epidermal growth factor receptor (EGF-R), known to be important for supporting tissue development particularly in the gut and brain, have also been implicated in regulating postnatal somatic growth. Although optimal levels of both milk-borne and endogenous EGF-R ligands are important for supporting postnatal somatic growth through regulating gastrointestinal growth and maturation, supraphysiological levels of EGF-R ligands can cause retarded and disproportionate growth and alter body composition because they can increase growth of epithelial tissues but decrease masses of muscle, fat, and bone. Apart from their indirect roles in influencing growth, possibly via regulating levels of IGF-I and IGF binding proteins, EGF-R ligands can regulate bone growth and modeling directly because they can enhance proliferation but suppress maturation of growth plate chondrocytes (for building a calcified cartilage scaffold for bone deposition), stimulate proliferation but inhibit differentiation of osteoblasts (for depositing bone matrix), and promote formation and function of osteoclasts (for resorption of calcified cartilage or bone). In addition, EGF-like ligands, particularly amphiregulin, can be strongly regulated by PTH, an important regulatory factor in bone modeling and remodeling. Finally, EGF-R ligands can regulate bone homeostasis by regulating a pool of progenitor cells in the bone marrow through promoting proliferation but suppressing differentiation of bone marrow mesenchymal stem cells.
Study of Association between Common Variation in the Insulin-Like Growth Factor 2 Gene and Indices of Obesity and Body Size in Middle-Aged Men and Women
Authors: Heude Barbara , Ong Ken K. , Luben Robert , Wareham Nicholas J. , Sandhu Manjinder S.
Published: May 2007

Context: The IGF2 gene (IGF2) plays a key role in growth and is a candidate for association with obesity. Previous studies have reported that polymorphisms in IGF2 are associated with body weight and body mass index (BMI), but the results have been inconsistent.

Objectives: The aim of this study was primarily to confirm the association with BMI and, secondarily, to study the associations with other indices of body size.

Methods: In a sample of 2797 women and 2203 men aged 39–79 participating in the Norfolk arm of the European Prospective Investigation of Cancer, we genotyped three single nucleotide polymorphisms (SNPs) in the IGF2 gene that were previously associated with BMI [6815 A/T, 1156 T/C (G/A), and 820 G/A (ApaI)].

Results: No significant associations were observed between these SNPs and BMI. However, all three SNPs were significantly associated with height (P = 0.03 to 0.001). In a backward elimination regression analysis, two SNPs, 1156 T/C (G/A) and 820 G/A, remained independently associated with height (P = 0.003 and P = 0.038, respectively). Haplotype analysis of these two SNPs showed that carriers of the GA haplotype were shorter than carriers of each of the other three haplotypes (P < 0.001 for all comparisons).

Conclusions: We did not confirm the previously reported associations between IGF2 polymorphisms and BMI. However, our results suggest that common variation in the IGF2 gene may be associated with adult height. IGF2 could be considered as a candidate gene for future research on mechanisms for the association between height and chronic diseases, such as cancer, diabetes, and coronary heart disease.
Evidence for Allograft Rejection in an Islet Transplant Recipient and Effect on β-Cell Secretory Capacity
Authors: Rickels Michael R. , Kamoun Malek , Kearns Jane , Markmann James F. , Naji Ali
Published: May 2007

Context: The majority of islet transplant recipients experience a gradual decline in islet graft function, but the identification of islet-specific immune responses remains uncommon.

Objectives: The aim was to present a case in which decline in islet graft function was accompanied by the appearance of islet donor-specific alloantibodies and demonstrate the effect on β-cell secretory capacity, an estimate of functional β-cell mass.

Setting: The study was conducted at the Transplant Center and General Clinical Research Center of the University of Pennsylvania.

Results: A 42-yr-old woman with type 1 diabetes who had a living-related kidney transplant received two intraportal islet infusions of a total 17,525 islet equivalents per kg body weight under daclizumab, prednisone, tacrolimus, and rapamycin immunosuppression. She became insulin independent, but 4 months later, the rapamycin was discontinued for associated colitis. She remained normoglycemic for another 6 months before manifesting impaired fasting glucose and requiring 5–10 U insulin daily. The decline in clinical islet graft function coincided with the detection of islet donor-specific human leukocyte antigen class I antibodies. β-Cell function and secretory capacity were assessed by the insulin secretory responses to iv glucose, arginine (AIRarg), and glucose-potentiated arginine (AIRpot) before and at alloantibody detection. The acute insulin response to glucose was almost entirely lost, whereas the AIRarg and AIRpot both decreased by approximately 50%.

Conclusions: Because the AIRpot, a measure of β-cell secretory capacity, provides an estimate of functional β-cell mass, this case documents that islet graft loss can coincide with donor human leukocyte antigen sensitization and that the effect on β-cell mass may be best estimated from the AIRarg or AIRpot.
Postprandial Lipemia Associates with Liver Fat Content
Authors: Matikainen Niina , Mänttäri Sakari , Westerbacka Jukka , Vehkavaara Satu , Lundbom Nina , Yki-Järvinen Hannele , Taskinen Marja-Riitta
Published: May 2007

Context/Objective: Postprandial lipemia and low adiponectin represent novel risk factors for vascular disease. This study aimed to determine whether liver fat content and adiponectin are predictors of postprandial triglyceride (TG)-rich lipoproteins (TRL).

Patients/Interventions: Twenty-nine men were allocated into subgroups with either low (≤5%) or high (>5%) liver fat measured with magnetic resonance proton spectroscopy. Subjects underwent an oral fat tolerance test with measurements of postprandial TG, cholesterol, apolipoprotein B-48 (apoB-48), and apoB-100 in TRL fractions, a euglycemic hyperinsulinemic clamp, and determination of abdominal fat volumes by magnetic resonance imaging.

Results: Subjects with high liver fat displayed increased response of postprandial lipids in plasma, chylomicron, and very-low-density lipoprotein 1 (VLDL1) (Svedberg flotation rate 60–400) fractions. Liver fat correlated positively with postprandial responses (area under the curve) of TG (r = 0.597; P = 0.001), cholesterol (r = 0.546; P = 0.002), apoB-48 (r = 0.556; P = 0.002), and apoB-100 (r = 0.42; P = 0.023) in the VLDL1 fraction. Respective incremental areas under the curve correlated significantly with liver fat. Fasting adiponectin levels were inversely correlated with both postprandial lipids and liver fat content. Liver fat remained the only independent correlate in a multiple linear regression analysis for chylomicron and VLDL1 responses.

Conclusions: Liver fat content is a close correlate of postprandial lipids predicting the responses of TRL in chylomicrons and VLDL1 better than measures of glucose metabolism or body adiposity. Low adiponectin concentration is closely linked to high liver fat content and impaired TRL metabolism. High liver fat content associated with postprandial lipemia represents potential risk factors for cardiovascular disease.
An audit of waiting times at a district general hospital sexual health department – how far are we from the 48 hours target?
Authors: Crowe G
Published: May 2007

The Government has stated that by 2008, anyone who wants an appointment at a genitourinary medicine clinic should be able to get one within 48 hours. We have performed an audit of waiting times for appointments in our clinic and compared this to the most recent Health Protection Agency (HPA) audit. Our audit showed that 75% of people were offered an appointment within 48 hours, but only 62% accepted – the rest wanted to be seen later. In contrast, the HPA audit suggests that only 63% of patients were offered an appointment within 48 hours, and 59% were seen within this time frame. Our audit highlights the fact that many people do not want to be seen within 48 hours and call in to question the validity of this as a target for all patients.
Condoms do not cover everything: an unusual presentation of herpes simplex virus-2 infection
Authors: van den Bos R R , van der Meijden W I
Published: May 2007

We report on a patient who presented with an unusual manifestation of primary herpes simplex virus (HSV) infection. Furthermore, this case again shows that even the correct use of a condom has limited protecting value. We emphasize the usefulness of informing patients carefully about transmission risks of HSV.