bluuebunny/crossref_metadata_2025 huggingface dataset:
Lichens and mosses promote alternate stable plant communities in the New Jersey Pinelands
Authors: Sedia Ekaterina G. , Ehrenfeld Joan G.
Published: March 2005

Severely burned areas in the pitch pine‐dominated forests of the New Jersey Pinelands may remain open and only vegetated with mats of lichens and mosses and sparse, scattered vascular plants for many decades. We hypothesize that climate‐driven alternation between moss and lichen domination of the cryptogam mats may foster and inhibit, respectively, vascular plant development. We propose that these processes are mediated by the inhibitory effects of lichens on seed germination and seedling establishment versus a facilitating effect of mosses. We tested the hypothesis by 1) detailed surveys of the composition of cryptogam mats and their association with vascular plants, 2) experimental studies of the effects of tissue leachates on seed germination, 3) observations of mycorrhizal infection in field‐collected plants, and 4) experimental tests of seedling emergence from mats. Lichen dominance in the mats was correlated with low densities of vascular plants (graminoids and ericoid shrubs), thin organic horizons on the soil, and high levels of light availability; moss dominance was correlated with higher vascular plant densities, thicker organic horizons, and lower light. Tissue extracts of lichens strongly inhibited seed germination, while moss extracts had no effect. Similarly, mycorrhizal infection by both ecto‐ and endomycorrhizae was lower in plants growing within lichen mats than in moss mats or in bare soil. However, thick mats of both types of cryptogam inhibited seedling emergence. We observed that moss‐dominated patches became overgrown with lichens during a series of very dry, hot summers during the study. These observations all support the hypothesis that fluctuating warm and dry versus cool and moist conditions allow alternative stable states (open cryptogam mats vs succession to pine forest) to develop.
Review article: an integrated approach to the irritable bowel syndrome
Authors: Drossman D.A.
Published: March 2005

Our understanding of the pathophysiology of irritable bowel syndrome (IBS) has evolved from a disorder of motility to a more integrated understanding of enhanced motility and visceral hypersensitivity associated with brain–gut dysfunction. Psychosocial factors contribute to the predisposition, precipitation and perpetuation of IBS symptoms, and affect the clinical outcome. Newer brain imaging techniques (e.g. PET, fMRI) may help us understand the relationship between altered emotional states with pain enhancement and other gastrointestinal symptoms. Diagnosis using symptom‐based (e.g. Rome) criteria and a conservative diagnostic approach is recommended. Treatment is based on an effective physician–patient relationship and a combined pharmacological and behavioural approach. Newer medications acting at the 5‐HT receptor may help in reducing pain and bowel dysfunction. For more severe pain, antidepressants may be considered.
Stimulation‐dependent recruitment of cytosolic phospholipase A2‐α to EA.hy.926 endothelial cell membranes leads to calcium‐independent association
Authors: Grewal Seema , Smith Jennifer , Ponnambalam Sreenivasan , Walker John
Published: March 2005

Cytosolic phospholipase A2‐α (cPLA2‐α) is a calcium‐activated enzyme involved in agonist‐induced arachidonic acid release. In endothelial cells, free arachidonic acid is predominantly converted into prostacyclin, a potent vasodilator and inhibitor of platelet activation. As the rate‐limiting step in prostacyclin production is the generation of free arachidonic acid by cPLA2‐α, this enzyme has become an attractive pharmacological target and the focus of many studies. Following stimulation with calcium‐mobilizing agonists, cPLA2‐α translocates to intracellular phospholipid membranes via its C2 domain. In this study, the calcium‐induced association of cPLA2‐α with EA.hy.926 endothelial cell membranes was investigated. Subcellular fractionation and immunofluorescence studies showed that following stimulation with histamine, thrombin or the calcium ionophore A23187, cPLA2‐α relocated to intracellular membranes. Treatment of A23187‐stimulated cells with EGTA or BAPTA‐AM demonstrated that a substantial pool of cPLA2‐α remained associated with membrane fractions in a calcium‐independent manner. Furthermore, immunofluorescence microscopy studies revealed that cells stimulated for periods of greater than 10 min showed a high proportion of calcium‐independent membrane‐associated cPLA2‐α. Calcium‐independent membrane association of cPLA2‐α was not due to hydrophobic or cytoskeletal interactions. Finally, the recombinant C2 domain of cPLA2‐α exhibited calcium‐independent membrane binding to membranes isolated from A23187‐stimulated cells but not those isolated from nonstimulated cells. These findings suggest that novel mechanisms involving accessory proteins at the target membrane play a role in the regulation of cPLA2‐α. Such regulatory associations could enable the cell to discriminate between the varying levels of cytosolic calcium induced by different stimuli.
Inactivation of copper‐containing amine oxidases by turnover products
Authors: Pietrangeli Paola , Nocera Stefania , Federico Rodolfo , Mondovì Bruno , Morpurgo Laura
Published: March 2005

For bovine serum amine oxidase, two different mechanisms of substrate‐induced inactivation have been proposed. One consists of a slow oxidation by H2O2 of a conserved residue in the reduced enzyme after the fast turnover phase [Pietrangeli, P., Nocera, S., Fattibene, P., Wang, X.T., Mondovì, B. & Morpurgo, L. (2000) Biochem. Biophys. Res. Commun.267, 174–178] and the other of the oxidation by H2O2 of the dihydrobenzoxazole in equilibrium with the product Schiff base, during the catalytic cycle [Lee, Y., Shepard, E., Smith, J., Dooley, D.M. & Sayre, L.M. (2001) Biochemistry40, 822–829]. To discriminate between the two mechanisms, the inactivation was studied using Lathyrus cicera (red vetchling) amine oxidase. This, in contrast to bovine serum amine oxidase, formed the Cu+‐semiquinolamine radical with a characteristic UV‐vis spectrum when oxygen was exhausted by an excess of any tested amine in a closed cuvette. The inactivation, lasting about 90 min, was simultaneous with the radical decay and with the formation of a broad band (shoulder) at 350 nm. No inactivation occurred when a thousand‐fold excess of amine was rapidly oxidized in an L. cicera amine oxidase solution stirred in open air. Thus, the inactivation is a slow reaction of the reduced enzyme with H2O2, following the turnover phase. Catalase protected L. cicera amine oxidase from inactivation. This effect was substrate‐dependent, varying from full protection (benzylamine) to no protection (putrescine). In the absence of H2O2, a specific inactivating reaction, without formation of the 350 nm band, was induced by some aldehydes, notably putrescine. Some mechanisms of inactivation are proposed.
Radiative lifetime of excitonic photoluminescence in amorphous semiconductors
Authors: Singh Jai , Oh I.-K.
Published: March 2005

A comprehensive theory for calculating the radiative lifetime of excitons in amorphous semiconductors is presented. Four possibilities for the radiative recombination of an exciton are considered: (i) both excited electron and hole are in their extended states, (ii) electron is in the extended and hole in tail states, (iii) electron is in the tail and hole in extended states and (iv) both in their tail states. Rates of radiative recombination corresponding to each of the four possibilities are derived: (a) within two-level approximation, and at (b) nonequilibrium and (c) equilibrium conditions. It is found that rates derived under the nonequilibrium condition have no finite peak values with respect to the photoluminescence energy. However, considering that the maximum value of a rate derived at equilibrium gives the inverse of the radiative lifetime, the latter is calculated for all the four possibilities in a-Si:H. The radiative lifetime of excitons is found to be in the ns time range for possibilities (i)–(iii) at temperatures 15–20K and in the μs range at 3.7K. When the recombination occurs from the tail states, the radiative lifetime gets prolonged due to the localization of charge carriers. Results agree very well with experiments and are compared with other theories as well.
Surface recombination velocity of silicon wafers by photoluminescence
Authors: Baek D. , Rouvimov S. , Kim B. , Jo T.-C. , Schroder D. K.
Published: March 2005

Photoluminescence (PL) and optical reflection measurements, obtained in the two-wavelength SiPHER PL instrument, are used to determine the surface recombination velocity of silicon wafers. Local measurements and contour maps are possible allowing surface recombination maps to be displayed. This instrument also allows doping and trap density measurements. Surface recombination velocities from 10 to 106cm∕s can be measured on low or high resistivity polished and epitaxial wafers.
Controlled growth of Zn-polar ZnO epitaxial film by nitridation of sapphire substrate
Authors: Mei Z. X. , Du X. L. , Wang Y. , Ying M. J. , Zeng Z. Q. , Zheng H. , Jia J. F. , Xue Q. K. , Zhang Z.
Published: March 2005

Surface nitridation is used to eliminate O-polar inversion domains and control the growth of single-domain Zn-polar ZnO film on sapphire (0001) substrate by rf-plasma-assisted molecular-beam epitaxy. It is found that the nitridation temperature is crucial for achieving quality AlN buffer layers and ZnO films with cation polarity, as demonstrated by ex situ transmission electron microscopy. Under optimal growth conditions, a 4×4 surface reconstruction was observed, which is confirmed to be a characteristic surface structure of the Zn-polar films, and can be used as a fingerprint to optimize the ZnO growth.
Using local band structure to image strain in semiconductor microstructures
Authors: Stievater T. H. , Rabinovich W. S. , Park D. , Goetz Peter G. , Boos J. B. , Katzer D. S. , Biermann M. L.
Published: March 2005

We demonstrate that polarization-specific nonlinear optical spectroscopy combined with an accurate band structure model can be used to provide a noncontact image of the strain fields within a micromachined quantum well. Optical measurements of the heavy hole excitonic transition strength and anisotropy are converted into measurements of the in-plane strain components with an 8-band k∙p model that includes deformation potentials. The resulting two-dimensional strain image is in excellent agreement with a finite-element structural model of the microstructure, demonstrating the validity of this technique.
The Aftiphilin/p200/γ-Synergin Complex
Authors: Hirst Jennifer , Borner Georg H.H. , Harbour Michael , Robinson Margaret S.
Published: March 2005

Aftiphilin is a protein that was recently identified in database searches for proteins with motifs that interact with AP-1 and clathrin, but its function is unknown. Here we demonstrate that aftiphilin has a second, atypical clathrin binding site, YQW, that colocalizes with AP-1 by immunofluorescence, and that is enriched in clathrin-coated vesicles (CCVs), confirming that it is a bona fide component of the CCV machinery. By gel filtration, aftiphilin coelutes with two other AP-1 binding partners, p200a and γ-synergin. Antibodies against any one of these three proteins immunoprecipitate the other two, and knocking down any of the three proteins by siRNA causes a reduction in the levels of the other two, indicating that they form a stable complex. Like AP-1–depleted cells, aftiphilin-depleted cells missort a CD8-furin chimera and the lysosomal enzyme cathepsin D. However, whereas AP-1–depleted cells recycle endocytosed transferrin more slowly than untreated cells, aftiphilin-depleted cells accumulate endocytosed transferrin in a peripheral compartment and recycle it more rapidly. These observations show that in general, the aftiphilin/p200/γ-synergin complex facilitates AP-1 function, but the complex may have additional functions as well, because of the opposing effects of the two knockdowns on transferrin recycling.
The Elusive Meaning of the Debate over Ratification
Authors: Edling Max. M
Published: March 2005

The first two sections of this chapter discuss the two main approaches to the analysis of the ratification debate over the US Constitution. Until the late 1960s, the predominant interpretation described the debate over ratification as a conflict between “aristocratic” and “democratic” ideals and interests, but at about that time, scholars began to shift to a second approach that used the terms “liberalism” and “classical republicanism” to account for ideological differences during the revolutionary era; this shift was also accompanied by a change in the interpreters’ concerns away from social struggle toward the study of the development of political ideas. The argument presented here is that the terminology so far favored by historians and political scientists has obscured important aspects of the ideological differences between the Federalists and their opponents because it has drawn attention away from the actual issues debated during the ratification struggle. This claim can be supported in different ways, but the approach used here is to look closely at what prominent interpreters say about the limits of their own interpretation, even though this it risks being unfair to the perspectives reviewed. The last two sections of the chapter present an approach that promises better to capture the essence of the ideological disagreement between the Federalists and the Antifederalists as presented in the debate over ratification, and suggest that the debate is best seen as neither about democracy nor about liberalism, but about state formation.
The Ideological Response to State Expansion
Authors: Edling Max. M
Published: March 2005

It would be a fundamental mistake to assume a priori a complete correspondence between the historical sociology of state formation and the conceptual history of the “state,” or, in more general terms, between institutional and intellectual development, and between political reality and political rhetoric. Equally, it would be a mistake to assume that there is no relation whatsoever, and it would have been remarkable if the great expansion of the fiscal and military capacity of central government in Britain in the early modern period had gone unnoticed by contemporaries, so as to leave no mark on historical, political, and social reflection. Shows that the European process of state formation had indeed influenced political commentary in giving rise to arguments analyzing and criticizing the growth of the state, and that these arguments found their way across the Atlantic from Britain to the American colonies in the form of “Country” thought, which gave rise to a complete vocabulary with which to respond to the growth of the British fiscal‐military state in the Anglo‐American world of political discourse. In fact, Antifederalism can be described as an expression of Country thought, although it cannot at the same time be claimed that Federalism was a repetition of the contrasting central Court defense of state expansion.
Government by Consent
Authors: Edling Max. M
Published: March 2005

Chapter 8 and the corresponding Ch. 13 in Part Three of the book show how the Federalists responded to the Antifederalist objections to a stronger national government in the “fiscal‐military” sphere, thereby creating an understanding of the kind of state that was proper to American conditions. In their defense of the military clauses of the US Constitution, the Federalists argued for the need to maintain a peace establishment of regulars, also arguing that the national government had to possess an unrestricted power over mobilization; in Federalist minds, both military professionalism and the unlimited power over mobilization were necessary to preserve the independence, liberties, and interests of the American nation. The Antifederalists, by contrast, raised objections to the right of Congress to create and maintain a standing army in time of peace, and were also concerned about the unrestricted nature of Congress's military powers. Their objections can be subsumed under three headings: first, they believed that the new system of government would change the administration of the laws from an administration based on the consent of the governed to an administration based on coercion or the threat of force; second, they believed that the national government would create a large army while neglecting the state militia, so that as a consequence, the national government would become independent of the people and be able to establish tyrannical rule; and third, the critics of the Constitution believed that Congress had been granted too much power to interfere in the private lives of the citizens through its command over the militia. In the debate over ratification, the Federalists answered these objections, and in doing so, they argued that it was possible to create a strong state without abandoning traditional Anglo‐American ideals about free government; their answers are the subject of this chapter.
Diverse roles for HspR in Campylobacter jejuni revealed by the proteome, transcriptome and phenotypic characterization of an hspR mutant
Authors: Andersen Marianne Thorup , Brøndsted Lone , Pearson Bruce M. , Mulholland Francis , Parker Mary , Pin Carmen , Wells Jerry M. , Ingmer Hanne
Published: March 2005

Campylobacter jejuniis a leading cause of bacterial gastroenteritis in the developed world. The role of a homologue of the negative transcriptional regulatory protein HspR, which in other organisms participates in the control of the heat-shock response, was investigated. Following inactivation ofhspRinC. jejuni, members of the HspR regulon were identified by DNA microarray transcript profiling. In agreement with the predicted role of HspR as a negative regulator of genes involved in the heat-shock response, it was observed that the transcript amounts of 13 genes were increased in thehspRmutant, including the chaperone genesdnaK,grpEandclpB, and a gene encoding the heat-shock regulator HrcA. Proteomic analysis also revealed increased synthesis of the heat-shock proteins DnaK, GrpE, GroEL and GroES in the absence of HspR. The altered expression of chaperones was accompanied by heat sensitivity, as thehspRmutant was unable to form colonies at 44 °C. Surprisingly, transcriptome analysis also revealed a group of 17 genes with lower transcript levels in thehspRmutant. Of these, eight were predicted to be involved in the formation of the flagella apparatus, and the decreased expression is likely to be responsible for the reduced motility and ability to autoagglutinate that was observed forhspRmutant cells. Electron micrographs showed that mutant cells were spiral-shaped and carried intact flagella, but were elongated compared to wild-type cells. The inactivation ofhspRalso reduced the ability ofCampylobacterto adhere to and invade human epithelial INT-407 cellsin vitro, possibly as a consequence of the reduced motility or lower expression of the flagellar export apparatus inhspRmutant cells. It was concluded that, inC. jejuni, HspR influences the expression of several genes that are likely to have an impact on the ability of the bacterium to successfully survive in food products and subsequently infect the consumer.
Genetic structure and chromosomal integration site of the cryptic prophage CP-1639 encoding Shiga toxin 1
Authors: Creuzburg Kristina , Köhler Bernd , Hempel Helena , Schreier Peter , Jacobs Enno , Schmidt Herbert
Published: March 2005

The sequence of 50 625 bp of chromosomal DNA derived from Shiga-toxin (Stx)-producing Escherichia coli (STEC) O111 : H− strain 1639/77 was determined. This DNA fragment contains the cryptic Stx1-encoding prophage CP-1639 and its flanking chromosomal regions. The genome of CP-1639 basically resembles that of lambdoid phages in structure, but contains three IS629 elements, one of which disrupts the gene of a tail fibre component. The prophage genome lacks parts of the recombination region including integrase and excisionase genes. Moreover, a capsid protein gene is absent. CP-1639 is closely associated with an integrase gene of an ancient integrative element. This element consists of three ORFs of unknown origin and a truncated integrase gene homologous to intA of CP4-57. By PCR analysis and sequencing, it was shown that this integrative element is present in a number of non-O157 STEC serotypes and in non-STEC strains, where it is located at the 3′-end of the chromosomal ssrA gene. Whereas in most E. coli O111 : H− strains, prophages are inserted in this site, E. coli O26 strains contain the integrative element not connected to a prophage. In E. coli O103 strains, the genetic structure of this region is variable. Comparison of DNA sequences of this particular site in E. coli O157 : H7 strain EDL933, E. coli O111 : H− strain 1639/77 and E. coli K-12 strain MG1655 showed that the ssrA gene is associated in all cases with the presence of foreign DNA. The results of this study have shown that the cryptic prophage CP-1639 is associated with an integrative element at a particular site in the E. coli chromosome that possesses high genetic variability.
The psychosocial functioning of children and spouses of adults with ADHD
Authors: Minde Klaus , Eakin Laurel , Hechtman Lily , Ochs Eric , Bouffard Rachelle , Greenfield Brian , Looper Karl
Published: March 2005

Background:  It is unclear what the impact of parental ADHD is on the day‐to‐day life of the rest of the family and how it contributes to the intergenerational transmission of this disorder.

Method:  The psychosocial functioning of 23 spouses and 63 children of 33 families with an ADHD parent and 20 spouses and 40 children of 26 comparison families was examined. Both adults and their spouses were assessed for lifetime and current Axis I and Axis II diagnoses, present general psychiatric symptoms and their marital relationships. Children were screened for ADHD and other problems, using the C‐DISC, CBLC, TRF and the Social Adjustment Inventory.

Results:  Children with an ADHD parent had higher rates of psychopathology than those from comparison families. Children with ADHD had more co‐morbidities than non‐ADHD children. Family and marital functions were impaired in ADHD families regardless of the gender of the affected parent. Children without ADHD from families with one psychiatrically healthy parent did well while the behaviour of children with ADHD was always poor and not associated with parental mental health.

Conclusion:  The results underscore the strong genetic contribution to ADHD and the need to carefully assess the non‐ADHD parent as they seem to influence the well‐being of non‐ADHD children in families with an ADHD parent.
Competition, predation and nest niche shifts among tropical cavity nesters: ecological evidence
Authors: Brightsmith Donald J.
Published: March 2005

I studied cavity‐nesting birds in an undisturbed site in lowland Peru to determine the relative roles of competition and predation in favoring termitarium nesting over tree cavity nesting. Occupancy rates of both nest boxes and natural tree cavities near 2% suggest that competition for tree cavities is not favoring the use of termitaria. Artificial nests and bird nests in termitaria suffer significantly lower predation rates than similar nests in old tree cavities showing that predation is favoring the use of termitaria over old tree cavities. Bird nests in newly excavated tree cavities also show lower predation rates than older cavities suggesting that cavity age is more important than substrate (tree or termitaria)per se. This study suggests that nest predation has a greater influence than nest competition on life history evolution for many cavity‐nesting birds.
Extended pathoanatomical studies point to a consistent affection of the thalamus in spinocerebellar ataxia type 2
Authors: Rüb U. , Turco D. Del , Bürk K. , Diaz G. Orozco , Auburger G. , Mittelbronn M. , Gierga K. , Ghebremedhin E. , Schultz C. , Schöls L. , Bohl J. , Braak H. , Deller T.
Published: March 2005

The involvement of the thalamus during the course of the currently known polyglutamine diseases is still a matter of debate. While it is well‐known that this diencephalic nuclear complex undergoes neurodegeneration in some polyglutamine diseases such as Huntington's disease (HD), it has remained unclear whether and to what extent the thalamus is also involved in spinocerebellar ataxia type 2 (SCA2) patients. Encouraged by our recentpost‐mortemfindings in one German SCA2 patient and the results of a recent nuclear magnetic resonance (NMR) study, we extended our pathoanatomical analysis to serial thick sections stained for lipofuscin granules and Nissl substance through the thalami of four additional German and Cuban SCA2 patients. According to this analysis the thalamus is consistently affected by the destructive process of SCA2. In particular, during our study we observed a consistent involvement of the lateral geniculate body, the lateral posterior, ventral anterior, ventral lateral, ventral posterior lateral, and ventral posterior medial thalamic nuclei as well as the extraterritorial reticular nucleus. In four of the SCA2 cases studied additional damage was seen in the inferior and lateral nuclei of the pulvinar, whereas in the minority of the patients a subset of the limbic nuclei of the thalamus (i.e. anterodorsal, anteroprincipal, laterodorsal, fasciculosus, mediodorsal, central lateral, central medial, cucullar, and paracentral nuclei, medial nucleus of the pulvinar) underwent neurodegeneration. These interindividual differences in the distribution pattern of thalamic neurodegeneration indicate that the thalamic nuclei differ in their proclivities to degenerate in SCA2 and may suggest that they become involved at different phases in the evolution of the underlying degenerative process.
The accuracy of meningioma grading: a 10‐year retrospective audit
Authors: Willis J. , Smith C. , Ironside J. W. , Erridge S. , Whittle I. R. , Everington D.
Published: March 2005

Although descriptive classifications of meningioma subtypes are well established, there has been inconsistency in the categorization of meningiomas into benign, atypical and anaplastic groups. The aim of this study was to reassess the incidence of atypical (grade II) meningiomas over a 10‐year period by applying the World Health Organization (WHO) 2000 classification system. A secondary aim was to determine if grade II and III tumours were becoming more common. Sections of 314 meningiomas resected between 1994 and 2003 were retrieved from the archives of the Western General Hospital's neuropathology unit in Edinburgh. They were reassessed and graded by using the WHO 2000 classification system. The reviewers were blind to the original classification and grading. There was a gradual increase in the numbers of meningiomas being resected annually over the 10‐year period. On reclassification, 78% of the meningiomas were classified as grade I, 20.4% as grade II and 1.6% as grade III. With regard to grade II meningiomas classified by using the WHO 2000 classification system, 38.1% had originally been classified as grade I prior to 2000, whereas 13.6% had originally been classified as grade I after 2000. In most cases, reclassification was due to formal counts of mitotic figures. Atypical meningiomas are diagnosed more frequently under the current WHO classification system than they were under the previous classification systems. Although the current WHO (2000) classification is more prescriptive than its predecessors, interobserver variability is likely to remain because of the subjective nature of some of the criteria.
Discovery of a perinecrotic 60 kDa MDM2 isoform within glioma spheroids and glioblastoma biopsy material
Authors: Bell H. S. , Whittle I. R. , Bader S. A. , Wharton S. B.
Published: March 2005

Necrosis in glioblastoma is often associated with high levels of Fas (APO‐1), HIF‐1α and PARP expression. The presence of such molecules suggests a regulative element to cell death within this tissue, which may involve p53. We aimed to establish whether p53 and its downstream targets Bax, MDM2 and p21 play a role in perinecrotic cell death in glioblastoma. Following sequencing of the p53 gene in U87 and U373 glioma cell lines, p53 was found to be reactive in the p53 wild‐type line U87 in response to hypoxia but not in the p53 mutant line, U373. Although no  increase  in  perinecrotic  p53  expression  was  detected in spheroid cultures derived from these lines, a 60 kDa MDM2 isoform lacking a C‐terminal domain showed perinecrotic localization, irrespective of p53 status. Similar findings were observed surrounding regions of necrosis in 80% of glioblastoma biopsies examined. Increasing levels of wild‐type p53 did not affect cell death in U87 spheroid cultures but killed all U373 cells 3 days post transfection. Dominant negative p53 did not affect cell death in U373 and U87 spheroid cultures. Although p53 accumulation appeared not to be important for the onset of cell death both in spheroid and biopsy cases, high levels of perinecrotic 60 kDa MDM2 may have implications for glioma cell death susceptibility in both p53 mutant and wild‐type tumour cell populations.
Conservation ecology ofPrimula sieboldii: Synthesis of information toward the prediction of the genetic/demographic fate of a population
Authors: WASHITANI IZUMI , ISHIHAMA FUMIKO , MATSUMURA CHIZURU , NAGAI MIHOKO , NISHIHIRO JUN , AJIMA NISHIHIRO MIHO
Published: March 2005

In an age of deepening biodiversity crisis, plant species biological studies integrating ecological and genetic approaches, especially exhaustive studies with a model plant species, are urgently needed for both assessing the present status and implementing effective conservation measures, as a comprehensive understanding of demographic/genetic interactions involved in the vicious cycle of plant population extinction is a prerequisite for any precise prediction regarding plant conservation. In this article, we summarize the major contributions to conservation ecological studies on a heterostylous clonal herbPrimula sieboldii,focusing on gene flow and reproductive success, which are dependent on the life‐history traits of the species and biological interactions with its effective pollinators, long‐tongued bumblebees.
Clinicopathologic analysis of the prognostic factors in women with coexistence of endometrioid adenocarcinoma in the endometrium and ovary
Authors: Nishimura Noriko , Hachisuga Toru , Yokoyama Masatoshi , Iwasaka Tsuyoshi , Kawarabayashi Tatsuhiko
Published: March 2005

Aim: To compare the survival and prognostic factors of patients with dual primary ovarian and endometrial cancers (primary group), and endometrial cancers metastatic to the ovaries (metastatic group).

Methods: Thirty‐six patients with gross tumors confined to the pelvis and of endometrioid adenocarcinoma subtype in both the endometrium and ovary were selected from our file of 546 Japanese women with endometrial carcinoma. The patients were divided into two groups. Eleven were classified into the primary group. Twenty‐five were classified into the metastatic group. Both univariate and multivariate regression analyses were carried out.

Results: The mean age of the primary group was significantly younger than that of the metastatic group (45.2 years vs 51.2 years; P < 0.01). The cumulative 10‐year survival of the primary group was significantly better than that of the metastatic group (90.9%vs 46.6%; P < 0.05). Univariate analyses showed that older age (P < 0.05) and the presence of lymphovascular space invasion (LVSI; P < 0.004) of the tumor of the uterus were significantly associated with a poor prognosis in the metastatic group. Multivariate analysis including the above variables showed no independent prognostic factor (older age, P < 0.60 and LVSI, P < 0.06).

Conclusion: When encountering women with coexisting endometrioid carcinoma in the endometrium and ovary with gross tumor limited to the pelvis, more attention should be paid to LVSI of the tumor of the uterus as a poor prognostic indicator.
Boundary at work: alternative medicine in biomedical settings
Authors: Mizrachi Nissim , Shuval Judith T. , Gross Sky
Published: March 2005

Abstract The study explores the process of boundary demarcation within hospital settings by examining a new phenomenon in modern medicine: collaboration between alternative and biomedical practitioners (primarily physicians) working together in biomedical settings. The study uses qualitative methods to examine the nature of this collaboration by calling attention to the ways in which the biomedical profession manages to secure its boundaries and to protect its hard‐core professional knowledge. It identifies the processes of exclusion and marginalization as the main mechanisms by which symbolic boundaries are marked daily in the professional field. These processes enable the biomedical profession to contain its competitors and at the same time to avoid overt confrontations and mitigate potential tensions between the two medical systems.
Racial and Ethnic Disparities and Perceptions of Health Care: Does Health Plan Type Matter?
Authors: Hunt Kelly A. , Gaba Ayorkor , Lavizzo‐Mourey Risa
Published: March 2005

Objective. To examine whether racial and ethnic differences in the distribution of individuals across types of health plans explain differences in satisfaction and trust with their physicians.

Data Sources. Data were derived from the 1998–1999 Community Tracking Household and Followback Studies and consisted of a nationwide sample of adults (18 years and older).

Data Collection. The data were collected by telephone survey. Surveys were administered in English and Spanish. The response rate for the Household Survey was 63 percent, and the match rate for the Followback Survey was 59 percent.

Study Design. Multivariate analyses used regression methods to detect independent effects of respondent race and ethnicity on satisfaction and trust with physician, while controlling for enrollment in different types of health plans.

Principal Findings. Racial and ethnic minorities are more likely than whites to have lower levels of trust and satisfaction with their physician. The most prominent differences occurred within the Latino and Native American/Asian American/Pacific Islander/Other (“Other”) populations. Plan type does not mitigate the relationship between race/ethnicity and trust and satisfaction for the overall adult population.

Conclusions. Disparate levels of trust and satisfaction exist within ethnic and minority populations, even when controlling for the distribution of individuals across types of health plans. The results demonstrate a need to better understand the health care‐related factors that drive disparate trust and satisfaction.
PSYCHOSOCIAL FACTORS IN PATIENTS WITH CHRONIC KIDNEY DISEASE: The Psychiatric Landscape of Withdrawal
Authors: Cohen Lewis M. , Germain Michael J.
Published: March 2005

Withdrawal from dialysis is an appropriate decision for situations in which the burdens of treatment outweigh the benefits. Alternately, it can be viewed as a public health problem and suicide equivalent that contributes to the high mortality of end‐stage renal disease (ESRD). More than one in five deaths of patients with ESRD are preceded by dialysis cessation, and approximately 15,000 Americans died last year following a determination to stop this life‐support treatment. This article discusses what is known about the psychosocial aspects of the patients who terminate dialysis, the role of depression and other psychiatric disorders, the family perspective, and the relationship of these decisions to suicide.
Isolation, purification and physicochemical characterization of water‐soluble Bacillus thuringiensis melanin
Authors: Aghajanyan Armen E. , Hambardzumyan Artur A. , Hovsepyan Anichka S. , Asaturian Rafael A. , Vardanyan Andranik A. , Saghiyan Ashot A.
Published: March 2005

Melanins are widely used in medicine, pharmacology, cosmetics and other fields. Although several technologies for the purification of water‐insoluble dioxyphenylalanine (DOPA) melanins have been described, a source of water‐soluble melanin is highly desirable. Here we describe an effective procedure for the isolation and purification of water‐soluble melanin using the culture medium of Bacillus thuringiensis subsp. galleriae strain K1. Water‐soluble melanin from this organism has an isoelectric point (pI = 3.0–3.2) and was purified optimally by adsorbtion using the IA‐1r resin and elution as a concentrated solution. The purified melanin obtained exhibited a similar infra‐red absorbtion spectrum to synthetic melanin and contained quinolic and phenolic structures and an amino acid content of around 20% after acid hydrolysis. The molecular weight of the purified melanin determined by SDS‐PAGE was 4 kDa and the electromagnetic spin resonance spectrum of the purified microbial melanin was a slightly asymmetric singlet without hyperfine structure with about 7 Gauss width of the line between points of the maximum incline and g = 2.006. The concentration of paramagnetic centers in melanin is 0.21 × 1018 spin/g. The results obtained provide a rapid, simple and inexpensive method for the large scale purification of water soluble melanin that may have widespread applications.
A Tyrosinase missense mutation causes albinism in the Wistar rat
Authors: Blaszczyk Wanda M. , Arning Larissa , Hoffmann Klaus‐Peter , Epplen Joerg T.
Published: March 2005

Tyrosinase serves as a key enzyme in the synthesis of melanin. In humans mutations in the TYR gene are associated with type 1 oculocutaneous albinism (OCA1) that leads to reduced or absent pigmentation of skin, hair and eye. Various mutations causing OCA in man, mouse, rabbit and cattle have been identified throughout the Tyrosinase gene including nonsense, missense, frameshift and splice site alterations. Here we report a missense substitution at codon R299H in exon 2 of the Tyr gene in the albino Wistar rat. As this very exchange has already been described in OCA patients, our findings reinforce the significance of this region for normal catalytic activity of tyrosinase protein.
Anatomy of the floral, bract, and foliar nectaries of Triumfetta semitriloba (Tiliaceae)
Authors: Espolador Leitão Carlos André , Strozi Alves Meira Renata Maria , Azevedo Aristéa Alves , de Araújo João Marcos , Silva Kellen Lagares Ferreira , Collevatti Rosane Garcia
Published: March 2005

Triumfetta semitriloba Jacq. (Tiliaceae) is a tropical weedy species with floral nectaries and glands located at the margins of the leaves. The objectives of this work were to describe the anatomy of these secretory structures and to analyze their exudates. Sucrose, glucose, and fructose were identified in the product released by these secretory structures, characterizing them as nectaries. The nectaries of T. semitriloba are of a specialized type; a secretory epidermis comprised of pluricellular and multiserial nectariferous trichomes covers a nectariferous parenchyma, vascularized by phloem and xylem. A mass of phenolic compounds occurs in the head cells of the nectariferous trichomes of the foliar and bract nectaries; however, it is absent in trichomes of the floral nectary. The leaf and bract nectaries differed from those from flowers in their length and diameter. Structural features of the nectaries of T. semitriloba are typical of other taxa of the Malvales.Key words: foliar anatomy, histochemistry, Malvales, nectaries, Tiliaceae, Triumfetta semitriloba.
Effect of α- and β-cyclodextrins on the photochemical activity of thylakoid membranes and photosystem II particles from barley (Hordeum vulgare): oxygen evolution and whole chain electron transport
Authors: Dudekula S , Sridharan G , Fragata M
Published: March 2005

The effect of α- and β-cyclodextrin (CD) concentration (016 mM) on oxygen evolution in photosystem II (PSII) and whole chain electron transport (H2O to photosystem I (PSI)) was studied in isolated thylakoid membranes and PSII particles from barley (Hordeum vulgare L.). The CDs are cyclic oligosaccharides containing, for example, six (α-CD) or seven (β-CD) α-D-glucose residues linked by α-1,4 glycosidic bonds. These compounds alter the lipid composition of the thylakoids and most likely also the structure of their membrane proteins. We show for the first time that in the thylakoid membranes, but not in the isolated PSII particles, the relationship between oxygen evolution in PSII and the CD concentration is represented by a S-shaped (sigmoidal) curve displaying a sharp inflexion point or transition. We found, in addition, that the CDs inhibit the whole chain electron transport from H2O to methyl viologen, that is, PSI, measured as oxygen uptake, according to a nonlinear dependence that is also sigmoidal. Moreover, another interesting observation is that in the thylakoid membranes the electron transport from H2O to PSI is quite well inhibited at low CD concentrations (<46 mM), whereas the oxygen evolution in PSII is only substantially enhanced at CD concentrations greater than 810 mM. To explain this, we suggest that the mechanisms underlying the inhibition of electron transfer from H2O to PSI become operative before those giving origin to the enhancement of oxygen evolution in PSII.Key words: cyclodextrins, electron transfer, nonlinearity, oxygen evolution, photosystem, thylakoid membrane.
Geochemistry of the active layer and near-surface permafrost, Mackenzie delta region, Northwest Territories, Canada
Authors: Kokelj S V , Burn C R
Published: March 2005

The soluble ion content of the active layer and near-surface permafrost was determined at 41 sites in the Mackenzie delta region, Northwest Territories, Canada. In delta soils, Ca2+ and Mg2+ are the dominant soluble cations, but the quantity and relative abundance of Na+ increase with proximity to the Beaufort Sea coast. Soils beneath frequently flooded surfaces are ion rich in comparison with ground above the level of decadal flooding. Within a terrain type, near-surface permafrost soil solute concentrations are similar between paired cores spaced <1 m apart, but at greater distances (cores spaced 313 m apart), solute concentrations are significantly different. Comparatively low soil solute concentrations in old upland surfaces near Inuvik may be a result of progressive removal of soluble materials from the active layer and permafrost during periods of deeper thaw. In sandy silt alluvium, solutes excluded during downward freezing may accumulate at the base of the active layer and be sequestered by a rising permafrost table. At sites with finer grained clayey silts, the correspondence between zones of ice and cation enrichment indicates coupled movement of water and solutes during freeze-back of the active layer and development of aggradational ice. Solute enrichment of near-surface permafrost is greatest at fine-grained ice-rich alluvial sites, where mean concentrations in permafrost are up to 7.5 times greater than those in the active layer.
Performance analysis of primary wood producers in British Columbia using data envelopment analysis
Authors: Salehirad Neda , Sowlati Taraneh
Published: March 2005

Despite its importance, performance assessment of the Canadian primary wood products sector has received little attention in the academic literature and business practices. In this research a nonparametric technique, called data envelopment analysis (DEA), was used to evaluate the performance of sawmills in British Columbia in 2002. Individual mills were inspected using different DEA models to capture their technical, scale, and aggregate efficiencies. Log consumption and labor utilization were considered as the inputs and lumber and chip production as the outputs of these models. Although British Columbia sawmills enjoyed high scale efficiency, only 7% of them were aggregately efficient. The results showed possible efficiency improvements by increasing the production and decreasing the labor usage. Post-hoc analyses with two nonparametric statistical tests, median quartile and KruskalWallis, revealed that the average efficiency of sawmills in different British Columbia forest regions varied significantly; however, the number of operating days had no effect on technical efficiency of sawmills at a 5% significance level.
Visual-Vestibular Interactions During Vestibular Compensation: Role of the Pretectal NOT in Horizontal VOR Recovery After Hemilabyrinthectomy in Rhesus Monkey
Authors: Stewart C. Matthew , Mustari Michael J. , Perachio Adrian A.
Published: March 2005

Damage to the vestibular labyrinth leads to profound nystagmus and vertigo. Over time, the vestibular-ocular system recovers in a process called vestibular compensation leading to reduced nystagmus and vertigo provided visual signals are available. Our study was directed at identifying sources of visual information that could play a role in vestibular compensation. Specifically, we investigated the role of the pretectal nucleus of the optic tract (NOT) in vestibular compensation after hemilabyrinthectomy (HL) in rhesus monkeys. We chose the NOT because this structure provides critical visual motion information for adaptive modification of the vestibular ocular reflex (VOR). We produced bilateral NOT lesions by injecting the excitotoxin ibotenic acid. We compared vestibular compensation after HL in NOT-lesioned and control animals with intact NOTs. We measured eye movements with an electromagnetic method employing scleral search coils. Measurements included slow-phase eye velocity during spontaneous nystagmus, per- and postrotatory nystagmus and the horizontal VOR (hVOR) gain (eye-velocity/head velocity) associated with per- and postrotatory and sinusoidal (0.2–2.0 Hz; 30–90°/s) whole body oscillation around the earth-vertical axis. VOR gain was low (<0.5) for rotation toward the HL side. Our control animal evinced significant vestibular compensation with VOR gains approaching unity by 100 days post HL. In contrast, monkeys with bilateral lesions of the NOT never obtained this significant recovery with hVOR gains well below unity at 100 days and beyond. Therefore our studies demonstrate that the NOT is an essential source of visual signals for the process of vestibular compensation after HL.
Benefits of Participating in Internet Interviews: Women Helping Women
Authors: Beck Cheryl Tatano
Published: March 2005

Advantages of face-to-face qualitative interviews for participants have been addressed in the literature. The benefits of participating in qualitative interviews over the Internet, however, have yet to be discussed. Based on the experiences of 40 women who made up the sample for an Internet study on birth trauma, the author describes in this article the benefits reaped by these mothers through their participation in qualitative e-mail interviews. She used content analysis to identify these benefits. Seven themes emerged: experiencing caring by being listened to and acknowledged, sense of belonging, making sense of it all, letting go, being empowered, women helping women, and providing a voice.
Disability-Induced Identity Changes in Persons With Multiple Chemical Sensitivity
Authors: Gibson Pamela Reed , Placek Elizabeth , Lane Jennifer , Brohimer Sacha Ostroff , Lovelace Amy C. Earehart
Published: March 2005

In this qualitative study, the authors asked respondents with multiple chemical sensitivity (MCS) in an open-ended question how having the condition affected their identities. Authors then examined responses for themes, which they discuss within the framework of critical theory. Emergent themes included loss of a stable, familiar personality, loss of self-positioning, emotional suppression to meet others’ expectations, redesigning the planned life, forced growth, struggling with support, discovering the spiritual self, and identity reconsolidation. The authors compare findings with published works on adjustment to chronic illness and other delegitimized illnesses, find them to be fairly congruent, and then discuss problems regarding cultural acceptance of MCS as a condition caused by chemical exposure.