bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards understanding the presence/absence of Human African Trypanosomosis in a focus of Côte d'Ivoire: a spatial analysis of the pathogenic system
Authors: Courtin Fabrice , Jamonneau Vincent , Oké Emmanuel , Coulibaly Bamoro , Oswald Yohan , Dupont Sophie , Cuny Gérard , Doumenge Jean-Pierre , Solano Philippe
Published: November 2005

Background

This study aimed at identifying factors influencing the development of Human African Trypanosomosis (HAT, or sleeping sickness) in the focus of Bonon, located in the mesophile forest of Côte d'Ivoire. A previous study mapping the main daytime activity sites of 96 patients revealed an important disparity between the area south of the town- where all the patients lived- and the area north of the town, apparently free of disease. In order to explain this disparity, we carried out a spatial analysis of the key components of the pathogenic system, i.e. the human host, the tsetse vector and the trypanosomes in their environment using a geographic information system (GIS).

Results

This approach at the scale of a HAT focus enabled us to identify spatial patterns which linked to the transmission and the dissemination of this disease. The history of human settlement (with the rural northern area exploited much earlier than the southern one) appears to be a major factor which determines the land use pattern, which itself may account for differences found in vector densities (tsetse were found six times more abundant in the southern rural area than in the northern). Vector density, according to the human and environmental context in which it is found (here an intense mobility between the town of Bonon and the rural areas), may explain the observed spatial differences in HAT prevalence.

Conclusion

This work demonstrates the role of GIS analyses of key components of the pathogenic system in providing a better understanding of transmission and dissemination of HAT. Moreover, following the identification of the most active transmission areas, and of an area unfavourable to HAT transmission, this study more precisely delineates the boundaries of the Bonon focus. As a follow-up, targeted tsetse control activities starting north of Bonon (with few chances of reinvasion due to very low densities) going south, and additional medical surveys in the south will be proposed to the Ivoirian HAT control program to enhance the control of the disease in this focus. This work also shows the evolution of HAT regarding time and environment, and the methodology used may be able to predict possible sleeping sickness development/extinction in areas with similar history and space organization.
Human leukocyte antigen class I, class II, and tumor necrosis factor-alpha polymorphisms in a healthy elder Mexican Mestizo population
Authors: Soto-Vega Elena , Richaud-Patin Yvonne , Llorente Luis
Published: November 2005

Background

There is strong evidence that an individual's genetic background is an important predisposing factor to longevity. In the present study we analysed the frequency of HLA class I, class II, as well as the TNF-α -308 polymorphism that may be related to an increased life span in Mexican Mestizo healthy elders.

Results

HLA typing was performed by polymerase chain reaction sequence specific oligonucleotide (PCR SSO) reverse dot blot. The TNF-α -308 polymorphism was assessed by PCR restriction fragment length polymorphism. A significant increased frequency of HLA-DRB1*11 was found in elderly women whereas this allele was not present in elderly males. The TNF2 allele was also increased in the elder group when compared to young controls. The frequencies of the remaining alleles tested were not statistically different among groups.

Conclusion

These data suggest an ethnicity independent tendency of HLA-DRB1*11 in elder females to increase life span and a possible role of the TNF2 allele with the successful remodelling of senescent immune system.
General practice and the New Zealand health reforms – lessons for Australia?
Authors: McAvoy Brian R , Coster Gregor D
Published: November 2005

New Zealand's health sector has undergone three significant restructures within 10 years. The most recent has involved a Primary Health Care Strategy, launched in 2001. Primary Health Organisations (PHOs), administered by 21 District Health Boards, are the local structures for implementing the Primary Health Care Strategy. Ninety-three percent of the New Zealand population is now enrolled within 79 PHOs, which pose a challenge to the well-established Independent Practitioner Associations (IPAs).

Although there was initial widespread support for the philosophy underlying the Primary Health Care Strategy, there are concerns amongst general practitioners (GPs) and their professional organisations relating to its implementation. These centre around 6 main issues:

1. Loss of autonomy

2. Inadequate management funding and support

3. Inconsistency and variations in contracting processes

4. Lack of publicity and advice around enrolment issues

5. Workforce and workload issues

6. Financial risks

On the other hand, many GPs are feeling positive regarding the opportunities for PHOs, particularly for being involved in the provision of a wider range of community health services. Australia has much to learn from New Zealand's latest health sector and primary health care reforms.

The key lessons concern:

• the need for a national primary health care strategy

• active engagement of general practitioners and their professional organisations

• recognition of implementation costs

• the need for infrastructural support, including information technology and quality systems

• robust management and governance arrangements

• issues related to critical mass and population/distance trade offs in service delivery models
Single Subject Pharmacological-MRI (phMRI) Study: Modulation of Brain Activity of Psoriatic Arthritis Pain by Cyclooxygenase-2 Inhibitor
Authors: Baliki M , Katz J , Chialvo J , Apkarian AV
Published: November 2005

We use fMRI to examine brain activity for pain elicited by palpating joints in a single patient suffering from psoriatic arthritis. Changes in these responses are documented when the patient ingested a single dose of a selective cyclooxygenase-2 inhibitor (COX-2 i). We show that mechanical stimulation of the painful joints exhibited a cortical activity pattern similar to that reported for acute pain, with activity primarily localized to the thalamus, insular, primary and secondary somatosensory cortices and the mid anterior cingulum. COX-2 i resulted in significant decreased in reported pain intensity and in brain activity after 1 hour of administration. The anterior insula and SII correlated with pain intensity, however no central activation site for the drug was detected. We demonstrate the similarity of the activation pattern for palpating painful joints to brain activity in normal subjects in response to thermal painful stimuli, by performing a spatial conjunction analysis between these maps, where overlap is observed in the insula, thalamus, secondary somatosensory cortex, and anterior cingulate. The results demonstrate that one can study effects of pharmacological manipulations in a single subject where the brain activity for a clinical condition is delineated and its modulation by COX-2 i demonstrated. This approach may have diagnostic and prognostic utility.
Knowledge and use of medicinal plants by local specialists in an region of Atlantic Forest in the state of Pernambuco (Northeastern Brazil)
Authors: Gazzaneo Luiz Rodrigo Saldanha , de Lucena Reinaldo Farias Paiva , de Albuquerque Ulysses Paulino
Published: November 2005

The study of local knowledge about natural resources is becoming increasingly important in defining strategies and actions for conservation or recuperation of residual forests. This study therefore sought to: collect information from local populations concerning the use of Atlantic Forest medicinal plants; verify the sources of medicinal plants used; determine the relative importance of the species surveyed, and; calculate the informant consensus factor in relation to medicinal plant use. Data was obtained using semi-structured forms to record the interviewee's personal information and topics related to the medicinal use of specific plants. The material collected represent 125 plants, distributed among 61 botanical families, with little participation of native plants. This study demonstrated that local people tend to agree with each other in terms of the plants used to treat blood-related problems, but cite a much more diverse group of plants to treat problems related to the respiratory and digestive systems – two important categories in studies undertaken in different parts of the world. The local medicinal flora is largely based on plants that are either cultivated or obtained from anthropogenic zones, possibly due to the use and access restrictions of the legally protected neighboring forest. Despite these restrictions, the species with the highest use-value by this community was Pithecellobium cochliocarpum (Gomez) Macb., a native plant of the Atlantic Forest.
The progestational and androgenic properties of medroxyprogesterone acetate: gene regulatory overlap with dihydrotestosterone in breast cancer cells
Authors: Ghatge Radhika P , Jacobsen Britta M , Schittone Stephanie A , Horwitz Kathryn B
Published: November 2005

Introduction

Medroxyprogesterone acetate (MPA), the major progestin used for oral contraception and hormone replacement therapy, has been implicated in increased breast cancer risk. Is this risk due to its progestational or androgenic properties? To address this, we assessed the transcriptional effects of MPA as compared with those of progesterone and dihydrotestosterone (DHT) in human breast cancer cells.

Method

A new progesterone receptor-negative, androgen receptor-positive human breast cancer cell line, designated Y-AR, was engineered and characterized. Transcription assays using a synthetic promoter/reporter construct, as well as endogenous gene expression profiling comparing progesterone, MPA and DHT, were performed in cells either lacking or containing progesterone receptor and/or androgen receptor.

Results

In progesterone receptor-positive cells, MPA was found to be an effective progestin through both progesterone receptor isoforms in transient transcription assays. Interestingly, DHT signaled through progesterone receptor type B. Expression profiling of endogenous progesterone receptor-regulated genes comparing progesterone and MPA suggested that although MPA may be a somewhat more potent progestin than progesterone, it is qualitatively similar to progesterone. To address effects of MPA through androgen receptor, expression profiling was performed comparing progesterone, MPA and DHT using Y-AR cells. These studies showed extensive gene regulatory overlap between DHT and MPA through androgen receptor and none with progesterone. Interestingly, there was no difference between pharmacological MPA and physiological MPA, suggesting that high-dose therapeutic MPA may be superfluous.

Conclusion

Our comparison of the gene regulatory profiles of MPA and progesterone suggests that, for physiologic hormone replacement therapy, the actions of MPA do not mimic those of endogenous progesterone alone. Clinically, the complex pharmacology of MPA not only influences its side-effect profile; but it is also possible that the increased breast cancer risk and/or the therapeutic efficacy of MPA in cancer treatment is in part mediated by androgen receptor.
Ligand-dependent de-repression via EcR/USP acts as a gate to coordinate the differentiation of sensory neurons in theDrosophilawing
Authors: Schubiger Margrit , Carré Clément , Antoniewski Christophe , Truman James W.
Published: November 2005

Loss of function of either the ecdysone receptor (EcR) or Ultraspiracle(USP), the two components of the ecdysone receptor, causes precocious differentiation of the sensory neurons on the wing of Drosophila. We propose that the unliganded receptor complex is repressive and that this repression is relieved as the hormone titers increase at the onset of metamorphosis. The point in development where the receptor complex exerts this repression varies for different groups of sensilla. For the chemosensory organ precursors along the wing margin, the block is at the level of senseless expression and is indirect, via the repressive control of broad expression. Misexpressing broad or senselesscan circumvent the repression by the unliganded receptor and leads to precocious differentiation of the sensory neurons. This precocious differentiation results in the misguidance of their axons. The sensory precursors of some of the campaniform sensilla on the third longitudinal vein are born prior to the rise in ecdysone. Their differentiation is also repressed by the unliganded EcR/USP complex but the block occurs after senseless expression but before the precursors undertake their first division. We suggest that in imaginal discs the unliganded EcR/USP complex acts as a ligand-sensitive `gate' that can be imposed at various points in a developmental pathway, depending on the nature of the cells involved. In this way, the ecdysone signal can function as a developmental timer coordinating development within the imaginal disc.
Fgf8expression defines a morphogenetic center required for olfactory neurogenesis and nasal cavity development in the mouse
Authors: Kawauchi Shimako , Shou Jianyong , Santos Rosaysela , Hébert Jean M. , McConnell Susan K. , Mason Ivor , Calof Anne L.
Published: November 2005

In vertebrate olfactory epithelium (OE), neurogenesis proceeds continuously, suggesting that endogenous signals support survival and proliferation of stem and progenitor cells. We used a genetic approach to test the hypothesis that Fgf8 plays such a role in developing OE. In young embryos, Fgf8 RNA is expressed in the rim of the invaginating nasal pit (NP), in a small domain of cells that overlaps partially with that of putative OE neural stem cells later in gestation. In mutant mice in which the Fgf8 gene is inactivated in anterior neural structures, FGF-mediated signaling is strongly downregulated in both OE proper and underlying mesenchyme by day 10 of gestation. Mutants survive gestation but die at birth,lacking OE, vomeronasal organ (VNO), nasal cavity, forebrain, lower jaw,eyelids and pinnae. Analysis of mutants indicates that although initial NP formation is grossly normal, cells in the Fgf8-expressing domain undergo high levels of apoptosis, resulting in cessation of nasal cavity invagination and loss of virtually all OE neuronal cell types. These findings demonstrate that Fgf8 is crucial for proper development of the OE,nasal cavity and VNO, as well as maintenance of OE neurogenesis during prenatal development. The data suggest a model in which Fgf8expression defines an anterior morphogenetic center, which is required not only for the sustenance and continued production of primary olfactory (OE and VNO) neural stem and progenitor cells, but also for proper morphogenesis of the entire nasal cavity.
Spectrochemical Analysis of Zirconium Oxide
Authors: Spitzer E. J. , Smith D. D.
Published: November 2005

A spectrochemical method is presented for the quantitative analysis of zirconium oxide for twenty-two impurities. Silver chloride is used as a acarrier in a carrier-distillation type arcing procedure. The general range is 10,000 ppm to 1 ppm on most elements and impurities can be determined by visual comparison to an accuracy of ± 50% of the element present.
Intensity Differences of Copper Lines Depending on Impurity Contents
Authors: Danielsson A. , Petersson S.
Published: November 2005

Differences in copper line intensities depending on changes in minor impurity contents of anode copper have been observed. A statistical investigation of this phenomenon has been made. The base for this statistical investigation is 400 plates and corresponding analytical records from our routine spectrochemical work. For the excitation condition used, namely an interrupted arc, a regression equation for the depending of copper line intensity on impurity amounts has been calculated according to the method of least squares.

Differences in thermal conductivity depending on impurity contents are regarded as the main cause for this phenomenon. This interpretation is confirmed by further investigations.

The significant differences in copper line intensity between different anode copper specimens diminish as the excitation gets more spark-like. Less heat is deliberated, and thus the influence from the difference in thermal conductivity diminishes. The globule arc technique gives hardly any significant intensity difference for different specimens. This is also in conformity with the above explanation, as in this case the influence of thermal conductivity of solid copper is eliminated.

Furthermore, the influence of the intensity variations on the spectrochemical results are discussed.
Controlled Atmosphere Excitation as Applied to the Spectrographic Analysis of Aluminum Alloy Chips
Authors: Goldspiel S. , Bernstein F.
Published: November 2005

An atmosphere-controlled excitation chamber which can be readily handled in spectrographic production analysis has been developed and constructed. This device is being investigated for use in the analysis of aluminum alloys in chip compacts sample form, to enable the analysis of chips with accuracies comparable to those now obtained by the use of solid samples. Desirability of controlled atmosphere techniques is indicated by the poor reproducibility obtained in the sparking of compacted chips in air, which may be attributed to the formation of refractory interfaces of variable thermal and electrical resistance. Some data accumulated using aluminum alloy compacted chip samples in atmospheres of Argon, Helium, and Air are presented, and some effects of atmosphere on reproducibility under various excitation conditions are discussed. Preliminary results of trials indicate decided improvement in reproducibilities are possible with Argon, judged from time of wait curves.
A Working Curve Calculator for Quantitative Spectrographic Analysis
Authors: Goldspiel S. , Canner I.
Published: November 2005

This paper describes a simple pocket size spectroanalytical calculator developed, in the authors' laboratory for the rapid and direct conversion of spectral line blackenings to percentage constituents. This calculator speeds up production control analysis and is considered convenient for trial of spectromethods in process of development. It is prepared in the form of a handy slide rule in which the emulsion calibration plot is replaced by a scale. While the calculator can be drawn up for any method, the scales illustrated are for low alloy steels and for aluminum Alcoa types A51S, 52S, 53S, S6S and 61S as currently used in the Material Laboratory.
Writing Characteristics of Suicidal People on the Internet: A Psychological Investigation of Emerging Social Environments
Authors: Barak Azy , Miron Ofra
Published: November 2005

Three studies were carried out to investigate the writings of suicidal people on the Internet, hypothesizing consistent findings to equivalent research of offline writing. In Study 1, suicidal persons' (n = 34) attributions as the cause of their condition, as expressed in their free online writing, were compared to those of emotionally distressed, nonsuicidal (n = 16) and to nondistressed (n = 15) individuals. Results showed that suicidal persons have significantly more stable and global attributions than do the other groups. In Study 2, expressions of self‐focus in online written messages were compared among suicidal, two levels of nonsuicidal but distressed, and nondistressed individuals (200 messages in each group). With the use of various expressions of self‐focus, findings showed that suicidal people were distinctively self‐focused in their writing, unlike their counterparts. In Study 3, psychologically relevant themes in the online writing of suicidal (n = 39) and highly distressed, nonsuicidal persons (n = 24) were compared. Results revealed that the former expressed significantly more unbearable psychological pain and cognitive constriction than did the latter. The findings of the three studies are consistent with those found in examinations of offline writing. The research has important implications for the use of online environments for psychological research and means for assessment, as well as for understanding suicidality.
Suicidal and Nonsuicidal Adolescents: Different Factors Contribute to Self‐Esteem
Authors: Grøholt Berit , Ekeberg Øivind , Wichstrøm Lars , Haldorsen Tor
Published: November 2005

Some risk and protective factors differ in their importance to suicidal and nonsuicidal people. In this research we explore the cross‐sectional differences between risk factors among suicidal adolescents and nonsuicidal adolescents by focusing on self‐esteem. Sixty‐five suicidal and 390 nonsuicidal adolescents were compared on Harter's Self‐Perceived Profile for Adolescents, self‐concept stability, seeking support, loneliness, and depression. Self‐concept stability, loneliness, and peer support correlated differently with self‐esteem. In multivariate regression analyses, variance in self‐esteem was explained by depression and loneliness, and among nonsuicidal adolescents also by self‐concept stability, support, and competencies. Loneliness and self‐concept stability related differently to self‐esteem in suicidal and nonsuicidal adolescents. When the aim is to enhance self‐esteem, this difference may delineate suicidal subgroups that need special interventions.
Utah Youth Suicide Study: Psychological Autopsy
Authors: Moskos Michelle , Olson Lenora , Halbern Sarah , Keller Trisha , Gray Doug
Published: November 2005

We conducted a psychological autopsy study to further understand youth suicide in Utah. While traditional psychological autopsy studies primarily focus on the administration of psychometric measures to identify any underlying diagnosis of mental illness for the suicide decedent, we focused our interviews to identify which contacts in the decedent's life recognized risk factors for suicidal behavior, symptoms of mental illness, as well as barriers to mental health treatment for the decedent. Parents and friends recognized most symptoms universally, although friends better recognized symptoms of substance abuse than any other contact. The study results suggest that parents and friends are the most appropriate individuals for gatekeeper training and, in conjunction with other innovative screening programs, may be an effective strategy in reducing adolescent suicide.
Factors Associated with Suicide Attempts in Female Inmates: The Hegemony of Hopelessness
Authors: Chapman Alexander L. , Specht Matthew W. , Cellucci Tony
Published: November 2005

In this study factors associated with past suicide attempts in female inmates were examined. Female inmate participants (N = 105) were given structured diagnostic assessments of antisocial and borderline personality disorders and substance dependence, as well as measures of depression, hopelessness, problem‐focused coping styles, and reasons for living. There was a high lifetime prevalence of past suicide attempts (38.1%). Suicide attempts were positively associated with personality disorders, hopelessness, depression, childhood physical/emotional abuse, and family history of suicide and mood disorders, and negatively associated with income, reasons for living, and problem‐focused coping. Controlling for hopelessness, borderline personality disorder and family history of suicide attempts were the only variables that remained uniquely associated with suicide attempts.
Multivariable State-space Adaptive Control (Adaptive Mehrgrößenzustandsregelung)
Authors: Gambier Adrian , Nazaruddin Yul Y.
Published: November 2005

The field of indirect adaptive control has been intensively studied for single input/single output (SISO) system as well as multivariable (MIMO) systems based on I/O models. State-space approaches for SISO system can also be found in the literature. Although the state-space representation is a very convenient description for multivariable systems, only few times it was applied to design indirect adaptive control systems. In this paper, the most important approaches are presented and analysed including advantages and drawbacks. Finally, the most common adaptive control schemes are illustrated with real-time results obtained from experiments carried out on a turbogenerator pilot plant.
Contribution of hyphenated CE-ICP/MS in metal/protein interactions studies
Authors: Chamoun J. , Hagège A.
Published: November 2005

By introducing a preliminary in-capillary preconcentration step, CE-ICP/MS was applied to trace metal speciation in proteins. Emphasis was put on metal/protein interactions where CE-ICP/MS is demonstrated to provide informations concerning metal binding and metal exchanges occuring in proteins. Preliminary studies on the fate of several metals in the presence of a mixture of standard proteins were performed. Cadmium was shown to bind mainly to albumin and ceruloplasmin. Cobalt and nickel were detected only in carbonic anhydrase and ceruloplasmin in the mixture of proteins but also in albumin when injected alone.
Actinide uptake by transferrin and ferritin metalloproteins
Authors: Den Auwer Christophe , Llorens I. , Moisy Philippe , Vidaud C. , Goudard F. , Barbot C. , Solari P. L. , Funke H.
Published: November 2005

In order to better understand the mechanisms of actinide uptake by specific biomolecules, it is essential to explore the intramolecular interactions between the cation and the protein binding site. Although this has long been done for widely investigated transition metals, very few studies have been devoted to complexation mechanisms of actinides by active chelation sites of metalloproteins. In this field, X-ray absorption spectroscopy has been extensively used as a structural and electronic metal cation probe. The two examples that are presented here are related to two metalloproteins in charge of iron transport and storage in eukaryote cells: transferrin and ferritin. U(VI)O2
2+, Np(IV) and Pu(IV) have been selected because of their possible role as contaminant from the geosphere.
Influence of thermodynamic database on the modelisation of americium(III) speciation in a simulated biological medium
Authors: Bion Lionel , Ansoborlo Eric , Moulin Valérie , Reiller Pascal , Collins Richard , Gilbin Rodolphe , Février Laureline , Perrier Thomas , Denison Frank , Cote Gérard
Published: November 2005

An intercomparison exercise was led in order to study the impact of thermodynamic database (TDB) on the speciation of americium(III) in biochemical media.

A first exercice was led, considering only the americium(III) species in solution. Even with different data sets, all the exercises are in relatively good agreement, concluding to successive complexation of the radioelement by phosphate (pH range from 0 to 3), citrate (pH range from 3 to 8) and hydroxo-carbonate (pH range from 8 to 14). Nevertheless, the speciation of americium differs for each pH range from one work to an other.

These results are still observed when the speciation calculation includes the formation of solids. Nevertheless, some workers did not integrate in their data set the formation constant of Am(PO4). This solid is known to be very insoluble in typical biological media. All the calculations where Am(PO4) was not in the TDB presented a speciation where americium is solvated (mostly under citrate forms). When the formation of Am(PO4) is considered, the actinide is quantitatively present under this solid species.

This work is a representative example of the impact of the thermodynamic data used in speciation exercises. Some exercices, using uncompleted TDB had wrong results and led to the conclusion of the necessity in the use of expertised and extended TDB.
The OECD/NEA TDB review of selected organic ligands
Authors: Hummel Wolfgang , Anderegg Giorgio , Puigdomènech Ignasi , Rao Linfeng , Tochiyama Osamu
Published: November 2005

Within the scope of the OECD Nuclear Energy Agency (NEA) Thermochemical Data Base Project (TDB) a comprehensive review of selected organic ligands has been carried out by the authors. The selected ligands are oxalate, citrate, ethylenediaminetetraacetate (edta) and α-isosaccharinate (isa), and the elements considered in the review are U, Np, Pu, Am, Tc, Ni, Se and Zr, as well as the necessary basic data concerning protonation of the ligands and interactions with the major competing elements Na, K, Mg and Ca. This review on organic ligands showed that the pragmatic ionic strength correction procedure, the Specific ion Interaction Theory (SIT), chosen as the default method for all NEA TDB reviews, can be applied successfully also to organic ligands. The SIT interaction parameters derived from ligand protonation data for different media, e.g. NaCl and KCl, pass the consistency test when applied to other systems evaluated in the organics review, e.g. solubility data. Hence, the thermodynamic constants selected in this NEA TDB organics review can be used with some confidence in real world applications, provided that SIT is used in the speciation calculations.
Search for α-decay of 229mTh produced from 229Ac β-decay following 232Th(γ, p2n) reaction
Authors: Kikunaga Hidetoshi , Kasamatsu Yoshitaka , Takamiya Koichi , Mitsugashira Toshiaki , Hara Mitsuo , Ohtsuki Tsutomu , Yuki Hideyuki , Shinohara Atsushi , Shibata Seiichi , Kinoshita Norikazu , Yokoyama Akihiko , Nakanishi Takashi
Published: November 2005

We produced 229Th in the nuclear reaction 232Th(γ, p2n) 229Ac, followed by disintegration to 229m,gTh. The 229mTh α-decay was searched for. Alpha-particle events of energy between 4.93 MeV and 5.05 MeV were observed in the separated thorium sample of β-decay products from an actinium source highly purified from the 232Th + γ reaction products. The energies of the α-particles coincide with those expected for 229mTh.
Energy shift of electronic X-rays emitted from pionic atoms
Authors: Ninomiya Kazuhiko , Sugiura Hironori , Kasamatsu Yoshitaka , Kikunaga Hidetoshi , Takamiya Koichi , Sato Wataru , Matsumura Hiroshi , Yokoyama Akihiko , Sueki Keisuke , Miura Taichi , Hamajima Yasunori , Shinohara Atsushi
Published: November 2005

The electronic K X-ray energies of pionic atoms were precisely measured on elements ranging from zinc to lead with a low-energy photon detection system. Some differences between pionic and muonic atoms were found in the atomic-number (Z) dependence of the energy shift. In the pionic atoms, the energy shift gradually decreases with an increase in atomic number, which is opposite to the trend for muonic atoms. In the low-Z region investigated elements, the energy shifts of K
β X-rays were obviously larger than those of K
α X-rays.
Influence of β radiation on UO2dissolution at different pH values
Authors: Clarens Frederic , Giménez Javier , Pablo Joan de , Casas Ignasi , Rovira Miquel , Dies Javier , Quiñones Javier , Martínez-Esparza Aurora
Published: November 2005

In this work we studied the effect of external β radiation (90Sr-90Y source with an activity of 7 mCi) on the dissolution rate of non-irradiated UO2as a chemical analogue of spent nuclear fuel (SF). The experiments were carried out at three different pH values inside a glove-box in nitrogen atmosphere to avoid oxygen contamination. The MAKSIMA code was used to model the generation of radiolytic products, both molecular species and radicals.

The formation of hydrogen peroxide in solution was observed in the experiments, as was predicted by the MAKSIMA code. When H2O2could be quantified, its concentration was within the range predicted by this code. In addition, the application to our data of an empirical model for UO2dissolution in the presence of H2O2gave similar results.

The UO2dissolution rates obtained in this work were similar to the UO2corrosion rates determined electrochemically and under γ irradiation with a similar dose rate. On the other hand, they were always lower than the ones obtained with "fresh" spent nuclear fuel, probably because in this case the dose rates to the solution are higher and, in addition, more than just β radiation is emitted by the fuel.
Development of a gas-jet-coupled multitarget system for multitracer production
Authors: Haba Hiromitsu , Kaji Daiya , Kanayama Yousuke , Igarashi Kaori , Enomoto Shuichi
Published: November 2005

A new multitracer production system, which consists of a gas-jet-coupled multitarget system for short-lived radioactive tracers and a gas- and water-cooled target system for intense beam irradiations, has been installed on a beam line of the K540 MeV RIKEN Ring Cyclotron. The performance of the gas-jet system was investigated with 50 radionuclides of 18 elements produced in the 135 MeV nucl.-1– 14N induced reaction on natCu. The gas-jet efficiencies of the nuclides varying from 61Cu to 24Na, except for the chlorine isotopes, show a smooth variation as a function of the mass difference between a product and a target. The multitracers on the natAg and 197Au targets were also produced by the 135 MeV nucl.-1– 14N beam with the intensity of 0.7 pμA, which was more than seven times the limit of the previous system.
Determination of nuclear constants of reactions induced on zinc by short irradiations with the epithermal and fast components of a reactor neutron spectrum
Authors: Cohen Isaac M. , Ribeiro Guevara S. , Arribére M. A. , Fornaciari Iljadica María C. , Kestelman A. J. , Ohaco R. A. , Segovia M. S. , Yunes A. N.
Published: November 2005

Cross sections, averaged over a235U fission neutron spectrum, of some threshold reactions induced on zinc after short irradiations, have been measured. The studied reactions and the corresponding values are:64Zn(n,p)64Cu, (37.4 ± 1.4) mb;64Zn(n, 2n)63Zn, (23.4 ± 2.0) μb;66Zn(n,p)66Cu, (0.775 ± 0.079) mb;68Zn(n,p)68mCu, (5.32 ± 0.65) μb; and68Zn(n, α)65Ni, (52.1 ± 2.3) μb, all referred to the cross section of the27Al(n,p)27Mg standard reaction, (3.84 ± 0.18) mb. Working values for the resonance integrals of the reactions70Zn(n, γ)71Zn and70Zn(n, γ)71mZn, referred to the tabulated value for the resonance integral of the68Zn(n, γ)69mZn reaction, (0.24 ± 0.03) b, were also obtained. The results were (0.1350 ± 0.0093) b and (0.157 ± 0.029) b, respectively.
Fission spectrum averaged cross section measurements of some neutron threshold reactions of relevance to medical radionuclide production
Authors: Zaidi Jamshed H. , Arif M. , Fatima I. , Waheed Shahida , Ahmad Shujaat , Qureshi I. H.
Published: November 2005

A resume is given of radiochemical measurements of nuclear reaction cross sections relevant to the production of some medically important radionuclides carried out at PINSTECH during the last decade. Systematic studies on fission neutron spectrum averaged cross sections of several threshold reactions, like (n, 2n), (n, p) and (n, α), on titanium, ruthenium, europium and dysprosium for the production of 45Ti, 96Tc, 153Sm and 153Gd are described.
Investigation of the production of the therapeutic radioisotope 114mIn through proton and deuteron induced nuclear reactions on cadmium
Authors: Tárkányi F. , Takács S. , Hermanne A. , Winkel P. van den , Zwart R. van der , Skakun Ye. A. , Shubin Yu. N. , Kovalev S. F.
Published: November 2005

For production of the therapeutic radionuclide 114mIn, proton and deuteron induced nuclear reactions were investigated using the stacked-foil technique on enriched 114Cd and natCd targets up to E
p = 36 MeV and E
d = 21 MeV. The experimental cross sections of the 114Cd(p, γ)115mIn, 114Cd(p, n)114mIn, 114Cd(p, 2n)113mIn, 114Cd(p, 4n)111m,gIn, 114Cd(p, αn)110mAg, 114Cd(p, α)111m,gAg, 114Cd(d, n)115mIn, 114Cd(d, 2n)114mIn, 114Cd(d, 3n)113mIn, 114Cd(d, p)115gCd, 114Cd(d, α) 112Ag, 114Cd(p, αn)111m,gAg, natCd(p, x)114mIn and natCd(d, x)114mIn reactions are reported. Thick target yields are derived and different routes for production of 114mIn are compared.
Production of111In from an In/In2O3target
Authors: Meulen Nick P. van der , Walt T.N. van der , Dolley S. G.
Published: November 2005

A method was developed to produce111In from an In/In2O3target, whereby the parent111Sn was separated from the target material by means of ion exchange, using AG1-X4 and AG MP-1 anion exchange resins. The chemical separation had to be performed as quickly as possible, to ensure the highest possible yield of the final product (111Sn has a half-life of 35.3 minutes). The111Sn is left on the resin to decay to111In, which is then eluted from the column. This method ensures that impurities in the final product are kept to a minimum.
Comparison of Mean Length at Age and Growth Parameters of Bluegills, Largemouth Bass, and Yellow Perch from Length-Stratified Subsamples and Samples in Michigan Lakes
Authors: Nate Nancy A. , Bremigan Mary T.
Published: November 2005

Estimates of mean length at age and von Bertalanffy growth parameters estimated from mean length at age can be biased if based only on age information collected from length-stratified subsamples. However, historic data are often limited to length-stratified subsample summaries. To evaluate the potential for using historic length-stratified subsamples to compare the average growth of fishes among Michigan lakes, we quantified the subsample bias in estimates of the mean lengths at ages 1–10 and von Bertalanffy growth parameters for bluegills Lepomis macrochirus, largemouth bass Micropterus salmoides, and yellow perch Perca flavescens. In regression analysis of estimates based on subsamples and full samples, only two of nine possible tests indicated significant bias in subsamples relative to samples. The mean lengths at ages 1–10 based on subsamples were not biased. Von Bertalanffy growth parameters indicated no bias for bluegill asymptotic length L∞, largemouth bass early growth rate ω, and yellow perch ω. In contrast, bluegill ω estimates were lower when estimated from subsamples than when estimated from samples, and the bias increased with the magnitude of the sample parameter estimate. While regression tests showed that subsample estimates were generally linearly related to sample estimates, the magnitude of the variability in relative bias around von Bertalanffy estimates across lakes was large for all species tested. Our findings suggest that mean lengths at ages 1–10 for bluegills, largemouth bass, and yellow perch estimated from length-stratified subsamples were not generally biased, but large variation in von Bertalanffy growth parameter estimates limits their usefulness for among-lake comparisons. Therefore, historic growth data sets that lack complete sampling information (e.g., full-sample length frequencies and individual fish from subsamples rather than summaries) can still provide meaningful comparisons of growth among lakes or over time if comparisons are limited to mean lengths at ages 1–10.
Seasonal Movements, Habitat Use, Aggregation, Exploitation, and Entrainment of Saugers in the Lower Yellowstone River: An Empirical Assessment of Factors Affecting Population Recovery
Authors: Jaeger Matthew E. , Zale Alexander V. , McMahon Thomas E. , Schmitz Brad J.
Published: November 2005

Migratory barriers, habitat loss, entrainment in irrigation canals, and overexploitation, especially at times of aggregation, have been suggested to explain the failure of Yellowstone River saugers Sander canadensis to return to historical abundances after a late-1980s decline that was attributed to drought. These factors are thought to affect saugers throughout their range and migratory large-river fishes in general. We characterized the seasonal movement patterns, habitat use, and aggregation of saugers and estimated movement, exploitation, and irrigation canal entrainment rates to test these hypotheses. Saugers aggregated near spawning areas in spring and subsequently dispersed 5–350 km to upstream home locations, where they remained for the rest of the year. Upstream movement was not overtly restricted by low-head diversion dams. During the spawning period, terrace and bluff pools, which are unique geomorphic units associated with bedrock and boulder substrate, were positively selected, while all other habitat types were avoided. Tributary spawning was rare. After moving to home locations, saugers used most habitat types in proportion to their availability but selected reaches in specific geologic types that allowed formation of deep, long pools. Exploitation occurred primarily in early spring and late autumn, was low annually (18.6%), and was not related to aggregation. Annual survival was high (70.4%). Entrainment in one irrigation diversion accounted for more than half of all nonfishing mortality. Therefore, habitat loss and overexploitation probably did not prevent sauger recovery, as the absence of migratory barriers allowed adult saugers unrestricted access to widely separated and diverse habitats and did not induce artificial aggregation. In other systems, population declines attributed to overexploitation during periods of aggregation may therefore have been caused fundamentally by migration barriers that created artificial aggregations.
Mortality Associated with Catch-and-Release Angling of Striped Bass in the Hudson River
Authors: Millard Michael J. , Mohler Jerre W. , Kahnle Andrew , Cosman Amanda
Published: November 2005

Catch-and-release fishing commonly occurs in recreational fisheries, including those for the striped bass Morone saxatilis of the Atlantic coast. The contribution of catch-and-release practices to overall fishing mortality is often not estimated. We estimated the catch-and-release mortality for the Hudson River spawning stock of striped bass in 2001. Volunteer anglers caught striped bass between April 30 and May 16, 2001. Fish were transferred to transport boats in live wells and placed in one of nine 15,000-L land-based holding tanks. Control fish were collected by electrofishing and otherwise handled similarly. Treatment and control fish were uniquely tagged and held together for 5 d. Hooking mortality was estimated via conditional rate and additive rates. These two estimation techniques partitioned total observed mortality into hooking mortality and handling mortality, the latter being estimated from control fish. Catch-and-release mortality for striped bass averaged 16% for traditional J hooks and 5% for circle hooks over the entire period. Hook location and the occurrence of bleeding were the most influential variables in determining the probability of death. Mortality rate increased when water temperatures reached 16°C. This mortality rate is significant and should be considered when accounting for Hudson River striped bass removals from their spawning population.
Habitat Use and Stranding Risk of Juvenile Chinook Salmon on a Seasonal Floodplain
Authors: Sommer Ted R. , Harrell William C. , Nobriga Matthew L.
Published: November 2005

Although juvenile Chinook salmon Oncorhynchus tshawytscha are known to use a variety of habitats, their use of seasonal floodplains, a highly variable and potentially risky habitat, has not been studied extensively. Particularly unclear is whether a seasonal floodplain is a net “source” or a net “sink” for salmonid production. To help address this issue, we studied salmon habitat use in the Yolo Bypass, a 24,000-ha floodplain of the Sacramento River, California. Juvenile salmon were present in the Yolo Bypass during winter–spring; fish were collected in all regions and substrates of the floodplain in diverse habitats. Experimental releases of tagged hatchery salmon suggest that the fish reared on the floodplain for extended periods (mean = 33 d in 1998, 56 d in 1999, and 30 d in 2000). Floodplain rearing and associated growth are also supported by the significantly larger size of wild salmon at the floodplain outlet than at the inlet during each of the study years. Several lines of evidence suggest that although the majority of young salmon successfully emigrated from the floodplain, areas with engineered water control structures had comparatively high rates of stranding. Adult ocean recoveries of tagged hatchery fish indicate that seasonal floodplains support survival at least comparable with that of adjacent perennial river channels. These results indicate that floodplains appear to be a viable rearing habitat for Chinook salmon, making floodplain restoration an important tool for enhancing salmon production.
Status and Conservation of Westslope Cutthroat Trout within the Western United States
Authors: Shepard Bradley B. , May Bruce E. , Urie Wendi
Published: November 2005

We describe the historical and current distributions and genetic status of westslope cutthroat trout Oncorhynchus clarkii lewisii (WCT) throughout its range in the western United States using data and expert opinion provided by fish managers. Westslope cutthroat trout historically occupied 90,800 km and currently occupy 54,600 km; however, these are probably underestimates due to the large-scale (1:100,000) mapping we used. Genetic analyses found no evidence of genetic introgression in 768 samples (58% of samples tested), but the numbers of individuals tested per sample were variable and sample sites were not randomly selected. Approximately 42% of the stream length occupied by WCT is protected by stringent land use restrictions in national parks (2%), wilderness areas (19%), and roadless areas (21%). A total of 563 WCT populations (39,355 km) are being managed as “conservation populations,” and while most (457, or 81%) conservation populations were relatively small, isolated populations, large and interconnected metapopulations occupied much more stream length (34,820 km, or 88%). While conservation populations were distributed throughout the historical range (occupying 67 of 70 historically occupied basins), they were much denser at the core than at the fringes. From the information provided we determined that conserving isolated populations (for their genetic integrity and isolation from nonnative competitors and disease) and metapopulations (for their diverse life histories and resistance to demographic extinction) is reasonable. We conclude that while the distribution of WCT has declined dramatically from historical levels, as a subspecies WCT are not currently at imminent risk of extinction because (1) they are still widely distributed, especially in areas protected by stringent land use restrictions; (2) many populations are isolated by physical barriers from invasion by nonnative fish and disease; and (3) the active conservation of many populations is occurring.
Movements of Walleyes in Claytor Lake and the Upper New River, Virginia, Indicate Distinct Lake and River Populations
Authors: Palmer George C. , Murphy Brian R. , Hallerman Eric M.
Published: November 2005

Inference that more than one genetic stock of walleyes Sander vitreus was present in Claytor Lake, Virginia, and its main influent, the New River, raised questions concerning the spawning movements, locations of spawning grounds, and home range of resident stocks. We conducted a radiotelemetry study of 52 walleyes in Claytor Lake and the upper New River over a period of 2 years. Our findings support the hypothesis that two populations coexist within the system, exhibiting different home ranges, spawning movements, and spawning grounds, even though there is no physical barrier to movement between the spatially disjunct populations. Walleyes living within Claytor Lake mostly spawn at the first riffle area above the reservoir, whereas those living in the New River mostly spawn at two riffle areas well upstream. Coexistence of distinct populations in the system justifies different management strategies. Management of the walleye population in Claytor Lake should focus on increasing the exploitation of the nonindigenous lake stock. Management of the upper New River walleye population should focus on conservation of the unique river stock through supportive breeding, strict harvest regulations, or both.