bluuebunny/crossref_metadata_2025 huggingface dataset:
An investigation of carbon release rate via leachate from an industrial solid waste landfill
Authors: Hee Jong Kim  , Matsuto Toshihiko , Tojo Yasumasa
Published: September 2010

Long-term behaviour of leachate pollutants is a key factor to estimate time and cost required for the leachate treatment in landfills. Estimating carbon release via leachate can be a good way by which to understand the long-term behaviour, however, most studies have had a timeline of only several months or years. In this study, a release rate of carbon via leachate for 20 years was estimated at an industrial solid waste landfill. The total carbon content in dumped waste was estimated based on combustible contents determined by collecting samples from other industrial landfills and pretreatment facilities, and carbon contents in literature values. Leachate quantity data, which were not recorded for the first ten years, were estimated using a macro-moisture balance model including the effect of snow melt. Because leachate quantity and quality at each site were only measured after leachates were mixed, the quantity at each site was calculated by assuming infiltration rates with and without final cover. Results indicated that less than 2% of total input carbon was released from each site via leachate regardless of landfill age.
Reconceptualizing the Role of Fear of Falling and Balance Confidence in Fall Risk
Authors: Hadjistavropoulos Thomas , Delbaere Kim , Fitzgerald Theresa Dever
Published: September 2010

Objective: This article aimed to critically examine preexisting conceptualizations of the relationship among fear of falling, falls efficacy, and falls and to offer a new theoretical model incorporating findings from the recent literature. Method: This is a theoretical article based on a review of preexisting findings pertaining to fear of falling and falls efficacy. Results: Traditional conceptualizations consider avoidance of activity and deconditioning to be mediators in the relationship between fear of falling and falls, but recent findings suggest that this mediational conceptualization may not be accurate. Moreover, the terms falls efficacy and fear of falling are often used interchangeably in the literature, which is conceptually problematic. Discussion: We conclude with the presentation and discussion of an alternative predictive model of fear of falling that incorporates important findings from the recent literature.
Art Groups for Marginalized Women With Breast Cancer
Authors: Collie Kate , Kante Anita
Published: September 2010

Professionally led support groups can significantly reduce distress, trauma symptoms, and pain for women with breast cancer. Despite the known benefits, women with breast cancer from marginalized groups tend not to participate in support groups. It is important to address barriers that prevent their participation and to identify types of support groups that appeal to as wide a range of women as possible. For this study, we interviewed women with breast cancer from marginalized groups in the San Francisco Bay Area (United States). We asked them about social, cultural, and psychological barriers that prevent participation in support groups, and about the potential of art groups to overcome these barriers. Our qualitative analysis of the interviews yielded findings that suggest a model for a type of support group that could make the benefits of support groups available to more women with breast cancer.
Effect of Micro-slip on the Damping Capacity of Jointed Riveted Structures with Unequal Thickness
Authors: Mohanty R.C. , Nanda B.K.
Published: September 2010

This paper addresses the influence of the partial slip phenomenon on the damping capacity of jointed riveted structures with unequal thickness. The dynamic response of built-up structures is influenced by the characteristics of the joints and the damping capacity of such joints has been analyzed by mathematical modeling and experiments. Damping at structural joints is associated with frictional losses caused by micro-slip and kinematics coefficient of friction at the interfaces. Such energy dissipation at various joints has a significant effect in limiting the magnitude of vibration. The free vibration of a beam jointed with rivets of unequal thickness with ratio of 2.0 undergoing a small dynamic deflection in the transverse direction has been studied using the energy approach to evaluate its damping capacity. The results of the theoretical analysis have been compared with the experimental results to verify the authenticity of the work. It has been found that the normal pressure and the micro-slip at the interfaces are the major parameters influencing the damping capacity of jointed riveted structures. The suggested method can be effectively utilized by the designers to fabricate the engineering built-up structures depending on the requirements of the damping capacity.
Mitigation of Building Responses to DDC Impacts by Soft and Stiff Wave Barriers
Authors: Ye Lu  , Yong Tan
Published: September 2010

This paper performed a systematic in-depth investigation into the effectiveness of both soft and stiff wave barriers in reducing building responses to deep dynamic compaction (DDC) impacts. The effectiveness of wave barriers was evaluated in terms of two parameters, i.e., the reduction in the vibration acceleration for the floors of the building and the reduction of the settlement of the building. This investigation was achieved by a series of comprehensive parametric studies via a two-dimensional finite element method combined with a dynamic approach for simulating DDC impacts. The dynamic approach is based on the time history of tamper penetration depth. Its accuracy and reliability was validated using the field measurements and experimental data from the literature. During the parametric studies, five wave barriers were examined, which included two soft barriers (an open trench and an in-filled slurry-bentonite trench) and three stiff barriers (an in-filled concrete trench, a wood panel barrier, and a steel sheet pile wall). The geometrical (barrier locations) and dimensional effects (barrier depths and widths) on mitigation of building responses were examined for each barrier, and the efficiencies of these wave barriers were compared.
Preview Control of Slow-active Suspension Systems
Authors: ElMadany M.M. , Al Bassam B.A. , Fayed A.A.
Published: September 2010

Preview control is investigated for active suspension systems. Two preview concepts are used: (1) look-ahead preview, where the information relating to roadway disturbances about to be encountered by the moving vehicle is assumed to be sensed, and (2) wheelbase preview, where knowledge of the front wheel states is used to improve performance at the rear of the vehicle. A method based on optimal control theory is presented to find the control laws for a half-car equipped with both fully active and slow-active systems under preview. The random road profile is assumed to be the output of a filtered white-noise process. Human perception of vibration is considered in the design of the active suspension systems. The design of the preview controller is reduced to the classical linear quadratic regulator of the original system and the previewed road inputs. Integral constraints are included in the performance index to achieve better body attitude control. The effect of preview control on vehicle performance characteristics in terms of ride comfort, suspension deflections and road-holding ability is investigated. The results show that the use of wheelbase preview along with look-ahead preview improves all aspects of the suspension performance.
Optimization criteria for tuned mass dampers for structural vibration control under stochastic excitation
Authors: Marano Giuseppe Carlo , Greco Rita
Published: September 2010

In this work a comparative analysis between different optimization criteria is performed for a linear Tuned Mass Damper (TMD) devices problem. Optimal TMD mechanical parameters are evaluated considering a simple one degree-of-freedom system subject to a base acceleration modeled as a stationary filtered stochastic process. Whereas common TMD optimization methods consider only TMD frequency and damping ratio as design variables, in this study a complete approach will be proposed, which takes into account also the TMD mass as design variable. The effectiveness of the vibration control strategy is evaluated expressing the objective function in terms of two different reduction factors of the system response: the displacement and the inertial acceleration, respectively. The mechanical characteristics of the TMD, frequency ratio, damping ration and mass ratio, represent the design variables of the optimization problem. This is carried out numerically and then various analyses of sensitivity are developed by varying the input and structural parameters in order to assess the efficiency of the TMD strategy under different input and mechanical configurations. Variations between different criteria are also evaluated.
Internet-Facilitated Commercial Sexual Exploitation of Children: Findings From a Nationally Representative Sample of Law Enforcement Agencies in the United States
Authors: Mitchell Kimberly J. , Jones Lisa M. , Finkelhor David , Wolak Janis
Published: September 2010

This article explores the variety of ways in which the Internet is used to facilitate the commercial sexual exploitation of children (CSEC) and provides national incidence estimates for the number of arrests involving such technology-facilitated crimes in 2006. The National Juvenile Online Victimization Study is a nationally representative longitudinal study of more than 2,500 local, county, state, and federal law enforcement agencies across the United States. The current article utilizes Wave 2 data, which surveyed arrests in 2006 for Internet-related sex crimes against minors. Detailed data were collected via telephone interviews with investigators about 1,051I individual arrest cases. Findings show that an estimated 569 arrests for Internet-facilitated commercial sexual exploitation of children (IF-CSEC) occurred in the United States in 2006. Offenders in IF-CSEC cases fell into two main categories: (1) those who used the Internet to purchase or sell access to identified children for sexual purposes including child pornography (CP) production (36% of cases), and (2) those who used the Internet to purchase or sell CP images they possessed but did not produce (64% of cases). Offenders attempting to profit from child sexual exploitation were more likely than those who were purchasing to have (a) prior arrests for sexual and nonsexual offenses, (b) a history of violence, (c) produced CP, (d) joined forces with other offenders, and (e) involved female offenders. Although the number of arrests for IF-CSEC crimes is relatively small, the victims of these crimes are a high-risk subgroup of youth, and the offenders who try to profit from these crimes are particularly concerning from a child welfare perspective.
Ethics and Development Evaluation: Introduction
Authors: Grasso Patrick G.
Published: September 2010

Although the instrumental value of evaluating international development projects, programs, and policies long has been understood, its ethical dimension has not often been addressed. Yet on examination it is apparent that failure to carry out sound evaluation runs the risks of continuing to implement faulty development activities and underinvesting in more successful approaches. Such ‘‘mistakes’’ bring with them huge opportunity costs for developing countries, waste of resources for donor country taxpayers, and most important, poorer life outcomes for those who should be the beneficiaries of development efforts. Data from a number of sources confirm that development evaluation often is underresourced, raising the specter of these negative consequences.
Longitudinal data for interdisciplinary ageing research. Design of the Linnaeus Database
Authors: Malmberg Gunnar , Nilsson Lars-Göran , Weinehall Lars
Published: September 2010

Rationale: To allow for interdisciplinary research on the relations between socioeconomic conditions and health in the ageing population, a new anonymized longitudinal database — the Linnaeus Database — has been developed at the Centre for Population Studies at Umeå University. This paper presents the database and its research potential. Design: Using the Swedish personal numbers the researchers have, in collaboration with Statistics Sweden and the National Board for Health and Welfare, linked individual records from Swedish register data on death causes, hospitalization and various socioeconomic conditions with two databases — Betula and VIP (Västerbottens Intervention Programme) — previously developed by the researchers at Umeå University. Whereas Betula includes rich information about e.g. cognitive functions, VIP contains information about e.g. lifestyle and health indicators. Population and sample size: The Linnaeus Database includes annually updated socioeconomic information from Statistics Sweden registers for all registered residents of Sweden for the period 1990 to 2006, in total 12,066,478. The information from the Betula includes 4,500 participants from the city of Umeå and VIP includes data for almost 90,000 participants. Both datasets include cross-sectional as well as longitudinal information. Potential: Due to the coverage and rich information, the Linnaeus Database allows for a variety of longitudinal studies on the relations between, for instance, socioeconomic conditions, health, lifestyle, cognition, family networks, migration and working conditions in ageing cohorts. Conclusions: By joining various datasets developed in different disciplinary traditions new possibilities for interdisciplinary research on ageing emerge.
Return to work among employees with common mental disorders: Study design and baseline findings from a mixed-method follow-up study
Authors: Nielsen Maj Britt D. , Bültmann Ute , Amby Malene , Christensen Ulla , Diderichsen Finn , Rugulies Reiner
Published: September 2010

Aims: Most research on return-to-work (RTW) has focused on musculoskeletal disorders. To study RTW in employees sick-listed with common mental disorders (CMD), e.g., stress, depression, and anxiety, the National Research Centre for the Working Environment initiated a study on ‘‘Common Mental Disorders, Return-to-work, and Long-term Sickness Absence’’ (CORSA). The aim of the study is (1) to identify predictors of RTW from the environmental, the individual, and the health-related domain and (2) to explore the RTW process based on study participants’ experiences. The purpose of this paper is to present the study design and the characteristics of the participants, including analyses on non-response and the prevalence of major depression. Methods: CORSA is a mixed-method follow-up study encompassing quantitative and qualitative analyses in a cohort of employees sick-listed with CMD. Participants were all employees who suffered from CMD and whose applications for sickness absence benefits were processed by the Job Centre Copenhagen (a subunit of the municipality) between July and December 2007 (n = 721). Data on predictors for RTW were collected from (1) administrative application forms filled out by all participants when applying for benefits (n = 721), and (2) baseline questionnaires sent to all participants (responders: n = 298). Data on RTW was retrieved from a national sickness absence registry and from 6-month follow-up questionnaires (n = 226). To explore the RTW process we will primarily use data from in-depth interviews with selected participants (n = 16) supplemented with data from the two questionnaires. Conclusions: The mixed method design allows for a more comprehensive understanding of RTW by triangulating qualitative and quantitative methods.
Dietary, social, and environmental determinants of obesity in Kenyan women
Authors: Steyn Nelia P. , Nel Johanna H. , Parker Whadi-Ah , Ayah Rosemary , Mbithe Dorcus
Published: September 2010

Aim: To assess the determinants of overweight and obesity in Kenyan women considered to be undergoing the nutrition transition. Methods: A nationally representative sample of women (n = 1008) was randomly drawn. Weight, height, waist, and hip circumference were measured. A 24-hour dietary recall was conducted with each participant and a socio-demographic questionnaire completed. Data was analysed by age, education, location, and socioeconomic status. Risk for obesity was calculated while adjusting for age and location. Results: Overweight and obesity (BMI ≥ 25 kg/m2) were highly prevalent in Kenya (43.3%). Urbanisation appears to be an important determinant of obesity since obesity was most prevalent in urban women in the high income group. Women in the high income group (7278 kJ) and in urban areas (7049 kJ) had the highest mean energy intakes. There were also significant urban/rural and income differences in the contribution of macronutrients to energy intake. Total fat intake was 34.5% of energy (E) in urban areas and 29.7% E in rural areas; while carbohydrates contributed 69.9% E in rural areas and 57.4% E in urban areas (p < 0.0001). Overweight was significantly more likely in the highest income group; among households where room density was low; electricity or gas was used for cooking; and households had own tap and/or own flush toilet. Conclusions: This study suggests that urbanisation and its associated economic advancement as well as changes in dietary habits are among the most important determinants of overweight and obesity in Kenyan women.
The PPE enterprise: A substantive research programme
Authors: Hamlin Alan
Published: September 2010

This article characterizes politics, philosophy, and economics (PPE) as a substantive research programme as a flexible and analytic debate on the relations between the individual and society that incorporates both positive and normative analyses. This, in contrast to a view of PPE as a series of interdisciplinary or multidisciplinary topics. To this end, I sketch the general shape of the research programme, it boundaries and its features, before offering a slightly more detailed account of some aspects of the PPE programme. I also defend the claim that there is some value in recognizing PPE as a research programme, and after discussing the conditions required for the programme to thrive, suggest that there is some reason to be concerned for its future.
The PPE enterprise: Common Hobbesian roots and perspectives
Authors: Kliemt Hartmut
Published: September 2010

Conceptualizing behavior decision theoretically as being ‘pulled’ (by an expected future) is fundamentally different from conceptualizing it as ‘pushed’ (or determined by past conditions according to causal laws). However, the fundamental distinction between teleological and non-teleological explanations not withstanding, decision-theoretic and evolutionary ‘ways of world making’ lead to strikingly similar forms of political, philosophical, and economic models. Common Hobbesian roots can account historically for the emergence of such a common ‘PPE’ outlook, while a game-theoretic framework of indirect evolution can accommodate the fundamental methodological tension between teleological and non-teleological approaches or the ‘humanities’ and the ‘science’ traditions in PPE’s disciplines.
Operations Intent and Effects Model
Authors: Gustavsson Per M , Hieb Michael R , Moore Philip , Eriksson Patric , Niklasson Lars
Published: September 2010

Military missions in the 21st century are characterized by combinations of traditional symmetric conventional warfare, irregular warfare, and operations other than war.The inherent uncertainty in an actual mission and the variety of potential organizations (e.g. multi-agency, non-governmental, private volunteer, international, international corporations) from several countries that support the mission makes collaboration and co-ordination a key capability for command and control. The ability to communicate and automatically process intent and effects is vital in order for a commander to cooperate with other organizations and agencies and lead subordinates in such a way that the overall mission is completed in the best possible way, including exploitation of fleeting opportunities, i.e. enable for self-synchronization amongst teams and allow for subordinate initiatives. However, intent and effects are often absent in the current and forthcoming digitalized information models, and if intent and effects are present it is likely to be found that the representations are made as free-text fields based on natural language. However, such messages are very difficult to disambiguate, particularly for automated machine systems. The overall objective for the Operations Intent and Effects Model is to support operational and simulated systems by a conceptual intent and effects model and a formalism that is human and machine interpretable.
A Multimethod Approach to the Study of Sensitive Organizational Issues
Authors: Jehn Karen A. , Jonsen Karsten
Published: September 2010

Sensitive organizational issues such as conflict, lying and deceit, and personal health issues are difficult to investigate because of their complex, elusive, and sometimes threatening nature as well as their potential consequences. In this article, an approach is presented that uses triangulation of multiple quantitative and qualitative methods to investigate sensitive organizational issues. This study of organizational conflict illustrates special data elicitation techniques (e.g., tree graphs, third-person questioning) designed to decrease the reluctance of employees to respond to various forms of inquiry. The qualitative approach complements the survey methods by identifying, categorizing, and verifying the existence of constructs. The benefits of the elicitation techniques, computerized text analysis, and multimethod comparison processes as remedies for research problems accentuated in studies of sensitive organizational issues are discussed.
Chamosite, a naturally occurring clay as a versatile catalyst for various organic transformations
Authors: Arundhathi R. , Sreedhar B. , Parthasarathy G.
Published: September 2010

The chlorite-group mineral chamosite occurs in nanocrystalline form (~200 nm grain size) as a naturally occurring clay in the Quaternary marine sedimentary deposits near Kudiamozhi, Tuticorin District, Tamil Nadu, India; samples were used in this study as a reusable catalyst. The clay has the usual alternating tetrahedral-octahedral-tetrahedral silicate/aluminate/silicate layer structural arrangement (sometimes called the 2:1 silicate or talc layer structure). The interlayer and the t-o-t layer are bound together by both electrostatic and hydrogen-bonding forces. This natural clay catalyst has been well characterized by various techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), X-ray diffraction (XRD), temperature programmed desorption (TPD), thermal analysis and BET surface area measurements (Sreedhar et al., 2009); it has been utilized for various organic transformations such as acylation of alcohols and amines, cyclization of arylaldehydes with O-phenylenediamines and C-O bond formation reactions.
A mineralogical identification of a Tunisian clayey soil and fabric changes during wetting
Authors: Souli H. , Fleureau J.-M. , Trabelsi Ayadi M. , Kbir-Ariguib N.
Published: September 2010

A clayey soil from southern Tunisia has been studied in order to assess its possible use as an anti-pollution barrier. The soil has been characterized from both geotechnical and physicochemical points of view. The physicochemical characterization was carried out using X-ray diffraction, thermogravimetric and differential thermal analyses, specific surface area and cation exchange capacity measurements. Hydration tests were carried out using oedometers to determine the swelling behaviour of compacted specimens under different stress conditions. The large swelling pressure (420 kPa) is in agreement with the mainly smectitic character of the soil highlighted by the physicochemical tests. The changes in the fabric of the soil and in its porosity after the hydration tests were investigated using the same physicochemical methods, and related to the macroscopic hydro-mechanical properties. X-ray diffraction and mercury intrusion measurements show that there are changes in the interlayer spacing, particle size and inter-aggregate pore distribution. Comparing the properties of the soil with the Belgian guidelines for the construction of anti-pollution barriers showed that the material was suitable for that use.
Clay resources in the Nelas region (Beira Alta), Portugal. A contribution to the characterization of potential raw materials for prehistoric ceramic production
Authors: Marques R. , Jorge A. , Franco D. , Dias M. I. , Prudêncio M. I.
Published: September 2010

Mineralogical and chemical compositions of residual and sedimentary clays (bulk and <2 μm fraction) from the Nelas region (schist, aplite-pegmatites, granites and Tertiary sediments from both Mondego River margins), Portugal, were studied, aiming to establish indicators for raw materials in ancient ceramic provenance studies. The mineralogy of bulk material does not provide a clear distinction between samples. Among clay minerals, kaolinite dominates, except in the aplite-pegmatites where illite prevails. Smectite was only found in sediments of the left river bank.

A more successful result was the geochemical differentiation of clay types. The weathered schist presents greater enrichment in Cr, whereas the clay fraction of aplite-pegmatites shows enrichment in all the chemical elements studied. The sediments and weathered granites are not easy to differentiate; the best geochemical indicators are U (lower contents in clay-size fraction of sediments) and REE patterns in both bulk and clay-size fraction.
Red soils developed from Quaternary deposits on the Linkuo terrace, northern Taiwan
Authors: Shao Ping Hua , Shea Kai-Shuan , Wang Ming Kuang , Shau Yen Hong , Chiang Kai Yin , Tsao Tsung Ming
Published: September 2010

The Linkuo terrace, situated to the west of the Taipei Basin in NW Taiwan, has thick red soils that have been little studied. This paper aims to interpret the development of these soils through chemical and micromorphological investigations, and relate the soils to their palaeo-environments. The soil samples were air dried, crushed and passed through a 2 mm sieve, and then subjected to conventional soil chemical and physical analyses, together with clay mineralogical and morphological characterization. Pedons I and II were clay with low base saturation (BS), cation-exchange capacity (CEC), and exchangeable cations. The pH of pedons I and II ranged from 3.80 to 5.26. The low magnetic susceptibility of these soils indicates that no magnetite (Fe3O4) or maghemite (γ-Fe2O3) are present. X-ray diffraction patterns of the magnetic clay fraction showed lepidocrocite, goethite and hematite, the amounts of which may relate to water fluctuation in the soil environments. Illite, kaolinite and quartz are major clay minerals in the red soil clay fractions. The micromorphology of all horizons showed a great accumulation of Fe-oxides. The upper horizon showed darkened isotropic Fe-oxide materials, and lower horizon showed a black to reddish dense plasma with soil matrix. The groundmass of the oxic horizon is generally characterized by a homogeneous distribution of the different coarse and fine constituents. The thick (4 m depth) and homogeneous red soils of the Linkuo terrace were developed from fine sediments after the gradual subsidence of the Taipei Basin. Alarge amount of gravel was flushed from the Xindian River before the Taipei Basin subsided. The Linkuo red soils can be classified as mesic, Typic Kandiudox. From the chemical compositions of clay fractions and the red soil features, these red soils can be considered as lateritic red earths or red earths that do not reach the criteria for laterite.
Coexistence of pyrophyllite, I-S, R1 and NH4+-rich illite in Silurian black shales (Sierra de Albarracín, NE Spain): metamorphic vs. hydrothermal origin
Authors: Bauluz B. , Subías I.
Published: September 2010

A set of Silurian black shales from Sierra de Albarracín (NE Spain) corresponding to two different sections was studied to determine the relative influence of diagenesis, igneous activity, and regional tectonics on the clay-mineral genesis. The coexistence of pyrophyllite, I-S interstratifications (R1), ammonium-rich illite, potassium illite, kaolin, and chlorite is not the result of prograde evolution during diagenesis – very low-grade metamorphism. Three different stages may be inferred: (1) sedimentation of black shales (Aeronian, Lower Silurian, to basal Ludfordian, Upper Silurian) and the subsequent diagenetic process producing the coexistence of quartz, illite, kaolinite, organic matter, etc.; (2) intrusion of andesitic sills producing hydrothermal alteration and crystallization of pyrophyllite, ammonium-rich illites, smectite, I-S R1 phases and jarosite; and (3) and folding of shales and sills and development of penetrative schistosity during the late Variscan leading to illite and paragonite recrystallization reaching the anchizone grade.
K-Ar, δ18O and REE constraints on the genesis of ammonium illite from the Harghita Bãi hydrothermal system, Romania
Authors: Clauer N. , Liewig N. , Bobos I.
Published: September 2010

Ammonium illite and ammonium illite-smectite mixed layers, together with potassium illite, smectite and minute amounts of kaolinite were identified in hydrothermally altered andesite rocks from the Harghita Bãi area of the Eastern Carpathians, Romania. K-Ar dating and oxygen isotope tracing, as well as rare-earth elemental analyses were made to provide new information on the timing and crystal-chemical processes characterizing the crystallization and further evolution of these illite-type mineral phases.

The combined results suggest the occurrence of hydrothermal activity in two distinct episodes with nucleation of two generations of illite-type particles of different chemistry and morphology. About 9.5 Ma ago, potassium illite crystallized in alteration halos of the porphyry Cu system, probably at a temperature of ~270ºC from fluids having a δ18O of ~2.9% (V-SMOW). Associated smectite seems to have precipitated slightly later in external alteration halos at a similar temperature, but from fluids depleted in alkalis and with a different δ18O. Alternately, ammonium-rich illite-smectite mixed layers formed very recently, less than ~1 million years ago at a temperature of ~90ºC from fluids of probable meteoric origin that altered the previously crystallized potassium illite, resulting in the crystallization of a new generation of ammonium illite-smectite mixed layers. Evidence of this dissolution-precipitation process is provided by a significant increase in the δ18O of the mixed-layer structures and by a significant change in their REE contents and distribution patterns. Occurrence of potassium in the ammonium-rich mixed layers probably relates to the progressive alteration of the first-generation potassium illite and a discrete concomitant take up of released K by the new NH4-rich interlayers of the ammonium mixed layered sequence.
The pathogenesis of Plasmodium falciparum malaria in humans: insights from splenic physiology
Authors: Buffet Pierre A. , Safeukui Innocent , Deplaine Guillaume , Brousse Valentine , Prendki Virginie , Thellier Marc , Turner Gareth D. , Mercereau-Puijalon Odile
Published: September 2010

Clinical manifestations of Plasmodium falciparum infection are induced by the asexual stages of the parasite that develop inside red blood cells (RBCs). Because splenic microcirculatory beds filter out altered RBCs, the spleen can innately clear subpopulations of infected or uninfected RBC modified during falciparum malaria. The spleen appears more protective against severe manifestations of malaria in naïve than in immune subjects. The spleen-specific pitting function accounts for a large fraction of parasite clearance in artemisinin-treated patients. RBC loss contributes to malarial anemia, a clinical form associated with subacute progression, frequent splenomegaly, and relatively low parasitemia. Stringent splenic clearance of ring-infected RBCs and uninfected, but parasite-altered, RBCs, may altogether exacerbate anemia and reduce the risks of severe complications associated with high parasite loads, such as cerebral malaria. The age of the patient directly influences the risk of severe manifestations. We hypothesize that coevolution resulting in increased splenic clearance of P. falciparum–altered RBCs in children favors the survival of the host and, ultimately, sustained parasite transmission. This analysis of the RBC–spleen dynamic interactions during P falciparum infection reflects both data and hypotheses, and provides a framework on which a more complete immunologic understanding of malaria pathogenesis may be elaborated.
Reduced-intensity conditioning significantly improves survival of patients with hemophagocytic lymphohistiocytosis undergoing allogeneic hematopoietic cell transplantation
Authors: Marsh Rebecca A. , Vaughn Gretchen , Kim Mi-Ok , Li Dandan , Jodele Sonata , Joshi Sarita , Mehta Parinda A. , Davies Stella M. , Jordan Michael B. , Bleesing Jack J. , Filipovich Alexandra H.
Published: September 2010

Recent experience suggests that reduced-intensity conditioning (RIC) regimens can improve the outcomes of patients with hemophagocytic lymphohistiocytosis (HLH) undergoing allogeneic hematopoietic cell transplantation (HCT). However, studies directly comparing RIC to myeloablative conditioning (MAC) regimens are lacking. Forty patients with HLH underwent allogeneic HCT between 2003-2009 at Cincinnati Children's Hospital. Fourteen patients received MAC consisting of busulfan, cyclophosphamide, and antithymocyte globulin plus or minus etoposide. Twenty-six patients received RIC consisting of fludarabine, melphalan, and alemtuzumab. All patients engrafted. Acute graft-versus-host disease grades II to III occurred in 14% of MAC patients and 8% of RIC patients (P = .3171). Posttransplantation mixed donor/recipient chimerism developed in 18% of MAC patients and 65% of RIC patients (P = .0110). The majority of patients with mixed chimerism received intervention with reduction of immune suppression plus or minus donor lymphocyte infusion or stem cell boost, which stabilized or increased donor contribution to hematopoiesis and prevented relapse of HLH in all but 1 patient. Grade II to III graft-versus-host disease occurred in 5 of 14 RIC patients after donor lymphocyte infusion. The overall estimated 3-year survival after HCT was 43% (confidence interval = ± 26%) for MAC patients and 92% (confidence interval = ± 11%) for RIC patients (P = .0001). We conclude that RIC significantly improves the outcome of patients with HLH undergoing allogeneic HCT.
RGS/Gi2α interactions modulate platelet accumulation and thrombus formation at sites of vascular injury
Authors: Signarvic Rachel S. , Cierniewska Aleksandra , Stalker Timothy J. , Fong Karen P. , Chatterjee Manash S. , Hess Paul R. , Ma Peisong , Diamond Scott L. , Neubig Richard R. , Brass Lawrence F.
Published: September 2010

Although much is known about extrinsic regulators of platelet function such as nitric oxide and prostaglandin I2 (PGI2), considerably less is known about intrinsic mechanisms that prevent overly robust platelet activation after vascular injury. Here we provide the first evidence that regulators of G-protein signaling (RGS) proteins serve this role in platelets, using mice with a G184S substitution in Gi2α that blocks RGS/Gi2 interactions to examine the consequences of lifting constraints on Gi2-dependent signaling without altering receptor:effector coupling. The results show that the Gi2α(G184S) allele enhances platelet aggregation in vitro and increases platelet accumulation after vascular injury when expressed either as a global knock-in or limited to hematopoietic cells. Biochemical studies show that these changes occur in concert with an attenuated rise in cyclic adenosine monophosphate levels in response to prostacyclin and a substantial increase in basal Akt activation. In contrast, basal cyclic adenosine monophosphate (cAMP) levels, agonist-stimulated increases in [Ca++]i, Rap1 activation, and α-granule secretion were unaffected. Collectively, these observations (1) demonstrate an active role for RGS proteins in regulating platelet responsiveness, (2) show that this occurs in a pathway-selective manner, and (3) suggest that RGS proteins help to prevent unwarranted platelet activation as well as limiting the magnitude of the normal hemostatic response.
In vivo efficacy of platelet-delivered, high specific activity factor VIII variants
Authors: Greene Teshell K. , Wang Cheng , Hirsch Jessica D. , Zhai Li , Gewirtz Jamie , Thornton Michael A. , Miao Hongzhi Z. , Pipe Steven W. , Kaufman Randal J. , Camire Rodney M. , Arruda Valder R. , Kowalska M. Anna , Poncz Mortimer
Published: September 2010

Ectopically expressed, human B-domainless (hB) factor 8 (F8) in platelets improves hemostasis in hemophilia A mice in several injury models. However, in both a cuticular bleeding model and a cremaster laser arteriole/venule injury model, there were limitations to platelet-derived (p) hBF8 efficacy, including increased clot embolization. We now address whether variants of F8 with enhanced activity, inactivation resistant F8 (IR8) and canine (c) BF8, would improve clotting efficacy. In both transgenic and lentiviral murine model approaches, pIR8 expressed at comparable levels to phBF8, but pcBF8 expressed at only approximately 30%. Both variants were more effective than hBF8 in cuticular bleeding and FeCl3 carotid artery models. However, in the cremaster injury model, only pcBF8 was more effective, markedly decreasing clot embolization. Because inhibitors of F8 are stored in platelet granules and IR8 is not protected by binding to von Willebrand factor, we also tested whether pIR8 was effective in the face of inhibitors and found that pIR8 is protected from the inhibitors. In summary, pF8 variants with high specific activity are more effective in controlling bleeding, but this improved efficacy was inconsistent between bleeding models, perhaps reflecting the underlying mechanism(s) for the increased specific activity of the studied F8 variants.
Effect of cAMP derivates on assembly and maintenance of tight junctions in human umbilical vein endothelial cells
Authors: Beese Michaela , Wyss Kristin , Haubitz Marion , Kirsch Torsten
Published: September 2010

Background

Endothelial tight and adherens junctions control a variety of physiological processes like adhesion, paracellular transport of solutes or trafficking of activated leukocytes. Formation and maintenance of endothelial junctions largely depend on the microenvironment of the specific vascular bed and on interactions of the endothelium with adjacent cell types. Consequently, primary cultures of endothelial cells often lose their specific junctional pattern and fail to establish tight monolayer in vitro. This is also true for endothelial cells isolated from the vein of human umbilical cords (HUVEC) which are widely used as model for endothelial cell-related studies.

Results

We here compared the effect of cyclic 3'-5'-adenosine monophosphate (cAMP) and its derivates on formation and stabilization of tight junctions and on alterations in paracellular permeability in HUVEC. We demonstrated by light and confocal laser microscopy that for shorter time periods the sodium salt of 8-bromoadenosine-cAMP (8-Br-cAMP/Na) and for longer incubation periods 8-(4-chlorophenylthio)-cAMP (pCPT-cAMP) exerted the greatest effects of all compounds tested here on formation of continuous tight junction strands in HUVEC. We further demonstrated that although all compounds induced protein kinase A-dependent expression of the tight junction proteins claudin-5 and occludin only pCPT-cAMP slightly enhanced paracellular barrier functions. Moreover, we showed that pCPT-cAMP and 8-Br-cAMP/Na induced expression and membrane translocation of tricellulin.

Conclusions

pCPT-cAMP and, to a lesser extend, 8-Br-cAMP/Na improved formation of continuous tight junction strands and decreased paracellular permeability in primary HUVEC. We concluded that under these conditions HUVEC represent a feasible in vitro model to study formation and disassembly of endothelial tight junctions and to characterize tight junction-associated proteins
Diversity of sponge mitochondrial introns revealed by cox 1sequences of Tetillidae
Authors: Szitenberg Amir , Rot Chagai , Ilan Micha , Huchon Dorothée
Published: September 2010

Background

Animal mitochondrial introns are rare. In sponges and cnidarians they have been found in the cox 1 gene of some spirophorid and homosclerophorid sponges, as well as in the cox 1 and nad 5 genes of some Hexacorallia. Their sporadic distribution has raised a debate as to whether these mobile elements have been vertically or horizontally transmitted among their hosts. The first sponge found to possess a mitochondrial intron was a spirophorid sponge from the Tetillidae family. To better understand the mode of transmission of mitochondrial introns in sponges, we studied cox 1 intron distribution among representatives of this family.

Results

Seventeen tetillid cox 1 sequences were examined. Among these sequences only six were found to possess group I introns. Remarkably, three different forms of introns were found, named introns 714, 723 and 870 based on their different positions in the cox 1 alignment. These introns had distinct secondary structures and encoded LAGLIDADG ORFs belonging to three different lineages. Interestingly, sponges harboring the same intron form did not always form monophyletic groups, suggesting that their introns might have been transferred horizontally. To evaluate whether the introns were vertically or horizontally transmitted in sponges and cnidarians we used a host parasite approach. We tested for co-speciation between introns 723 (the introns with the highest number of sponge representatives) and their nesting cox 1 sequences. Reciprocal AU tests indicated that the intron and cox 1 tree are significantly different, while a likelihood ratio test was not significant. A global test of co-phylogeny had significant results; however, when cnidarian sequences were analyzed separately the results were not significant.

Conclusions

The co-speciation analyses thus suggest that a vertical transmission of introns in the ancestor of sponges and cnidarians, followed by numerous independent losses, cannot solely explain the current distribution of metazoan group I introns. An alternative scenario that includes horizontal gene transfer events appears to be more suitable to explain the incongruence between the intron 723 and the cox 1 topologies. In addition, our results suggest that three different intron forms independently colonized the cox 1 gene of tetillids. Among sponges, the Tetillidae family seems to be experiencing an unusual number of intron insertions.
Effect of a multispecies probiotic supplement on quantity of irritable bowel syndrome-related intestinal microbial phylotypes
Authors: Lyra Anna , Krogius-Kurikka Lotta , Nikkilä Janne , Malinen Erja , Kajander Kajsa , Kurikka Kyösti , Korpela Riitta , Palva Airi
Published: September 2010

Background

Probiotics can alleviate the symptoms of irritable bowel syndrome (IBS), possibly by stabilizing the intestinal microbiota. Our aim was to determine whether IBS-associated bacterial alterations were reduced during multispecies probiotic intervention consisting of Lactobacillus rhamnosus GG, L. rhamnosus Lc705, Propionibacterium freudenreichii ssp. shermanii JS and Bifidobacterium breve Bb99. The intervention has previously been shown to successfully alleviate gastrointestinal symptoms of IBS.

Methods

The faecal microbiotas of 42 IBS subjects participating in a placebo-controlled double-blind multispecies probiotic intervention were analysed using quantitative real-time polymerase chain reaction (qPCR). Eight bacterial targets within the gastrointestinal microbiota with a putative IBS association were measured.

Results

A phylotype with 94% similarity to Ruminococcus torques remained abundant in the placebo group, but was decreased in the probiotic group during the intervention (P = 0.02 at 6 months). In addition, the clostridial phylotype, Clostridium thermosuccinogenes 85%, was stably elevated during the intervention (P = 0.00 and P = 0.02 at 3 and 6 months, respectively). The bacterial alterations detected were in accordance with previously discovered alleviation of symptoms.

Conclusions

The probiotic supplement was thus shown to exert specific alterations in the IBS-associated microbiota towards the bacterial 16S rDNA phylotype quantities described previously for subjects free of IBS. These changes may have value as non-invasive biomarkers in probiotic intervention studies.
Is elevated SUA associated with a worse outcome in young Chinese patients with acute cerebral ischemic stroke?
Authors: Zhang Bin , Gao Cong , Yang Ning , Zhang WeiZhi , Song XingWang , Yin JianRui , Pu ShuXiang , Yi YongHong , Gao QingChun
Published: September 2010

Background

Elevated serum uric acid (SUA) levels can enhance its antioxidant prosperities and reduce the occurrence of cerebral infarction. Significantly elevated SUA levels have been associated with a better prognosis in patients with cerebral infarction; however, the results from some studies on the relationship between SUA and the prognosis of patients with cerebral infarction remain controversial.

Methods

We analyzed the relationship between SUA and clinical prognosis of 585 young Chinese adults with acute ischemic stroke as determined by the modified Rankin Scale at discharge. Using multivariate logistic regression modeling, we explore the relationship between SUA levels and patient's clinical prognosis.

Results

Lower SUA levels at time of admission were observed more frequently in the lowest quintile for patients with severe stroke (P = 0.02). Patients with cerebral infarction patients caused by small-vessel blockage had higher SUA concentrations (P = 0.01) and the lower mRS scores (P < 0.01) were observed in, while the lowest SUA concentrations and the highest mRS scores were seen in patients with cardiogenic cerebral infarction patients. Logistic regression analysis adjusted for confounders confirmed the following independent predictors for young cerebral infarction: uric acid (-0.003: 95%CI 0.994 to 0.999) and platelet (0.004, 95%CI 0.993 to 0.996).

Conclusion

Elevated SUA is an independent predictor for good clinical outcome of acute cerebral infarction among young adults.