Health professionals' attitudes and emotions towards working with adults with intellectual disability (ID) and mental ill health

OBJECTIVES

Mainstream mental health services are providing more care for individuals with an intellectual disability (ID); this has implications for staff and service users. Attitudes of staff towards people with ID in mental health services may be negative and negative staff attitudes may have a detrimental impact on service provision.

DESIGN

A cross-sectional design was used.

METHODS

A questionnaire designed to investigate the attitudes and emotions of staff towards delivering mental health care to adults with ID was completed by 84 staff from mainstream and specialist ID services.

RESULTS

Staff in both services experienced more positive emotions when working with clients whom they are currently employed to work with. When the frequency of contact with adults with ID, the number of individuals worked with and the amount of formal ID training received were considered, there was no significant difference between the attitudes of staff in both services. Positive correlations were found between attitude scores and positive emotional experiences in both services.

CONCLUSIONS

The research suggests that numerous factors, including the role of emotional experience and a number of environmental aspects, need to be considered in the context of providing mental health services to adults with ID to ensure the highest quality. Research limitations and clinical implications of the study are also considered.

Effects of pine bark supplementation on performance, rumen fermentation, and carcass characteristics of Kiko crossbred male goats

Twenty-two Kiko crossbred male goats (Capra hircus; initial BW = 27.5 ± 1.04 kg) were used in a randomized complete block design to determine the effects of feeding pine bark (PB; Pinus taeda L.) on animal performance, rumen fermentation, blood parameters, fecal egg counts (FEC), and carcass characteristics in goats. Experimental treatments included the control diet [0% PB plus 30% wheat straw (WS)], 15% PB plus 15% WS, and 30% PB plus 0% WS (on as-fed basis), where PB replaced WS. Freshly air-dried PB and WS were finely (1.5 to 3.0 mm) ground and incorporated in the grain mixes. Experimental diets provided a total of 1.9, 16.3, and 32 g of condense tannins (CT)/kg DM in 0%, 15%, and 30% PB diets, respectively. The grain mixes were fed daily at 85% of the feed offered, with remaining 15% consisting of Bermuda grass hay (Cynodon dactylon). Animals were fed once a day at 0800 h, and feed offered and refused was monitored for an 83-d performance period. Rumen and blood samples were collected at d 0, 50, and 80 of the study. Carcass traits were assessed after slaughter at the end of performance period. There was no difference in initial BW, hay, and total NDF intake among treatments; however, final BW (P = 0.06), ADG (P < 0.01), grain mix intake (P < 0.001), total DMI (P < 0.001), and G:F (P < 0.04) increased linearly as the PB increased in the diets. Rumen ammonia N, acetate, isovalerate and acetate-to-propionate ratio were reduced linearly (P < 0.05). There was no difference in carcass traits except cold carcass weight (P = 0.06), which tended to increase linearly in goats fed 15% and 30% PB. Breast, sirloin, trim trait, liver, and hide weight increased (linear; P < 0.01) with addition of PB. Blood basophils, alanine transaminase, aspartate aminotransferase, albumin, Na, and Cl concentrations decreased (linear; P < 0.02 to 0.01) as PB supplementation increased. Supplementation of PB reduced (linear; P < 0.01) average FEC. Addition of PB in the diets improved performance, reduced FEC, and favorably modified rumen fermentation.

Knowledge of HIV transmission through breast milk among drug-dependent pregnant women

Abstract The current study examined the correlates of knowledge about human immunodeficiency virus (HIV) transmission through breast milk among drug-dependent pregnant women. There is a tremendous need to examine the knowledge about HIV transmission through breastfeeding among this largely understudied, but high-risk subset of pregnant women in order to minimize the extent to which they pass HIV to their children after giving birth. Participants included 97 pregnant women from Baltimore, MD, USA. Prevalence of drug use over the last 6 months included 37.1% reporting smoking marijuana, 36.1% injecting heroin, and 67.0% smoking crack. When asked whether HIV could be transmitted through breast milk, 72 women (74.2%) answered correctly. Our results indicate that the overall knowledge about transmission through breast milk is relatively low. Furthermore, participants who smoked crack during the past 6 months and participants who were white were significantly less likely to have correct knowledge about this topic. Our findings have important implications with regard to preventive interventions for this population. Future research is needed to determine how to best modify these interventions to address the specific needs of drug-dependent pregnant women, and how to specifically target white women and women who smoke crack.

Appendiceal endometriosis presenting as a cecal mass

Appendiceal intussusception is described, in the surgical literature, as a rare entity with a 0.01% incidence (1). Presenting symptoms can be vague, and preoperative diagnosis is difficult. Given concerns about malignancy, complete surgical removal of the mass and histologic examination of the specimen are paramount, in order to ensure correct diagnosis and proper treatment. Herein, we describe the case of a 44-year-old woman with appendiceal endometriosis leading to intussusception.

Problem recognition, intention to stop use, and treatment use among regular heroin injectors

This study investigated frequency of recent use as an explanatory variable in problem recognition and intention to stop use among regular injection heroin users. Data from the NEURO-HIV Epidemiologic Study, an investigation of neuropsychological and social-behavioral risk factors for HIV and hepatitis A, B, and C among injection and noninjection drug users, were used in the analyses. Participants (N = 337) consisted of those who reported injecting heroin daily or nearly daily for a period of 3 months. Multiple linear regression analysis revealed that frequency of recent injection drug use predicted problem recognition (β = .17), but not intention to stop use; although marginal, being female (β = .15), and homeless (β = .14) contributed to intention to stop use. Past 6-month treatment participation was 48%, and current treatment enrollment was 26% among study participants. This study highlights the importance of capitalizing on injection drug users' recent use as a mechanism for treatment interventions.

The relationship between challenging behaviour, burnout and cognitive variables in staff working with people who have intellectual disabilities

BACKGROUND

There is evidence to suggest a relationship between the way in which staff perceive challenging behaviour and burnout in staff working with people with intellectual disabilities (ID) and challenging behaviour. However, the evidence of a direct link is equivocal and it is possible that a number of different variables mediate this relationship. The aim of the study is to confirm whether there is a relationship between challenging behaviour and staff burnout, and in addition, to test whether staff perceptions about challenging behaviour mediate this relationship.

METHOD

Seventy-eight staff completed measures of burnout, challenging behaviour and perceptions about challenging behaviour. The perceptions explored included beliefs about the timeline of behaviour, staff's perception of whether they themselves have control over the behaviour, beliefs about clients' ability to control the behaviour and staff's negative emotional responses.

RESULTS

Significant positive correlations were found between challenging behaviour and burnout, challenging behaviour and cognitive variables, and cognitive variables and burnout. Regression analyses demonstrated that negative emotions mediate the relationship between challenging behaviour and burnout.

CONCLUSIONS

The results show evidence that there is a relationship between challenging behaviour and burnout that is mediated by negative emotion, namely the fear of potential assault.

A new, fast algorithm for detecting protein coevolution using maximum compatible cliques

BACKGROUND

The MatrixMatchMaker algorithm was recently introduced to detect the similarity between phylogenetic trees and thus the coevolution between proteins. MMM finds the largest common submatrices between pairs of phylogenetic distance matrices, and has numerous advantages over existing methods of coevolution detection. However, these advantages came at the cost of a very long execution time.

RESULTS

In this paper, we show that the problem of finding the maximum submatrix reduces to a multiple maximum clique subproblem on a graph of protein pairs. This allowed us to develop a new algorithm and program implementation, MMMvII, which achieved more than 600× speedup with comparable accuracy to the original MMM.

CONCLUSIONS

MMMvII will thus allow for more more extensive and intricate analyses of coevolution.

AVAILABILITY

An implementation of the MMMvII algorithm is available at: http://www.uhnresearch.ca/labs/tillier/MMMWEBvII/MMMWEBvII.php.

Assessment of comparative skills between hand-assisted and straight laparoscopic colorectal training on an augmented reality simulator

PURPOSE

The aim of this study was to compare skills sets during a hand-assisted and straight laparoscopic colectomy on an augmented reality simulator.

METHODS

Twenty-nine surgeons, assigned randomly in 2 groups, performed laparoscopic sigmoid colectomies on a simulator: group A (n = 15) performed hand-assisted then straight procedures; group B (n = 14) performed straight then hand-assisted procedures. Groups were compared according to prior laparoscopic colorectal experience, performance (time, instrument path length, and instrument velocity changes), technical skills, and operative error.

RESULTS

Prior laparoscopic colorectal experience was similar in both groups. Both groups had better performances with the hand-assisted approach, although technical skill scores were similar between approaches. The error rate was higher with the hand-assisted approach in group A, but similar between both approaches in group B.

CONCLUSIONS

These data define the metrics of performance for hand-assisted and straight laparoscopic colectomy on an augmented reality simulator. The improved scores with the hand-assisted approach suggest that with this simulator a hand-assisted model may be technically easier to perform, although it is associated with increased intraoperative errors.

Temporal variations in arsenic uptake by rice plants in Bangladesh: the role of iron plaque in paddy fields irrigated with groundwater

The transfer of arsenic to rice grains is a human health issue of growing relevance in regions of southern Asia where shallow groundwater used for irrigation of paddy fields is elevated in As. In the present study, As and Fe concentrations in soil water and in the roots of rice plants, primarily the Fe plaque surrounding the roots, were monitored during the 4-month growing season at two sites irrigated with groundwater containing approximately 130microgl(-1) As and two control sites irrigated with water containing <15microgl(-1) As. At both sites irrigated with contaminated water, As concentrations in soil water increased from <10microgl(-1) to >1000microgl(-1) during the first five weeks of the growth season and then gradually declined to <10microgl(-1) during the last five weeks. At the two control sites, concentrations of As in soil water never exceeded 40microgl(-1). At both contaminated sites, the As content of roots and Fe plaque rose to 1000-1500mgkg(-1) towards the middle of the growth season. It then declined to approximately 300mgkg(-1) towards the end, a level still well above As concentration of approximately 100mgkg(-1) in roots and plaque measured throughout the growing season at the two control sites. These time series, combined with simple mass balance considerations, demonstrate that the formation of Fe plaque on the roots of rice plants by micro-aeration significantly limits the uptake of As by rice plants grown in paddy fields. Large variations in the As and Fe content of plant stems at two of the sites irrigated with contaminated water and one of the control sites were also recorded. The origin of these variations, particularly during the last month of the growth season, needs to be better understood because they are likely to influence the uptake of As in rice grains.

Next-generation acceleration and code optimization for light transport in turbid media using GPUs

A highly optimized Monte Carlo (MC) code package for simulating light transport is developed on the latest graphics processing unit (GPU) built for general-purpose computing from NVIDIA - the Fermi GPU. In biomedical optics, the MC method is the gold standard approach for simulating light transport in biological tissue, both due to its accuracy and its flexibility in modelling realistic, heterogeneous tissue geometry in 3-D. However, the widespread use of MC simulations in inverse problems, such as treatment planning for PDT, is limited by their long computation time. Despite its parallel nature, optimizing MC code on the GPU has been shown to be a challenge, particularly when the sharing of simulation result matrices among many parallel threads demands the frequent use of atomic instructions to access the slow GPU global memory. This paper proposes an optimization scheme that utilizes the fast shared memory to resolve the performance bottleneck caused by atomic access, and discusses numerous other optimization techniques needed to harness the full potential of the GPU. Using these techniques, a widely accepted MC code package in biophotonics, called MCML, was successfully accelerated on a Fermi GPU by approximately 600x compared to a state-of-the-art Intel Core i7 CPU. A skin model consisting of 7 layers was used as the standard simulation geometry. To demonstrate the possibility of GPU cluster computing, the same GPU code was executed on four GPUs, showing a linear improvement in performance with an increasing number of GPUs. The GPU-based MCML code package, named GPU-MCML, is compatible with a wide range of graphics cards and is released as an open-source software in two versions: an optimized version tuned for high performance and a simplified version for beginners (http://code.google.com/p/gpumcml).

Quantification of diffusivities of the human cervical spinal cord using a 2D single-shot interleaved multisection inner volume diffusion-weighted echo-planar imaging technique

BACKGROUND AND PURPOSE

DTI is a highly sensitive technique, which can detect pathology not otherwise noted with conventional imaging methods. This paper provides the atlas of reliable normative in vivo DTI parameters in the cervical spinal cord and its potential applications toward quantifying pathology.

MATERIALS AND METHODS

In our study, we created a reference of normal diffusivities of the cervical spinal cord by using a 2D ss-IMIV-DWEPI technique from 14 healthy volunteers and compared parameters with those in 8 patients with CSM. The 2D ss-IMIV-DWEPI technique was applied in each subject to acquire diffusion-weighted images. FA, lambda( parallel), and lambda( perpendicular) were calculated. A reference of normal DTI indices from 12 regions of interest was created and compared with DTI indices of 8 patients.

RESULTS

A map of reference diffusivity values was obtained from healthy controls. We found statistically significant differences in diffusivities between healthy volunteers and patients with CSM with different severities of disease, by using FA, lambda( parallel), and lambda( perpendicular) values.

CONCLUSIONS

DTI using 2D ss-IMIV-DWPEI is sensitive to spinal cord pathology. This technique can be used to detect and quantify the degree of pathology within the cervical spinal cord from multiple disease states.

Combining size fractionation, scanning electron microscopy, and X-ray absorption spectroscopy to probe zinc speciation in pig slurry

Zinc occurs in high quantity in pig slurry since it is used as an essential micronutrient at high concentrations in animal feeds despite the low Zn assimilation by pigs. Zinc accumulation was measured in soil surface layers that had been amended with pig slurry, while also determining the phytotoxicity as well as the extent of groundwater quality degradation. To accurately predict the mobility and bioavailability of Zn derived from pig slurry spreading, the speciation of this element has to be assessed since the total concentration is not sufficient. This study involved a combination of techniques to investigate Zn speciation in pig slurry. Size fractionation was first performed to account for the complexity of pig slurry, and 75% of total Zn was detected in the 0.45- to 20-mum particle-size range. Then X-ray diffraction, scanning electron microscopy, coupled with energy dispersive spectrometer, and extended X-ray absorption fine structure analyses were combined to assess Zn speciation. The findings highlighted the presence of 49% Zn bound to organic matter, 37% amorphous Zn hydroxides [Zn(OH)(2)], and 14% sphalerite (ZnS).

Continuous long-term immunomodulatory therapy in relapsing multiple sclerosis: results from the 15-year analysis of the US prospective open-label study of glatiramer acetate

The ongoing US Glatiramer Acetate (GA) Trial is the longest evaluation of continuous immunomodulatory therapy in relapsing-remitting multiple sclerosis (RRMS). The objective of this study was to evaluate up to 15 years of GA as a sole disease-modifying therapy. Two hundred and thirty-two patients received at least one GA dose since study initiation in 1991 (mITT cohort), and 100 (43%, Ongoing cohort) continued as of February 2008. Patients were evaluated every 6 months using the Expanded Disability Status Scale (EDSS). Mean GA exposures were 8.6 +/- 5.2, 4.81 +/- 3.69, and 13.6 +/- 1.3 years and mean disease durations were 17, 13, and 22 years for mITT, Withdrawn and Ongoing cohorts, respectively. For Ongoing patients, annual relapse rates (ARRs) maintained a decline from 1.12 +/- 0.82 at baseline to 0.25 +/- 0.34 per year; 57% had stable/improved EDSS scores (change < or = 0.5 points); 65% had not transitioned to secondary progressive multiple sclerosis (SPMS); 38%, 18%, and 3% reached EDSS 4, 6, and 8. For all patients on GA therapy (the mITT cohort), ARRs declined from 1.18 +/- 0.82 to 0.43 +/- 0.58 per year; 54% had stable/improved EDSS scores; 75% had not transitioned to SPMS; 39%, 23%, and 5% reached EDSS 4, 6, and 8. In conclusion, multiple sclerosis patients with mean disease duration of 22 years administering GA for up to 15 years had reduced relapse rates, and decreased disability progression and transition to SPMS. There were no long-term safety issues.

Speciation of Cd and Pb in dust emitted from sinter plant

Many studies have provided evidence of the impact of heavy metals in atmospheric emission. Sinter plants represent the first step in steel production, and are important emitters of Cd and Pb. The toxicity of these two metals depends above all on their speciation. Particles collected before and after the filtration system were analysed to determine the Cd- and Pb-bearing phases, using analytical tools such as XRF, EXAFS or ICP-AES and chemical leaching (sequential extractions adapted to steel dusts). Results show that Pb is associated with carbonate and Cd with chloride. These two types of speciation lead to high solubility under common environmental conditions, which may produce impacts on the environment and health.

405 LEVELS OF HORMONES AND NITRIC OXIDE PRESENT IN FOLLICULAR FLUID UNDER OR NOT UNDER SUPEROVULATION IN MARES

The aim of the present study was to compare the levels of 17β-estradiol, testosterone, progesterone, inibin, and nitric oxide in follicular fluid between superovulated mares (G1) using equine pituitary extract (EPE) and nonsuperovulated mares (G2) used as control. Two estrus cycles from 24 mares (G1 = 12; G2 = 12) were monitored. In G1, the first cycle was used to determine the ovulation day (Day 0), followed by the administration of PGF2 (250 μg daily of cloprostenol; Sincrocio™, Ouro Fino, São Paulo, Brazil) on the first and second day of treatment with EPE. During the second cycle, EPE (25 mg i.m.) was administered twice daily from Day 7 to the ultrasound detection of a majority of follicles at least 35 mm in diameter. At this time, 2500 IU of hCG IV (Vetecor™, Hertape Calier, Minas Gerais, Brazil) was given. The same protocol was used for G2 as was used for G1 except that EPE administration was replaced by saline injections. For follicular aspiration, the mares were sedated with xilazine (0.5 mg kg-1; Sedazine™, Fort Dodge, São Paulo, Brazil) and acepromazine (0.05 mg kg-1; Acepram 1%™, Univet, Milton, Ontario Canada); hioscin bromide (Buscofin™, Agener União, São Paulo, Brazil) was also administered to reduce intestinal motility and to make ovary manipulation by way of the rectum easier. All follicles larger than 35 mm were aspirated using a Cook® double lumen needle (12 GA) in a transvaginal aspiration probe guided by ultrasonography. The number of aspirated preovulatory follicles was 4.75 ± 2.7 and 1.0 ± 0.0 for G1 and G2, respectively. The follicular fluid collected was centrifuged at 600 × g for 10 min in order to separate the fluid from the cells. The fluid was stored at -20°C and sent to the University of California (Davis, USA) for hormonal assay. The nitric oxide dosage was determined at São Paulo State University (Botucatu, Brazil) using the luminescent reaction of Griess. The comparison between groups of hormonal levels and nitric oxide was performed using the t-test at 5% significance. The results of the present study showed that the EPE treatment (G1), under the experimental conditions, did not lead to a significant change in the mean concentrations of the evaluated hormones or of nitric oxide in the follicular fluid when compared with the levels in G2. However, differences were found among the individuals only in G1 in all hormones (P < 0.05), with exception of progesterone (P > 0.05). Table 1.Mean and standard error of the follicular fluid hormones and nitric oxide levels of groups G1 and G2 Supported by FAPESP, Brazil.

Parenting stress in mothers of adults with an intellectual disability: parental cognitions in relation to child characteristics and family support

BACKGROUND

There is a body of evidence that indicates that the cognitions of parents of children with intellectual disabilities (ID) play an important role in influencing parental stress. However, there is a paucity of evidence about the experience of parents of adult children with ID. This study sought to apply a model of parenting stress to mothers of adults with ID. Of particular interest were the parental cognitions of parenting self-esteem and parental locus of control.

METHOD

Face-to face interviews were administered with 44 mothers of adults with ID. They completed the Vineland Adaptive and Maladaptive Behaviour Scale, the Family Support Scale, the Parenting Sense of Competence Scale, a shortened version of the Parental Locus of Control Scale and the Parenting Stress Index.

RESULTS

Correlations were observed between parenting stress and the other study variables. Regression analysis revealed that parental cognitive variables predicted 61% of the variance in parenting stress. Parenting satisfaction, a subscale of the measure of parenting sense of competence, mediated the relationships between adaptive behaviour and parenting stress and between family support and parenting stress.

CONCLUSIONS

These results indicate the importance of cognitive variables in the stress of mothers of adults with ID. Potential avenues of future research might focus on the experience of fathers and the impact of positive perceptions as a cognitive factor.

Rhenium migration at the Maqarin natural analogue site (Jordan)

Rock analysis and study of groundwater data was combined with a short duration column experiment in order to better understand the behavior of rhenium (Re) in the site of Maqarin (Jordan). Results show that the combustion metamorphism having affected rock masses in Maqarin (Jordan), and led to the formation of “natural cements”, has strongly modified the spatial distribution of several elements, among which Re, creating a specific source term for this element leached by groundwaters. Unaltered cements are shown to contain up to 1.2 μg/g Re to be compared to 0.15 μg/g in the initial biomicrite. Re is rapidly leached from unaltered cements and can be used as a tracer of recent cement alteration episodes. Preliminary data suggest that Re, a chemical analogue of Tc, could be partially retained in fracture minerals.

Rhizosphere pH gradient controls copper availability in a strongly acidic soil

Using a root mat approach, we quantified how root-induced alkalization controlled the establishment of copper (Cu) gradients in the rhizosphere of durum wheat (Triticum turgidum durum L.) cropped in a strongly acidic, Cu-contaminated soil. Rhizosphere pH increased over 6 mm in soil, reaching up to +2.8 units close to root mat surface. Conversely, free Cu2+ activity decreased by 3 orders of magnitude and total Cu concentration by 3-fold in the rhizosphere solution, while labile Cu assessed by DGT (diffusive gradients in thin films) was halved. The DIFS (DGT-induced flux in soils and sediments) model failed to adequately simulate Cu depletion in the rhizosphere solution, showing that root-induced alkalization almost entirely explained Cu depletion while plant uptake had little impact. We modeled the observed pH gradient to recalculate its radial extension around a single root. The gradient of free Cu2+ activity in solution, deduced from pH modeling, extended over 1-4 mm in the rhizosphere depending on root radius and OH- efflux from root. Rhizosphere alkalization dramatically decreased root exposure to Cu, substantiating that root-induced chemical changes in the rhizosphere should be better accounted for to assess metal bioavailability to plants.

Diffusion tensor imaging of ex vivo cervical spinal cord specimens: the immediate and long-term effects of fixation on diffusivity

Diffusion tensor imaging (DTI) is an emerging noninvasive method for evaluating tissue microstructure, but is highly susceptible to in vivo motion artifact. Ex vivo experiments on fixed tissues are needed to improve DTI techniques, which require fixed tissue specimens. Several efforts have been made to study the effect of fixation on both human and mouse tissue, with varying results. Four human cervical cords and three segments of pig cervical spinal cord specimens were imaged both before and after tissue fixation using 3D multishot diffusion weighted imaging (ms-DWEPI). Fixation caused a significant decrease in the longitudinal diffusivity whereas the relative anisotropy (RA) and radial diffusivity remained unaffected. Additionally, once adequately preserved, the diffusivity parameters of fixed tissue remain constant over time. Fixation has important effects on the diffusivity of tissue specimens. These findings have important implications for the determination of tissue microstructure and function using DTI technologies.

Hardware acceleration of a Monte Carlo simulation for photodynamic therapy [corrected] treatment planning

Monte Carlo (MC) simulations are being used extensively in the field of medical biophysics, particularly for modeling light propagation in tissues. The high computation time for MC limits its use to solving only the forward solutions for a given source geometry, emission profile, and optical interaction coefficients of the tissue. However, applications such as photodynamic therapy treatment planning or image reconstruction in diffuse optical tomography require solving the inverse problem given a desired dose distribution or absorber distribution, respectively. A faster means for performing MC simulations would enable the use of MC-based models for accomplishing such tasks. To explore this possibility, a digital hardware implementation of a MC simulation based on the Monte Carlo for Multi-Layered media (MCML) software was implemented on a development platform with multiple field-programmable gate arrays (FPGAs). The hardware performed the MC simulation on average 80 times faster and was 45 times more energy efficient than the MCML software executed on a 3-GHz Intel Xeon processor. The resulting isofluence lines closely matched those produced by MCML in software, diverging by only less than 0.1 mm for fluence levels as low as 0.00001 cm(-2) in a skin model.

Determination of zinc speciation in basic oxygen furnace flying dust by chemical extractions and X-ray spectroscopy

There is a growing concern regarding the environmental and public health risks associated with airborne particulate matter (PM). The basic oxygen furnace is one of the most important atmospheric dust sources of the steel manufacturing process. It emits dust enriched in heavy metal such as Zn, which is assumed to contribute to the toxic potential of atmospheric PM. Dust collected before and after the filtration system was analyzed to determine Zn speciation. To this end, a variety of analytical tools were used and a sequential extraction protocol has been specifically developed for iron and steel dust. The Zn speciation results obtained by EXAFS and sequential extraction were in excellent agreement. Before filtration, the speciation of Zn in BOF was 43% ZnFe(2)O(4), 23% ZnCO(3) and 16% ZnO. The same species were detected after filtration with different proportions. BOF dust after filtration contains more soluble Zn phases which may play a role in the toxic effects of the emissions.

Apatite and Portland/apatite composite cements obtained using a hydrothermal method for retaining heavy metals

Apatite and Portland/apatite composite cements containing steelwork dusts have been prepared using a low temperature hydrothermal method (200 degrees C, 48h). The produced solids were characterized by means of XRD, IR, and SEM-EDX, and the remaining liquid was analyzed by ICP. The results clearly show the capability of these cements to inertise the heavy metals contained in steelwork dusts, that is Fe, Pb, Mo, Cr, Mn, Ni, and Zn. In the case of apatitic cements, Fe, Mg, Cr, Mn, and Pb coming from steel dust replaced Ca in the divalent cation position of the apatite structure, while Si and Mo replaced P in tetrahedral position. The average crystal size of the apatite-containing dust is smaller than in pure apatite synthesized using the same procedure, which is related to the magnesium content of the dust, since magnesium seems to inhibit the crystal growth. XRD diagrams of composite cements show only peaks corresponding to phases observed in the single cements, and in that no new phases are found. However, EDX analysis reveals the introduction of cations coming from Portland cement into the apatite structure. From the results of water analysis it could be concluded that the capability of retention is higher in composite matrices than in the pure apatite one. In conclusion, the obtained data allow stating that the proposed method, the hydrothermal synthesis of steelwork dust containing cement, is a reliable one for immobilization of toxic residues containing heavy leachable cations.

Experimental characterization of superradiance in a single-pass high-gain laser-seeded free-electron laser amplifier

In this Letter we report the first experimental characterization of superradiance in a single-pass high-gain free-electron laser (FEL) seeded by a 150 femtosecond (FWHM) Ti:sapphire laser. The nonlinear energy gain after an exponential gain regime was observed. We also measured the evolution of the longitudinal phase space in both the exponential and superradiant regimes. The output FEL pulse duration was measured to be as short as 81 fs, a roughly 50% reduction compared to the input seed laser. The temporal distribution of the FEL radiation as predicted by a numerical simulation was experimentally verified for the first time.

CDRAP is expressed in adult articular cartilage, but its expression is not significantly regulated in osteoarthritic chondrocytes

OBJECTIVE

In this study we assessed the differential in vivo mRNA expression levels of CDRAP, a potential marker of cartilage degeneration.

METHODS

Conventional and real time PCR in a large series of normal (n = 18) and late stage osteoarthritic (n = 24) cartilage specimens were performed.

RESULTS

Conventional PCR analysis could demonstrate the presence of CDRAP mRNA in normal and osteoarthritic chondrocytes. Real time quantitative PCR confirmed the presence of CDRAP mRNA expression in normal articular chondrocytes in vivo (and in vitro). No significant up-regulation of CDRAP was observed in osteoarthritic chondrocytes in vivo.

CONCLUSION

The presented results confirm expression of CDRAP by normal and osteoarthritic articular chondrocytes, but indicate that increased expression levels by chondrocytes are not the cause of the increased levels of CDRAP in the synovial fluid of patients with osteoarthritis.

Impact of irrigating rice paddies with groundwater containing arsenic in Bangladesh

Soil and soil-water As profiles were obtained from 4 rice paddies in Bangladesh during the wet growing season (May-November), when surface water with little arsenic is used for irrigation, or during the dry season (January-May), when groundwater elevated in arsenic is used instead. In the upper 5 cm of paddy soil, accumulation of 13+/-12 mg/kg acid-leachable As (n=11) was observed in soil from 3 sites irrigated with groundwater containing 80-180 microg/L As, whereas only 3+/-2 mg/kg acid-leachable As (n=8) was measured at a control site. Dissolved As concentrations averaged 370+/-340 microg/L (n=7) in the upper 5 cm of the soil at the 3 sites irrigated with groundwater containing 80-180 microg/L As, contrasting with soil water As concentrations of only 18+/-7 microg/L (n=4) over the same depth interval at the control site. Despite the accumulation of As in soil and in soil water attributable to irrigation with groundwater containing elevated As levels, there is no evidence of a proportional transfer to rice grains collected from the same sites. Digestion and analysis of individual grains of boro winter rice from the 2 sites irrigated with groundwater containing 150 and 180 microg/L As yielded concentrations of 0.28+/-0.13 mg/kg (n=12) and 0.44+/-0.25 mg/kg (n=12), respectively. The As content of winter rice from the control site was not significantly different though less variable (0.30+/-0.07; n=12). The observations suggest that exposure of the Bangladesh population to As contained in rice is less of an immediate concern than the continued use of groundwater containing elevated As levels for drinking or cooking, or other potential consequences of As accumulation in soil and soil-water.

Liver transplantation for hepatitis B in the United States

AIM

To evaluate the impact of hepatitis B virus (HBV) on US health care system, we reviewed the Organ Procurement and Transplantation (OPTN, formerly UNOS) HBV database.

METHOD

We reviewed records of liver transplantations (LTx) performed in the United States listed for the diagnoses of HBV between 1993 and mid-October 2004. Both acute as well as chronic cases were included. Coinfection with hepatitis C virus was excluded from study. The specific states selected for review were chosen from those areas that are receiving large numbers of new immigrants from high HBV endemic areas (ie, Texas, Pennsylvania, California, New York, and Florida). One-, 3-, and 5-year patient survival rates for both cadaveric and living related donors were analyzed. Survival rates were obtained from OPTN database as Kaplan-Meyer survival test.

RESULTS

Between 1993 and mid-October 2004, 53,312 LTx had been performed nationwide. Of these, 2314 (4.34%) were performed for the diagnosis of HBV; 1816 cases (78%) were due to chronic HBV infection (45 of them were living donor LTx) and 498 cases (22%) were due to HBV-induced acute liver failure (seven of them were living donor LTx). Three- and 5-year survival rates of chronic HBV-related LTx patients were better than acute HBV-related and overall LTx patients.

CONCLUSION

HBV is generally considered to have a minor health significance by many community gastroenterologists. With growing immigration from overseas, it may eventually have a higher impact on LTx. Therefore, it is crucial to further educate gastroenterologists and primary care physicians caring for this specific group of patients.

Evolution of iron speciation during hydration of C4AF

It is now well accepted and demonstrated that calcium silicate, calcium aluminate and calcium sulfo aluminate (ettringite, AFm) phases exhibit a good capability to fix metals and metalloids. Unfortunately the role of minor phases and especially calcium-ferric aluminate phase, shorthand C4AF is not well defined. In other systems like in soils or sediments iron phases play a key role in the fixation of pollutant. In cement sorption isotherms, indicated that various metals can be retained by the C4AF hydrated products. Therefore the capabilities of those phase to retain heavy metal should not be neglected. Previous investigations have shown that the minerals formed during the hydration of C4AF are similar to those formed from C3A (pure tri-calcium aluminate) under comparable conditions. Nevertheless no investigation was conducted at the molecular level and there is still a controversy whether Fe substitutes for Al in the hydrated minerals in whole or in part, or if it forms FeOOH clusters scattered throughout the matrix. In this context we have conducted XAS experiments using synchrotron radiation. It was found that the hydration of C4AF forms C3AH6 (hydrogarnet) in which Fe randomly substitutes for Al as well as an amorphous FeOOH phase. Intermediate products like AFm (i.e., an ill organized lamellar phase) are also formed but rapidly evolve to C3AH6; iron does not seem to be incorporated in the AFm structure.