bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of community nurses in the prevention of tuberculosis in the Tshwane Health District of Gauteng
Authors: Mnisi Siphiwe D. , Peu Mmapheko D. , Meyer Salomé M.
Published: November 2012

The objectives of this study were to identify the role of community nurses in the prevention of tuberculosis (TB) and to identify problems experienced by them when fulfilling this role in the Tshwane Health District of Gauteng. A non-experimental, descriptive, quantitative research design method was used to collect data from community nurses. The sample included 59 registered nurses who voluntarily agreed to participate in the study. A questionnaire was used to collect data and quantitative data analysis methods were employed. Various opinions and ideas on the role of community nurses in the prevention of TB and the problems experienced were identified. Based on the results of this research, measures to protect community nurses from contracting TB whilst on duty should be a priority. Government should support TB programmes by providing money to non-governmental organisations and direct observed treatment short course (DOTS) supporters to make follow-up visits to patients possible, thus reducing the number of defaulters. Stringent measures should be taken at all border points to ensure that foreigners are screened for TB, multidrug-resistant TB and extensively drugresistant TB. This study was limited to community nurses in the Tshwane Health District of Gauteng who were registered with the South African Nursing Council (SANC) and therefore this study could not be generalised to registered nurses in the hospital setting or even to clinics in the rest of South Africa.
An evaluation of University of Cape Town medical students’ community placements in South Africa
Authors: Naidu Claudia S. , Zweigenthal Virginia , Irlam James , London Leslie , Keikelame Johannah
Published: November 2012

Background: Fourth-year medical students at the University of Cape Town (UCT) work closely with stakeholders in community teaching sites to conduct community-based research projects and follow-up health promotion interventions during their Public Health training.Objectives: This study evaluated the placements as a learning experience from the perspectives of past students and community stakeholders.Methods: A total of 32 projects were randomly selected out of 232 projects undertaken during 2006, 2008 and 2009. Two students and a stakeholder involved with each project were sampled. A standardised survey was emailed to students and in-depth interviews were held with stakeholders.Results: Fifty two per cent of 64 students and 57% of 25 stakeholders responded. Most students felt that the placements enhanced their academic experience and confidence in research skills, and were an effective form of learning. Perceived challenges included time constraints and, for a minority, inadequately prepared settings and stakeholders. Stakeholders felt that the placements empowered the communities and prepared students for the realities of working as a medical professional. They viewed students as a valuable resource and believed that student projects addressed important community myths and health problems. Recommendations from students and stakeholders included more time for the Public Health block, followup interventions for greater continuity, and better alignment of projects with stakeholder programmes.Conclusion: The evaluation reveals both the importance and challenges of community placements and identifies areas of improvement. Despite the limited duration of the placements, they offered valuable community-based learning experiences for the students and worthwhile benefits for the communities.
Measurement of Organisation-Professional Conflict in the industrial psychology profession
Authors: Lourens Colette , Van Vuuren Leon J. , Eiselen Riëtte
Published: November 2012

Orientation: Professionals, employed in organisations, operate within professional and organisational contexts serving different stakeholders. Subsequently, professionals may experience tension or conflict between their role as professional and employee.Research purpose: To establish the measurement of the perceptions and experiences of industrial psychology (IP) professionals, employed in South African organisations, with regard to Organisation-Professional Conflict (OPC) as well as the antecedents associated with this phenomenon.Motivation for the study: Although the extent to which professionals experience OPC is well documented for medical and accountancy professionals, the extent to which IP professionals experience this phenomenon remains unclear.Research design, approach and method: A structured questionnaire was developed and applied as a cross-sectional survey to all registered South African IP professionals employed in organisations. Responses based on the N = 143 self-selecting respondents were captured and utilised for statistical analysis.Main findings: OPC in the IP profession can be considered as the incongruence between professional organisational roles and duties, and their responsibility to adhere to professional obligations. Professional autonomy and strategic alignment were found to mitigate the occurrence of OPC, whereas power tension and compromise of professionalism seem to exacerbate the occurrence thereof.Practical/managerial implications: The research might create an awareness of the existence of OPC amongst the respective stakeholders. Knowledge of OPC may have implications for professionals who render their professional services to organisations.Contribution/value-add: The findings may inform formal professional associations, industrial psychologists employed by organisations, their employing organisations, and the governing board, about the nature and extent of OPC.
99m Tc glucarate as a potential radiopharmaceutical agent for assessment of tumor viability: From bench to the bed side
Authors: Choudhury Partha , Savio E. , Solanki K. , Alonso O. , Gupta A. , Gambini J. , Doval Dinesh , Sharma P. , Dondi M.
Published: November 2012

Several radiotracers have been used for assessing cell death, whether by necrosis or apoptosis. 99m Tc glucarate, which has initially been reported to be concentrating/accumulating in myocardial infarction or zones of cerebral injury, has also shown some tumor-seeking properties in a few preliminary studies. Under International Atomic Energy Agency (IAEA)′s coordinated research program, we report here the standardization, quality control, and clinical evaluation (detection, evaluation of response, and comparison with 18 F Fluorodeoxyglucose) of this tracer in well-characterized lung cancer and head neck malignancies in a single-arm prospective observational study. Forty-seven patients (29 inoperable lung carcinoma and 18 head and neck malignancies) were prospectively enrolled and underwent 99m Tc glucarate imaging [whole body planar and single-photon emission computed tomography of the region of interest] 4-5 hours after injection of 20 mCi of the radiopharmaceutical. Excellent 99m Tc glucarate concentration was noted in the target lesion in lung cancer and head and neck malignancies. The sensitivity was found to be better in lung cancer. Avid concentration of tracer was seen in the metastatic sites. During response evaluation, the glucarate concentration correlated well with the clinical and other radiological findings. 99m Tc glucarate showed avid concentration of tracer in the tumor, suggesting it to be a potential tumor imaging agent which can be used for detection and assessment of therapeutic response in malignancy.
Monte carlo study of the effect of collimator thickness on T-99m source response in single photon emission computed tomography
Authors: Islamian Jalil , Toossi Mohammad Taghi , Momennezhad Mahdi , Zakavi Seyyed , Sadeghi Ramin , Ljungberg Michael
Published: November 2012

In single photon emission computed tomography (SPECT), the collimator is a crucial element of the imaging chain and controls the noise resolution tradeoff of the collected data. The current study is an evaluation of the effects of different thicknesses of a low-energy high-resolution (LEHR) collimator on tomographic spatial resolution in SPECT. In the present study, the SIMIND Monte Carlo program was used to simulate a SPECT equipped with an LEHR collimator. A point source of 99m  Tc and an acrylic cylindrical Jaszczak phantom, with cold spheres and rods, and a human anthropomorphic torso phantom (4D-NCAT phantom) were used. Simulated planar images and reconstructed tomographic images were evaluated both qualitatively and quantitatively. According to the tabulated calculated detector parameters, contribution of Compton scattering, photoelectric reactions, and also peak to Compton (P/C) area in the obtained energy spectrums (from scanning of the sources with 11 collimator thicknesses, ranging from 2.400 to 2.410 cm), we concluded the thickness of 2.405 cm as the proper LEHR parallel hole collimator thickness. The image quality analyses by structural similarity index (SSIM) algorithm and also by visual inspection showed suitable quality images obtained with a collimator thickness of 2.405 cm. There was a suitable quality and also performance parameters′ analysis results for the projections and reconstructed images prepared with a 2.405 cm LEHR collimator thickness compared with the other collimator thicknesses.
An incidental detection of popliteal vein aneurysm during labeled leukocyte scintigraphy
Authors: Hassan H. , Nazri M. , Azman R.
Published: November 2012

Technetium (99mTc) exametazime (hexamethylpropyleneamine oxime, HMPAO) labeled leukocyte scintigraphy is mainly used to exclude occult infection in our institution. On review of previously published article, no case of popliteal venous aneurysm was ever diagnosed and detected on labeled leukocyte scintigraphy. We present a rare case of popliteal venous aneurysm which was detected on labeled leukocyte scintigraphy and was further confirmed with single-photon emission computed tomography and computed tomography fusion.
False-negative bone scan and choline PET/CT study in a case of prostate cancer: The pitfall of the small cell prostate carcinoma variant
Authors: Al-Tamimi Ammad , Tan Andrew , Kwong Sidney , Sam Christopher , Chong Angela , Tan Cher
Published: November 2012

We present a rare variant of prostate carcinoma. The patient is a 45-year-old male with elevated prostate-specific antigen levels at screening. Magnetic resonance imaging revealed hyperenhancing lesions throughout the axial skeleton. The fluorine-18 fluorocholine (FCH) positron emission tomography/computed tomography (PET/CT) scan showed no abnormal bone findings. Subsequently, a technetium-99 methydiphosphonate (Tc99m-MDP) bone scan was performed, with additional correlative single-photon emission computed tomography (SPECT)/CT imaging of the pelvis and the results were essentially normal. A percutaneous core biopsy of one of the bone lesions in L5 was performed and histology confirmed small cell (neuroendocrine) variant of prostate cancer. Our case illustrates a possible pitfall in molecular imaging of prostate carcinomas, whereby both bone scintigraphy and FCH PET/CT scans showed no definite bone lesions to correlate with marrow signal abnormalities seen on MR imaging. This highlights the need for caution in the diagnostic evaluation of prostate cancers with known small cell variants.
Assessment of smile architecture and pink aesthetics: A successful methodology in cosmetic dentistry
Authors: Hungund Shital , Gohil Dhwani , Mishra Rakesh
Published: November 2012

Objective: Aesthetic restorative treatment plays a very essential role in smile appearance. The aim of this study is to assess smile architecture and periodontium outlook for aesthetic evaluation. Materials and Methods: One hundred subjects (50 women and 50 men) aged from 18 to 62 years were enrolled and photographed. Standardized digital photographs were taken to assess smile architecture and gingival biotype during regular and expanded smile. Smile was assessed on the basis of following criteria: 1) extremely high smile line; 2) high smile line; 3) moderate smile line; and 4) low smile line. Patients were also classified by age group and gender as follows: a) males aged from 18 to 30 years; b) females aged from 18 to 30 years; c) males aged 31 years and above; and d) females aged 31 years and above. Gingival biotype was analysed using visual assessment method. Statistical analysis was performed using Chi-square test to assess differences between groups. Results: Assessment revealed that subjects with regular smile had the following: Class 1, 2%; Class 2, 10%; Class 3, 45%; and Class 4, 43%. With expanded smile, subjects revealed the following: Class 1, 9%; Class 2, 13%; Class 3, 58%; and Class 4, 20%. The periodontal outlook was more prevalent in the expanded and regular smile for younger age group than the older one. Age and gender influenced the position of the smile architecture. About 80% of the subjects were concerned of aesthetics. Conclusion: Assessment of smile architecture and pink aesthetics becomes mandatory for both regular and expanded smile for both the genders.
Forced eruption for all four maxillary incisors prior to implant rehabilitation
Authors: Ribeiro Gerson Luiz Ulema , Maciel José Vinicius Bolognesi , Pereira Juliana da Silva , Tanaka Orlando Motohiro
Published: November 2012

Periodontally compromised teeth are a common problem observed in adults, and the extraction is a viable solution in some of these situations. When prosthetic rehabilitation with implants take place after the extraction, orthodontic extrusion may convert the tooth indicated for extraction into a useful tooth. A 48-year-old woman′s chief complaint was the esthetics of her maxillary incisors with advanced periodontal disease. The incisors were orthodontically erupted to augment the bone topography for implant recipient sites and prosthetic rehabilitation. Three implants were selected and inserted in a single surgical procedure without any complications. A 10 months follow-up showed that the implants were stable with the prosthetic crowns preserving the surrounding soft tissues, and improving overall aesthetics and function.
Granular cell ameloblastoma: A diagnostic dilemma for histopathologist
Authors: Biradar Vijaykumar G. , Latturiya Rahul G. , Biradar Surekha V.
Published: November 2012

A rare case of granular cell ameloblastoma in the posterior mandible of a 45-year-old female has been studied both histologically and immunohistochemically. Histopathologically, hematoxylin and eosin and Periodic acid Schiff (PAS) prepared sections of granular cell ameloblastoma showed granular neoplastic cells residing within the tumor follicles. To characterize the granular cells in ameloblastoma, we examined the expression of low molecular weight cytokeratin and S-100 protein using immunohistochemistry. Granular cells exhibited positivity only with cytokeratin while S-100 protein was negative. This result allowed easy distinction of granular cell ameloblastomas from similar tumors exhibiting granular cell changes, and indicated that the granularity in ameloblastoma cells is consequent to lysosomal overload.
Medicaid Disproportionate Share Hospital Payment: How Does it Impact Hospitals' Provision of Uncompensated Care?
Authors: Hsieh Hui-Min , Bazzoli Gloria J.
Published: November 2012

This study examines the association between hospital uncompensated care and reductions in Medicaid Disproportionate Share Hospital (DSH) payments resulting from the 1997 Balanced Budget Act. We used data on California hospitals from 1996 to 2003 and employed two-stage least squares with a first-differencing model to control for potential feedback effects. Our findings suggest that nonprofit hospitals did reduce provision of uncompensated care in response to reductions in Medicaid DSH, but the response was inelastic in value. Policymakers need to continue to monitor uncompensated care as sources of support for indigent care change with the Patient Protection and Affordable Care Act (ACA).
Climatologies from satellite measurements: the impact of orbital sampling on the standard error of the mean
Authors: Toohey M. , von Clarmann T.
Published: November 2012

Abstract. Climatologies of atmospheric observations are often produced by binning measurements according to latitude, and calculating zonal means. The uncertainty in these climatological means is characterized by the standard error of the mean (SEM). However, the usual estimator of the SEM, i.e. the sample standard deviation divided by the square root of the sample size, holds only for uncorrelated randomly sampled measurements. Measurements of the atmospheric state along a satellite orbit cannot always be considered as independent because (a) the time-space interval between two nearest observations is often smaller than the typical scale of variations in the atmospheric state, and (b) the regular time-space sampling pattern of a satellite instrument strongly deviates from random sampling. We have developed an experiment where global chemical fields from a chemistry climate model are sampled according to real sampling patterns of satellite-borne instruments. As case studies, sampling patterns of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) and Atmospheric Chemistry Experiment Fourier-Transform Spectrometer (ACE-FTS) satellite instruments are used to iteratively subsample the model O3 fields and produce empirical estimates of the standard error of monthly mean zonal mean model O3 in 5° latitude bins. We find that generally the classic SEM estimator is a conservative estimate of the SEM, i.e. the empirical SEM is often less than the classic estimate. Exceptions occur in instances where the zonal sampling distribution shows non-uniformity with a similar zonal structure as variations in the sampled field, leading to maximum sensitivity to arbitrary phase shifts between the sample distribution and sampled field. The occurrence of such instances is thus very sensitive to slight changes in the sampling distribution, and to the variations in the measured field. This study highlights the need for caution in the interpretation of the oft-used classically computed SEM, and outlines a relatively simple methodology that can be used to assess one component of the uncertainty in monthly mean zonal mean climatologies produced from measurements from satellite-borne instruments.
Nitrate leaching from short-hydroperiod floodplain soils
Authors: Huber B. , Luster J. , Bernasconi S. M. , Shrestha J. , Graf Pannatier E.
Published: November 2012

Abstract. Numerous studies have shown the importance of riparian zones to reduce nitrate (NO3−) contamination coming from adjacent agricultural land. Much less is known about nitrogen (N) transformations and nitrate fluxes in riparian soils with short hydroperiods (1–3 days of inundation) and there is no study that could show whether these soils are a N sink or source. Within a restored section of the Thur River in NE Switzerland, we measured nitrate concentrations in soil solutions as an indicator of the net nitrate production. Samples were collected along a quasi-successional gradient from frequently inundated gravel bars to an alluvial forest, at three different depths (10, 50 and 100 cm) over a one-year period. Along this gradient we quantified N input (atmospheric deposition and sedimentation) and N output (leaching) to create a nitrogen balance and assess the risk of nitrate leaching from the unsaturated soil to the groundwater. Overall, the main factor explaining the differences in nitrate concentrations was the field capacity (FC). In subsoils with high FCs and VWC near FC, high nitrate concentrations were observed, often exceeding the Swiss and EU groundwater quality criterions of 400 and 800 μmol L−1, respectively. High sedimentation rates of river-derived nitrogen led to apparent N retention up to 200 kg N ha−1 yr−1 in the frequently inundated zones. By contrast, in the mature alluvial forest, nitrate leaching exceeded total N input most of the time. As a result of the large soil N pools, high amounts of nitrate were produced by nitrification and up to 94 kg N-NO3− ha−1 yr−1 were leached into the groundwater. Thus, during flooding when water fluxes are high, nitrate from soils can contribute up to 11% to the total nitrate load in groundwater.
Organic nitrogen in precipitation across Europe
Authors: Cape J. N. , Tang Y. S. , González-Beníez J. M. , Mitošinková M. , Makkonen U. , Jocher M. , Stolk A.
Published: November 2012

Abstract. Measurements of total nitrogen and inorganic nitrogen in precipitation samples from NitroEurope sites across Europe permit the calculation of organic nitrogen concentrations and wet deposition, by difference. The contribution of organic N to total N in precipitation ranged from only a few % to around 40% across 18 sites from northern Finland to Italy, similar to results from previous individual studies. This paper presents the absolute and relative contributions of organic N to wet N deposition across Europe, and examines seasonal trends. There were only weak correlations with other solutes in precipitation. These simple statistics indicate that sources of organic N in precipitation vary across Europe, and that no single source is responsible. The organic N contributes to total N deposition, yet this input is rarely quantified in nitrogen budgets.
Inclusion of vegetation in the Town Energy Balance model for modelling urban green areas
Authors: Lemonsu A. , Masson V. , Shashua-Bar L. , Erell E. , Pearlmutter D.
Published: November 2012

Abstract. Cities impact both local climate, through urban heat islands and global climate, because they are an area of heavy greenhouse gas release into the atmosphere due to heating, air conditioning and traffic. Including more vegetation into cities is a planning strategy having possible positive impacts for both concerns. Improving vegetation representation into urban models will allow us to address more accurately these questions. This paper presents an improvement of the Town Energy Balance (TEB) urban canopy model. Vegetation is directly included inside the canyon, allowing shadowing of grass by buildings, better representation of urban canopy form and, a priori, a more accurate simulation of canyon air microclimate. The surface exchanges over vegetation are modelled with the well-known Interaction Soil Biosphere Atmosphere (ISBA) model that is integrated in the TEB's code architecture in order to account for interactions between natural and built-up covers. The design of the code makes possible to plug and use any vegetation scheme. Both versions of TEB are confronted to experimental data issued from a field campaign conducted in Israel in 2007. Two semi-enclosed courtyards arranged with bare soil or watered lawn were instrumented to evaluate the impact of landscaping strategies on microclimatic variables and evapotranspiration. For this case study, the new version of the model with integrated vegetation performs better than if vegetation is treated outside the canyon. Surface temperatures are closer to the observations, especially at night when radiative trapping is important. The integrated vegetation version simulates a more humid air inside the canyon. The microclimatic quantities (i.e., the street-level meteorological variables) are better simulated with this new version. This opens opportunities to study with better accuracy the urban microclimate, down to the micro (or canyon) scale.
Groundwater surface water interactions and the role of phreatophytes in identifying recharge zones
Authors: Ahring T. S. , Steward D. R.
Published: November 2012

Abstract. Groundwater and surface water interactions within riparian corridors impact the distribution of phreatophytes that tap into groundwater stores. The changes in canopy area of phreatophytes over time is related to changes in depth to groundwater, distance from a stream or river, and hydrologic soil group. Remote sensing was used to determine the location of trees with pre-development and post-development aerial photography over the Ogallala Aquifer in the central plains of the United States. It was found that once the depth to groundwater becomes greater than about 3 m, tree populations decrease as depth to water increases. This subsequently limited the extent of phreatophytes to within 700 m of the river. It was also found that phreatophytes have a higher likelihood of growing on hydrologic soil groups with higher saturated hydraulic conductivity. Phreatophytes exist along portions of the Arkansas River corridor where significant decreases in groundwater occurred as long as alluvium exists to create perched conditions where trees survive dry periods. Significant decreases (more that 50%) in canopy cover exists along river segments where groundwater declined by more than 10 m, indicating areas with good hydraulic connectivity between surface water and groundwater. Thus, interpretation of changes in phreatophyte distribution using historical and recent aerial photography is important in delineating zones of enhanced recharge where aquifers might be effectively recharged through diversion of surface water runoff.
Deriving global flood hazard maps of fluvial floods through a physical model cascade
Authors: Pappenberger F. , Dutra E. , Wetterhall F. , Cloke H. L.
Published: November 2012

Abstract. Global flood hazard maps can be used in the assessment of flood risk in a number of different applications, including (re)insurance and large scale flood preparedness. Such global hazard maps can be generated using large scale physically based models of rainfall-runoff and river routing, when used in conjunction with a number of post-processing methods. In this study, the European Centre for Medium Range Weather Forecasts (ECMWF) land surface model is coupled to ERA-Interim reanalysis meteorological forcing data, and resultant runoff is passed to a river routing algorithm which simulates floodplains and flood flow across the global land area. The global hazard map is based on a 30 yr (1979–2010) simulation period. A Gumbel distribution is fitted to the annual maxima flows to derive a number of flood return periods. The return periods are calculated initially for a 25 × 25 km grid, which is then reprojected onto a 1 × 1 km grid to derive maps of higher resolution and estimate flooded fractional area for the individual 25 × 25 km cells. Several global and regional maps of flood return periods ranging from 2 to 500 yr are presented. The results compare reasonably to a benchmark data set of global flood hazard. The developed methodology can be applied to other datasets on a global or regional scale.
Additional studies on heterodiffusion coefficients in periclase
Authors: Dologlou E.
Published: November 2012

Abstract. By using a thermodynamical model, the activation entropy is extracted from the experimental diffusion data of Al in MgO. Furthermore, we estimate the activation volume. We find a value for the activation entropy of (4.21 ± 0.05) k. As for the activation volume, we calculate the value (3.65 ± 0.16) cm3 mol −1 which is comparable with the experimental values when errors are considered.
Causes of earthquakes and lithospheric plates movement
Authors: Ostřihanský L.
Published: November 2012

Abstract. The goal of the paper was to verify triggering of earthquakes by the length of day variations, i.e. the sidereal 13.66 days Earth's rotation variations, in contrast with tidal biweekly 14.76 days variations (full and new Moon), which for hundred years of investigation give negative results. Earthquake triggering governed by sidereal variations caused by variable Moon's declination accelerates and decelerates the Earth's rotation. Profound Schuster's test proved that earthquakes are triggered both in Earth's deceleration and acceleration. For this investigation the most prominent earthquakes from 2010–2011 were used from Mid-Atlantic Ridge, Southeast Indian Ridge, Sumatra and Andaman Sea, Chile trench, Haiti and Honshu region including important older earthquakes of Sumatra 26 December 2004 and Denali Fault 3 November 2002. Dominant number of earthquake occurring in extremes of length of day variations initiated the calculation of forces acting in these time intervals. Calculated forces of tidal force acting on Earth's flattening and the westward drift are strong enough to trigger earthquakes and the movement of plates follows from GPS performed immediately after earthquakes on continents and from increased number of earthquakes of the side of the mid-ocean ridge belonging to the moving plate. Generally the Northern Hemisphere moves quicker westward than the Southern one. Earthquakes are repeated in 19 yr Metonic cycle. Repetitions caused by tidal force acting on Earth's fattening are exact in date. Repetitions caused by westward drift are delayed for several months.
Ocular Pulse Amplitude in Patients with Thyroid-associated Ophthalmopathy
Authors: Božić Marija M. , Knežević Miroslav M. , Risimić Dijana S. , Čubrilo Katarina M.
Published: November 2012

Purpose

TO determine ocular pulse volume values in patients with thyroid-associated ophthalmopathy with normal intraocular pressure, and to test the hypothesis that changes in orbital tissue that accompany thyroid-associated ophthalmopathy can in turn give changes in choroidal perfusion.

Methods

In a prospective study, we evaluated 30 eyes of 30 consecutive patients with TAO, and 30 eyes of 30 healthy subjects. Complete ophthalmologic examination including dynamic contour tonometry was done. Possible differences in ocular parameters between the tested groups were assessed.

Results

NO significant difference was found in ocular pulse volume values between the tested subjects (paired test p=0.23).

Conclusions

The orbit tissue changes that are involved in thyroid-associated ophthalmopathy do not have much implication on choroidal perfusion, at least when intraocular pressure values remain within the normal range.
Venous Aneurysms in Autogenous Hemodialysis Fistulas: Is There an Association with Venous Outflow Stenosis?
Authors: Rajput Anshu , Rajan Dheeraj K. , Simons Martin E. , Sniderman Kenneth W. , Jaskolka Jeffrey D. , Beecroft John R. , Kachura John R. , Tan Kong T.
Published: November 2012

Purpose

To determine whether patients with venous aneurysms in their arteriovenous fistulas (AVFs) have associated venous outflow stenoses.

Materials and Methods

A retrospective study was performed, which included all patients presenting with dysfunction and had venous aneurysms in their AVFs. Patient's medical records and imaging studies were examined and data collected including access characteristics, patient demographics and imaging findings. Data were analyzed using Fisher's exact test.

Results

A total of 89 patients (58 men, 31 women; mean age 60) presented for intervention related to access dysfunction with incident venous aneurysms over the study period. Of the 89 patients with venous aneurysms (mean diameter 2.3 cm) of their AVF's, 69 (78%) patients had an associated venous outflow stenosis. The stenoses were present most commonly in the outflow cephalic vein (57%), followed by the cephalic arch (20%), brachiocephalic vein (10%) and subclavian vein (6%). Outflow stenoses in AVFs with venous aneurysms were observed in 87% of brachiocephalic AVFs, 60% of radiocephalic AVFs and 80% of brachiobasilic AVFs. Brachiocephalic AVFs with venous aneurysms were significantly more likely to have an associated outflow stenosis than radiocephalic AVFs with venous aneurysms (P=0.007). AVFs with outflow stenosis were on average 1502 days old while AVFs without outflow stenosis were on average 2351 days old, which was a statistically significant difference (P=0.031). No statistically significant differences were observed for sex and side of the fistula.

Conclusions

Outflow stenosis was observed to be associated with venous aneurysms in AVFs with a more statistically significant association in brachiocephalic AVFs compared to other AVFs.
Thioethers as Directing Group for the Palladium‐Catalyzed Direct Arylation of Arenes
Authors: Yao Jinzhong , Yu Ming , Zhang Yuhong
Published: November 2012

Thioethers have proven to be efficient directing groups for the arylation of arenes under palladium catalysis. The thioether group can be readily removed or converted to other functional groups. Kinetic isotopic effect studies reveal that the CH cleavage of arenes might be the turnover‐limiting step.
Twenty years of work‐related injury and illness among union carpenters in Washington State
Authors: McCoy Amanda J. , Kucera Kristen L. , Schoenfisch Ashley L. , Silverstein Barbara A. , Lipscomb Hester J.
Published: November 2012

Background

Individuals who work in the construction industry are at high risk of occupational injury. Robust surveillance systems are needed to monitor the experiences of these workers over time.

Methods

We updated important surveillance data for a unique occupational cohort of union construction workers to provide information on long‐term trends in their reported work‐related injuries and conditions. Combining administrative data sources, we identified a dynamic cohort of union carpenters who worked in Washington State from 1989 through 2008, their hours worked by month, and their workers' compensation claims. Incidence rates of reported work‐related injuries and illnesses were examined. Poisson regression was used to assess risk by categories of age, gender, time in the union, and calendar time contrasting medical only and paid lost time claims.

Results

Over the 20‐year study period, 24,830 carpenters worked 192.4 million work hours. Work‐related injuries resulting in medical care or paid lost time (PLT) from work occurred at a rate of 24.3 per 200,000 hr worked (95% CI: 23.5–25.0). Medical only claims declined 62% and PLT claims declined 77%; more substantive declines were seen for injuries resulting from being struck and falls to a lower level than from overexertion with lifting. Differences in risk based on union tenure and age diminished over time as well.

Conclusions

Significant declines in rates of reported work‐related injuries and illnesses were observed over the 20‐year period among these union carpenters. Greater declines were observed among workers with less union tenure and for claims resulting in PLT. Am. J. Ind. Med. 56:381–388, 2013. © 2012 Wiley Periodicals, Inc.
Evaluating the performance of geographical locations within scientific networks using an aggregation—randomization—re‐sampling approach (ARR)
Authors: Hennemann Stefan
Published: November 2012

Knowledge creation and dissemination in science and technology systems are perceived as prerequisites for socioeconomic development. The efficiency of creating new knowledge is considered to have a geographical component, that is, some regions are more capable in terms of scientific knowledge production than others. This article presents a method of using a network representation of scientific interaction to assess the relative efficiency of regions with diverse boundaries in channeling knowledge through a science system. In a first step, a weighted aggregate of the betweenness centrality is produced from empirical data (aggregation). The subsequent randomization of this empirical network produces the necessary null model for significance testing and normalization (randomization). This step is repeated to provide greater confidence about the results (re‐sampling). The results are robust estimates for the relative regional efficiency of brokering knowledge, which is discussed along with cross‐sectional and longitudinal empirical examples. The network representation acts as a straightforward metaphor of conceptual ideas from economic geography and neighboring disciplines. However, the procedure is not limited to centrality measures, nor is it limited to geographical aggregates. Therefore, it offers a wide range of applications for scientometrics and beyond.
Untersuchungen zum Verhalten von mit Nanopartikeln imprägniertem Holz bei Freibewitterung
Authors: Niemz Peter , Mannes David , Herbers Yvonne , Koch Walter
Published: November 2012

Es wurde die Witterungsbeständigkeit von Fichtenholz und Buchen holz nach Beschichtung mit verschiedenen nanoskaligen Hydrophobierungsmitteln und vergleichsweise dazu mit einem üblichen Lack getestet. Die Imprägnierung des Holzes erfolgte über Streich‐ oder Druckimprägnierung. Erfasst wurden Änderungen der Farbkennwerte, der Benetzungswinkel, der Holzfeuchte sowie der visuelle Gesamteindruck. Bei allen Materialien und Beschichtungs arten trat bereits nach kurzer Zeit eine Vergrauung auf. Diese war beim Standardlack am geringsten. Diese Tendenz spiegeln auch die Farbmessungen wieder. Der Benetzungsrandwinkel reduzierte sich zunehmend, das zeigt, dass der Hydrophobierungseffekt nach lässt. Beim Standardlack war der Effekt deutlich geringer ausgeprägt. Insgesamt zeigt sich, dass es weder mit Streich‐ noch mit Druckimprägnierung gelang, das Imprägnierungsmittel ausreichend tief in das Holz einzubringen und zu fixieren. Dies deckt sich mit den Ergebnissen der Flüssigkeitsaufnahmekoeffizienten, über die in vorangegangenen Arbeiten berichtet wurde.

Investigation regarding the behaviour of wood impregnated with nano‐particles and exposed to the open weather. The weather resistance of Norway spruce and beech wood has been tested following coating with various nano‐scale hydrophobising compounds, and has been compared with reference samples that were coated with a standard varnish. The impregnation of the timber was carried out by brush coating or a pressure process. The test results focused on changes in colorimetric values, wetting angle, timber moisture and the overall appearance. All materials and types of coating were subject to a greying of colour after a short while. The standard varnish showed the least discoloration. This tendency was also reflected in the colorimetric measurements. The wetting edge angle increasingly reduced, indicating that the hydrophobising effect was also reducing. With the standard varnish, this effect was clearly less pronounced. Overall, the tests showed that it had not been possible to inject the timber sufficiently deeply with the impregnation compound, and fix it, with either the brush or pressure impregnation method. This confirms the findings obtained in fluid retention co‐efficient tests which were reported in previous articles.
Geschichte ohne Kausalität. Abgrenzungsstrategien gegen die Wissenschaftssoziologie in zeitgenössischen Ansätzen historischer Epistemologie
Authors: Kinzel Katherina
Published: November 2012

History Without Causality. How Contemporary Historical Epistemology Demarcates Itself From the Sociology of Scientific Knowledge. Contemporary proponents of historical epistemology often try to delimit their enterprise by demarcating it from the sociology of scientific knowledge and other sociologically oriented approaches in the history of science. Their criticism is directed against the use of causal explanations which are deemed to invite reductionism and lead to a totalizing perspective on science. In the present article I want to analyse this line of criticism in what I consider are two paradigmatic works of contemporary historical epistemology: Lorraine Daston's und Peter Galison's Objectivity and Hans‐Jörg Rheinberger's Toward a History of Epistemic Things. I first present their arguments against the sociological and causal analysis of scientific knowledge and practice and then try to defend sociological work in the history of science against their charges. I will, however, not do so by defending causal explanations directly. Rather, I will show that the arguments against sociological analysis put forward in contemporary historical epistemology, as well as historical epistemology's own models of historical explanation and narration, bear problematic consequences. I argue that Daston, Galison and Rheinberger fail to create productive resonances between macro‐ and microhistorical perspectives, that they reproduce an internalist picture of scientific knowledge, and finally that Rheinberger's attempt to deconstruct the dichotomy between subject and object leads him to neglect questions about the political dimension of scientific research.
Science and the History of the Sciences. Conceptual Innovations Through Historicizing Science in the Eighteenth Century
Authors: Ziche Paul
Published: November 2012

Wissenschaft und die Geschichte der Wissenschaften. Begriffliche Innovationen im Zuge der Historisierung der Wissenschaften im 18. Jahrhundert. Die historische Rekonstruktion der Wissenschaften ist auf vielfältige Weise mit philosophischen Diskussionen des 18. Jahrhunderts verknüpft. Insbesondere teilen die Philosophiegeschichtsschreibung und die Historiographie der Wissenschaften das konzeptuelle Problem, eine Vielzahl wissenschaftlicher bzw. philosophischer Praktiken unter einem gemeinsamen Oberbegriff zu versammeln. Die historische Analyse der Entwicklung der Wissenschaften bietet hierzu einen Zugang, in dem die Definition von “Wissenschaft” bzw. “Wissenschaften” ebenso zur Diskussion steht wie die Systematisierung der Wissenschaften. In einer Analyse dieses begrifflichen Problems und einer Typologisierung wissenschaftshistorischer Ansätze des 18. Jahrhunderts wird die enge Interaktion philosophischer und wissenschaftshistorischer bzw. – allgemeiner – wissenschaftsreflexiver Diskurse im 18. Jahrhundert aufgezeigt.
Wissenschaftsgeschichte und Wissenschaftsphilosophie – Einführende Bemerkungen
Authors: Ash Mitchell G.
Published: November 2012

History of Science and Philosophy of Science. Introductory Remarks. This article introduces two special issues of the journal History of Science Reports (Berichte zur Wissenschaftsgeschichte) with contributions on the relationships of history and philosophy of science since the seventeenth century. The introduction begins with a brief reminder of Thomas Kuhn's provocative discussion of the relationship in the 1970s, placing it in the context of the debate of the period over whether the foundation of university departments for History and Philosophy of Science in the United States had led to a mere “marriage of convenience” or something more. Following this the paper briefly outlines the transformative impact of the “practical turn” in both philosophy and history of science since the 1990s, and contends that the relationship of history and philosophy of science has nonetheless become increasingly distant over time. This is due in large part to the professionalisation of history of science and to the recent turn to cultural approaches in that field; both trends have led to the adoption of strictly historicist rather than analytical perspectives on knowledge. General historians, too, are paying more attention to the increasing impact of science and technology, but have at most instrumental use for philosophical perspectives. Thus, the distinct possibility arises that the debate between historical and analytical approaches in philosophy of science is becoming a conversation within one discipline rather than a dialogue between two disciplines: what was once a „marriage of convenience”︁ could end in respectful separation or amicable divorce. The article concludes with brief summaries of the articles published in the two special issues, indicating their relations to specific aspects of the broader topic at hand.
The effect of protein a cycle number on the performance and lifetime of an anion exchange polishing step
Authors: Iskra Timothy , Bolton Glen R. , Coffman Jonathan L. , Godavarti Ranga
Published: November 2012

Most mAb platform purification processes consist of an affinity capture step followed by one or two polishing steps. An understanding of the performance linkages between the unit operations can lead to robust manufacturing processes. In this study, a weak‐partitioning anion‐exchange chromatography polishing step used in a mAb purification process was characterized through high‐throughput screening (HTS) experiments, small‐scale experiments including a cycling study performed on qualified scale‐down models, and large‐scale manufacturing runs. When material from a Protein A column that had been cycled <10× was loaded on the AEX resin, early breakthrough of impurities and premature loss of capacity was observed. As the cycle number on the Protein A resin increased, the capacity of the subsequent AEX step increased. Different control strategies were considered for preventing impurity breakthrough and improving AEX resin lifetimes. Depth filtration of the Protein A peak pool significantly improved the AEX resin capacity, robustness, and lifetime. Further, the turbidity of the Protein A pool has the potential for use as an in‐process control parameter for monitoring the performance of the AEX step. Biotechnol. Bioeng. 2013; 110: 1142–1152. © 2012 Wiley Periodicals, Inc.
Shear stress during early embryonic stem cell differentiation promotes hematopoietic and endothelial phenotypes
Authors: Wolfe Russell P. , Ahsan Tabassum
Published: November 2012

Pluripotent embryonic stem cells (ESCs) are a potential source for cell‐based tissue engineering and regenerative medicine applications, but their translation into clinical use will require efficient and robust methods for promoting differentiation. Fluid shear stress, which can be readily incorporated into scalable bioreactors, may be one solution for promoting endothelial and hematopoietic phenotypes from ESCs. Here we applied laminar shear stress to differentiating ESCs using a 2D adherent parallel plate configuration to systematically investigate the effects of several mechanical parameters. Treatment similarly promoted endothelial and hematopoietic differentiation for shear stress magnitudes ranging from 1.5 to 15 dyne/cm2 and for cells seeded on collagen‐, fibronectin‐ or laminin‐coated surfaces. Extension of the treatment duration consistently induced an endothelial response, but application at later stages of differentiation was less effective at promoting hematopoietic phenotypes. Furthermore, inhibition of the FLK1 protein (a VEGF receptor) neutralized the effects of shear stress, implicating the membrane protein as a critical mediator of both endothelial and hematopoietic differentiation by applied shear. Using a systematic approach, studies such as these help elucidate the mechanisms involved in force‐mediated stem cell differentiation and inform scalable bioprocesses for cellular therapies. Biotechnol. Bioeng. 2013; 110: 1231–1242. © 2012 Wiley Periodicals, Inc.
Biomimetic injectable HUVEC‐adipocytes/collagen/alginate microsphere co‐cultures for adipose tissue engineering
Authors: Yao Rui , Zhang Renji , Lin Feng , Luan Jie
Published: November 2012

Engineering adipose tissue that has the ability to engraft and establish a vascular supply is a laudable goal that has broad clinical relevance, particularly for tissue reconstruction. In this article, we developed novel microtissues from surface‐coated adipocyte/collagen/alginate microspheres and human umbilical vein endothelial cells (HUVECs) co‐cultures that resembled the components and structure of natural adipose tissue. Firstly, collagen/alginate hydrogel microspheres embedded with viable adipocytes were obtained to mimic fat lobules. Secondly, collagen fibrils were allowed to self‐assemble on the surface of the microspheres to mimic collagen fibrils surrounding the fat lobules in the natural adipose tissue and facilitate HUVEC attachment and co‐cultures formation. Thirdly, the channels formed by the gap among the microspheres served as the room for in vitro prevascularization and in vivo blood vessel development. The endothelial cell layer outside the microspheres was a starting point of rapid vascular ingrowth. Adipose tissue formation was analyzed for 12 weeks at 4‐week intervals by subcutaneous injection into the head of node mice. The vasculature in the regenerated tissue showed functional anastomosis with host blood vessels. Long‐term stability of volume and weight of the injection was observed, indicating that the vasculature formed within the constructs benefited the formation, maturity, and maintenance of adipose tissue. This study provides a microsurgical method for adipose regeneration and construction of biomimetic model for drug screening studies. Biotechnol. Bioeng. 2013; 110: 1430–1443. © 2012 Wiley Periodicals, Inc.