bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of quenching and aging on residual stress in Al–Zn–Mg–Cu alloy 7449
Authors: Robinson J S , Tanner D A , van Petegem S , Evans A
Published: February 2012

The present investigation aims to quantify the size and distribution of residual stresses remaining in rectilinear aluminium forged alloy blocks after they had been partially and fully heat treated. Various quench conditions were used, including water at different temperatures and polyoxyethylene glycol in two concentrations. The influence of standard and novel aging procedures, including retrogression and reaging, has been determined. Residual stresses were characterised using X-ray and neutron diffraction. Residual stress magnitudes were found to vary significantly with rapidity of cooling from the solution treatment temperature, with the subsequent aging treatments having a much smaller effect. The influence of heat treatments on the mechanical properties of the alloy was predicted by means of quench factor analysis and measured using indentation hardness and tensile testing. Quench factor analysis is also used to predict the change in lattice parameter arising from different quench paths in the strain free reference samples d0.
Effect of solution heat treatments on superalloys Part 1 – alloy 718
Authors: Andersson J , Sjöberg G P , Viskari L , Chaturvedi M C
Published: February 2012

The hot ductility as measured by Gleeble testing of Alloy 718 at four different solution heat treatments (954°C/15 h, 954°C/1 h, 982°C/1 h and 1050°C/3 h+954°C/1 h) has been investigated. It is concluded that constitutional liquation of NbC assisted by δ phase takes place and deteriorates the ductility. Parameters established by analysing the ductility dependence on temperature indicate a reduced weldability of the material in the coarse grain size state (ASTM 3) while indicating an increased weldability when containing a large amount of δ phase due to a grain boundary pinning effect. The accumulation of trace elements during grain growth at the highest temperature is believed to be the cause for the observed reduced on-cooling ductility.
Heat treatment of thixoformed EN AW 7075 alloy
Authors: Birol Y
Published: February 2012

Heat treatment of thixoformed EN AW 7075 alloy was investigated in the present work. The hardness of the thixoformed alloy is 76±7 HV. This is nearly equivalent to the soft temper for this particular alloy. Zn, Cu and Mg are predominantly in the eutectic phase in the thixoformed state and have no favourable impact on strength. Besides, forming has occurred in the semisolid state with no evidence of plastic deformation. The maximum hardness that can be achieved after a commercial aging cycle, 16 h at 121°C, is 105 HV. The failure of the thixoformed alloy to adequately age harden is attributed to the lack of Zn, Mg and Cu in solution to offer adequate precipitation hardening capacity. It takes at least a 2 h long solution heat treatment at 470°C to solutionise the interglobular eutectic phase and to offer sufficient precipitation hardening capacity. The T6 and T7 hardness values thus obtained are 181 and 170 HV respectively, and demonstrate a remarkable age hardening potential. The superior T6 hardness of the thixoformed alloy with respect to the hot extruded counterpart is attributed to improved aging kinetics in the former, possibly due to a globular matrix morphology which provides relatively shorter diffusion paths.
Potential of cast EN AW7075 billet as thixoforging feedstock
Authors: Birol Y
Published: February 2012

The potential of cast 7075 billets for thixoforging without prior thermomechanical processing was investigated. Slugs machined from EN AW7075 cast billet were thixoformed at 615°C with a liquid fraction of 20. The dendritic as cast matrix has transformed into a more compact structure during heating into the semisolid temperature range. This structural change was facilitated by the reversion of the fine precipitates along the dendrite boundries inherited from dendritic segregation of the as cast billet and the coalescence of the neighbouring dendrite arms. The equiaxed polygonal grains thus obtained have become increasingly globular upon holding at 615°C. The liquid phase penetrated between the grains, forming a more or less continous intergranular network. Microstructural features essential for forming in the semisolid state were obtained after ∼10 min at this temperature. The forming process has taken place in the semisolid state with no evidence of grain deformation. The thixoformed 7075 part was solutionised at 470°C for 6 h and was subsequently quenched in water. Artificial aging at 121°C has produced hardness values as high as 175 HV after 16 h. It is thus fair to conclude that the cast EN AW7075 billet can be readily thixoformed after a 3 min heating ramp and a 10 min isothermal hold at 615°C.
Relation between strain hardening exponent of metals and residual profiles of deep spherical indentation
Authors: Pintaude G. , Hoechele A. R. , Cipriano G. L.
Published: February 2012

Strain hardening exponent is an important mechanical property usually obtained from tensile tests, which implies that a specific specimen preparation and long routines of calculus should be performed. An alternative way to obtain this property is the use of spherical indentation hardness, measuring the profiles of indentation morphology: piling up or sinking in. In the present investigation, the indentation morphologies observed after tests with a spherical indenter for aluminium alloys (AA 6063-T5 and AA 1350) and steels (AISI 1020 and AISI 316L) are presented. Indentation tests were performed with different sphere diameters and test loads, to obey the Meyer law and to keep constant the relation between load and indentation diameter, varying the plastic strain level. Tensile tests were performed to make use of reference values. The residual profiles were obtained using a two-dimensional profilometer. The results allow discussing the range of validity of several models proposed in the literature. For some test conditions, 316L stainless steel and 1350 aluminium alloy partially recovered present an unexpected behaviour, which the models are unable to predict.
New theoretical equation for effective thermal conductivity of two-phase composite materials
Authors: Li X Y , Zhao X L , Guo X Y , Shao Z M , Ai M X
Published: February 2012

A new theoretical equation that describes the thermal conductivity of a two-phase composite is proposed. The Cheng–Vachon equation has been modified, and a new parameter, i.e. the modified volume fraction, is introduced. The modified volume fraction is a function of the physical volume fraction and thermal conductivity ratio of constituent phases. It was found that the new equation can describe the thermal conductivity of different two-phase composites, such as Cu/solder, Al/water, Al/air and cellular concrete, very accurately.
Finite element model based elastoplastic contact model and some aspects on indentation response
Authors: Mayuram M. M.
Published: February 2012

Indentation tests are useful in evaluating the response of materials. They can be applied to determine the mechanical properties of bulk materials, thin films and coatings. Control of some factors that affect the test and the resulting property evaluation is important. Finite element model based elastoplastic contact analysis of a spherical indenter on a flat half space has revealed some interesting behaviours, which highlight certain limitations associated with the response. Under elastoplastic behaviour, it is observed that the constraint factor value sometimes defies the limit set for the validity of the analysis, and the variation is sensitive to yield strength, with a decreasing effect on the critical depth of deformation. Failure to acknowledge such effects will lead to erroneous evaluation of the response. The present work highlights the observations of the numerical simulation results and some experimental data on static indentation response evaluation of metallic and sprayed ceramic composite coatings.
Historical origins of indentation hardness testing
Authors: Walley S. M.
Published: February 2012

Although it has been known for thousands of years that materials differ in hardness, quantitative methods of measuring hardness by performing careful indentation experiments only began to be developed during the nineteenth century. At the beginning of the twentieth century, hardness testing machines began to be commercially available. The methods that have persisted to this day may be divided into two broad categories: (1) those where a hardened steel ball or cone is pressed into a surface under a known load; and (2) those where sharp diamonds of various shapes are pressed into a surface also under a known load. An issue that has long been of interest is the relation of hardness to simpler measures of material strength, particularly the tensile strength. The review will cover the development of the various static and dynamic techniques and their subsequent application to a wide range of materials.
Studying flow effects on dendrite fragmentation using Rayleigh–Bénard convection
Authors: Aveson J W
Published: February 2012

The present paper reports on an in situ experiment to investigate the effects of fluid flow on dendrite fragmentation. A Bénard cell was constructed for the solidification of a transparent alloy under Rayleigh–Bénard convection. Dendrite fragmentation was observed, and the flow field was mapped. It was found that a Bénard cell provides a useful apparatus for studying dendrite fragmentation under controlled conditions in transparent alloys. Preliminary results showed that structural fragmentation occurs under relatively quiescent flow conditions, suggesting that deformation processes play little role in this system.
Constitutive modelling for high temperature behaviour of 12CrNiMoWV martensitic stainless steel
Authors: Zhong J , Xiao Y H , Guo C
Published: February 2012

Hot deformation behaviour of 12CrNiMoWV steel was investigated by hot compression tests on a Gleeble 1500 simulator in a wide range of temperatures (950–1150°C) and strain rates (0·1–10 s−1). The results show that the stress–strain curves at lower strain rate (0·1 s−1) exhibit a single peak stress, indicating a typical dynamic recrystallisation (DRX) behaviour of the steel. In addition, further microstructural observation confirms the occurrence of the DRX behaviour. The stress level decreases with increasing deformation temperature and decreasing strain rate, which can be predicted by the Zener–Hollomon Z parameter in the Arrhenius type equation. The influence of strain was incorporated in the constitutive equation by considering the effect of strain on the material constants. By taking the arithmetic average of the mean errors of flow stress for each of the stress–strain curves, almost all the values are under 5, which validates the efficiency of the constitutive equation in describing the hot deformation behaviour of this steel.
Aiming at WM with both barrels blocked
Authors: Boise Lawrence H.
Published: February 2012

Proteasome inhibition has proven to be a successful therapeutic strategy in B-cell malignancies including WM. In this issue of Blood, Roccaro and colleagues report preclinical studies, providing the rationale for clinical investigation of a novel orally available proteasome inhibitor in this disease.1
The TREC to less CMV after UCBT
Authors: Beck Jill C. , Verneris Michael R.
Published: February 2012

In this issue of Blood, Brown and colleagues demonstrate the importance of thymic recovery and T-cell reconstitution in CMV-specific immunity after allogeneic UCB transplantation.
Aluminum tolerance association mapping in triticale
Authors: Niedziela Agnieszka , Bednarek Piotr T , Cichy Henryk , Budzianowski Grzegorz , Kilian Andrzej , Anioł Andrzej
Published: February 2012

Background

Crop production practices and industrialization processes result in increasing acidification of arable soils. At lower pH levels (below 5.0), aluminum (Al) remains in a cationic form that is toxic to plants, reducing growth and yield. The effect of aluminum on agronomic performance is particularly important in cereals like wheat, which has promoted the development of programs directed towards selection of tolerant forms. Even in intermediately tolerant cereals (i.e., triticale), the decrease in yield may be significant. In triticale, Al tolerance seems to be influenced by both wheat and rye genomes. However, little is known about the precise chromosomal location of tolerance-related genes, and whether wheat or rye genomes are crucial for the expression of that trait in the hybrid.

Results

A mapping population consisting of 232 advanced breeding triticale forms was developed and phenotyped for Al tolerance using physiological tests. AFLP, SSR and DArT marker platforms were applied to obtain a sufficiently large set of molecular markers (over 3000). Associations between the markers and the trait were tested using General (GLM) and Multiple (MLM) Linear Models, as well as the Statistical Machine Learning (SML) approach. The chromosomal locations of candidate markers were verified based on known assignments of SSRs and DArTs or by using genetic maps of rye and triticale.

Two candidate markers on chromosome 3R and 9, 15 and 11 on chromosomes 4R, 6R and 7R, respectively, were identified. The r

2
values were between 0.066 and 0.220 in most cases, indicating a good fit of the data, with better results obtained with the GML than the MLM approach. Several QTLs on rye chromosomes appeared to be involved in the phenotypic expression of the trait, suggesting that rye genome factors are predominantly responsible for Al tolerance in triticale.

Conclusions

The Diversity Arrays Technology was applied successfully to association mapping studies performed on triticale breeding forms. Statistical approaches allowed the identification of numerous markers associated with Al tolerance. Available rye and triticale genetic maps suggested the putative location of the markers and demonstrated that they formed several linked groups assigned to distinct chromosomes (3R, 4R, 6R and 7R). Markers associated with genomic regions under positive selection were identified and indirectly mapped in the vicinity of the Al-tolerant markers. The present findings were in agreement with prior reports.
Pulmonary function, respiratory symptoms, and dust exposures among workers engaged in early manufacturing processes of tea: a cohort study
Authors: Shieh Tzong-Shiun , Chung Jui-Jung , Wang Chung-Jing , Tsai Perng-Jy , Kuo Yau-Chang , Guo How-Ran
Published: February 2012

Background

To evaluate pulmonary function and respiratory symptoms in workers engaged in the early manufacturing processes of tea and to identify the associated factors, we conducted a study in a tea production area in Taiwan.

Methods

We recruited tea workers who engaged in the early manufacturing process in the Mountain Ali area in Taiwan and a comparison group of local office workers who were matched for age, gender, and smoking habits. We performed questionnaire interviews, pulmonary function tests, skin prick tests, and measurement of specific IgE for tea on the participants and assessed tea dust exposures in the tea factories.

Results

The 91 participating tea workers had higher prevalence of respiratory symptoms than the comparison group (32 participants). Among tea workers, ball-rolling workers had the highest prevalence of symptoms and the highest exposures of inhalable dusts. At baseline, tea workers had similar pulmonary functions as the comparison group, but compared to the other tea workers ball-rolling workers had a lower ratio of the 1-second forced expiratory volume to forced vital capacity (FEV1/FVC) and a lower maximal mid-expiratory flow rate expressed as% of the predicted value--MMF (%pred). A total of 58 tea workers participated in the on-site investigation and the cross-shift lung function measurements. We found ball-rolling yielded the highest inhalable dust level, panning yielded the highest respirable dust level, and withering yielded the lowest levels of both dusts. Ball-rolling also yielded the highest coarse fraction (defined as inhalable dusts minus respirable dusts), which represented exposures from nose to tracheobronchial tract. During the shift, we observed significant declines in pulmonary function, especially in ball-rolling workers. Multiple regressions showed that age, height, work tasks, coarse fraction, and number of months working in tea manufacturing each year were independent predictors of certain pulmonary function parameters in tea workers.

Conclusions

Tea workers engaged in early manufacturing processes of tea have higher prevalence of respiratory symptoms and pulmonary function impairment, which might be related to tea dust exposures, especially the coarse fraction.
Intimate partner physical violence among women in Shimelba refugee camp, northern Ethiopia
Authors: Feseha Girmatsion , G/mariam Abebe , Gerbaba Mulusew
Published: February 2012

Background

Domestic violence has unwanted effects on the physical and psychological well-being of women, which have been recognized globally as an important public health problem. Violence perpetrated by intimate partner is one form of domestic violence, a serious human rights abuse and a public health issue, among refugees owing to its substantial consequences for women's physical, mental and reproductive health problems. Because the incidents are under-reported, the true scale of the problem is unknown and unexamined among refugee women in Ethiopia. Thus, this study aim to assess the magnitude of intimate partner physical violence and associated factors among women in Shimelba refugee camp, Northern Ethiopia.

Methods

A community-based cross-sectional study was conducted among a sample of 422 refugee women from March to April 2011. A simple random sampling method was used to select the study subjects from seven zones of the refugee camp. Census was done to identify all households with women having an intimate partner. A pre-tested interviewer guided structured questionnaire was used for data collection. Data were entered, cleaned and analyzed using SPSS software version 16.0. Descriptive, bivariate and multivariate logistic regression analyses were done where applicable. A p-value less than 0.05 with 95% CI were set and used as a cut-off point to examine the statistical association between the explanatory and outcome variables.

Results

The prevalence of physical violence in the last 12 months and lifetime were 107(25.5%) and 131(31.0%) respectively. The commonest forms of physical violence reported included slapping 101(61.6%) and throwing objects 32(19.5%). Significant risk factors associated with experiencing physical violence were being a farmer (AOR = 3.0[95%CI: 1.7, 5.5]), knowing women in neighborhood whose husband to beat them (AOR = 1.87[95%CI: 1.0, 3.5]), being a Muslim (AOR = 2.4 [95%C.I: 1.107, 5.5]), and having a drunkard partner (AOR = 2.1[95%C.I:1.0, 4.5]).

Conclusions

Intimate partner physical violence was found to be high and a serious problem among women in Shimelba refugee camp. Multifaceted interventions such as male counseling, increasing awareness on the consequences of intimate partner violence and the effect of substance use like alcohol will help to reduce intimate partner violence.
Protein L: a novel reagent for the detection of Chimeric Antigen Receptor (CAR) expression by flow cytometry
Authors: Zheng Zhili , Chinnasamy Nachimuthu , Morgan Richard A
Published: February 2012

Background

There has been significant progress in the last two decades on the design of chimeric antigen receptors (CAR) for adoptive immunotherapy targeting tumor-associated antigens. Structurally CARs consist of a single chain antibody fragment directed against a tumor-associated antigen fused to an extracellular spacer and transmembrane domain followed by T cell cytoplasmic signaling moieties. Currently several clinical trials are underway using gene modified peripheral blood lymphocytes (PBL) with CARs directed against a variety of tumor associated antigens. Despite the improvements in the design of CARs and expansion of the number of target antigens, there is no universal flow cytometric method available to detect the expression of CARs on the surface of transduced lymphocytes.

Methods

Currently anti-fragment antigen binding (Fab) conjugates are most widely used to determine the expression of CARs on gene-modified lymphocytes by flow cytometry. The limitations of these reagents are that many of them are not commercially available, generally they are polyclonal antibodies and often the results are inconsistent. In an effort to develop a simple universal flow cytometric method to detect the expression of CARs, we employed protein L to determine the expression of CARs on transduced lymphocytes. Protein L is an immunoglobulin (Ig)-binding protein that binds to the variable light chains (kappa chain) of Ig without interfering with antigen binding site. Protein L binds to most classes of Ig and also binds to single-chain antibody fragments (scFv) and Fab fragments.

Results

We used CARs derived from both human and murine antibodies to validate this novel protein L based flow cytometric method and the results correlated well with other established methods. Activated human PBLs were transduced with retroviral vectors expressing two human antibody based CARs (anti-EGFRvIII, and anti-VEGFR2), two murine antibody derived CARs (anti-CSPG4, and anti-CD19), and two humanized mouse antibody based CARs (anti-ERBB2, and anti-PSCA). Transduced cells were stained first with biotin labeled protein L followed by phycoerythrin (PE)-conjugated streptavidin (SA) and analyzed by flow cytometry. For comparison, cells were stained in parallel with biotin conjugated goat-anti-mouse Fab or CAR specific fusion proteins. Using protein L, all CAR transduced lymphocytes exhibited specific staining pattern ranging from 40 to 80% of positive cells (compared to untransduced cells) and staining was comparable to the pattern observed with anti-Fab antibodies.

Conclusion

Our data demonstrate the feasibility of employing Protein L as a general reagent for the detection of CAR expression on transduced lymphocytes by flow cytometry.
Psychiatric symptoms of patients with primary mitochondrial DNA disorders
Authors: Inczedy-Farkas Gabriella , Remenyi Viktoria , Gal Aniko , Varga Zsofia , Balla Petra , Udvardy-Meszaros Agnes , Bereznai Benjamin , Molnar Maria Judit
Published: February 2012

Background

The aim of our study was to assess psychiatric symptoms in patients with genetically proven primary mutation of the mitochondrial DNA.

Methods

19 adults with known mitochondrial mutation (MT) have been assessed with the Stanford Health Assessment Questionnaire 20-item Disability Index (HAQ-DI), the Symptom Check List-90-Revised (SCL-90-R), the Beck Depression Inventory-Short Form (BDI-SF), the Hamilton Depression Rating Scale (HDRS) and the clinical version of the Structured Clinical Interview for the the DSM-IV (SCID-I and SCID-II) As control, 10 patients with hereditary sensorimotor neuropathy (HN), harboring the peripheral myelin protein-22 (PMP22) mutation were examined with the same tools.

Results

The two groups did not differ significantly in gender, age or education. Mean HAQ-DI score was 0.82 in the MT (range: 0-1.625) and 0.71 in the HN group (range: 0-1.625). Level of disability between the two groups did not differ significantly (p = 0.6076). MT patients scored significantly higher on the BDI-SF and HDRS than HN patients (12.85 versus 4.40, p = 0.031, and 15.62 vs 7.30, p = 0.043, respectively). The Global Severity Index (GSI) of SCL-90-R also showed significant difference (1.44 vs 0.46, p = 0.013) as well as the subscales except for somatization. SCID-I interview yielded a variety of mood disorders in both groups. Eight MT patient (42%) had past, 6 (31%) had current, 5 (26%) had both past and current psychiatric diagnosis, yielding a lifetime prevalence of 9/19 (47%) in the MT group. In the HN group, 3 patients had both past and current diagnosis showing a lifetime prevalence of 3/10 (30%) in this group. SCID-II detected personality disorder in 8 MT cases (42%), yielding 3 avoidant, 2 obsessive-compulsive and 3 personality disorder not otherwise specified (NOS) diagnosis. No personality disorder was identified in the HN group.

Conclusions

Clinicians should be aware of the high prevalence of psychiatric symptoms in patients with mitochondrial mutation which has both etiologic and therapeutic relevance.
miRviewer: a multispecies microRNA homologous viewer
Authors: Kiezun Adam , Artzi Shay , Modai Shira , Volk Naama , Isakov Ofer , Shomron Noam
Published: February 2012

Background

MicroRNAs (miRNAs) are short non-coding RNAs that regulate gene expression via binding to the 3' ends of mRNAs. MiRNAs have been associated with many cellular events ascertaining their central role in gene regulation. In order to better understand miRNAs of interest it is of utmost importance to learn about the genomic conservation of these genes.

Findings

The miRviewer web-server, presented here, encompasses all known miRNAs of currently fully annotated animal genomes in a visual 'birds-eye' view representation. miRviewer provides a graphical outlook of the current miRNA world together with sequence alignments and secondary structures of each miRNA. As a test case we experimentally examined the expression of several miRNAs in various animals.

Conclusions

miRviewer completes the homologous miRNA space with hundreds of unreported miRNAs and is available at: http://people.csail.mit.edu/akiezun/miRviewer
Serological survey of Toxoplasma gondii in Tibetan mastiffs (Canis lupus familiaris) and yaks (Bos grunniens) in Qinghai, China
Authors: Wang Meng , Wang Yan-hua , Ye Qiang , Meng Peng , Yin Hong , Zhang De-lin
Published: February 2012

Background

Toxoplasma gondiiis an amphixenosis which has extensive hosts. In recent years, the prevalence ofT. gondiiin China has been reported, while little is known on the survey ofT. gondiiinfection in northwest China, especially in yaks (Bos grunniens) and Tibetan mastiffs (Canis lupus familiaris). The current study survey the infection ofT. gondiiin Tibetan mastiffs and yaks in Qinghai Province, China.

Methods

The indirect hemagglutination test (IHAT) was used to examineT. gondiiantibodies in 1 795 serums, including 192 Tibetan mastiffs and 1603 yaks in Qinghai Province, China.

Results

In this study, the seroprevalence ofT. gondiiinfection was 8.52%. Twenty (10.42%) of 192 serums of Tibetan mastiffs and 133 (8.30%) of 1603 serums of yaks were seropositive. The seroprevalence ofT.gondiiinfection in Tibetan mastiffs in breeding farm (1.08%) was lower than that in the field (19.19%), and the difference was statistically significant (P<0.05). The seroprevalence of antibodies toT.gondiiin yaks ranged from 5.45% to 13.28% among the four different areas. The seroprevalence in different age groups were determined with apparent association.

Conclusions

The results indicated thatT.gondiiinfection was prevalent in Tibetan mastiffs and yaks, which have implications for public health in this region. To our knowledge, this is the first seroprevalence survey of Tibetan mastiffs infected byT. gondiiin The People’s Republic of China.
Co-infection of HIV and intestinal parasites in rural area of China
Authors: Tian Li-Guang , Chen Jia-Xu , Wang Tian-Ping , Cheng Guo-Jin , Steinmann Peter , Wang Feng-Feng , Cai Yu-Chun , Yin Xiao-Mei , Guo Jian , Zhou Li , Zhou Xiao-Nong
Published: February 2012

Background

Intestinal parasite infections (IPIs) are among the most significant causes of illness and disease of socially and economically disadvantaged populations in developing countries, including rural areas of the People's Republic of China. With the spread of the human immunodeficiency virus (HIV) among rural Chinese populations, there is ample scope for co-infections and there have been increasing fears about their effects. However, hardly any relevant epidemiological studies have been carried out in the country. The aim of the present survey was to assess the IPI infection status among a representative sample of HIV-positive Chinese in rural Anhui province, and compare the findings with those from a cohort of non-infected individuals.

Methods

A case control study was carried out in a rural village of Fuyang, Anhui province, China. Stool samples of all participants were examined for the presence of intestinal parasites. Blood examination was performed for the HIV infection detection and anemia test. A questionnaire was administered to all study participants.

Results

A total of 302 HIV positive and 303 HIV negative individuals provided one stool sample for examination. The overall IPI prevalence of intestinal helminth infections among HIV positives was 4.3% (13/302) while it was 5.6% (17/303) among HIV negatives, a non-significant difference. The prevalence of protozoa infections among HIV positives was 23.2% while the rate was 25.8% among HIV negatives. The species-specific prevalences among HIV positives were as follows: 3.6% for hookworm, 0.7% for Trichuris trichiura, zero for Ascaris lumbricoides, 0.3% for Clonorchis sinensis, 1.3% for Giardia intestinalis, 16.2% for Blastocystis hominis, 1.7% for Entamoeba spp. and 8.3% for Cryptosporidium spp.. Cryptosporidium spp. infections were significantly more prevalent among HIV positives (8.3%) compared to the HIV negative group (3.0%; P < 0.05). Among people infected with HIV, Cryptosporidium spp. was significantly more prevalent among males (12.6%) than females (4.4%; P < 0.05). According to multivariate logistic regression, the factors significantly associated with parasite infections of the people who were HIV positive included sex (male: OR = 6.70, 95% CI: 2.030, 22.114), younger age (less than 42 years old: OR = 4.148, 95% CI: 1.348, 12.761), and poor personal hygiene habits (OR = 0.324, 95% CI: 0.105, 0.994).

Conclusions

HIV positive individuals are more susceptible to co-infections with Cryptosporidium spp. than HIV negative people, particularly younger males with poor personal hygiene habits, indicating a need for targeted hygiene promotion, IPI surveillance and treatment.
Measuring the Impact of Negative Demand Shocks on Car Dealer Networks
Authors: Albuquerque Paulo , Bronnenberg Bart J.
Published: February 2012

The goal of this paper is to study the behavior of consumers, dealers, and manufacturers in the car sector and present an approach that can be used by managers and policy makers to investigate the impact of significant demand shocks on profits, prices, and dealer networks. More specifically, we investigate consumer demand, substitution patterns, and price decisions across different cars and dealer locations to identify dealerships with low margins or high fixed costs and measure the value of closing down dealerships for manufacturers. We apply our model empirically to the San Diego area using a transactional data set with information about the locations of dealers and consumers, as well as manufacturer and retail prices. We find strong consumer disutility for travel and find that dealers have local demand areas that are shared with a small set of competitors. We show that a reduction of market demand by 30% over two years, similar to the economic crisis of 2008–2009, results in an annual drop in prices of approximately 11%. We discuss this price drop in the context of the 2009 federal policy measure known as the Car Allowance Rebate System program. We compare predictions and actual dealership closings in the General Motors and Chrysler dealer networks as an application of our approach.
Commentaries and Rejoinder to “Marketing of Vice Goods: A Strategic Analysis of the Package Size Decision” by Sanjay Jain
Authors: Rao Ram , Wansink Brian , Jain Sanjay
Published: February 2012

Jain [Jain, S. 2012. Marketing of vice goods: A strategic analysis of the package size decision. Marketing Sci. 31(1) 36–51] examines the impact of consumers' self-control problem on the equilibrium package sizes offered by firms marketing vice goods. This series of discussions offers commentaries and a rejoinder that discuss competitive implications of firms offering small sizes and the impact of smaller sizes on the total consumer expenditure.
Transmission for a finite superlattice with a linear modulation of the potential barriers height.
Authors: Rodríguez-Magdaleno K. A. , Martínez-Orozco J. C. , Contreras-Solorio D. A.
Published: February 2012

Using the transfer matrix method and the Ben Daniel-Duke equation for variable mass electrons propagation, we calculate the transmittance for a finite superlattice where the potential barriers height follows a linear dependence like that of an inverted “V” letter. The energy dependence of the transmittance presents intervals of stopbands and nearly flat passbands. We calculate these properties for several numbers of barriers as well as for different barrier and wells widths and compare those with a regular superlattice.
Determining loading kinetics of drug releasing degradable shape-memory polymers
Authors: Wischke Christian , Steuer Susi , Lendlein Andreas
Published: February 2012

Modern concepts for biofunctional implants often comprise the controlled release of bioactive compounds to gain specific biofunctionalities. Here, amorphous and semi-crystalline copolyester-based shape-memory polymer (SMP) networks are reported as matrix for pharmaceutical applications. Drug loading of such crosslinked networks by swelling techniques requires tools to determine the actual payload. In this report, the capability of determining loading kinetics by mass increase or changes of drug concentration in the swelling medium is explored for two types of copolyester-based SMP networks differing in their crosslinking chemistry. Nitrofurantoin and ethacridine lactate served as hydrophobic and hydrophilic model drugs. It was found, that the absolute values of the determined payload did not systematically agree with those obtained by the more reliable technique of network cleavage and spectrophotometric quantification. However, the studies indicate that for both types of SMP materials and both drugs, maximum incorporation of the drugs occurred within a few hours. The time until equilibration depended on the network properties.
Synthesis and Coating of Aluminum NanoCrystals
Authors: Kaplowitz Dan A. , Jouet Jason , Zachariah Michael R.
Published: February 2012

We show a low temperature gas-phase synthesis route to produce faceted aluminum crystals in the aerosol phase. Use of triisobutylaluminum whose decomposition temperature is below the melting point of elemental aluminum enabled us to grow nanocrystals from its vapor. Combustion tests show an increase in energy release compared to commercial nanoaluminum. Production of aluminum in an oxygen free environment resulted in a bare aluminum surface that was passivated in separate experiments with nickel and iron by decomposition of their carbonyl precursors.
GaN-Based Neutron Scintillators with a 6LiF Conversion Layer
Authors: Melton Andrew G. , Burgett Eric , Hertel Nolan , Ferguson Ian T.
Published: February 2012

Thin film gallium nitride (GaN) scintillators have been produced by MOCVD and made neutron-sensitive by applying an enriched lithium-6 fluoride (6LiF) conversion layer. The 6Li(n,α) reaction produces both alpha and triton particles, which have very penetration depths in GaN. The range and energy deposition characteristics of these particles in GaN have been simulated. Alpha-induced scintillation was measured in silicon-doped GaN using an americium-241 (241Am) source. The thermal neutron responses of the 6LiF-coated GaN scintillator were tested using two thermal neutron sources, an 241Am-Be source inside a graphite pile and a reactor source. The scintillator was found to have a linear response to thermal neutron flux level over a range of more than three orders of magnitude.
Investigation of water adsorption on metal oxide surfaces under conditions representative of PuO2 storage containers.
Authors: Murphy Patrick , Boxall Colin , Taylor Robin
Published: February 2012

We have developed a QCM (Quartz Crystal Microbalance) based method for direct gravimetric determination of water adsorption on PuO2 surrogate surfaces, especially CeO2, under conditions representative of those in a typical PuO2 storage can. In this application, the method of transduction of the QCM relies upon the linear relationship between the resonant frequency of piezoelectrically active quartz crystals and the mass adsorbed on the crystal surface. The spurious effect of high temperatures on the resonant frequency of coated QCM crystals has been compensated for by modeling the temperature dependence of the frequency response of the surrogate coated-QCM crystal in the absence of water. Preliminary results indicate that water is readily adsorbed from the vapor phase into porous metal oxide structures by capillary condensation, an observation that may have important ramifications for water uptake within the packed powder beds that may obtain in PuO2 storage cans.
Obtaining and characterization of the alumina-zirconia nanocomposite
Authors: Pallone Eliria M. J. A. , Silva Kátia L. , Tomasi Roberto , Hernandes Vania T. , Zavaglia Cecilia
Published: February 2012

Ceramics of alumina of high density and purity can have a broad application area due to the combination of the excellent properties such as resistance to corrosion, good biocompatibility, and high resistance to wear and moderate mechanical resistance. But its low fracture toughness limits its range of applications. One possibility of improvement in the properties of these materials might be in the use of nanometric inclusions of ZrO2 into the matrix of Al2O3. The aim of this paper was to obtain and characterize the nanocomposites of alumina containing 0, 5, 10, 15 and 30 vol% of nanometric zirconium, seeking improvements in the mechanical properties and its comparison with values found for the matrix without the inclusion. For that, nanometric particles of ZrO2 were added into the matrix of alumina in the different proportions, using mixture of suspensions. The samples of alumina and nanocomposites of alumina-zirconium were physically, microstructurally and mechanically characterized. The results obtained, showed the efficiency of the used process, obtaining a good dispersion of the particles of zirconium in the matrix of alumina. The adding of up to 15vol% nanometric zirconium in the matrix of alumina promoted an increase in the values of the mechanical properties when compared with alumina. For the nanocomposites containing 30vol%, a good dispersion of the zirconium inclusions did not happen, leading to inferior values in the measured properties.
Deposition of Bronze Microwires on Ultrananocrystalline Diamond (UNCD) Electrodes
Authors: Grodek Corina , Lepak Lori A. , Sumant Anirudha V. , Divan Ralu , Auciello Orlando , Rosenmann Daniel , Miller Suzanne , Daniels Ephriam , Zach Michael P.
Published: February 2012

As technology advances, ever smaller wires are needed for devices, for applications in electronics, medicine, and clean energy. Many of these applications will require the precise control of not only wire shapes and diameters, but alloy compositions as well. The recently developed technique of Electroplate-and-Lift (E&L) Lithography developed by our group has demonstrated the capability of quickly and easily producing patterned micro- and nanowires of a large variety of electrodeposited materials. Here we report the first E&L- based synthesis of microwires with controlled alloy compositions, in the model system of bronze.

Wires of several different compositions, ranging from 100% copper to 100% tin, were deposited on patterned ultrananocrystalline diamond (UNCD)TM templates, by varying the relative concentrations of copper and tin salts in the plating solution. All wires were deposited at 55oC, -1.0 V vs. the saturated calomel electrode (SCE). Wire morphology and elemental composition was observed with scanning electron microscopy (SEM) equipped with energy-dispersive spectroscopy (EDS). For some alloy compositions, wires were interrupted at irregular intervals by nodules. All alloy wires were highly enriched in copper relative to the solution composition.
Shape-Memory Properties of Electrospun Non-wovens Prepared from Amorphous Polyetherurethanes Under Stress-free and Constant Strain Conditions
Authors: Sauter Tilman , Kratz Karl , Lendlein Andreas
Published: February 2012

The shape-memory properties of electrospun polyetherurethanes (PEU) non-wovens with a single fiber diameter of around 1 μm were explored. In uniaxial cyclic, thermomechanical tensile tests a dual-shape shape-memory creation procedure (SMCP) was applied and the shape recovery was examined under stress-free and constant strain conditions. The thermal properties of the electrospun PEU non-wovens were found to be similar to those obtained for bulk PEU samples, whereas the mechanical properties revealed differences with respect to the elongation at break (εb) at increased temperatures. Excellent dual-shape properties were achieved for the PEU non-wovens with a high shape fixity rate (Rf) and shape recovery rate (Rr). A significant higher recovery stress (σmax) was obtained under constant strain recovery conditions for the electrospun non-wovens compared to the bulk PEU samples, which might be attributed to the higher degree of orientation of the polymer chains in the microfibers. Therefore the influence of different (single) fiber diameters as well as the variation of the programming elongation εm and temperature Tprog on σmax is an interesting issue for future investigations.
Creeping Bentgrass (Agrostis stolonifera) Golf Green Tolerance to Bispyribac-Sodium Tank-Mixed with Paclobutrazol
Authors: Moss Justin Q. , Xiong Xi , Su Kemin , Poudel Bishow P. , Haguewood John B.
Published: February 2012

Annual bluegrass is a troublesome weed in golf course putting greens. The objective of this research was to evaluate creeping bentgrass putting green tolerance to bispyribac-sodium tank-mixed with paclobutrazol in the transition zone. Field trials with four replications were conducted in Oklahoma during 2009 and 2010 and in Missouri during 2010. The results of this study suggest that tank-mixing bispyribac-sodium with paclobutrazol may discolor creeping bentgrass putting greens but will not reduce turf quality below acceptable levels. Normalized vegetative difference index readings indicated no treatment differences in turf greenness at 4 and 8 wk after initial treatment. Weekly application of bispyribac-sodium at 12.4 g ha−1 or biweekly application at 24.8 g ha−1 alone or with monthly applications of paclobutrazol at 224 g ha−1 did not cause unacceptable injury to creeping bentgrass putting greens during the spring.
Economic Evaluation of Common Sunflower (Helianthus annuus) Competition in Field Corn
Authors: Falkenberg Nyland R. , Cogdill Todd J. , Rister M. Edward , Chandler James M.
Published: February 2012

Field studies were conducted near College Station, TX, in 2006 and 2007 to evaluate the economic impact of common sunflower interference in field corn. A density of one common sunflower per 6 m of crop row caused a yield loss of 293 kg ha−1. Estimated losses at a net corn price of $0.08 kg−1was $92 ha−1for infestation levels of four common sunflower plants per 6 m of row. Corn yield was increased by 32 kg ha−1by each 1,000 plant ha−1increase in corn planting density. Corn planting densities of 49,400 and 59,300 plants ha−1provided the greatest net returns with or without the presence of common sunflower competition. Corn yields were reduced by extended duration of sunflower competition, with losses exceeding 1,500 kg ha−1per week and increasing in magnitude at a decreasing rate throughout the growing season. Herbicide treatments provided net returns of $600 to $1,300 ha−1above no weed control in both 2006 and 2007. Net returns of $609 and $653 ha−1were obtained without the use of any herbicide for sunflower control. Determining the economic impact of common sunflower interference in field corn allows producers to estimate the overall net return on the basis of duration of common sunflower interference and density, while considering varying net corn prices, crop planting density, and herbicide application costs.
Economic Evaluations of Imazethapyr Rates and Timings on Rice
Authors: Carlson Tyler P. , Webster Eric P. , Salassi Michael E. , Bond Jason A. , Hensley Justin B. , Blouin David C.
Published: February 2012

Field studies were conducted in Crowley, LA, and Stoneville, MS, in drill-seeded rice to evaluate economical returns of weed control with imazethapyr. Red rice and barnyardgrass control was evaluated with imazethapyr alone at various rates and application timings. Imazethapyr, averaged across rate, controlled red rice 89% and barnyardgrass 90% when the initial application of imazethapyr was applied at emergence followed by a second application of imazethapyr 2 wk later. No difference in red rice and barnyardgrass control was observed with imazethapyr, averaged across timing. Yield and economical returns were maximized when the initial application of imazethapyr was applied at rice emergence followed by a second application of imazethapyr 2 wk later.
Controlling Grass Weeds on Hard Surfaces: Effect of Time Intervals between Flame Treatments
Authors: Rask Anne M. , Kristoffersen Palle , Andreasen Christian
Published: February 2012

An experiment was conducted on a specially designed hard surface to study the impact of time interval between flaming treatments on the regrowth and flower production of two grass weeds. The goal of this experiment was to optimize the control of annual bluegrass and perennial ryegrass, both species that are very difficult to control without herbicides. Aboveground biomass from 72 plants per treatment was harvested and dry weights were recorded at regular intervals to investigate how the plants responded to flaming. Regrowth of the grasses was measured by harvesting aboveground biomass 2 wk after the second flaming treatments that were implemented at different time intervals. Flaming treatments decreased plant biomass of both species and also the ratio of flowering annual bluegrass plants. However, few plants were killed. The first flaming treatment affected aboveground biomass more than the second flaming treatment. A treatment interval of 7 d provided the greatest reduction in regrowth of perennial ryegrass, whereas the effect of treatment interval varied between the first and second repetitions of this experiment for annual bluegrass. In general, short treatment intervals (3 d) should be avoided, as they did not increase the reduction of aboveground biomass compared with the 7-d treatment interval. Knowledge on the regrowth of grass weeds after flaming treatments provided by this study can help improve recommendations given to road keepers and park managers for management on these weeds.