bluuebunny/crossref_metadata_2025 huggingface dataset:
Induction and Selection of Sox17-Expressing Endoderm Cells Generated from Murine Embryonic Stem Cells
Authors: Schroeder Insa S. , Sulzbacher Sabine , Nolden Tobias , Fuchs Joerg , Czarnota Judith , Meisterfeld Ronny , Himmelbauer Heinz , Wobus Anna M.
Published: November 2011

Embryonic stem (ES) cells offer a valuable source for generating insulin-producing cells. However, current differentiation protocols often result in heterogeneous cell populations of various developmental stages. Here we show the activin A-induced differentiation of mouse ES cells carrying a homologous dsRed-IRES-puromycin knock-in within the Sox17 locus into the endoderm lineage. Sox17-expressing cells were selected by fluorescence-assisted cell sorting (FACS) and characterized at the transcript and protein level. Treatment of ES cells with high concentrations of activin A for 10 days resulted in up to 19% Sox17-positive cells selected by FACS. Isolated Sox17-positive cells were characterized by defini- tive endoderm-specific Sox17/Cxcr4/Foxa2 transcripts, but lacked pluripotency-associated Oct4 mRNA and protein. The Sox17-expressing cells showed downregulation of extraembryonic endoderm (Sox7, Afp, Sdf1)-, mesoderm (Foxf1, Meox1)- and ectoderm (Pax6, NeuroD6)-specific transcripts. The presence of Hnf4α, Hes1 and Pdx1 mRNA demonstrated the expression of primitive gut/foregut cell-specific markers. Ngn3, Nkx6.1 and Nkx2.2 transcripts in Sox17-positive cells were determined as properties of pancreatic endocrine progenitors. Immunocytochemistry of activin A-induced Sox17-positive embryoid bodies revealed coexpression of Cxcr4 and Foxa2. Moreover, the histochemical demonstration of E-cadherin-, Cxcr4-, Sox9-, Hnf1β- and Ngn3-positive epithelial-like structures underlined the potential of Sox17-positive cells to further differentiate into the pancreatic lineage. By reducing the heterogeneity of the ES cell progeny, Sox17-expressing cells are a suitable model to evaluate the effects of growth and differentiation factors and of culture conditions to delineate the differentiation process for the generation of pancreatic cells in vitro.
Impact of Silent Ischemic Lesions on Cognition following Carotid Artery Stenting
Authors: Huang Kuo-Lun , Ho Meng-Yang , Chang Chien-Hung , Ryu Shan-Jin , Wong Ho-Fai , Hsieh I-Chang , Chang Ting-Yu , Wu Tai-Cheng , Lee Tsong-Hai , Chang Yeu-Jhy
Published: November 2011

Objective: The occurrence of silent ischemic lesions (SILs) is a common finding after carotid artery stenting (CAS). This study aimed to evaluate the impact of SILs on cognitive functioning following CAS. Methods: The retrospective study separated 131 patients with unilateral carotid stenosis into three groups: medication only, MRI-evaluated CAS and CT-evaluated CAS, and compared the sociodemographic factors, post-CAS images and Mini-Mental State Examination scores performed before and 6–12 months after enrollment. Results: Seven minor strokes occurred in the 99 patients receiving CAS. SILs were detected in 12 of 55 patients with diffusion-weighted MR imaging (DWI) and in 3 of 37 patients with CT 1 week after CAS. In patients with DWI follow-up, the frequency of SILs was 8, 24, 43 and 60% in patients with 0-, 1-, 2- and 3-vessel coronary artery disease (p = 0.006). The frequency of SILs on DWI was 0, 32 and 33% in patients with improved, unchanged, or deteriorated cognitive functioning (p = 0.02). Such an association was not observed if based on SILs on CT or manifesting stroke. Conclusion: The presence of coronary artery disease increases the risk for having post-CAS SILs, and the occurrence of SILs may be associated with cognitive changes after CAS.
Developmental expression and organisation of fibrinogen genes in the zebrafish
Authors: Vorjohann Silja , Béna Frédérique , Fort Alexandre , Fish Richard J. , Neerman-Arbez Marguerite
Published: November 2011

The zebrafish is a model organism for studying vertebrate development and many human diseases. Orthologues of the majority of human coagulation factors are present in zebrafish, including fibrinogen. As a first step towards using zebrafish to model human fibrinogen disorders, we cloned the zebrafish fibrinogen cDNAs and made in situ hybridisations and quantitative reverse transcription-polymerase chain reactions (qRT-PCR) to detect zebrafish fibrinogen mRNAs. Prior to liver development or blood flow we detected zebrafish fibrinogen expression in the embryonic yolk syncytial layer and then in the early cells of the developing liver. While human fibrinogen is encoded by a three-gene, 50 kilobase (kb) cluster on chromosome 4 (FGB-FGA-FGG), recent genome assemblies showed that the zebrafish fgg gene appears distanced from fga and fgb, which we confirmed by in situ hybridisation. The zebrafish fibrinogen Bβ and γ protein chains are conserved at over 50% of amino acid positions, compared to the human polypeptides. The zebrafish Aα chain is less conserved and its C-terminal region is nearly 200 amino acids shorter than human Aα. We generated transgenic zebrafish which express a green fluorescent protein reporter gene under the control of a 1.6 kb regulatory region from zebrafish fgg. Transgenic embryos showed strong fluorescence in the developing liver, mimicking endogenous fibrinogen expression. This regulatory sequence can now be used for overexpression of transgenes in zebrafish hepatocytes. Our study is a proof-of-concept step towards using zebrafish to model human disease linked to fibrinogen gene mutations.
Long-term therapy with low-molecular-weight heparin in cancer patients with venous thromboembolism
Authors: Marchena Pablo , Nieto José , Guil María , García-Bragado Ferrán , Rabuñal Ramón , Boccalon Henri , Trujillo-Santos Javier , Monreal Manuel ,   RIETE Investigators
Published: November 2011

Long-term therapy with low-molecular-weight heparin (LMWH) is the treatment of choice for cancer patients with venous thromboembolism (VTE). However, the ideal doses of LMWH have not been thoroughly studied. We used the RIETE Registry data to assess the influence of the daily LMWH dosage on outcome during the first three months after VTE. We used propensity score-matching to compare patients who received <150 vs. those receiving ≥150 UI/kg/day LMWH. Up to July 2010, 3,222 cancer patients with VTE received long-term therapy with fixed doses of LMWH. Of these, 1,472 (46%) received <150 IU/kg/day (mean, 112 ± 28), and 1,750 received ≥150 IU/kg/day (mean, 184 ± 32). Results of the propensity score matching involved 1269 matched pairs. During follow-up, the incidence of pulmonary embolism (PE) recurrences was similar (1.2% vs. 1.9%), but patients receiving <150 IU/kg/day LMWH had a lower incidence of fatal PE than those treated with ≥150 IU/kg/day (0.2% vs. 1.0%; p=0.004). Multivariate analysis confirmed that patients receiving <150 IU/kg/day LMWH had a lower risk for fatal PE (odds ratio [OR]: 0.2; 95% confidence interval [CI]: 0.06–0.8) and for major bleeding (OR: 0.6; 95% CI: 0.3–1.0) than those treated with ≥150 IU/kg/day. In real life, one in every two cancer patients with VTE received lower doses of LMWH than those used in randomised trials, with large variations from patient to patient. Unexpectedly, patients treated with <150 IU/kg/day LMWH had fewer fatal PE cases and fewer major bleeding events than those receiving ≥150 IU/kg/day LMWH. This finding, however, should be validated in prospective clinical trials.
A point mutation in the EGF-4 domain of β3 integrin is responsible for the formation of the Seca platelet alloantigen and affects receptor function
Authors: Sachs Ulrich J. , Bakchoul Tamam , Eva Olga , Giptner Astrid , Bein Gregor , Aster Richard H. , Gitter Maria , Peterson Julie , Santoso Sentot
Published: November 2011

Neonatal alloimmune thrombocytopenia (NAIT) is caused by fetomaternal platelet incompatibility with maternal antibodies crossing the placenta and destroying fetal platelets. Antibodies against human platelet antigen-1a (HPA-1a) and HPA-5b are responsible for the majority of NAIT cases. We observed a suspected NAIT in a newborn with a platelet count of 25 G/l and petechial haemorrhages. Serological analysis of maternal serum revealed an immunisation against αIIbβ3 on paternal platelets only, indicating the presence of an antibody against a new rare alloantigen (Seca) residing on αIIbβ3. The location of Seca on αIIbβ3 was confirmed by immunoprecipitation. Nucleotide sequence analysis of paternal β3 revealed a single nucleotide exchange (G1818T) in exon 11 of the β3 gene (ITGB3), changing Lys580 (wild-type) to Asn580 (Seca). Two additional members of the family Sec were typed Seca positive, but none of 300 blood donors. Chinese hamster ovary cells expressing Asn580, but not Lys580 αIIbβ3, bound anti-Seca, which was corroborated by immunoprecipitation. Adhesion of transfected cells onto immobilised fibrinogen showed reduced binding of the Asn580 variant compared to wild-type αIIbβ3. Analysis of transfected cells with anti-LIBS and PAC-1 antibody showed reduced binding when compared to the wild-type. No such effects were observed with Seca positive platelets, which, however, are heterozygous for the Lys580Asn mutation. In this study, we describe a NAIT case caused by maternal alloimmunisation against a new antigen on αIIbβ3. Analysis with mutant transfected cells showed that the Lys580Asn mutation responsible for the formation of the Seca antigenic determinant affects αIIbβ3 receptor function.
Matching the Message
Authors: Fransen Marieke L. , ter Hoeven Claartje L.
Published: November 2011

The experiments presented here examine how managers and executives can improve the effectiveness of their negative written communications (i.e., refusal of employees’ requests) by incorporating the concept of fit into their message framing. By applying regulatory focus theory, the authors suggest that an outcome-based fit between the message and the recipient leads to more favorable work outcomes. The results of Experiment 1 show that employees retain greater feelings of psychological empowerment when they receive a written refusal framed in terms that match (versus mismatch) their current regulatory focus. Moreover, data from Experiment 2 demonstrate that employees perceive a written refusal as more fair when it is framed in terms that match (versus mismatch) their activated regulatory focus. However, this effect was not found when an employee’s request was approved, an observation that stresses the importance of regulatory fit in negative managerial communications specifically. Finally, this article discusses management implications for designing successful negative written managerial communications.
The Electronic Water Cooler
Authors: Kulik Carol T. , Pepper Molly B. , Shapiro Debra L. , Cregan Christina
Published: November 2011

The boundary between organizational insiders (e.g., employees) and outsiders (e.g., customers) has become increasingly permeable due to Internet discussion boards that enable members of both groups to share experiences of organizational fairness and unfairness. We studied discussion board threads on Vault.com , focusing on threads initiated by postings containing organizational justice content and authored by an organizational insider or outsider. Consistent with predictions of the social identity model of deindividuation effects, organizational insiders capitalized on anonymity to post messages that were significantly more negative in both cognitive content (describing organizations as less fair) and emotional tone (using more negative emotional language) than messages posted by organizational outsiders. As predicted by contagion theory, cognitive content influenced the emotional tone of reply messages, especially when initial postings were from organizational outsiders.
Evaluation of three hollow-fiber membrane oxygenators without integrated arterial filters for neonatal cardiopulmonary bypass
Authors: Dogal NM , Mathis RK , Lin J , Qiu F , Kunselman A , Ündar A
Published: November 2011

The cardiopulmonary bypass (CPB) procedure has been shown to be a possible cause of postoperative neurological morbidity for various reasons, including: large amounts of gaseous microemboli (GME) reaching the patient and hypoperfusion of the patient due to “stolen” blood flow. This study used a simulated CPB circuit identical to that in a clinical setting to examine three different hollow-fiber membrane oxygenators without intergrated arterial filters - the Capiox RX05, the Quadrox-i neonatal, and the KIDS D100 - to determine their ability to reduce the number of GME delivered to the neonatal patient and their hemodynamic properties in response to varying flow rates, normothermic vs hypothermic conditions, and open vs closed purge line. The circuit was primed with Ringer’s Lactate and then human blood with a hematocrit of 30%. Injections of 5cc bolusses of air were injected into the venous line proximal to the venous reservoir over a thirty-second interval. Six injections were done for each oxygenator at each of the eight different experimental conditions for a total of 64 experiments per oxygenator (192 total injections). A flow probe, pressure transducer, and Emboli Detection and Classification (EDAC) quantifier transducer were positioned both upstream and downstream of the oxygenator to measure differences in each parameter. Results demonstrated that the Capiox RX05 is the most effective oxygenator at reducing the number of microemboli that potentially can be delivered to the neonatal patient. In regards to the hemodynamic properties, the Quadrox-i has the most favorable results, with the lowest mean pressure drop and the best energy retention across the oxygenator.
Differentiating Offenders by Index Offense and Personality Inventories
Authors: Shechory Mally , Weiss Joshua M. , Weinstain Rachel
Published: November 2011

The current study examines the differences between four groups of offenders ( N = 230) according to the type of crime they committed: domestic violence, sex offenses, traffic violations, and nonspecific violence offenses. The study was conducted on the offenders undergoing treatment in the Israeli Adult Probation Service. A comparison between the groups included an examination of the differences in aggression levels, anxiety levels, and two Minnesota Multiphasic Personality Inventory–2 (MMPI-2) scales—the Psychopathic Deviate (PD-4) and the Antisocial Practices (ASP) scales. The findings provide a glimpse of the features that characterize each group, in relation to each other and in relation to the body of literature. The domestic violence group differed from the other groups in most of the research variables. They were found to have low anxiety levels and high aggression levels. Together with other findings that pointed to antisocial practices and attitudes, this group constitutes a population that is violent and aggressive to a far greater extent compared with the other groups. Sex offenders were found to be a unique group that does not fit in the “classic offenders” category. They were found to have low aggression levels and high anxiety levels and their scores on PD-4 and ASP scales were low compared with the other groups. The traffic group was characterized with typically low levels of anxiety and high levels of physical aggression. This group also obtained high scores on ASP scale and the measure that examined confrontation with authority figures. Finally, study findings did not indicate characteristics that typify the nonspecific violence offenses.
Prescription patterns in preventive and abortive migraine medication
Authors: Sumelahti Marja-Liisa , Mattila Kari , Sillanmäki Lauri , Sumanen Markku
Published: November 2011

Background: Migraine is considered a common but under-diagnosed and untreated condition. Treatment patterns have pointed at frequent over-the-counter medication use and low use of preventive therapies. Studies exploring migraine prescription practice among doctors are few.

Methods: A population-based study was carried out to examine the prescription practice in the use of acute and preventive migraine medications. The data covered 4864 working-age people reporting they have been diagnosed with migraine. Data on reimbursed prescription medicines from 1 January 1998 to 31 December 2006 were drawn from the registers of the Social Insurance Institute of Finland and compared with age- and sex-matched controls.

Results: Anti-inflammatory analgesics were prescribed for 71% of female and 62% of male migraine patients vs. 56% and 50% of controls. Triptans were prescribed for 21% of female and 10% of male patients. Combinations of analgesics and muscle relaxants were offered to 37% of female and 29% of male patients vs. 26% and 21% of controls, and antidepressants to 19% of women and 14% of men vs. 13% and 9% of controls.

Conclusion: Although use of preventive medication among migraineurs was high, the prescription patterns in acute treatments showed that NSAIDS were used more often than triptans. Assimilation of national guidelines to treat migraine published in 2002 in Finland was not reflected in the prescription patterns up to 2006.
The Hispanic Americans Baseline Alcohol Survey (HABLAS)
Authors: Caetano Raul , Vaeth Patrice A. C. , Rodriguez Lori A.
Published: November 2011

The purpose of this study was to examine the association between acculturation, birthplace, and alcohol-related social problems across Hispanic national groups. A total of 5,224 Hispanic adults (18+ years) were interviewed using a multistage cluster sample design in Miami, New York, Philadelphia, Houston, and Los Angeles. Multivariate analysis shows no association between acculturation and problems among men or women. Birthplace is a risk factor for social problems among both genders. Among men, Mexican Americans, Puerto Ricans, and South/Central Americans are more likely to report social problems than Cuban Americans. Other risk factors for men are unemployment, a higher volume of drinking, and a higher frequency of binge drinking. Among women, Mexican American origin and binge drinking are also risk factors for reporting problems. U.S.-born Hispanics may experience stress and other detrimental effects to health because of their minority status, which may increase the likelihood of more drinking and the development of alcohol-related problems.
Treatment of Addison Disease and Subsequent Hypophosphatemic Respiratory Failure
Authors: Meisterling Leah , Chawla Lakhmir S. , Seneff Michael G.
Published: November 2011

A 38-year-old man was found unresponsive with hypoglycemia by emergency medical service (EMS) personnel. He was intubated in the emergency department after reports of seizure activity. With supportive care and empiric steroids, the patient was extubated the next day. He reported a diagnosis of Addison disease and noncompliance with his steroid replacement therapy. Within 12 hours, respiratory failure and altered mental status required reintubation. Laboratory studies revealed rhabdomyolysis and hypophosphatemia. The replacement of glucose likely stimulated glycolysis, formation of phosphorylated glucose compounds, and an intracellular shift of phosphorus. This patient required phosphate replacement and was extubated on hospital day 5. We report a unique case of hypoglycemia due to Addison disease, leading to hypophosphatemic respiratory failure.
Design and analysis of an internally cooled smart cutting tool for dry cutting
Authors: Sun X , Bateman R , Cheng K , Ghani S C
Published: November 2011

Cutting fluid is traditionally used to remove heat generated during the cutting process, but it can cause environmental pollution, health hazards, and high cost of production. Dry cutting, without using the cooling liquid, is thus desirable and promising for the machining industry to produce components and products, both ecologically and more economically. In this paper, an internally cooled cutting tool for dry cutting is presented as a temperature-sensored smart cutting tool in its own right, with further applications for adaptive machining purposes. The cutting tool is characterized by a simple changeable internal cooling structure near the cutting tip. Simulations were performed to study the theoretical cooling efficiency and to optimize the cooling structure by combining it with the Taguchi Method. Furthermore, cutting trials were carried out to validate the novel cutting tool experimentally.
Innovative solution for the pump impeller shaft sealing
Authors: Batalovic V B
Published: November 2011

The hydraulic transport of solids, crude oil, waste waters etc. imposes the need for the use of pumps whose quality and reliable sealing of the rotating elements is a precondition to successful operation. The noticed problems, on the sealing of the existing facilities, has imposed numerous questions, to which answers should be provided. The conclusion is as follows: in order to make greater progress in this sphere, it is necessary, before the designing of a new facility, or the reconstruction of the old one, to apply research to define all the significant values that influence the sealing quality and the sealing life span. The task of this paper is to find a procedure that would improve impellers shaft sealing, to display the manner of research and apply the acquired results. The set goal has been realized, and the realized reconstruction is characterized by a longer life span and reliable operation.
Environmental change and Neolithic settlement movement in the lower Yangtze wetlands of China
Authors: Zong Y , Innes JB , Wang Z , Chen Z
Published: November 2011

Previous studies have suggested that, over the course of the Neolithic period, settlements in the Yangtze coastal plain gradually moved seawards and concentrated to the east of Lake Taihu, probably responding to the effects of sea-level change during the middle to late Holocene. To test this hypothesis, sediment cores adjacent to six Neolithic settlement sites across the study area were collected and analyzed for pollen and other microfossils. These records reveal details of the environmental conditions before, during and after the Neolithic occupation at each site. Results show that a freshwater marsh environment became established before each human occupation and persisted throughout and after it. There is no evidence at any site of a sudden or drastic change in environmental conditions towards the end of human settlement. After c. 7000 cal. yr BP the study area had become a wetland enclosed by Chenier ridges on the east (the southern shore of the Yangtze) and the south (the northern shore of Hangzhou Bay). During the Neolithic period ( c. 7000-3000 cal. yr BP) sea level rose slowly by c. 2 m, and elevated water-tables saw the inland Taihu area become lacustrine, while to seaward on slightly higher ground enhanced sedimentation maintained freshwater marshes, fens and swamp-woodland, particularly near the Chenier ridges. These wetland-fringed coastal areas provided resources, including shellfish, deer, boar and migratory birds, that might have attracted the Neolithic communities that were abandoning their former settlement sites in the lower-lying inland area, flooded by the expanded lakes around Taihu, after c. 4200 cal. BP.
Vertical displacement trends in the Aegean coastal zone (NE Mediterranean) during the Holocene assessed by geo-archaeological data
Authors: Pavlopoulos Kosmas , Kapsimalis Vasilios , Theodorakopoulou Katerina , Panagiotopoulos Ioannis P
Published: November 2011

Trends in the vertical displacement (i.e. uplift or subsidence) of the Aegean Sea coastal zone have been assessed by comparing observational data with those derived from the predictive glacio-hydro-isostatic model of Lambeck and Purcell (2005) for a period spanning from the Mesolithic to the late Roman times. The data base comprises published studies that use both geomorphological (with associated biological material) and archaeological sea level indicators/markers. Localities demonstrating uplift of high amplitude were detected in front of the Hellenic Arc (Antikythira, Crete, Rhodes, Nisyros) and in the northeast Aegean region (Thrace), whilst areas experiencing tectonic subsidence were mainly observed in the central Aegean region which is characterized by an extensional tectonic domain. However, regional-scale tectonic particularities have caused uplift in parts of the west and east coast of central Aegean. Tectonically ‘stable’ sites can be found in the Cyclades Plateau, however, this is due to a balance between uplifting and subsiding movements. Sediment compaction and sediment loading may have affected districts with high sedimentation rates such as the Thessaloniki Plain-Thermaikos Gulf (NW Aegean). Finally, tectonic fragmentation of the coastal area in Minor Asia is responsible for localised uplifting and subsiding events.
Holocene climatic development in Skagerrak, eastern North Atlantic: Foraminiferal and stable isotopic evidence
Authors: Erbs-Hansen Dorthe Reng , Knudsen Karen Luise , Gary Anthony Cavedo , Gyllencreutz Richard , Jansen Eystein
Published: November 2011

A high-resolution multiproxy study of core MD99-2286 reveals a highly variable hydrographic environment in the Skagerrak from 9300 cal. yr BP to the present. The study includes foraminiferal faunas, stable isotopes and sedimentary parameters, as well as temperature and salinity reconstructions of a c. 29 m long radiocarbon-dated core record. The multivariate technique fuzzy c-means was applied to the foraminiferal counts, and it was extremely valuable in defining subtle heterogeneities in the foraminiferal faunal data corresponding to hydrographic changes. The major early-/mid-Holocene (Littorina) transgression led to flooding of large former land areas in the North Sea, the opening of the English Channel and Danish straits, and initiation of the modern circulation system. This is reflected by fluctuating C/N values and an explosive bloom of Hyalinea balthica. A slight indication of ameliorated conditions between 8000 and 5750 cal. yr BP is related to the Holocene Thermal Maximum. A subsequent increase in freshwater/Baltic water influence between 5750 and 4350 cal. yr BP is reflected by dominance of Bulimina marginata and depleted δ18O values. The Neoglacial cooling (after 4350 cal. yr BP) is seen in the Skagerrak as enhanced turbidity, increasing TOC values and short-term changes in an overall Cassidulina laevigata-dominated fauna suggesting a prevailing influence of Atlantic waters. This is in agreement with increased strength of westerly winds, as recorded for this period. The last 2000 years were also dominated by Atlantic Water conditions with generally abundant nutrient supply. However, during warm periods, particularly the ‘Medieval Warm Period’and the modern warming, the area was subject to a restriction in the supply of nutrients and/or the nutrient supply had a more refractory character.
Environmental changes in Northern Iceland since the Younger Dryas inferred from periglacial slope deposits
Authors: Veit Heinz , Marti Thomas , Winiger Lukas
Published: November 2011

The slopes in Northern Iceland show the widespread occurrence of solifluction features, indicative of an active periglacial environment due to annual mean temperatures around 3°C at sea level and seasonal soil frost. In order to reconstruct periods with active and inactive solifluction in the past we excavated 18 solifluction lobes for analysing the sediment sequences. Dating of the sediments was realised mainly by tephrochronology and 14C. The oldest solifluction layer could be dated to the Younger Dryas (YD), just after the deglaciation of Northern Iceland. The early to mid Holocene up to the deposition of Hekla 3 Tephra (~3 ka BP) is characterized by the accumulation of loess and tephra layers, which show no signs of secondary remobilisation or erosion, indicating stable slopes during the mid-Holocene climatic optimum (MCO). After the deposition of Hekla 3 Tephra and especially during the ‘Little Ice Age’ (LIA), solifluction reappeared in the profiles as a probable consequence of Neoglacial cooling. The results fit well with other proxies from Iceland (glacier variations, pollen), from North Atlantic marine cores and from Greenland ice records.
Gualas Glacier sedimentary record of climate and environmental change, Golfo Elefantes, Western Patagonia (46.5°S)
Authors: Fernandez Rodrigo , Anderson John , Bertrand Sebastien , Wellner Julia
Published: November 2011

Gualas Glacier is an outlet glacier of the Northern Patagonian Icefield, one of the largest temperate ice bodies on Earth. Golfo Elefantes, the depositional basin of Gualas Glacier, has a sedimentary record that spans, with some hiatuses, at least the last ~11.3±3.0 ka. During this period the gulf remained free of ice, as suggested by the absence of proximal glacimarine sediment and till in the sedimentary section. This implies that the arcuate terminal moraines that occur along the edges of Golfo Elefantes were formed during the waning stages of the local glacial maxima (Late Pleistocene) or the early Holocene. Between ~11.3±3.0 ka and ~4.2±0.3–1.4 ka, the basin received low sediment input consisting of fine-grained sediments in the form of low concentration density currents that filled bathymetric lows. Sediment discharge increased several times in the late Holocene (~<1.4 ka) and started with the accumulation of ~ 0.5 km3 of sandy sediments in a relatively short time span (~670 yr). This high discharge of sandy sediments is interpreted as being the result of glacial reworking of sediments stored in Gualas Glacier proglacial lake and thus implies that the glacier advanced at ~1.4–0.8 ka. The overall increase in sediment discharge in the late Holocene indicates a sharp increase in centennial timescale precipitation, which in turn suggests an increase in the intensity of the westerly winds in the area. Two recent periods of interannual sedimentation variability were identified at ~ad 1160–1460 and ~ad 1680–1890 and correlate with documented regional glacier advances.
‘What we should strive for is Britishness’: An attitudinal investigation of ethnic diversity and the public library
Authors: Birdi Briony , Wilson Kerry , Mansoor Sami
Published: November 2011

This paper considers the role of the public library in ameliorating relations between communities, and the appropriateness of a multicultural or assimilationist approach via which to deliver socially inclusive services. Qualitative findings from two inductive studies, each of which focused on different aspects of the capacity of public library staff to deliver culturally inclusive services, are analysed in relation to concepts such as social capital, cultural and ethnic diversity, institutional racism and cultural awareness. The paper focuses on staffing issues and on the provision of the ‘multicultural text’. It is concluded that recruitment strategies are slow to address the homogeneity of the current library workforce, and that a revised approach to recruitment and subsequent training should be made. Furthermore, it is suggested that a community-wide exposure to materials about other ethnic cultures can contribute to the reduction of existing social fragmentation.
Validation of the Child and Youth Resilience Measure-28 (CYRM-28) Among Canadian Youth
Authors: Liebenberg Linda , Ungar Michael , Vijver Fons Van de
Published: November 2011

Objectives: This article presents the validation of the 28-item Child and Youth Resilience Measure (CYRM-28) among two Canadian samples of youth with complex needs. Method: The CYRM-28 was administered to two groups of concurrent service using youth in Atlantic Canada ( n1 = 497; n2 = 410) allowing for use of exploratory and confirmatory factor analysis. Results: Reproducibility agreement is achieved and subscales of the measure are confirmed and show adequate psychometric properties. Conclusions: Findings add support to the CYRM-28 as a reliable and valid self-report instrument that measures three components of resilience processes in the lives of complex needs youth. Advanced statistical modeling yielded evidence that the scale, originally developed for use in various countries, can be used to assess resilience in youth from various ethnocultural backgrounds in Atlantic Canada.
On the nonlinear theory of viscoelasticity of differential type
Authors: Pucci Edvige , Saccomandi Giuseppe
Published: November 2011

We consider nonlinear viscoelastic materials of differential type and for some special models we derive exact solutions of initial boundary value problems. These exact solutions are used to investigate the reasons for the non-existence of global solutions for such equations.
On symmetries of crystals with defects related to a class of solvable groups (S1)
Authors: Nicks Rachel , Parry Gareth P
Published: November 2011

We consider distributions of dislocations in continuum models of crystals which are such that the corresponding dislocation density tensor relates to a particular class of solvable Lie group, and discrete structures which are embedded in these crystals. We provide a canonical form of these structures and, by finding the set of all generators of a corresponding discrete subgroup, we determine the ‘material’ symmetries that constrain appropriate strain energy functions.
A modified CIE mesopic table and the effectiveness of white light sources
Authors: Kostic MB , Djokic LS
Published: November 2011

Since practical application of the recently developed CIE mesopic system assumes the development of new measurement devices, recommendations and software for road lighting design, this paper presents a corrected photopic luminance table, which enables lighting designers to use the existing design procedures and measurement methods until all of these tasks are accomplished. It is also shown that there are numerous reasons for the practical application of the CIE mesopic system, although only photopic vision is involved in on-axis object recognition. Using the corrected photopic luminance table, an analysis is conducted regarding the potential electricity and cost savings when applying white light sources, which are more visually effective in the mesopic range.
A Blue Tide in the Golden State
Authors: Dyck Joshua J. , Johnson Gregg B. , Wasson Jesse T.
Published: November 2011

Party identification is notoriously “sticky,” yet over the last three decades the California electorate has changed tremendously. A once red state has become one of the most reliable Democratic strongholds in the nation. What explains this change? One common explanation rests with population shifts and macropartisan trends. Another claims the combination of a rapidly expanding Latino electorate and a series of high-profile anti-immigrant ballot initiatives supported by the state’s Republicans drove partisan change in California. Building off of previous research, we seek to reconcile the differential impacts of these factors on the state’s Latinos and non-Hispanic Whites. Our analyses partially confirm and clarify previous findings regarding Latino partisan change, while directly challenging findings regarding partisan change among non-Hispanic Whites.
Composite anterolateral thigh perforator flaps in the management of complex hand injuries
Authors: Meky M. , Safoury Y.
Published: November 2011

The anterolateral thigh (ALT) fasciocutaneous flap has been well described for hand skin cover, however its use in its composite (multiple tissue) form incorporating bone, muscle and/or fascia has been less well described. We report the usefulness of the composite ALT flap in six complex hand trauma cases, four male and two female (age range 14–46 years). The palm of the hand was affected by injury in three cases, the dorsum in two cases, and the radial side in one case. The first web formed part of the injury in three cases. There was variable involvement of the tendons, nerves and bones. Fascia lata was included in the flap to provide a gliding surface in four cases, part of the vastus lateralis muscle was included to obliterate dead space in two cases and to create a first web in one case, and a bone block from the iliac crest was included to reconstruct the lost metacarpals in one case. All flaps survived with minimal complications. This work shows that the anterolateral thigh composite flap is a reliable option when multiple tissue types are required in hand reconstruction.
Role of the extensor carpi ulnaris and its sheath on dynamic carpal stability
Authors: Salva-Coll G. , Garcia-Elias M. , Leon-Lopez M. M. , Llusa-Perez M. , Rodríguez-Baeza A.
Published: November 2011

Ten cadaveric forearms were tested using a wrist testing apparatus specifically designed to investigate the mechanisms of muscle stabilization of the wrist. The specimens were set in a jig allowing the distal row to migrate proximally and rotate around the axis of pronosupination. The extensor carpi ulnaris (ECU) was loaded with specific weights. Reactive rotations of the scaphoid, triquetrum, and capitate were measured by an electromagnetic motion tracking device. Loading the ECU caused pronation of both proximal and distal rows. After sectioning its sheath, the overall direction of the movement remained unchanged, but there was a 40% and 50% decrease of the pronation power over the distal and proximal carpal row, respectively. In addition to stabilizing the distal radiolunar joint, the ECU is an important structure that contributes to the dynamic stability of the wrist. Furthermore, its sheath plays a crucial role in maintaining the effect of the ECU muscle on the carpus.
Effect of phase transformation and indium addition on workhardening characteristics of Al–Zn alloy
Authors: Abd El-Khalek A M
Published: November 2011

Tensile characteristics of both Al–10Zn and Al–10Zn–0·2In (wt-%) alloys were investigated in the temperature range from 413 to 473 K. The workhardening coefficient, the yield stress, the fracture stress, resilience, toughness and fracture time generally decrease with increasing deformation temperature. On the other hand, the fracture strain and dislocation slip distance increased with increasing deformation temperature. The two observed temperature regions around the transformation temperature (443 K), which characterise the magnitude of variation of these parameters point to two fracture mechanisms activated with 23·2 and 49·4 kJ mol−1 for the low and high temperature regions respectively. Indium addition caused general increase for all the measured strength parameters. The microstructures of the samples under investigation have been examined after stress–strain deformation by X-ray diffraction analysis.
Microstructure and mechanical properties of in situ synthesised (TiC+TiB)/Ti–6Al–4V composites prepared by powder metallurgy
Authors: Zhou P , Qin J N , Lu W J , Zhang D
Published: November 2011

Titanium matrix composites (TMCs) reinforced with hybrid reinforcements were synthesised by blending Ti–6Al–4V, Ti, B4C and C powders followed by reactive hot pressing. The phases were identified by X-ray diffraction, and the microstructures were examined by optical microscopy and scanning electron microscopy (SEM). Mechanical properties were tested at room temperature (RT), 400, 450 and 500°C respectively. The results show that Ti–6Al–4V produced by hot pressing has higher strength and better plasticity than by casting; there are four kinds of reinforcements in TMCs, and the TMCs’ strength increases significantly with the addition of reinforcements both at RT and elevated temperature; the TMCs with 5 vol.- of reinforcements have higher strength than that with 10 vol.- at high temperature. The fracture surfaces were examined by SEM. It shows that the bond between the reinforcements and matrix is not so well that reinforcements’ debonding occurs even at RT.
Tool life model for Al2O3 particle reinforced MMCs using genetic expression programming
Authors: Kök M , Kanca E , Eyercioğlu Ö
Published: November 2011

In the present work, the wear of cutting tools in the machining of 7075Al alloy composites reinforced with 10 and 25 wt- and 16 μm average size Al2O3 particles was investigated. Machining tests were performed on both as cast and heat treated composites by turning process using a physical vapour deposition coated carbide tool CP500 at different cutting conditions. A new model was developed to predict the tool life by genetic expression programming. The training and validation data sets were obtained from the well established machining test results. The weight fraction of particle Pw, cutting speed V, feedrate f and heat treatment Ht were used as independent input variables, while tool life T was used as a dependent output variable. Different models for tool life were predicted on the basis of the training data set using genetic programming, and the accuracy of the best model was proved with validation data set. The test results showed that the genetic expression programming model has produced correlation coefficient R values of ∼0·958 for the training data and 0·952 for the validation data. The predicted tool life results were compared with experimental results and found to be in good agreement with the experimentally observed ones.
Microstructural investigation on strengthening mechanisms of AISI 304L austenitic stainless steel during cryogenic deformation
Authors: Behjati P , Najafizadeh A , Kermanpur A
Published: November 2011

In the present paper, microscopy techniques and mechanical tests were used to investigate in detail the strengthening mechanisms of an AISI 304L austenitic stainless steel during cryogenic deformation. The strain hardening rate–strain response of the alloy indicated three distinct regimes of hardening, being very similar to that previously reported for other low stacking fault energy alloys. The hardening rate initially decreased up to a strain of ∼6 (stage I). Then, a second stage of increasing hardening rate began (stage II). At strains larger than ∼25, stage III with decreasing hardening rate followed. It was suggested that the formation of ϵ-martensite and α′-martensite together is responsible for the appearance of stage II. The high strain hardening values of the alloy in stage II were related to the increased fraction of α′-martensite and dislocation pile-ups behind the Lomer–Cottrell locks. The appearance of stage III was attributed to the difficulty of α′-martensite nucleation and ease of dislocation cross-slip at higher strains.
Magnetic pulse welding of Al to Mg alloys: Structural–mechanical properties of the interfacial layer
Authors: Stern A , Aizenshtein M
Published: November 2011

The magnetic pulse welding of Al-A1050 to Mg alloys was successfully performed, and the structural–mechanical properties of the interfacial bonding layer produced between dissimilar metals were studied. The morphology of the interface layer has a typical wavy pattern with an average thickness of 20 μm. Compositional microanalysis showed that the composition of the interfacial layer is Al–50 at-Mg and is practically uniform, being a direct outcome of the local melting effect, intensive mixing of the melt and a rapid rate of solidification. The composition of the bonding layer corresponds to the Al supersaturated intermetallic β phase (Mg17Al12). The elastic modulus (and the hardness) of the interfacial layer was measured using the nanoindentation technique, and its value of 60·2±1·4 GPa is in good agreement with the value calculated from first principles in the literature (57·3 GPa) for the Mg17Al12 intermetallic phase.
Microstructural evaluation of melt conditioned twin roll cast Al–Mg alloy
Authors: Kumar S , Hari Babu N , Scamans G M , Fan Z
Published: November 2011

Aluminium alloy strip has been successfully cast using the melt conditioned twin roll casting (MC-TRC) process. The liquid metal to be strip cast was fed into a melt conditioner, where it was intensively sheared under conditions of high shear rate and high turbulence induced by corotating twin screws. Melt conditioning provides a melt which has a uniform temperature and chemical composition and well dispersed nuclei. The conditioned melt was then fed into a twin roll caster. The MC-TRC process produced high quality Al–Mg alloy strip with fine and uniformly distributed intermetallics throughout the cross-section with minimal centreline segregation compared to conventional TRC strip. The Erichsen height value of MC-TRC sheet was superior to that of TRC sheet. The lower formability of the TRC sheet is attributed to the severe centreline segregation.
Strain driven grain boundary sliding and/or rotation during tensile deformation of ultrafine grained C–Mn steel
Authors: Du L X , Yao S J , Zhou M , Wang G D
Published: November 2011

The microstructure evolution of ultrafine grained C–Mn steel during tensile deformation was investigated using scanning electron microscopy. The surface morphologies and orientation imaging micrographs at different locations near the fractures were discussed. No obvious evident work hardening was identified and partially attributed to the strain driven grain boundary motion of grain rotation and/or grain boundary sliding, especially at the initial stage, while the dislocation activities gradually participate in as deformation proceeds.
Mechanical behaviours of workhardening and worksoftening bulk metallic glasses
Authors: Jiang W H , Jiang F , Liu F X , Wang Y D , Dang H M , Yang F Q , Choo H , Liaw P K
Published: November 2011

The workhardening Cu47·5Zr47·5Al5 and the worksoftening Zr52·5Cu17·9Ni14·6Al10·0Ti5·0 bulk metallic glasses before and after precompression deformation were characterised for thermal and mechanical behaviours. The predeformation introduces excessive free volume in both glasses. Cu47·5Zr47·5Al5 and Zr52·5Cu17·9Ni14·6Al10·0Ti5·0 exhibit substantial workhardening and worksoftening behaviours respectively. For Cu47·5Zr47·5Al5, the precompression has a negligible effect on serrations in the plastic flow during nanoindentation, which is related to the hardening of a shear band, while for Zr52·5Cu17·9Ni14·6Al10·0Ti5·0, the precompression moderates serrations in the plastic flow during nanoindentation, which is associated with the softening of a shear band. Strengthening from mechanically induced nanocrystallites at shear bands is responsible for the workhardening of Cu47·5Zr47·5Al5, which overwhelms softening due to the introduction of excessive free volume.
Three-dimensional simulation of quenching process of plain carbon steel gears incorporating phase transformations
Authors: Eshraghi-Kakhki M , Kermanpur A , Golozar M-A
Published: November 2011

In the present work, a numerical model was developed for the simulation of the quenching process of plain carbon steel gears in water and oil using finite element method. For diffusional transformations, the Johnson–Mehl–Avrami equation was coupled with the additivity rule, while for non-diffusional transformation, the empirical model of Koistinen–Marburger was employed. In addition, the model of Maynier et al. was used to compute the hardness distribution throughout the parts. To evaluate the cooling power of quenching media, the heat transfer coefficients of quenching media were calculated by solving an inverse problem using a stainless steel probe. In addition, a novel approach was applied for computing the actual phase fractions in the multiphase steel. The effects of the latent heat releases during phase transformations along with the effect of temperature and phase fractions on the variation of thermophysical properties were considered. Experimental tests including cooling curve analysis, metallographic investigations and hardness measurements were performed to evaluate the validity of the model. The comparisons indicated that the simulation results were consistent with the experimental results. The multiphase transformation model presented here is capable to predict the distribution of temperature, microstructures and hardness during continuous cooling of steel.