bluuebunny/crossref_metadata_2025 huggingface dataset:
New Light on Neolithic Rock Carving The petroglyphs at Greenland (Auchentorlie), Dunbartonshire
Authors: MacKie E W , Davis A
Published: February 2011

Summary

Because of a quarrying threat the carved rock surfaces at Greenland were recorded afresh in 1984 but the site fortunately still exists. On the two carved outcrops are many cup-marks (some with tails) and a variety of cups-with-rings, mostly with short tails. The site is the first which can be shown to have been carved in two distinct phases, far apart in time, and the first at which the carving (as opposed to the re-use) of some of the symbols can be approximately dated. The later petroglyphs were evidently done after the main outcrop was quarried, and the construction nearby of a timber-framed dun in the late Bronze Age provides an explanation for this damage. Other archaeological evidence supports this view which has important implications. (EWM)

The Greenland carvings have been used to test the hypothesis that many cup-and-ring carvings were initially laid out using a very elementary 'equal width' geometry using a simple trammel and, further, that the diameters of such rings were usually measured in multiples of a unit of measurement approximately equal to the 'megalithic inch' of 0.816ins proposed by Alexander Thorn. Most of the rings from the Greenland site have shapes consistent with the geometrical hypothesis, and evidence for the proposed unit of measurement is obtained which is statistically significant at the 2%level. (AD)
The Use of Wood as a Natural Resource at a Scottish Mesolithic Site
Authors: Boyd W. E. , Kenworthy J. B.
Published: February 2011

Summary

The excavation of the archaeological site at Nethermills Farm yielded Mesolithic material, including large quantities of carbonised wood and nut fragments, discussed in this paper. Their analysis indicates a pronounced domination of Quercus (oak). This probably means that wood was collected from local woodland in which oak was dominant. A similar pattern – in which wood use reflects local availability – has been seen at other Mesolithic sites and suggests that no resource management was practised at that time.
Excavation of a shell midden site at Carding Mill Bay near Oban, Scotland
Authors: Connock K. D. , Finlayson B. , Mills C. M.
Published: February 2011

Summary

Rescue excavation of a shell midden was undertaken after its discovery during construction work. The site showed evidence of disturbance prior to excavation but it clearly consisted of two main elements, a shell midden containing ‘Obanian’ artefacts and, at the top of this, a fragmentary second millennium cist burial. The main significance of the site lies in the late date it provided for the ‘Obanian’ material. The site was excavated by the Lorn Archaeological Society and the post-excavation work was funded and organised by Historic Scotland.
Metastatic Tumor Dormancy in Cutaneous Melanoma: Does Surgery Induce Escape?
Authors: Tseng William  W. , Fadaki Niloofar , Leong Stanley  P.
Published: February 2011

According to the concept of tumor dormancy, tumor cells may exist as single cells or microscopic clusters of cells that are clinically undetectable, but remain viable and have the potential for malignant outgrowth. At metastatic sites, escape from tumor dormancy under more favorable local microenvironmental conditions or through other, yet undefined stimuli, may account for distant recurrence after supposed “cure” following surgical treatment of the primary tumor. The vast majority of evidence to date in support of the concept of tumor dormancy originates from animal studies; however, extensive epidemiologic data from breast cancer strongly suggests that this process does occur in human disease. In this review, we aim to demonstrate that metastatic tumor dormancy does exist in cutaneous melanoma based on evidence from mouse models and clinical observations of late recurrence and occult transmission by organ transplantation. Experimental data underscores the critical role of impaired angiogenesis and immune regulation as major mechanisms for maintenance of tumor dormancy. Finally, we examine evidence for the role of surgery in promoting escape from tumor dormancy at metastatic sites in cutaneous melanoma.
La monoparentalité dans l'accueil familial
Authors: Bely Béatrice
Published: February 2011

Résumé Pour chacun d’entre nous, il y a toujours un tiers qui peut partager le fait d’apprendre à avoir la force de réagir pour résister à une épreuve physique ou morale.
Handicap et captation : un modèle pour penser la subjectivité ?
Authors: Dufour Véronique , Morvan Jean-Sébastien
Published: February 2011

Résumé La notion de handicap a permis, dans les travaux antérieurs de J.-S. Morvan, de décliner la notion de captation, tel un phénomène où l’entourage ne voit plus que le handicap dans l’individu handicapé, mettant la subjectivité à l’écart. La description clinique de l’intégration scolaire d’un enfant handicapé moteur permettra d’illustrer le propos. De la notion de captation pensée à partir du handicap, nous proposons aujourd’hui une généralisation à d’autres difficultés telles que celles concernant hyperactifs , surdoués , pour penser la place de la subjectivité. Notre champ théorique se réfère aux travaux de Freud depuis la loi de Totem et tabou sur l’interdit de l’inceste.
Eugène Huzar et l'invention du catastrophisme technologique
Authors: Fressoz Jean-Baptiste
Published: February 2011

En 1855, paraît La fin du monde par la science . Son auteur : un avocat obscur au nom d’Eugène Huzar ; son originalité : proposer la première philosophie catastrophiste du progrès technologique. Huzar nous intéresse aujourd’hui en tant que symptôme : à l’encontre du grand récit postmoderne, il nous montre que la modernité positiviste qui aurait pensé les techniques sans leurs conséquences lointaines semblait déjà caduque lors de la révolution industrielle. Découvrir l’œuvre de Huzar aujourd’hui nous force à penser la réflexivité environnementale des sociétés de la révolution industrielle.
Secretory Leukocyte Protease Inhibitor Plays an Important Role in the Regulation of Allergic Asthma in Mice
Authors: Marino Rafael , Thuraisingam Thusanth , Camateros Pierre , Kanagaratham Cynthia , Xu Yong Zhong , Henri Jennifer , Yang Jingxuan , He Guoan , Ding Aihao , Radzioch Danuta
Published: February 2011

Secretory leukocyte protease inhibitor (SLPI) is an anti-inflammatory protein that is observed at high levels in asthma patients. Resiquimod, a TLR7/8 ligand, is protective against acute and chronic asthma, and it increases SLPI expression of macrophages in vitro. However, the protective role played by SLPI and the interactions between the SLPI and resiquimod pathways in the immune response occurring in allergic asthma have not been fully elucidated. To evaluate the role of SLPI in the development of asthma phenotypes and the effect of resiquimod treatment on SLPI, we assessed airway resistance and inflammatory parameters in the lungs of OVA-induced asthmatic SLPI transgenic and knockout mice and in mice treated with resiquimod. Compared with wild-type mice, allergic SLPI transgenic mice showed a decrease in lung resistance (p < 0.001), airway eosinophilia (p < 0.001), goblet cell hyperplasia (p < 0.001), and plasma IgE levels (p < 0.001). Allergic SLPI knockout mice displayed phenotype changes significantly more severe compared with wild-type mice. These phenotypes included lung resistance (p < 0.001), airway eosinophilia (p < 0.001), goblet cell hyperplasia (p < 0.001), cytokine levels in the lungs (p < 0.05), and plasma IgE levels (p < 0.001). Treatment of asthmatic transgenic mice with resiquimod increased the expression of SLPI and decreased inflammation in the lungs; resiquimod treatment was still effective in asthmatic SLPI knockout mice. Taken together, our study showed that the expression of SLPI protects against allergic asthma phenotypes, and treatment by resiquimod is independent of SLPI expression, displayed through the use of transgenic and knockout SLPI mice.
β2-Adrenergic Receptor Activation Prevents Rodent Dopaminergic Neurotoxicity by Inhibiting Microglia via a Novel Signaling Pathway
Authors: Qian Li , Wu Hung-ming , Chen Shih-Heng , Zhang Dan , Ali Syed F. , Peterson Lynda , Wilson Belinda , Lu Ru-Band , Hong Jau-Shyong , Flood Patrick M.
Published: February 2011

The role of the β2 adrenergic receptor (β2AR) in the regulation of chronic neurodegenerative inflammation within the CNS is poorly understood. The purpose of this study was to determine neuroprotective effects of long-acting β2AR agonists such as salmeterol in rodent models of Parkinson’s disease. Results showed salmeterol exerted potent neuroprotection against both LPS and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine/1-methyl-4-phenylpyridinium–induced dopaminergic neurotoxicity both in primary neuron-glia cultures (at subnanomolar concentrations) and in mice (1–10 μg/kg/day doses). Further studies demonstrated that salmeterol-mediated neuroprotection is not a direct effect on neurons; instead, it is mediated through the inhibition of LPS-induced microglial activation. Salmeterol significantly inhibited LPS-induced production of microglial proinflammatory neurotoxic mediators, such as TNF-α, superoxide, and NO, as well as the inhibition of TAK1-mediated phosphorylation of MAPK and p65 NF-κB. The anti-inflammatory effects of salmeterol required β2AR expression in microglia but were not mediated through the conventional G protein-coupled receptor/cAMP pathway. Rather, salmeterol failed to induce microglial cAMP production, could not be reversed by either protein kinase A inhibitors or an exchange protein directly activated by cAMP agonist, and was dependent on β-arrestin2 expression. Taken together, our results demonstrate that administration of extremely low doses of salmeterol exhibit potent neuroprotective effects by inhibiting microglial cell activation through a β2AR/β-arrestin2–dependent but cAMP/protein kinase A-independent pathway.
Dermatitis Herpetiformis Sera or Goat Anti–Transglutaminase-3 Transferred to Human Skin-Grafted Mice Mimics Dermatitis Herpetiformis Immunopathology
Authors: Zone John J. , Schmidt Linda A. , Taylor Ted B. , Hull Christopher M. , Sotiriou Michael C. , Jaskowski Troy D. , Hill Harry R. , Meyer Laurence J.
Published: February 2011

Dermatitis herpetiformis (DH) is characterized by deposition of IgA in the papillary dermis. However, indirect immunofluorescence is routinely negative, raising the question of the mechanism of formation of these immune deposits. Sárdy et al. (2002. J. Exp. Med. 195: 747–757) reported that transglutaminase-3 (TG3) colocalizes with the IgA. We sought to create such deposits using passive transfer of Ab to SCID mice bearing human skin grafts. IgG fraction of goat anti-TG3 or control IgG were administered i.p. to 20 mice. Separately, sera from seven DH patients and seven controls were injected intradermally. Biopsies were removed and processed for routine histology as well as direct immunofluorescence. All mice that received goat anti-TG3 produced papillary dermal immune deposits, and these deposits reacted with both rabbit anti-TG3 and DH patient sera. Three DH sera high in IgA anti-TG3 also produced deposits of granular IgA and TG3. We hypothesize that the IgA class anti-TG3 Abs are directly responsible for the immune deposits and that the TG3 is from human epidermis, as this is its only source in our model. These deposits seem to form over weeks in a process similar to an Ouchterlony immunodiffusion precipitate. This process of deposition explains the negative indirect immunofluorescence results with DH serum.
A New Zealand Black-Derived Locus Suppresses Chronic Graft-versus-Host Disease and Autoantibody Production through Nonlymphoid Bone Marrow-Derived Cells
Authors: Xu Zhiwei , Vallurupalli Anusha , Fuhrman Christopher , Ostrov David , Morel Laurence
Published: February 2011

The development of lupus pathogenesis results from the integration of susceptibility and resistance genes. We have used a chronic graft-versus-host disease (cGVHD) model to characterize a suppressive locus at the telomeric end of the NZM2410-derived Sle2 susceptibility locus, which we named Sle2c2. cGVHD is induced normally in Sle2c2-expressing mice, but it is not sustained. The analysis of mixed bone marrow chimeras revealed that cGVHD resistance was eliminated by non-B non-T hematopoietic cells expressing the B6 allele, suggesting that resistance is mediated by this same cell type. Furthermore, Sle2c2 expression was associated with an increased number and activation of the CD11b+ GR-1+ subset of granulocytes before and in the early stage of cGVHD induction. We have mapped the Sle2c2 critical interval to a 6-Mb region that contains the Cfs3r gene, which encodes for the G-CSFR, and its NZM2410 allele carries a nonsynonymous mutation. The G-CSFR–G-CSF pathway has been previously implicated in the regulation of GVHD, and our functional data on Sle2c2 suppression suggest a novel regulation of T cell-induced systemic autoimmunity through myeloid-derived suppressor cells. The validation of Csf3r as the causative gene for Sle2c2 and the further characterization of the Sle2c2 MDSCs promise to unveil new mechanisms by which lupus pathogenesis is regulated.
Ly49-Dependent NK Cell Licensing and Effector Inhibition Involve the Same Interaction Site on MHC Ligands
Authors: Choi Taewoong , Ferris Stephen T. , Matsumoto Naoki , Poursine-Laurent Jennifer , Yokoyama Wayne M.
Published: February 2011

NK cells become functionally competent to be triggered by their activation receptors through the interaction of NK cell inhibitory receptors with their cognate self-MHC ligands, an MHC-dependent educational process termed “licensing.” For example, Ly49A+ NK cells become licensed by the interaction of the Ly49A inhibitory receptor with its MHC class I ligand, H2Dd, whereas Ly49C+ NK cells are licensed by H2Kb. Structural studies indicate that the Ly49A inhibitory receptor may interact with two sites, termed site 1 and site 2, on its H2Dd ligand. Site 2 encompasses the α1/α2/α3 domains of the H2Dd H chain and β2-microglobulin (β2m) and is the functional binding site for Ly49A in effector inhibition. Ly49C functionally interacts with a similar site in H2Kb. However, it is currently unknown whether this same site is involved in Ly49A- or Ly49C-dependent licensing. In this study, we produced transgenic C57BL/6 mice expressing wild-type or site 2 mutant H2Dd molecules and studied whether Ly49A+ NK cells are licensed. We also investigated Ly49A- and Ly49C-dependent NK licensing in murine β2m-deficient mice that are transgenic for human β2m, which has species-specific amino acid substitutions in β2m. Our data from these transgenic mice indicate that site 2 on self-MHC is critical for Ly49A- and Ly49C-dependent NK cell licensing. Thus, NK cell licensing through Ly49 involves specific interactions with its MHC ligand that are similar to those involved in effector inhibition.
Intravesical prostaglandin e2 effectiveness in the prevention of urinary retention after transvaginal reconstruction of the pubo-cervical fascia and short arm sling according to Lahodny: a prospective randomized clinical trial
Authors: QUADRI G. , NATALE N. , SPREAFICO C. , BELLONI C. , BARISANI D. , LAHODNY J.
Published: February 2011

Intravesical prostaglandin E2 is effective in the recovery of spontaneous voiding after transvaginal reconstruction of the pubocervical fascia and short arm sling according to Lahodny. The aim of the study was to compare the effects of intravesical prostaglandin E2 in the prevention of urinary retention after transvaginal reconstruction of the pubocervical fascia and short arm sling according to Lahodny. STUDY DESIGN: From November 1996 to June 1999 fifty women underwent the Lahodny procedure for moderate/severe cystocele and stress urinary incontinence. Women were randomly assigned to 1 of the 2 study groups: intravesical prostaglandin E2 versus controls. Data obtained were analyzed with the Student t test and the Fisher exact test. RESULTS: Two patients of the treatment group had to be excluded from the study, one because of the wrong measurement of the post-voidal residual volume and another due to a fastidious burning sensation which appeared immediately after prostaglandin instillation and required the suspension of the treatment. No other side effects such as nausea, vomiting, diarrhea or hyperthermia were observed. Patients who underwent the prostaglandin E2 treatment showed a recovery of spontaneous voiding after 7.9±6.7 days, whereas this interval was significantly longer in the control group, being 12.9±9.7 days (p=0.04, Two tailed Unpaired Student's T test). CONCLUSION: The effectiveness and the low associated morbidity mark the treatment with intravesical prostaglandin E2 useful in the recovery of normal voiding after transvaginal pubocervical fascia reconstruction and short arm sling with the procedure according to Lahodny.
EVALUATION OF EFFICACY OF DIFFERENT SURGICAL PROCEDURES IN THE TREATMENT OF SUI AND GENITAL PROLAPSE
Authors: Albiero A. , Gazzoni A. , Giudici S. , Poggi S. , Fedele L.
Published: February 2011

The aim of this study is to evaluate the efficacy and compare the middle- long term results of various surgical procedures in the treatment of stress urinary incontinence and genital prolapse.
TVT PROCEDURE FOR THE TREATMENT OF SUI: OUR EXPERIENCE
Authors: Magatti F. , Sirtori P.L. , Rumi C. , Belloni C.
Published: February 2011

In this study we determined the efficacy of TVT for the treatment of female urinary incontinence in a first group of patients (69) of our urogynaecology service from April 1998 to December 2000. The TVT procedure is a minimally invasive technique, using local or spinal anaesthesia, which consists in the implantation of a Prolene tape around the mid-urethra. On the basis of our results (92.3 % success rate) we consider the TVT procedure to be a safe and effective surgical procedure for the treatment of female urinary stress incontinence.
IMPACT OF URINARY INCONTINENCE ON THE QUALITY OF LIFE AND FEMALE SEXUALITY
Authors: Adile B. , Palma P. , Pollina A. , Bandiera S. , Amico M.L. , Mercurio A. , Gugliotta G.
Published: February 2011

The prevalence of urinary incontinence is around 20% of healthy middle-aged women. Incontinence has a negative impact on quality of life and sexuality. From August 2002 to January 2004, 30 patients (mean age 43 years) with stress urinary incontinence (59%) overactive bladder (15%0) and mixed incontinence (26%) answered the ICIQSF (International Consultation on Incontinence Questionnaire – Short From) and FSFI (Female Sexual Function Index) questionnaires before and after treatment. The follow up ranged from 12 to 53 months. Mean ICIQ score was 17 and 7 before and after treatment respectively (p< 0,001). Overactive bladder showed the worst scores in all domains. The patients underwent surgery to increase desire (p=0,02), satisfaction (p=0,05) and t otal score (p=0,02). In 13 patients the ICIQ score did not increase: desire (p=0,01), satisfaction (p=0,05) and total score (p=0,01). Urinary incontinence significantly affects the quality of life. A sexuality evaluation in incontinence patients is recommended.
MINIMALLY-INVASIVE TRANSOBTURATOR CORRECTION OF CYSTOCELE
Authors: Baccichet R. , Braghin C. , Azzena A.
Published: February 2011

We present our initial experience with the Perige™ System for correction of prolapse of the anterior vaginal wall. We recruited twenty patients with anterior vaginal prolapse, underwent a prosthetic operation using the Perigee System, which consists of a large-pore, monofilament polypropylene mesh and four lateral arms made of the same material, positioned via the transobturator foramen. This system permits simultaneous correction of central and lateral defects. Prolapse and therapeutic outcome were evaluated using the POP-Q system. The 20 patients were suffering from grade III cystocele. The follow-up was conducted after six weeks, three months, six months, twelve months and eighteen months. After six weeks and three months the cystocele was MInIMally-InVaSIVe correzIone proteSIca tranSoBturator MInIInVaSIVa per VIa correctIon tranSotturatorIa of cyStocele Del cIStocele r Baccichet*, c Braghin, a azzena Obstetrics and GynaecOlOGy Unit, Ospedale civile di cOneGlianO venetO, Ulss 7 *UrOGynaecOlOGy department, Obstetrics and GynaecOlOGy Unit, O.c. cOneGlianO venetO, Ulss 7 Key words: prolapse anterior vaginal wall, cystocele, transobturator foramen, minimally-invasive urogynecological surgery, tension-free technique of mesh, entirely resolved (grade 0) in the 20 patients. After six months the cystocele was resolved (grade 0) in 17 patients, while three had grade I cystocele. After 12 months and 18 months the cystocele remain grade 0 in 16 patients, while four had grade I cystocele. No vascular damage or significant bleeding was observed. Two cases of vaginal erosion and one of de novo urinary incontinence were observed. Our experience appears to show that transobturator prosthetic correction of cystocele represents a safe, effective and reproducible minimally-invasive surgical technique that permits adequate restoration of normal anatomy.
SURGICAL TREATMENT OF STRESS URINARY INCONTINENCE: A 3-YEAR FOLLOW-UP
Authors: Bandiera S. , Giunta G. , Aloisi A. , Arena M. , Iozza I. , Matarazzo M.G. , Morello R. , Raciti G. , Rapisarda F. , Vitale S.G. , Cianci A.
Published: February 2011

OBJECTIVES: To evaluate the objective and subjective midterm outcomes of transobturator tape (TOT) in the treatment of female stress urinary incontinence (SUI). MATERIALS AND METHODS: A total of 114 consecutive patients affected by stress urinary incontinence (mean age 59±10 years), who underwent the TOT procedure between July 2004 and May 2008 (46 patients received the Safyre, 30 patients the PelviLace, 20 patients the Monarc, 10 patients the DynaMesh and 8 the Align sling), were assessed in June 2008. An evaluation of the patients, based on history, physical examination, stress test, urodynamic tests, and the compilation of two specific quality of life questionnaires, was performed before and after surgery. RESULTS: The therapeutic midterm failure rate for the TOT procedure was 4.4% (5 of 114 patients). The midterm cure rate was 95.6% (109 of 114 patients), 7 (6.1%) of those patients only improved, still with minimal residual urinary leakage. Clinical signs for bowel, urethral, or bladder injuries were undetectable. Intraoperative bleeding, postoperative field infections, or postoperative pelvic floor relaxations were not noted. Three patients (2.6%) presented a little small area of mesh erosion within 6 months from surgery. We also noticed a few obstructive symptoms and irritative symptoms: 4 of 114 (3.,5%) patients showed urge de novo urge symptoms. A high grade degree of satisfaction was assessed reported by QoL questionnaires ( p<0.001). CONCLUSIONS : The midterm results of this study show that the TOT procedure is a simple, safe, and effective technique in thefor treatingment of female stress urinary incontinence.
A COMPARISON BETWEEN SYNTHETIC AND BIOSYNTHETIC MESHES IN THE SURGICAL TREATMENT OF SEVERE GENITAL PROLAPSE: RESULTS AND COMPLICATIONS
Authors: Dati S. , De Lellis V. , Palermo P. , Carta G.
Published: February 2011

The effectiveness, tolerability and complications of two surgical procedures using prosthetic materials with different physical and structural properties were assessed with a full Urogynecology work-up, through a retrospective study of 158 patients with severe genital prolapse (POP-Q staging III-IV) selected from November 2006 to April 2009. Eighty-six patients underwent fascial replacement surgery with ProliftTM System with a dual transobturator access in the anterior district and a transperineal posterior access with a synthetic polypropylene type I mesh (Group A). Seventy-two patients who underwent pelvic organ prolapse surgery with Avaulta/Avaulta PlusTM System with a dual transobturator access in the anterior district and a dual transperineal posterior access with a biosynthetic polypropylene type I mesh coated with a film of hydrophilic porcine collagen were placed in Group B. There were no intra and postoperative complications. Results of mean 20.8 month follow-up showed an effective anatomical cure rate of 89.5% in group A and 86.1% in group B and a low percentage of erosive complications, 8.1% and 5.6% respectively. Validated questionnaires for prolapse, the UDI 6 s.f., the IIQ7 s.f. and the PISQ-12 all showed a statistically significant improvement of quality of life in patients undergoing the two procedures (Wilcoxon test: P<0.001).
Jetzt wird es ernst: strukturbasiertes Design von Mdm2/Mdmx‐p53‐Inhibitoren
Authors: Popowicz Grzegorz M. , Dömling Alexander , Holak Tad A.
Published: February 2011

Das zelluläre p53‐Protein ist das Bollwerk im Kampf gegen Tumor‐assoziierte DNA‐Schäden. Allgemein auch als “Beschützer des Genoms” bekannt, ist p53 für das Schicksal der Zelle verantwortlich, wenn eine substanzielle DNA‐Schädigung vorliegt. Tumoren können sich nur entwickeln, wenn diese Verteidigungslinie durchbrochen wird. Alle bekannten Tumorzellen mutieren das p53‐Gen oder nutzen interne p53‐Modulatoren, wie die beiden Proteine Mdm2 und Mdmx, um p53 zu desaktivieren. Das Freisetzen von p53 aus den Komplexen mit Mdm2 oder Mdmx sollte daher eine effiziente und nicht gentoxische Krebstherapie ermöglichen. Dank mehrerer Kristallstrukturen von Mdm2/x im Komplex mit p53‐imitierenden Molekülen, sowohl Peptiden als auch niedermolekularen Verbindungen, gab es in den letzten Jahren fundamentale Fortschritte bei der Entwicklung neuer p53‐aktivierender Moleküle. Das Verständnis der Bindungseigenschaften des Liganden ermöglicht die Entwicklung neuer, hoch aktiver und selektiver Wirkstoff‐Kandidaten. Zwei niedermolekulare Verbindungen werden seit Kurzem in klinischen Studien untersucht.
A Markov Chain Monte Carlo comparison of variance estimators for the sampling of particulate mixtures
Authors: Cheng Hao , Geelhoed Bastiaan , Bode Peter
Published: February 2011

During the sampling of particulate mixtures, samples taken are analyzed for their mass concentration, which generally has non‐zero sample‐to‐sample variance. Bias, variance, and mean squared error (MSE) of a number of variance estimators, derived by Geelhoed, were studied in this article. The Monte Carlo simulation was applied using an observable first‐order Markov Chain with transition probabilities that served as a model for the sample drawing process. Because the bias and variance of a variance estimator could depend on the specific circumstances under which it is applied, Monte Carlo simulation was performed for a wide range of practically relevant scenarios. Using the ‘smallest mean squared error’ as a criterion, an adaptation of an estimator based on a first‐order Taylor linearization of the sample concentration is the best. An estimator based on the Horvitz–Thompson estimator is not practically applicable because of the potentially high MSE for the cases studied. The results indicate that the Poisson estimator leads to a biased estimator for the variance of fundamental sampling error (up to 428% absolute value of relative bias) in case of low levels of grouping and segregation. The uncertainty of the results obtained by the simulations was also addressed and it was found that the results were not significantly affected. The potentials of a recently described other approach are discussed for extending the first‐order Markov Chain described here to account also for higher levels of grouping and segregation. Copyright © 2013 John Wiley & Sons, Ltd.
Induction of Cell–Cell Connections by Using in situ Laser Lithography on a Perfluoroalkyl‐Coated Cultivation Platform
Authors: Okano Kazunori , Yu David , Matsui Ai , Maezawa Yasuyo , Hosokawa Yoichiroh , Kira Atsushi , Matsubara Mie , Liau Ian , Tsubokawa Hiroshi , Masuhara Hiroshi
Published: February 2011

This article describes a novel laser‐directed microfabrication method carried out in aqueous solution for the organization of cell networks on a platform. A femtosecond (fs) laser was applied to a platform culturing PC12, HeLa, or normal human astrocyte (NHA) cells to manipulate them and to facilitate mutual connections. By applying an fs‐laser‐induced impulsive force, cells were detached from their original location on the plate, and translocated onto microfabricated cell‐adhesive domains that were surrounded with a cell‐repellent perfluoroalkyl (Rf) polymer. Then the fs‐laser pulse‐train was applied to the Rf polymer surface to modify the cell‐repellent surface, and to make cell‐adhesive channels of several μm in width between each cell‐adhesive domain. PC12 cells elongated along the channels and made contact with others cells. HeLa and NHA cells also migrated along the channels and connected to the other cells. Surface analysis by X‐ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) confirmed that the Rf polymer was partially decomposed. The method presented here could contribute not only to the study of developing networks of neuronal, glial, and capillary cells, but also to the quantitative analysis of nerve function.
The Stability of Cα Peptide Radicals: Why Glycyl Radical Enzymes?
Authors: Hioe Johnny , Savasci Gökcen , Brand Harald , Zipse Hendrik
Published: February 2011

The conformational space of dipeptide models derived from glycine, alanine, phenylalanine, proline, tyrosine, and cysteine has been searched extensively and compared with the corresponding Cα dipeptide radicals at the G3(MP2)‐RAD level of theory. The results indicate that the (least‐substituted) glycine dipeptide radical is the thermochemically most stable of these species. Analysis of the structural parameters indicates that this is due to repulsive interactions between the Cα substituents and peptide units in the radical. A comparison of the conformational preferences of dipeptide radicals and their closed‐shell parents also indicates that radical stability is a strongly conformation‐dependent property.
Case study of drives for petrochemical compressors
Authors: Birrell Bruce
Published: February 2011

The characteristics of drivers for large petroleum refinery compressors are discussed. Gas turbines, steam turbines and electric motors are compared for six different applications. If cheap refinery gas is available the gas turbine has an advantage but otherwise electric drivers are favored.
The settling behavior of uranium trioxide‐water slurries
Authors: Boyd A. W. , Whitton J. L.
Published: February 2011

Measurements have been made of the settling rates of uranium trioxide‐water slurries in the range of 100 to 800 grams per litre at temperatures of 25° and 53°C. The applicability of several equations proposed by others to relate the rate of hindered settling to surface area, concentration and viscosity has been examined. It is shown that the data are best fitted by an empirical equation similar to one proposed by Allison and Murray for zinc, aluminum and magnesium oxide suspensions.
Solar energy: Economics and engineering research at the university of Wisconsin
Authors: Duffie J. A. , Löf G. O. G.
Published: February 2011

The use of solar energy, in most applications, is dependent primarily on economic considerations; solar energy can become an important energy source when the costs of its use become competitive with the costs of energy from other sources. The basic and usually most costly item of equipment for solar energy utilization is the collector, or solar heat exchanger, and the amortization of the first cost of this and associated equipment is the major cost of solar energy. In this paper, the probable economic feasibility of several solar applications is assessed by using the costs of energy from present sources as a basis for estimating upper limits on the first cost of solar heat exchangers and their associated equipment. For example, for space heating in temperate climates, heat exchanger costs would have to be in the range of $1–6 for solar heating to be competitive; this appears to be within an attainable range. Economic considerations have helped shape the development of the Wisconsin solar energy program, and studies of solar heat exchangers and their application to heating, cooling and power generation are briefly described.
A radioactive tracer technique for particle velocity measurement in solids‐gas systems
Authors: Gauvin W. H. , Pasternak I. S. , Torobin L. B. , Yaffe L.
Published: February 2011

To record the velocity history of a particle in complex problems of solid‐gas flow with greater accuracy than is possible with existing methods, a technique was developed which in essence consists of following the flight of the particle under test—which has been previously tagged with a suitable gamma‐emitting nuclide—by means of Geiger probes placed at predetermined points along the outside surface of the duct or reactor and parallel to its axis. Sharp timing pulses are thus obtained on the screen of a cathode‐ray oscilloscope, which permit the estimation of the time elapsed between probe stations to less than 1/1000 second. Complete description of the electronic aspects of the method is given, and details of the particle preparation are outlined.

A brief description is given of the application of the method to the determination of the rate of mass and heat transfer from particles in accelerated motion in a turbulent co‐current gas stream and to the study of the effects of the turbulent flow parameters on the drag coefficients of particles in highly turbulent fields.
Thermodynamic properties of some organic compounds: I. PVT relationships and calculated thermodynamic properties for normal butanol
Authors: Shemilt L. W. , Esplen R. W. , Mann R. Singh
Published: February 2011

Pressure‐volume‐temperature measurements on n‐butanol have been carried out using the Kay type of pressure‐block apparatus and glass capillary cell. Determinations were made isothermally in the saturated vapor and liquid and superheated vapor regions to above the critical point. Compressibility factors have been calculated. Constants in the Beattie‐Bridgman equation of state have been determined from 250° to 300° C. at pressures up to 75 atmospheres.

The thermodynamic properties of normal butanol have been calculated over a temperature range of 0°C. to 300°C. and at pressures up to 1000 lb./sq. in. abs. from the PVT data. Values for the saturated liquid, saturated vapor, and superheated vapor are presented on a pressure‐enthalpy diagram with specific volume and entropy as parameters. The entropy of the saturated vapor increases with temperature over a considerable region, indicating a positive specific heat of the saturated vapor in contrast to the lower alcohols of the same series.
Graphical‐numerical determination of variable diffusion coefficient in solids
Authors: Hall Raymond C.
Published: February 2011

Considerable gain in information in characteristics of diffusion coefficient may be obtained if data are analysed for variable diffusion coefficient instead of for a constant value of diffusivity. This paper presents a simple method for graphical analysis of concentration gradients in solids to determine the diffusion coefficient as a function of concentration.

Consideration is given to problems encountered in extrapolation of data. It is shown that, if relative values of diffusion coefficient is the objects of consideration, no great need exists for exacting extrapolation. Two extrapolations are employed on any given functional model; the results of one extrapolation are greater, while those of the other arc less than the results predicted by the model.
The efficiency of fibrous aerosol filters: Deposition by diffusion of particles of finite diameter
Authors: Pasceri Ralph E. , Friedlander S. K.
Published: February 2011

A brief review is given of the derivation of a semi‐theoretical expression for the filtration efficiency of fibrous aerosol filters operated at low velocities. The correlation is compared with new data taken from the literature and is presented in a simplified form for design calculations. The existence of a minimum filtration efficiency is discussed and theory and data are compared.
Some rheological parameters of clays and their thixotropic behavior
Authors: Yalcin A. S. , McIntosh R.
Published: February 2011

Rheological characteristics and thixotropic behavior of four clay minerals belonging to different types of morphology and lattice structure were investigated.

Clay‐water samples were prepared at about their liquid limits and the testing was accomplished by unconfined compression applied at different rates of deformation.

From the stress to strain rate relationships the yield value was determined as an intercept on the stress axis at zero rate of strain, and the slope gave the viscosity coefficient.

Regain of strength or thixotropic character of the samples was evaluated in terms of the viscosity and yield values at various periods of aging.

The influence of temperature on the aging process was studied using attapulgite at three temperatures, 21°C., 36°C., 51°C.

The activation energy of the process of aging for attapulgite was calculated using both viscosity coefficients and ultimate yields. The values were within experimental uncertainty for the two sets of data and it was thereby concluded that changes of these parameters were due to a single reaction. The activation energy was found to be 9.4 kcal mole−1, which suggests a physical rather than a chemical change.
An apparatus for the measurements of light transmittance of emulsions
Authors: Cengel J́. A. , Knudsen J. G. , Landsberg A. , Faruqui A. A.
Published: February 2011

This paper describes an apparatus for the measurement of the light transmittance of emulsions. A photoelectric technique was employed to determine the effect of flow rate, mixing time, and dispersed phase concentration on the light transmittance of a liquid‐liquid emulsion composed of a commercial petroleum solvent and water. For a given concentration, light transmittance was independent of flow rate and became constant after 10 minutes of mixing in the test apparatus. Light transmittance decreased with solvent (dispersed phase) concentration. Up to 5% solvent concentration, the light transmittance‐concentration curve could be used to measure solvent concentration accurately.
Determination of vapor‐liquid equilibrium data from total pressure‐liquid composition measurements
Authors: Ho James C. K. , Boshko O. , Lu Benjamin C.‐Y.
Published: February 2011

Digital computer methods are developed for evaluating equilibrium data from total pressure‐liquid composition measurements of volatile binary non‐electrolyte mixtures. The Redlich‐Kister equation is employed for representing liquid activity coefficients. The constants B, C and D are evaluated by the method of least squares for non‐linear formulas. Equilibrium vapor compositions are also evaluated by means of a step‐wise integration procedure. A comparison of both methods is presented.
Treatment of uranium leach plant solutions by liquid‐liquid extraction to produce high purity uranium products
Authors: Simard R. , Gilmore A. J. , McNamara V. M. , Parsons H. W. , Smith H. W.
Published: February 2011

Three liquid‐liquid extraction processes were tested in continuous equipment, on bench scale, to determine their relative merits in the purification of uranium as found in ion exchange eluates of various Canadian leach plants. Tri‐n‐butyl phosphate and dibutyl butylphosphonate were used as extractants on nitrate eluates. A tertiary amine was used in the case of sulphuric acid eluates. Optimum conditions for high recovery and low reagent costs were established, and the adaptability of the processes to existing leach plants is discussed. The suitability of the ammonium diuranate product as a source of ceramic‐grade UO2 was also investigated. Suggested changes to the adopted flowsheets are given, for further testing on a pilot plant scale.
Possible applications of various reduction processes to canadian iron ores
Authors: Rogers R. R. , Viens G. E. , Campbell R. A.
Published: February 2011

A survey is made of (1) the factors which make possible a Canadian iron production industry, and (2) a number of the iron reduction processes which are now available, and their requirements. Based on this information an attemps is made to forecast the general nature of the Canadian iron production industry in the foreseeable future.
Horizontal annular‐mist flow of natural gas‐water mixtures
Authors: Aziz K. , Govier G. W.
Published: February 2011

A survey of the literature having possible application to the annular‐mist flow problem is presented.

The horizontal annular‐mist flow of natural gaswater mixtures in one‐ and two‐in. diameter, schedule 40 aluminum pipes was investigated. The input gasliquid volume ratios were varied between 10 and 100,000 for superficial gas velocities between 25 and 300 ft./sec. The mid‐point pressure was held constant at 120 p.s.i.g. Some data for variable mid‐point pressure and constant liquid and gas rates are also presented to show the effect of gas density.

The pressure drop data for constant mid‐point density are presented as a function of the superficial velocities of the two phases. The same data are also presented in terms of the ratio of the two‐phase pressure gradient to the single‐phase gas pressure gradient. Possible mechanisms of the flow in the annular‐mist region are discussed and the possibility of microscopic changes in flow pattern is indicated. A large effect of a small quantity of water was observed over the gas rates investigated. Higher water rates had much greater effect at low gas rates than at high gas rates. It is proposed that the high pressure drop is caused by the formation of a liquid film on the inside wall of the pipe. The thickness of this film decreases as the gas rate is increased until it reaches some minimum value. The breakup of this film was not indicated over the range of gas rates investigated.

The data are also interpreted in terms of a friction factor and Reynolds number based on the mixture properties.

The data are compared with the correlations of Lockhart and Martinelli, and Chenoweth and Martin.
A study of the flotation characteristics of galena
Authors: Nagy E. , Van Cleave A. B.
Published: February 2011

A modified Hallimond tube technique has been used to obtain information on the flotation characteristics of galena. The technique has general application to 1 to 2 gram samples of any relatively pure mineral. The influences of stirring rate, gas flow rate, flotation time, pH, particle size, xanthate chain length, and collector concentration have been measured and correlations between some of these factors discussed. The effect of high xanthate concentration on flotation rate has been studied in some detail and discussed in relation to the adsorption of the collector on the mineral.
An analysis of spray evaporation in a high‐temperature environment: II. Calculation of the evaporative load distribution
Authors: Hoffman T. W. , Gauvin W. H.
Published: February 2011

This paper deals with the calculation of the evaporative load distribution in a spray of droplets suspended in an absorbing gas medium contained in a cylindrical column after a temperature profile for the gas has been assumed.

Preliminary experimental data obtained for water sprays in an 8‐in. i.d. by 10‐ft. high pilot‐plant atomized suspension reactor at wall temperatures up to 800°C. are used to illustrate the method of calculation.

The calculated results emphasize the importance of the physical characteristics of the spray, such as initial drop‐size and distribution, drop velocities and spray angle. They also indicate that the dynamics of such spray systems, as well as their heat and mass transfer aspects, require further elaboration.
Mass transfer from fluid and solid spheres at low Reynolds numbers: Part II
Authors: Ward D. M. , Trass O. , Johnson A. I.
Published: February 2011

Rates of mass transfer from water drops into cyclohexanol and from drops of cyclohexanol, isobutanol, and o‐toluidine into water were measured. These experimental data were augmented by published results, to cover, at drop Reynolds numbers less than 10, a Peelet number range of 0.01 to 5,000,000 for non‐circulating spheres and 700 to 24,000,000 for circulating spheres. Transfer rates, expressed as Sherwood numbers, were in substantial agreement with those predicted from a theoretical model. The contribution of natural convection, inherent in the measurements, but omitted in the model, was approximately accounted for. Data for circulating spheres verified the hypothesis that internal motion affects the external transfer rate. This effect depends on the ratio of continuous to disperse phase viscosity of the system; a four to six‐fold enhancement of mass transfer due to internal circulation was found for water drops falling in cyclohexanol.
A theoretical and experimental investigation of fiber suspension drainage in the turbulent regime: Part 1: Presentation of a new theory for the turbulent drainage of fiber suspensions
Authors: Meadley C. K.
Published: February 2011

A brief literature review, covering most of the major studies of fiber suspension drainage is given and it is found that a basic knowledge of the process is lacking when the flow is predominantly turbulent. The conventional viscous flow model of drainage is summarized for comparison purposes, and then a new theory, derived for the purpose of predicting fiber suspension drainage properties in the turbulent regime as a function of fiber, fiber mat and machine characteristics, is presented and discussed.

A theoretical model of turbulent drainage is adopted, for which it is assumed that pressure drops arise predominantly due to turbulent dissipation rather than to viscous shear stress losses, and for which the resistance is proportional to the square of the drainage rate. A turbulent resistance function is thus formulated, relating drainage resistance characteristics to certain basic fiber and fiber mat properties and involving two general parameters, which remain to be evaluated experimentally. Use of this resistance function with the appropriate equation of motion for the drainage mechanics results in formulae for the calculation of drainage profiles and properties for various machine conditions.
Absorption of carbon dioxide by aqueous ammonia in a packed tower
Authors: Vassilatos G. , Trass O. , Johnson A. I.
Published: February 2011

New data were obtained for absorption of carbon dioxide from an air‐carbon dioxide mixture by aqueous ammonia solutions in a tower packed with 1/2 in. Raschig rings. The rates of absorption of carbon dioxide, expressed as over‐all volumetric coefficients KGa, were correlated with the ammonia concentration and the liquid flow rate.

The data were analyzed in the light of the film, penetration and Kishinevsky theories for absorption with simultaneous chemical reaction. Effective interfacial areas, calculated from the data with the aid of the first two theories, were reasonable, and three to four times larger than the corresponding areas for pure physical absorption or vaporization under the same hydrodynamic conditions. Distinction between the two theories was not possible because, for the present system, both give nearly the same results. Results from Kishinevsky's theory were quite unreasonable.
Phase inversion in the mixing of immiscible liquids
Authors: Quinn J. A. , Sigloh D. B.
Published: February 2011

Data are reported on phase inversion in concentrated oil‐water mixtures dispersed in a fully‐baffled stirred tank. The results indicate that water continuous dispersions in which the water concentration is as small as 40% by volume can be formed.

For a vertically centered impeller the concentration of the organic liquid required for phase inversion varies inversely with the rate of energy input. The effect of impeller position is also discussed.
Latent heat of vaporization of 1‐pentene
Authors: Cuffel R. F. , Kozicki William , Sage B. H.
Published: February 2011

The enthalpy change upon vaporization of l‐pentene was experimentally determined by calorimetric measurements at temperatures between 100° and 280°F. The results are in good agreement with available data at the lower temperatures and are presented in graphical and tabular form.