bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphology, Ultrastructure, Molecular Phylogeny, and Autecology of Euplotes elegans Kahl, 1932 (Hypotrichida; Euplotidae) Isolated from the Anoxic Mariager Fjord, Denmark
Authors: JULIAN SCHWARZ M. V. , ZUENDORF ALEXANDRA , STOECK THORSTEN
Published: February 2007

ABSTRACT. The morphology, autecology, and molecular phylogeny of an euryhaline Euplotes isolate collected from the anoxic water column of the Mariager Fjord in Denmark were investigated. The isolate matches the original description of Euplotes elegans Kahl, 1932 very well. However, its dorsal silverline system is clearly distinct from the redescription of this species by Tuffrau. Thus, a neotypification is proposed for E. elegans Kahl, 1932. The oval‐shaped cell has a mean size of 107 × 51 μm and is characterized by 9.4 dorsolateral kineties, seven prominent dorsal ridges, large elongated ampullae, which encircle the dorsal kinetids, 18 kinetids in the middorsal row, nine frontoventral cirri, five transversal cirri, and three caudal cirri (two right caudal cirri and one left marginal cirrus). The dorsal silverline system is of the double type with the narrow polygons located on the right side of the dorsal kinetids. The ecological tolerances of this species to pH, salinity, temperature, and oxygen match the ambient environmental conditions of the sampling site. Molecular phylogeny was studied using small subunit rRNA (SSU rRNA) gene sequences. The molecular data cluster E. elegans with Euplotes raikovi, a member of the Euplotopsis group. The data suggest that the E. elegans–E. raikovi clade represents an isolated and deep branch at the base of the Euplotes tree.
Mitochondrial Genome of a Tertiary Endosymbiont Retains Genes for Electron Transport Proteins
Authors: IMANIAN BEHZAD , CARPENTER KEVIN J. , KEELING PATRICK J.
Published: February 2007

ABSTRACT. Mitochondria and plastids originated through endosymbiosis, and subsequently became reduced and integrated with the host in similar ways. Plastids spread between lineages through further secondary or even tertiary endosymbioses, but mitochondria appear to have originated once and have not spread between lineages. Mitochondria are also generally lost in secondary and tertiary endosymbionts, with the single exception of the diatom tertiary endosymbiont of dinoflagellates like Kryptoperidinium foliaceum, where both host and endosymbiont are reported to contain mitochondria. Here we describe the first mitochondrial genes from this system: cytochrome c oxidase 1 (cox1), cytochrome oxidase 3 (cox3), and cytochrome b (cob). Phylogenetic analyses demonstrated that all characterized genes were derived from the pennate diatom endosymbiont, and not the host. We also demonstrated that all three genes are expressed, that cox1 contains spliced group II introns, and that cob and cox3 form an operon, all like their diatom relatives. The endosymbiont mitochondria not only retain a genome, but also express their genes, and are therefore likely involved in electron transport. Ultrastructural examination confirmed the endosymbiont mitochondria retain normal tubular cristae. Overall, these data suggest the endosymbiont mitochondria have not reduced at the genomic or functional level.
UDP‐N‐Acetylglucosamine 4′‐Epimerase from the Intestinal Protozoan Giardia Intestinalis Lacks UDP‐Glucose 4′‐Epimerase Activity1
Authors: LOPEZ ALEX B. , ŞENER KERIMAN , TROSIEN JULIA , JARROLL EDWARD L. , VAN KEULEN HARRY
Published: February 2007

ABSTRACT. The protozoan parasite Giardia intestinalis has a simple life cycle consisting of an intestinal trophozoite stage and an environmentally resistant cyst stage. The cyst is formed when a trophozoite encases itself within an external filamentous covering, the cyst wall, which is crucial to the cyst's survival outside of the host. The filaments in the cyst wall consist mainly of a β (1–3) polymer of N‐acetylgalactosamine. Its precursor, UDP‐N‐acetylgalactosamine, is synthesized from fructose 6‐phosphate by a pathway of five inducible enzymes. The fifth, UDP‐N‐acetylglucosamine 4′‐epimerase, epimerizes UDP‐N‐acetylglucosamine to UDP‐N‐acetylgalactosamine reversibly. The epimerase of G. intestinalis lacks UDP‐glucose/UDP‐galactose 4′‐epimerase activity and shows characteristic amino acyl residues to allow binding of only the larger UDP‐N‐acetylhexosamines. While the Giardia epimerase catalyzes the reversible epimerization of UDP‐N‐acetylglucosamine to UDP‐N‐acetylgalactosamine, the reverse reaction apparently is favored. The enzyme has a higher Vmax and a smaller Km in this direction. Therefore, an excess of UDP‐N‐acetylglucosamine is required to drive the reaction towards the synthesis of UDP‐N‐acetylgalactosamine, when it is needed for cyst wall formation. This forms the ultimate regulatory step in cyst wall biosynthesis.
Electroantennogram and behavioral responses of workers of the stingless bee Oxytrigona mediorufa to mandibular gland volatiles
Authors: Cruz‐López L. , Aguilar S. , Malo E. A. , Rincón M. , Guzman M. , Rojas J. C.
Published: February 2007

Gas chromatography‐mass spectrometric analysis showed that the mandibular gland secretion of workers of the stingless bee Oxytrigona mediorufa (Cockerell) (Hymenoptera: Apidae) is composed of 3‐hepten‐2,5‐dione, 3‐nonene‐2,5‐dione, 2‐heptanone, hydrocarbons, tetradecyl, and hexadecyl acetates and minor compounds related to these. Behavioral and electroantennographic tests were carried out on conspecific workers to observe the effect of worker mandibular gland secretion, individual compounds (2‐heptanone, 2‐nonanone, and tetradecyl acetate), and a blend of these three. Bioassays showed that biting responses of O. mediorufa to the odor of the mandibular gland secretion were similar to that of 2‐heptanone and to the three‐component blend. Oxytrigona mediorufa workers exhibited antennal olfactory responses to the gland extract, 2‐heptanone, and the synthetic mixture. The function of the mandibular gland secretion and 2‐heptanone is discussed in terms of an alarm pheromone and defensive substances.
Males of the predatory mirid bug Macrolophus caliginosus exploit plant volatiles induced by conspecifics as a sexual synomone
Authors: Moayeri Hamid R. S. , Ashouri Ahmad , Brødsgaard Henrik F. , Enkegaard Annie
Published: February 2007

The olfactory responses of male and female Macrolophus caliginosus Wagner (Heteroptera: Miridae) adults towards volatiles from green bean plants previously exposed to feeding by conspecifics and to direct odours from conspecifics were tested in a Y‐tube olfactometer. Female M. caliginosus did not respond to volatiles from plants exposed to mirid feeding or to odours emitted directly by adult mirids. In contrast, male mirid bugs were attracted both to volatiles from plants previously exposed to feeding by conspecific females and to odours emitted by conspecifics only with a marginally significant preference for the former. The gas chromatography‐mass spectrometry analysis showed that mirid feeding induced the release of 11 additional compounds as compared to the volatiles emitted from clean plants. Three of these substances (5‐ethyl‐2(5H)‐furanone, Z‐3‐hexenyl tiglate, and E,E‐α‐farnesene) were released only after feeding by females. Furthermore, 21 compounds were identified in volatiles emitted directly by mirids, 12 of which were unique to the mirids (i.e., not present in clean plants or plants previously exposed to mirid feeding). The results suggest that female‐specific herbivore‐induced plant volatiles play a role as mate‐finding cues by the male mirids. The ecological implications of the findings are discussed, and the term ‘sexual synomone’ is introduced.
Electrophysiological subtypes of psychotic states
Authors: John E. R. , Prichep L. S. , Winterer G. , Herrmann W. M. , DiMichele F. , Halper J. , Bolwig T. G. , Cancro R.
Published: February 2007

Objective: This research sought neurobiological features common to psychotic states displayed by patients with different clinical diagnoses.

Method: Cluster analysis with quantitative electroencephalographic (QEEG) variables was used to subtype drug‐naïve, non‐medicated, and medicated schizophrenic, depressed and alcoholic patients with psychotic symptoms, from the USA and Germany. QEEG source localization brain images were computed for each cluster.

Results: Psychotic patients with schizophrenia, depression and alcoholism, and drug‐ naïve schizophrenic patients, were distributed among six clusters. QEEG images revealed one set of brain regions differentially upregulated in each cluster and another group of structures downregulated in the same way in every cluster.

Conclusion: Subtypes previously found among 94 schizophrenic patients were replicated in a sample of 390 non‐schizophrenic as well as schizophrenic psychotics, and displayed common neurobiological abnormalities. Collaborative longitudinal studies using these economical methods might improve differential understanding and treatment of patients based upon these features rather than clinical symptoms.
Chronic periodontitis and pre‐term labour in Brazilian pregnant women: an association to be analysed
Authors: Santos‐Pereira Silvio A. , Giraldo Paulo C. , Saba‐Chujfi Eduardo , Amaral Rose L. G. , Morais Sirlei S. , Fachini Ana Maria , Gonçalves Ana Katherine S.
Published: February 2007

Aim: To investigate the association between chronic periodontitis (CP) and pre‐maturity in a group of Brazilian pregnant women from the State of São Paulo.

Materials and Methods: One hundred and twenty‐four women were investigated consecutively in a cross‐sectional study, between December 2003 and May 2005. Sixty‐eight women had pre‐term labour (PTL) and 56 had term labour. A periodontal examination was carried out to identify the presence of CP. Statistical analysis used the Fisher's exact test or χ2 for the discrete variables and the Mann–Whitney test for the non‐parametric variables. Odds ratio (OR) was calculated with a 95% confidence interval (CI), to evaluate the relation between CP and pre‐maturity.

Results: Periodontal indicators, such as clinical attachment loss (p<0.0001) and bleeding on probing (p=0.012), were observed more in the PTL group. The presence of CP increased the risk for PTL (OR: 4.7, 95% CI: 1.9–11.9), pre‐term birth (PTB; OR: 4.9, 95% CI: 1.9–12.8) and low birth weight (<2500 g; OR: 4.2, 95% CI: 1.3–13.3). The pregnant women with PTL presented low levels of schooling (p=0.029) and the lowest number of pre‐natal appointments (p=0.0001) when compared with those with term labour.

Conclusion: CP is strongly associated with PTL, PTB and low birth weight in a group of Brazilian pregnant women. These data point to the necessity of regularly investigating CP during pregnancy.
Clinical changes following four different periodontal therapies for the treatment of chronic periodontitis: 1‐year results
Authors: Haffajee Anne D. , Torresyap G. , Socransky Sigmund S.
Published: February 2007

Objective: To compare clinical changes occurring in chronic periodontitis subjects receiving SRP alone or with systemically administered azithromycin, metronidazole or a sub‐antimicrobial dose of doxycycline.

Material and Methods: 92 chronic periodontitis subjects were randomly assigned to receive SRP alone (N=23) or combined with 500 mg azithromycin per day for 3 days (N=25), 250 mg metronidazole tid for 14 days (N=24) or 20 mg doxycycline bid for 3 months (N=20). Gingival redness, bleeding on probing, suppuration, pocket depth and attachment level were measured at baseline and 3, 6 and 12 months post therapy. The significance of changes in clinical parameters within groups over time was sought using the Friedman test and among groups using ANCOVA or the Kruskal Wallis test.

Results: All groups showed clinical improvements at 12 months, with subjects receiving adjunctive agents showing a somewhat better response. Sites with initial pocket depth >6 mm showed significantly greater pocket depth reduction and greater attachment gain in subjects receiving metronidazole or azithromycin than subjects in the other groups. Some subjects showed attachment loss at 12 months in each group ranging from 15% to 39% of subjects in the SDD and SRP only groups respectively.

Conclusion: This study, demonstrated that periodontal therapy provides clinical benefits and that antibiotics provide a clinical benefit over SRP alone, particularly at initially deeper periodontal pockets.
Nature of cell kinetics in psoriatic epidermis
Authors: Doger Furuzan K. , Dikicioglu Emel , Ergin Filiz , Unal Emel , Sendur Neslihan , Uslu Meltem
Published: February 2007

Background: Psoriasis vulgaris is a common chronic inflammatory dermatosis. Disorders in keratinocyte proliferation, differentiation, inflammation and immune dysregulation are the major factors implicated in the pathogenesis of psoriasis vulgaris.

Methods: The study was performed in skin specimens of 25 patients with psoriasis vulgaris and a control group of 10 individuals without a skin disease. Biopsy specimens from lesional and normal skin were analyzed by immunohistochemical method for expressions of Ki‐67, Bcl‐2, terminal deoxynucleotidyl transferase‐mediated dUTP‐biotin nick‐end labeling (TUNEL), tumor necrosis factor alpha (TNF‐α) and nuclear factor kappa B (NF‐κB). In addition, densities of mast cell infiltration were also investigated.

Results: Ki‐67 and TUNEL indexes and TNF‐α and NF‐κB expressions were significantly higher in psoriatic epidermis than in normal epidermis (p < 0.05). There was no significant difference at Bcl‐2 reactivity between the normal and the psoriatic epidermis (p > 0.05); however, Bcl‐2 staining intensity of lymphocytes was higher in psoriatic lesions than in normal dermis (p < 0.05). Additionally, the number of mast cells was significantly higher in psoriatic dermis than in normal skin (p < 0.05).

Conclusions: There were several complex factors involved in the pathogenesis of psoriasis. We conclude that cellular damage and apoptosis temporarily coincide with epidermal proliferation during the course of psoriatic hyperplasia.
Golgi Complex Organization in Skeletal Muscle: A Role for Golgi‐Mediated Glycosylation in Muscular Dystrophies?
Authors: Percival Justin M. , Froehner Stanley C.
Published: February 2007

The Golgi complex (GC) is the central organelle of the classical secretory pathway, and it receives, modifies and packages proteins and lipids en route to their intracellular or extracellular destinations. Recent studies of congenital muscular dystrophies in skeletal muscle suggest an exciting new role for an old and well‐established function of the GC: glycosylation. Glycosylation is the exquisitely regulated enzymatic addition of nucleotide sugars to proteins and lipids mediated by glycosyltransferases (GTs). Mutations in putative Golgi‐resident GTs, fukutin, fukutin‐related protein and large1 cause these progressive muscle‐wasting diseases. The appropriate localization of GTs to specific subcompartments of the Golgi is critical for the correct assembly line‐like addition of glycan groups to proteins and lipids as they pass through the GC. Consequently, these studies of congenital muscular dystrophies have focused attention on the organization and function of the GC in skeletal muscle. In contrast to other cells and tissues, the GC in skeletal muscle has received relatively little attention; however, in recent years, several studies have shown that GC distribution in muscle is highly dynamic or plastic and adopts different distributions in muscle cells undergoing myogenesis, denervation, regeneration and maturation. Here, we review the current understanding of the dynamic regulation of GC organization in skeletal muscle and focus on the targeting of fukutin, fukutin‐related protein and large1 to the GC in muscle cells.
Lipid Microdomain‐Dependent Macropinocytosis Determines Compartmentation of Afipia felis
Authors: Schneider Bianca , Schueller Christian , Utermoehlen Olaf , Haas Albert
Published: February 2007

Phagocytic compartments are specialized endocytic organelles and usually mature along the degradative pathway into phagolysosomes. The rare human pathogen Afipia felis localizes to a compartment that is different from canonical phagocytic compartments. Here, we present evidence that internalization of Afipia by macrophages and unusual phagosome development are considerably decreased by attachment of cholera toxin B subunit to macrophage ganglioside GM1 or by extraction or oxidation of plasma membrane cholesterol. Amiloride (an inhibitor of Na+/H+ exchanger and macropinocytosis) strongly inhibited uptake of A. felis at a late step, i.e. the closure of macropinocytic structures rather than the production of membrane ruffles. Ultrastructural evidence showed that A. felis was taken up by macrophages via macropinocytosis. In contrast, A. felis opsonized with a monoclonal IgG antibody was ingested by a zipper‐like mechanism, resulting in normal phagosome maturation. Hence, while the preferred path of A. felis uptake is dependent on the integrity of lipid microdomains and on macropinocytosis, and while this uptake leads to an unusual phagosome and to intracellular survival of A. felis, those bacteria that enter using Fcγ receptors are delivered to a late endocytic compartment.
Polarized Transport of Alzheimer Amyloid Precursor Protein Is Mediated by Adaptor Protein Complex AP1‐1B
Authors: Icking Ann , Amaddii Monia , Ruonala Mika , Höning Stefan , Tikkanen Ritva
Published: February 2007

Alzheimer amyloid precursor protein (APP) is the precursor for the Aβ peptide involved in pathogenesis of Alzheimer's disease. The soluble ectodomain fragment of APP (sAPP) functions as a growth factor for epithelial cells, suggesting an important function for APP outside neuronal tissue. Previous studies have shown that in polarized epithelial cells, APP is targeted to the basolateral domain. Tyr653 within the cytoplasmic tail of APP mediates the basolateral targeting of APP, but the sorting machinery that binds to this residue has largely remained unknown. In this study, we analyzed the role of adaptor complexes in the polarized sorting of APP. We show that the medium subunit μ1B of the epithelia‐specific adaptor protein (AP)‐1B binds onto the cytoplasmic tail of APP in a Tyr653‐dependent way. Moreover, ectopic expression of μ1B in cells lacking AP‐1B resulted in correction of apical missorting of wild‐type but not Tyr653Ala APP. Basolateral secretion of sAPP was found to be independent of Tyr653. We propose a model for polarized targeting of APP according to which sorting of APP to basolateral domain is dependent on binding of AP‐1B on Tyr653 in basolateral endosomes. This model is in accordance with the current understanding of sorting mechanisms mediating polarized targeting of membrane proteins.
Phosphoinositide‐Regulated Retrograde Transport of Ricin: Crosstalk Between hVps34 and Sorting Nexins
Authors: Skånland Sigrid S. , Wälchli Sébastien , Utskarpen Audrun , Wandinger‐Ness Angela , Sandvig Kirsten
Published: February 2007

The plant toxin ricin is transported from the plasma membrane via early endosomes and the Golgi apparatus to the endoplasmic reticulum. From this compartment, it enters the cytosol and inhibits protein synthesis. Lipid phosphorylation is an important regulator of vesicular transport, and in the present study we have investigated the role of the phosphatidylinositol (PI) 3‐kinase hVps34 in retrograde transport of ricin. Our data demonstrate that transport of ricin from endosomes to the Golgi apparatus in human embryonic kidney cells (HEK 293) is dependent on PI(3)P. By using PI 3‐kinase inhibitors, by sequestering the hVps34 product PI(3)P and by expressing mutants of hVps34 or small interfering RNA targeted against its messenger RNA, we show that hVps34 and its product PI(3)P are involved in transport of ricin from endosome to Golgi apparatus. Furthermore, we identify two effector proteins in the hVps34‐dependent pathway, namely sorting nexin (SNX) 2 and SNX4. Knockdown of SNX2 or SNX4 inhibits ricin transport to the Golgi apparatus to the same extent as when hVps34 is perturbed. Furthermore, inhibition or knockdown of hVps34 redistributes these proteins. Interestingly, knocking down both SNX2 and SNX4 results in a better inhibition than knocking down only one of them, suggesting that they may act on separate pathways.
Macrophage Activation Downregulates the Degradative Capacity of the Phagosome
Authors: Yates Robin M. , Hermetter Albin , Taylor Gregory A. , Russell David G.
Published: February 2007

The phagosome is key to most macrophage functions. It is the site of degradation of particulate material, of bacterial killing and the generation of peptides for antigen presentation. Despite its role at the fulcrum of the innate and acquired immune systems, little is known about the physiology of this organelle in activated macrophages. In this study, we utilize fluorometric techniques to characterize functional alterations in the lumenal environment of the maturing phagosome following stimulation of macrophages with interferon‐γ and/or lipopolysaccharide. In addition to modulating the kinetics of phagosomal acidification, activation results in a phagosome with diminished hydrolytic activities that varies markedly with the activation status of the cell. Differential levels of proteolytic, lipolytic and β‐galactosidase activities were observed in the phagosome but not in the total lysosomal extract, indicating selective delivery of enzymes to the developing phagosome. Despite the suppression of hydrolytic activities observed in early phagosomes, late phagosomes exhibit an enhanced and protracted accumulation of lysosomal cargo. The data are consistent with limiting proteolysis in the early phagosome to maximize epitope generation and antigen presentation while sequestering the degradative capacity in the late phagolysosome.
Multidisciplinary approach for the treatment of an oblique root fracture: a case report
Authors: Demiralp Burak , Keçeli Hüseyin Gencay , Kökat Ali Murat , Muhtarogullari Mehmet , Tuncel Behram , Eratalay Kenan
Published: February 2007

Abstract –  This clinical case study describes a multidisciplinary modified technique for the treatment of an oblique root fracture. A‐38‐year old woman with a history of trauma and a broken tooth was referred to our clinic. There was an oblique crown fracture extending the coronal third of the root just underneath the cingulum of the crown. The patient was willing to keep her tooth in function by any means. Two weeks after root canal therapy the flap was raised. The coronal two third of the root canal was enlarged. An impression of the enlarged root canal and tooth surface with surrounding bone was taken. The flap was sutured and the impression was sent to the laboratory for the post‐casting preparation. After 7 days, the flap was opened again and casting was cemented. The flap was sutured. Ten days after the second surgery, three anterior teeth were prepared and a final impression was taken for the preparation of porcelain crowns. Restoration was finished 15 days after the second operation. The patient is still under maintenance therapy and the 12 month results are presented in this report. Extraction may not be the only alternative for the root fractures. Even for fractures under the alveolar margin, alternative multidisciplinary approaches can be used to restore and allow the tooth to survive.
Root fracture in immature tooth: report of a case
Authors: Cem Güngör H. , Büyükgüral Bülent , Uysal Serdar
Published: February 2007

Abstract –  Root fracture injuries affect 0.5–7% of permanent teeth. Although this type of injury is rarely seen in teeth with immature root formation, the prognosis is generally good depending on the site of the fracture. A case report of horizontal root fracture in maxillary central incisor of an 8‐year and 3‐month‐old girl and its treatment was presented.
Reattachment of subgingivally fractured central incisor with an open apex
Authors: Eden Ece , Yanar Saniye Çiçek , Sönmez Şule
Published: February 2007

Abstract –  A case report of a 6‐year‐old girl with a fractured maxillary left central incisor with an open apex is presented. The procedure used to repair the fracture included flap surgery with an intrasulcular incision and endodontic treatment. The patient was called for 3 months regular follow‐up to check the root formation. At the end of 32 months just before the root was obturated by guttaperka, she fractured the same tooth. Flap surgery was repeated and the tooth was restored. The root canal was obturated with a root filling paste and guttaperka as the apex was closed. Examination 10 months after treatment revealed good periodontal health, aesthetics and normal function.
Self‐replantation of an avulsed tooth in torsoversion: a 10‐year follow‐up
Authors: Rai Priyank , Gupta Udayan , Kalra Namita
Published: February 2007

Abstract –  A 15‐year‐old moderately built boy reported to the dental outpatient department with a complaint of pus discharge from the upper front teeth. There was a clear history of traumatic avulsion followed by self‐replantation 6 years earlier. No dental treatment was taken by the child. On clinical examination the left upper central incisor was in torsoversion (anatomical labial surface on palatal side and vice versa). The child had probably self‐replanted in torsoversion. Endodontic treatment was successfully completed, and final rehabilitation was done by a porcelain crown. The case highlights the excellent results of immediate replantation even when it is done by a child. It also highlights the value of school level dental education.
A Structure‐based, Quantitative Structure–Activity Relationship Approach for Predicting HLA‐A*0201‐restricted Cytotoxic T Lymphocyte Epitopes
Authors: Zhou Peng , Tian Feifei , Li Zhiliang
Published: February 2007

In this investigation, we first constructed four types of non‐bonding interaction matrixes by defining direct contacting residue types for HLA‐A*0201 protein in interaction with each position of HLA‐A*0201‐restricted cytotoxic T lymphocyte epitope as well as several formulae calculating ligand/receptor non‐bonding interactions. Relative to these studies, a method which we refer to as structure‐based, quantitative structure–activity relationship is proposed and utilized for studies on 266 HLA‐A*0201‐restricted cytotoxic T lymphocyte epitopes. The resulting genetic algorithm‐partial least square regression model is consistent with both published studies and molecular graphics analysis. Two non‐bonding interactions (i.e. hydrophobic and hydrogen bonding), are found to play important roles in antigen recognition and presentation, especially exerting effects at positions of anchor residues in antigen peptides.
Structure–function Relationships and Conformational Properties of α‐MSH(6–13) Analogues with Candidacidal Activity
Authors: Carotenuto Alfonso , Saviello Maria Rosaria , Auriemma Luigia , Campiglia Pietro , Catania Anna , Novellino Ettore , Grieco Paolo
Published: February 2007

α‐Melanocyte‐stimulating hormone (α‐MSH) is an endogenous linear tridecapeptide with potent anti‐inflammatory effects. We firstly demonstrated that α‐MSH and its C‐terminal sequence Lys‐Pro‐Val [α‐MSH(11–13)] have antimicrobial effects against two major and representative pathogens: Staphylococcus aureus and Candida albicans. Successively, in an attempt to improve the candidacidal activity of α‐MSH and to better understand the peptide structure–antifungal activity relations, we have recently designed and synthesized novel peptide analogues. We focused on the sequence α‐MSH(6–13), which contains the invariant melanocortin core sequence His‐Phe‐Arg‐Trp (6–9) and also contains the sequence Lys‐Pro‐Val (11–13) important for antimicrobial activity. In that structure–activity study, we discovered several compounds that have greater candidacidal activity than α‐MSH, among which the peptide [d‐Nal‐7,Phe‐12]‐α‐MSH(6–13) was the most potent. Here, we report a detailed conformational analysis by spectroscopic and computational methods of three peptides, α‐MSH(6–13) (1), [d‐Nal‐7,Phe‐12]‐α‐MSH(6–13) (2) and [d‐Nal‐7,Asp‐12]‐α‐MSH(6–13) (3). Peptides were chosen on the basis of their candidacidal activities and were studied in membrane mimetic environment (SDS micelles). Different turn structures were observed for the three peptides and a conformation–activity model was developed based on these results. This study offers a structural basis for the design of novel peptide and non‐peptide analogues to be used as new antimicrobial agents.
Using fluvial geomorphology to inform integrated river basin management
Authors: Eyquem Joanna
Published: February 2007

Recent years have seen a trend towards larger scale, multidisciplinary approaches to river management. This reflects changes in policy and legislation, particularly the drive towards integrated river basin management as required by the EC Water Framework Directive. Fluvial geomorphology is a discipline that links the physical function of the river to its ecological status, and thus has a fundamental role to play in future river basin management. This is becoming more widely recognised at a project level, as well as nationally and internationally. This paper will demonstrate, using the case study of the Axe Catchment Fluvial Audit, how fluvial geomorphology can be successfully applied to inform river basin management. The outputs from the project are described together with some of the key limitations and lessons learned.
Floodplain nutrient and sediment dynamics on the Kent Stour
Authors: Cook H. F.
Published: February 2007

Floodplain land use is currently of concern. Agri‐environmental policy favours grass over arable agriculture, while urban development is deemed unsuitable. The role of meadowland requires evaluation because it exhibits a potential to deliver environmental goods beyond flood detention and habitat creation; it has the potential to take up particular elements and trap sediment. This is particularly important where there is eutrophication of water from agriculture and wastewater and also physical degradation of the channel and floodplain. In this study, carbon (C), nitrogen and phosphorus (P) status and sediment deposition at typical locations on a southern English floodplain were investigated. It is concluded that C sequestration could be significant and there is sediment trapping during times of flood but further P accumulation in the topsoil of grazing land is limited. It is concluded that nutrient loading of the river from sewage effluent and from agriculture is best prevented at source.
Using linked process models to improve urban groundwater management: an example from Doncaster England
Authors: Morris B. , Rueedi J. , Cronin A. A. , Diaper C. , DeSilva D.
Published: February 2007

Linked water process models that simulate the complexities of urban water systems for towns overlying productive aquifers can help improve and better integrate urban water resource management. The Assessing and Improving the Sustainability of Urban Water Resources and Systems (AISUWRS) project has successfully linked together water scheduling, pipe leakage and groundwater flow models and applied these models to case studies in Europe and Australia. This paper describes the application and results of the modelling tools for a case study suburb in Doncaster England. The linking of process models offers the prospect of better quantification of flows and contaminant loads, and diverse scenarios were readily simulated once the base case had been set‐up. The linked models produced higher estimates of recharge than previous estimates, and this may suggest that suburban catchments are an underutilised resource. At a time when increasing urbanisation and rising water use is predicted for groundwater‐dependent southern England, there is a need for such tools to make the most of increasingly urbanised aquifers.
The Natural Philosophy of Agency
Authors: Gallagher Shaun
Published: February 2007

A review of several theories and brain‐imaging experiments shows that there is no consensus about how to define the sense of agency. In some cases the sense of agency is construed in terms of bodily movement or motor control, in others it is linked to the intentional aspect of action. For some theorists it is the product of higher‐order cognitive processes, for others it is a feature of first‐order phenomenal experience. In this article I propose a multiple aspects account of the sense of agency.
Investigation of Effect of Phase Transformations on Mechanical Behavior of AISI 1010 Steel in Laser Forming
Authors: Fan Yajun , Yang Zhishang , Cheng Peng , Egland Keith , Yao Lawrence
Published: February 2007

In laser forming, phase transformations in the heat affected zone take place under steep cooling rates and temperature gradients, and have a significant affect on the laser forming process and final mechanical properties of products. In this work, phase transformations during laser forming of AISI 1010 steel are experimentally and numerically investigated and the transient volume fraction of each available phase is calculated by coupling the thermal history from finite element analysis with a phase transformation kinetic model. Consequently, the flow stresses of material are obtained from the constitutive relationship of the phases, and the laser forming process is modeled considering the effect of work hardening, recrystallization and phase transformation. A series of carefully controlled experiments are also conducted to validate the theoretically predicted results.
Optimal Feed-Rate Scheduling for High-Speed Contouring
Authors: Dong J. , Stori J. A.
Published: February 2007

The majority of efforts to improve the contouring performance of high-speed CNC systems has focused on advances in feedback control techniques at the single-axis servo level. Regardless of the dynamic characteristics of an individual system, performance will inevitably suffer when that system is called upon to execute a complex trajectory beyond the range of its capabilities. The intent of the present work is to provide a framework for abstracting the capabilities of an individual multiaxis contouring system, and a methodology for using these capabilities to generate a time-optimal feed-rate profile for a particular trajectory on a particular machine. Several constraints are developed to drive the feed-rate optimization algorithm. First, simplified dynamic models of the individual axes are used to generate performance envelopes that couple the velocity versus acceleration capabilities of each axis. Second, bandwidth limitations are introduced to mitigate frequency related problems encountered when traversing sharp geometric features at high velocity. Finally, a dynamic model for the instantaneous following error is used to estimate the contour error as a function of the instantaneous velocity and acceleration state. We present a computationally efficient algorithm for generating a minimum-time feed-rate profile subject to the above constraints, and demonstrate that significant improvements in contouring accuracy can be realized through such an approach. Experimental results are presented on a conventional two-axis X−Y stage executing a complex trajectory.
Modeling and Optimization of Caliber Rolling Process
Authors: Hsiang Su-Hai , Lin Sheng-Li
Published: February 2007

In practice of caliber rolling, it is highly desirable to obtain optimal processing parameters to achieve the best quality in a short time. A sophisticated and faster simulation model of caliber rolling is proposed, and then a global optimal searching method—simulated annealing algorithm (SA)—is applied to find the optimal processing parameters of caliber rolling. The simulation model of caliber rolling in this paper was established by the back-propagation neural network (BPNN) model, which replaces the complex numerical analytical model, proposed in an earlier paper. This replacement improved the speed of simulation significantly.
Whirling Vibrations in Boring Trepanning Association Deep Hole Boring Process: Analytical and Experimental Investigations
Authors: Al-Wedyan Hussien M. , Bhat Rama B. , Demirli Kudret
Published: February 2007

An approach to study the whirling motion of the BTA (boring trepanning association) deep hole boring system is presented by introducing the system excitation in the form of internal forces between the boring bar and the workpiece. This involves nonhomogeneous boundary conditions with homogeneous equations. The mathematical approach with the boring bar-workpiece internal cutting forces and external suppression forces will transform the problem into nonhomogeneous equations with homogenous boundary conditions. Using this approach the whirling motion of the boring bar is obtained at different points on the boring bar-workpiece assembly. External suppression forces will reduce the whirl amplitude at the same locations. Further, an experimental investigation is carried out on the BTA deep hole boring process while drilling at four cutting speeds using proximity pickups for displacement measurements.
Evaluation of Chip Morphology in Hard Turning Using Constitutive Models and Material Property Data
Authors: Poulachon Gérard , Moisan Alphonse L. , Jawahir I. S.
Published: February 2007

Modeling of machining operations requires the use of constitutive relations which could represent as close as possible the material behavior in the primary and secondary zones. The knowledge of these behavior laws involves the use of different types of sophisticated mechanical tests which should provide with sufficient accuracy the material behavior for the relevant conditions of machining. In this paper, first, the flow stress of 100Cr6 (AISI 52100) bearing steel in its HV730 hardness state has been identified in order to assess the machinability in case of hard turning. With this, the dependence of the flow stress on strain, strain rate and temperature, which poses significant difficulty, is presented. Second, the material machinability is evaluated with a shear instability criterion, enabling the prediction of chip formation with or without the shear localization. Quick-stop tests have been carried out on the bearing steel treated at different hardness values showing the chip formation variation. Micro-hardness tests performed on these quick-stop test samples show the effects of cutting temperature. A greater understanding of applied machinability is gained through this precise study of work material physical properties and behavior.
Process Maps for Predicting Residual Stress and Melt Pool Size in the Laser-Based Fabrication of Thin-Walled Structures
Authors: Vasinonta Aditad , Beuth Jack L. , Griffith Michelle
Published: February 2007

Thermomechanical models are presented for the building of thin-walled structures by laser-based solid freeform fabrication (SFF) processes. Thermal simulations are used to develop quasi-non-dimensional plots (termed process maps) that quantify the effects of changes in wall height, laser power, deposition speed, and part preheating on thermal gradients, with the goal of limiting residual stresses in manufactured components. Mechanical simulations are used to demonstrate the link between thermal gradients and maximum final residual stresses. The approach taken is analogous to that taken in previous research by the authors in developing process maps for melt pool length, for maintaining an optimal melt pool size during component fabrication. Process maps are tailored for application to the laser engineered net shaping process; however, the general approach, insights, and conclusions are applicable to most SFF processes involving a moving heat source, and to other laser-based fusion processes. Results from the residual stress simulations identify two mechanisms for reducing residual stresses and quantify maximum stress reductions achievable through manipulation of all process variables. Results from thermal gradient and melt pool length process maps are used to identify a manufacturing strategy for obtaining a consistent melt pool size while limiting residual stress in a thin-walled part.
Mechanistic Modeling of Process Damping in Peripheral Milling
Authors: Huang C. Y. , Wang J. J. Junz
Published: February 2007

This paper extends analytical modeling of the milling process to include process damping effects. Two cutting mechanisms (shearing and plowing mechanisms) and two process damping effects (directional and magnitude effects) are included. The directional effect is related to vibration energy dissipation due to directional variation of cutter∕workpiece relative motion. The magnitude effect is associated with change in force magnitude due to variation of rake angle and clearance angle. Process damping is summarized as containing these separate components: direction-shearing, direction-plowing, magnitude-shearing, and magnitude-plowing. The total force model including the process damping effect is obtained through convolution integration of the local forces. The analytical nature of this model makes it possible to determine two unknown dynamic cutting factors from measured vibration signal during milling. The effects of cutting conditions (cutting speed, feed, axial and radial depths of cut) on process damping are systematically examined. It is shown that total process damping increases with increasing feed, axial and radial depths of cut, but decreases with increasing cutting velocity. Predictions based on the analytical model are verified by experiment. Results show that plowing mechanism contributes more to the total damping effect than the shearing mechanism, and magnitude-plowing effect has by far the greatest influence on total damping.
Modeling and Analysis of Aerodynamic Noise in Milling Cutters
Authors: Sampath Karthikeyan , Kapoor Shiv G. , DeVor Richard E.
Published: February 2007

Aerodynamic noise generated in high speed face milling cutters is usually much higher than the noise exposure limit set by OSHA. Experiments were conducted on two different face milling cutters to understand the aerodynamic noise generation in face milling cutters. It is observed that dipole sources of noise are most important in determining the noise generation in rotating face milling cutters. The aerodynamic noise spectrum consists of discrete tones at the rotational frequency and a broad range of higher frequencies, with the broadband spectrum contributing significantly to overall noise. A mathematical model based on the Ffowcs Williams-Hawkings Equation is used to predict (un-weighted) aerodynamic noise. The noise predicted compares well with the experimental observations. The cutter gullet shape was found to be an important factor in determining broadband noise.
Online Inspection for Glass Fiber Forming
Authors: Lin Paul P. , Guo Qing , Li Xiaolong
Published: February 2007

Glass fiber forming is a complicated process in which many factors could affect the quality of fibers. The forming machine has many fiber-forming tubes that are close to each other and arranged in several layers. The closeness results in inadequate lighting and unwanted video signals. An anti-causal zero-phase filter was employed to remove noise with insignificant pixel location shift or distortion. In addition to the noise, the unwanted video signals constantly moving from one place to another also presented a challenge in image analysis. These signals were identified by a trained neural network that classified patterns. The unwanted signal identification through instant pattern classification made online inspection possible. During the fiber drawing process, the diameters of glass forming tubes and the profiles of glass melting cones were closely monitored and measured online in order to control the final fiber diameter. The accurate diameter measurements were accomplished by the noise removal along with a subpixel-resolution based edge detection technique. The results thus obtained for noise removal and unwanted video signals identification were quite good. The fiber diameter measurements were performed online, and the entire inspection process was automated with the aid of a programmable logic controller.
Dynamics and Stability of Plunge Milling Operations
Authors: Ko Jeong Hoon , Altintas Yusuf
Published: February 2007

Plunge milling operations are used to remove excess material rapidly in roughing operations. The cutter is fed in the direction of the spindle axis which has the highest structural rigidity. This paper presents a comprehensive model of plunge milling process by considering rigid body motion of the cutter, and three translational and torsional vibrations of the structure. The time domain simulation model allows prediction of cutting forces, torque, and vibrations while considering tool setting errors and time varying process parameters. The stability law is formulated as a four-dimensional eigenvalue problem, and the stability lobes are predicted directly with analytical solution in frequency domain. Time domain prediction of cutting forces and vibrations, as well as the frequency domain and chatter stability solution are verified with a series of plunge milling experiments.
Effect of Forging Force on Fatigue Behavior of Spot Welded Joints of Aluminum Alloy 5182
Authors: Chang B. H. , Du D. , Sui B. , Zhou Y. , Wang Z. , Heidarzadeh F.
Published: February 2007

Using experimental and finite element analysis methods, the effects of electrode forging force are investigated on fatigue behavior and residual stress of spot welded joints of aluminum alloy 5182. Results show that applying forging force significantly reduces the residual stresses in the heat affected zone and the fatigue cracks no longer initiate from there; instead, all cracks begin from the nugget edge. In addition, the mitigation of residual stress by forging force decreases the driving force for crack propagation and leads to longer fatigue life. It can be concluded that applying forging force appropriately has a positive effect on the fatigue strength of resistance spot welded joints.
Manufacturing Modeling of Three-Dimensional Resin Injection Pultrusion Process Control Parameters for Polyester/Glass Rovings Composites
Authors: Jeswani A. L. , Roux J. A.
Published: February 2007

Pultrusion, sometimes referred to as continuous resin transfer molding process, is a continuous, cost-effective method for manufacturing composite materials with constant cross sections (such as rod stock, beams, channels, and tubing). The objective of this study is to improve the fiber reinforcement wetout and thus the quality of the pultruded part in the injection pultrusion process. The complete wetout of the dry reinforcement by the liquid resin depends on various design and process parameters. The process parameters modeled in this study are fiber pull speed, fiber volume fraction, and viscosity of the resin. In the present work, a three-dimensional finite volume technique is employed to simulate the liquid resin flow through the fiber reinforcement in the injection pultrusion process. The numerical model simulates the flow of polyester resin through the glass rovings and predicts the impact of the process parameters on wetout, resin pressure field, and resin velocity field. The location of the liquid resin flow front has been predicted for an injection slot as well as for five discrete injection ports.