bluuebunny/crossref_metadata_2025 huggingface dataset:
Habitat selection, diet, arthropod availability and growth of a moorland wader: the ecology of European Golden Plover Pluvialis apricaria chicks
Authors: Pearce‐Higgins J. W. , Yalden D. W.
Published: November 2004

Habitat use, diet and food supply of European Golden Plover Pluvialis apricaria chicks were studied on blanket bog in the South Pennines, UK. The home ranges occupied by chicks until fledging averaged 40 ha; they contained relatively more cotton grass and bare peat than was available generally, but less heather and grassland. Use of Bilberry Vaccinium myrtillus and Crowberry Empetrum nigrum increased with age, whereas that of cotton grass Eriophorum spp. declined. Dietary composition, as assessed by faecal analysis, was similar to that obtained from the crops of dead birds. The diet of younger chicks, assessed by dry weight of prey, consisted of about 30% each of adult and larval tipulids, whereas for chicks older than 16 days, about 70% was tipulid larvae. Beetles, spiders and caterpillars each comprised 5–20% of the diet, depending on age. Older chicks took larger prey. The exploitation of larval tipulids was correlated positively with the chicks’ use of cotton grass and bare peat areas, whereas caterpillars, beetles and spiders were more often taken from dwarf shrubs, reflecting variation in prey abundance. Bare peat was an important foraging habitat, whose exploitation was associated positively with the growth rate of young chicks, and with mean prey size. Both weight gain and survival of young chicks were positively correlated with the abundance of tipulid adults, confirming the hypothesis that the flush of tipulid hatching is an important determinant of breeding success. Golden Plover chicks are capable of considerable movements to track variation in prey availability. This behaviour is likely to be an important survival strategy facilitating the utilization of a mosaic of cotton grass and dwarf shrub habitats. Appropriate rotational strip‐burning or grazing management could be used to create and maintain such habitats.
Five‐year evaluation of the impact of the Arable Stewardship Pilot Scheme on birds
Authors: BRADBURY RICHARD B. , BROWNE STEPHEN J. , STEVENS DANAË K. , AEBISCHER NICHOLAS J.
Published: November 2004

Agri‐environment schemes could play a key role in the reversal of farmland bird declines. The effectiveness of the Arable Stewardship Pilot Scheme for delivering farmland birds was tested in a replicated, farm‐scale field trial, in two lowland farmland regions of England. Changes in numbers of birds over five years were compared between control and scheme farms. In East Anglia, productivity of Grey Partridges Perdix perdix was significantly higher on scheme than on control farms, although such an effect was not seen in the West Midlands where the species was rarer. At the field scale, wintering granivorous passerines and Skylarks Alauda arvensis responded to stewardship habitats (options) such as stubble and wild bird cover designed specifically to benefit them. However, at the farm scale, winter bird counts were higher on scheme than control farms only in the West Midlands, and not in East Anglia where the availability of set‐aside and features managed for game in the wider landscape was higher. In the absence of other high‐quality habitat, arable options are effective at providing good quality habitat, but the amount needed to exert an influence at the bird population level remains uncertain.
Conservation management of Lapwing Vanellus vanellus on lowland arable farmland in the UK
Authors: SHELDON ROB , BOLTON MARK , GILLINGS SIMON , WILSON ANDY
Published: November 2004

Lapwing Vanellus vanellus is known to be declining throughout much of its UK breeding range. The ecological requirements of the species are well known and a variety of mechanisms exist which can be implemented to help recovery. Arable options within agri‐environment schemes can be used to provide breeding habitat throughout the species’ UK range, and targeted recovery projects have been shown to have the potential to deliver increases in breeding pairs at the local level. The farming community need to be made aware of the requirements of Lapwing if agriculture and conservation needs are to be integrated.
NEUTRON RESONANCE CAPTURE ANALYSIS OF SOME GENUINE AND FAKE ETRUSCAN COPPER ALLOY STATUETTES*
Authors: POSTMA H. , SCHILLEBEECKX P. , HALBERTSMA R. B.
Published: November 2004

The probability of nuclei capturing neutrons reveals sharp peaks, so‐called ‘resonances’, which occur at neutron energies that are specific for each element. These resonances are very suitable for analysing the elemental composition of objects. They are the basis of a new analytical method, ‘neutron resonance capture analysis’ (NRCA). This is a fully non‐destructive method, which is applicable to almost all stable isotopes, determines the bulk elemental composition, does not require any sample preparation and results in a negligible residual activity. Recently, NRCA has been applied in a study of a series of bronze statuettes, obtained from the National Museum of Antiquity in Leiden (NL).
Azathioprine as a Treatment for Severe Atopic Eczema in Children with a Partial Thiopurine Methyl Transferase (TPMT) Deficiency
Authors: Murphy Lesley‐Ann , Atherton David J.
Published: November 2004

Abstract:  Azathioprine is a valuable agent in the treatment of severe childhood atopic eczema. Thiopurine methyl transferase (TPMT) exhibits autosomal codominant polymorphism and plays an important role in the metabolism of azathioprine. In most large population groups studied to date, approximately 10% of the population had intermediate activity due to heterozygosity at the TPMT locus, and about 0.33% were TPMT deficient. TPMT deficiency results in the accumulation of thioguanine nucleotides and cytotoxic 6‐mercaptopurine metabolites. Previously it was considered unsafe to treat this group with azathioprine because of what was considered to be an unacceptably high risk of toxicity (profound myelosuppression). Better understanding of the pharmacogenetics of purine metabolism has changed this, and with appropriate dose adjustments, individuals who have a partial TPMT deficiency (heterozygotes) can now be treated with thiopurines. It seems probable that these individuals are more likely to have a therapeutic response while being at lower risk of developing dose‐related hepatotoxicity because of the reduced doses required to effect a therapeutic response. Two patients with severe refractory atopic eczema, both of whom had a partial TPMT deficiency, have had an excellent response to treatment with azathioprine. They were treated with half‐standard doses and response to treatment occurred within 2 weeks.
Topographic and Dipolar Analysis of Laser‐Evoked Potentials During Migraine Attack
Authors: De Tommaso Marina , Guido Marco , Libro Giuseppe , Losito Luciana , Difruscolo Olimpia , Puca Francomichele , Specchio Luigi Maria , Carella Aristide
Published: November 2004

Objective.—The aim of this study was to perform further evaluation of laser‐evoked potentials (LEPs) during migraine attacks using multichannel recording and topographic analysis. Specifically, this study aimed to confirm the pattern previously observed in acute migraine, while also defining the components of LEPs that are mainly modified during headache, as well as the correlation between features of LEPs and clinical variables. In addition, we aimed to conduct a dipolar source analysis of the main LEP waves in migraine patients to check the variability in the source location of LEPs during acute migraine.

Background.—An amplitude enhancement of LEPs was previously detected during migraine attack using a single scalp derivation on the vertex; hyperalgesia to heat stimuli was also detected for both the face and hand.

Methods.—Eighteen patients suffering from migraine without aura were analyzed. The supraorbital zones and the dorsum of the hand were stimulated on both the symptomatic and nonsymptomatic sides in all patients. The LEPs were recorded via 25 scalp electrodes. Dipolar source analysis of the P2 components was performed using a spherical model in all patients and using a realistic Magnetic Resonance model in four patients.

Results.—During attacks, the later waves, and particularly the P2 component, were significantly enhanced; the amplitude of the P2 component obtained during the attack by stimulation of the supraorbital zone on the side of the headache was significantly correlated with the intensity of pain and the frequency of headache. In our patients, the P2 wave was generated in the anterior cingulate cortex, with a shift toward its rostrocaudal portion, and was mainly devoted to elaboration of the emotive compound of pain during migraine attack.

Conclusions.—Cortical activation by laser stimuli during migraine attack was confirmed. This effect was more pronounced in patients with a higher frequency of migraine attacks. This may be due to a lack of inhibitory control over the transmission of pain to the cortex. The increased activation of cortical areas devoted to attention and emotion may be linked to headache.
Choosing Qualitative Methods for Entrepreneurial Cognition Research: A Canonical Development Approach
Authors: Hindle Kevin
Published: November 2004

This article presents a structured, manageable approach to the complex problem of how to choose, from the vast arsenal loosely labeled “qualitative methods,” sets of techniques appropriate to advancement of the emerging field of entrepreneurial cognition. Summary consideration is given to four key issues of philosophical context as a necessary predicate to presentation of a “canonical development” approach, stylized in diagrammatic form. The approach is able to accommodate due regard for both methodological controversy and operational complexity without being overwhelmed by either. Three illustrative examples indicate how use of the approach can stimulate a researcher to create productive matches between questions evolved from the entrepreneurial cognition canon and techniques selected from the complex array of qualitative methods.
Optimizing the Alliance in Couple Therapy
Authors: Symonds Dianne , Horvath Adam O.
Published: November 2004

The complexity of the relation between alliance and outcome in couple therapy was investigated in a study of 47 couples in brief therapy. Self‐rated alliance was measured after the first and third sessions using the couple version of the Working Alliance Inventory. The results indicated that the correlation between alliance and outcome was significantly stronger when the partners agreed about the strength of the alliance, when the male partner's alliance was stronger than the female's, and when the strength of both partners' alliance increased as therapy progressed. The authors suggest that a unique feature of couple therapy is that the partners have both a preexisting relationship with each other (allegiance) and an alliance with the therapist to balance.
Does nicotine affect D2 receptor upregulation? A case–control study
Authors: Silvestri S. , Negrete J. C. , Seeman M. V. , Shammi C. M. , Seeman P.
Published: November 2004

Objective:  Nicotine has a powerful preventive effect on neuroleptic‐induced dopamine D2 receptor upregulation in the rat. The aim of this human positron emission tomography (PET) study was to compare upregulation in a smoker and a non‐smoker, both of whom had received haloperidol for the same duration of time.

Method:  Two subjects who had been treated for 16 years with a constant dose of haloperidol were scanned after temporary haloperidol withdrawal, using [11C]‐raclopride.

Results:  The non‐smoker, who had received a dose of 10 mg/day, showed a D2 upregulation of 98% and developed severe and persistent symptoms of tardive dyskinesia (TD) upon withdrawal. The chronic smoker, who had been treated with 40 mg/day, displayed a D2 upregulation of 71% and did not develop TD.

Conclusion:  These human observations agree with animal data which showed that nicotine can decrease neuroleptic‐induced D2 receptor upregulation. This property of nicotine may play a protective role in movement disorders whose pathophysiology involves D2 receptor hypersensitivity.
Long‐term implant survival in the grafted maxilla: results of a 12‐year retrospective study
Authors: Yerit Kaan C. , Posch Martin , Hainich Sibylle , Turhani Dritan , Klug Clemens , Wanschitz Felix , Wagner Arne , Watzinger Franz , Ewers Rolf
Published: November 2004

Objective: The aim of this study was to determine the long‐term outcome of implant insertion in the augmented severely atrophied maxilla.

Study design: Three hundred and twenty‐four implants were inserted in 35 patients (eight males, 27 females, average age 57.6 years) in extremely atrophied maxillae after osteotomy and interposition of iliac crest bone. One hundred implants were installed in 12 patients simultaneously with the osteotomy and grafting; 224 implants were placed in 23 patients in a second procedure 6–12 months later. Implant parameters like osseointegration and peri‐implant bone loss; peri‐implant tissue parameters like bleeding, gingival and plaque index; and patients' satisfaction were evaluated.

Results: Of 324 implants, 29 (8.9%) were lost during the entire follow‐up: 14 in six patients of the one‐step and 15 in 11 patients of the two‐step group. The overall input–output survival in 141.1 months was 91.1%. The overall 2‐year failure‐free fraction of implants was 95.5%; the 5‐year failure‐free fraction was 89.3%. In the one‐step group, the 2 (5)‐year failure‐free fraction was 95.9% (86.9%), and in the two‐step group 95% (91.3%) (log‐rank test P=0.57). Marginal peri‐implant bone loss was 1.7±1.3 mm mesial and 1.8±1.3 mm distal.

Conclusion: Implant insertion after osteotomy and iliac bone grafting is a reliable operation method for the dental rehabilitation of the severely atrophied maxilla showing good long‐term results.
Safety of rituximab therapy during the first trimester of pregnancy: a case history
Authors: Kimby Eva , Sverrisdottir Asgerdur , Elinder Göran
Published: November 2004

The optimal treatment of non‐Hodgkin's lymphoma (NHL) during pregnancy is currently undefined. The potential teratogenic effects of conventional chemotherapy preclude its use during the first trimester of pregnancy. We report the case of a pregnant woman with relapsed indolent follicular NHL who was treated with rituximab (unintentionally) during the first trimester. The treatment stabilised the disease. Following an uncomplicated pregnancy, a healthy child was born at full term and careful haematological and immunological monitoring has revealed no adverse effects resulting from exposure to rituximab. Data of using rituximab during pregnancy are scarce, but the present case shows that rituximab may be one option for treatment of NHL in early pregnancy.
A novel recombinant dual human SCF expressed in and purified from silkworm, Bombyx mori, possesses higher bioactivity than recombinant monomeric human SCF
Authors: Han Junhai , Zang Yuhui , Lu Haiqin , Zhu Jie , Qin Junchuan
Published: November 2004

A novel recombinant dual human stem cell factor (rdhSCF) gene was constructed which consisted of a full‐length hSCF cDNA plus a truncated hSCF cDNA (1–145 aa), linked by a peptide (GGGGSGGGGSGG) coding region. The rdhSCF gene was cloned into baculovirus transfer vector pAcSecG2T under the polyhedrin promoter control. Silkworm larvae infected with the recombinant virus expressed rdhSCF up to 15 800 units/mL in haemolymph. The specific activity of rdhSCF purified from the haemolymph was up to 3.0 × 106 units/mg, about 8.6 times as high as that of monomer rhSCF from Escherichia coli, and about 9.1 times as high as that of monomer rhSCF from insect cell. The binding affinity of rdhSCF to the cell surface receptor was higher than that of monomer rhSCF.
Seasonal and interannual components of intrapopulation variation in clutch size and egg size of a darter
Authors: Heins D. C. , Baker J. A. , Guill J. M.
Published: November 2004

Abstract –  Previous studies have offered suggestive but sometimes conflicting glimpses at the range and patterns of seasonal and interannual variation in female darter life‐history traits. The present study examined clutch‐size and egg‐size variation from a single Mississippi population of brighteye darters (Etheostoma lynceum), collected at regular intervals over four sequential spawning seasons. Both life‐history traits were significantly correlated with body size, and they both showed significant variation within and among breeding seasons. The overall intraseasonal trends in these traits involved an increase in clutch size (CS) and a decrease in egg size from early to late periods of the spawning season. Clutch size and egg size showed a weak but significant negative correlation, which was indicative of a trade‐off between the two clutch parameters. Seasonal changes in temperature appear to be related to differing patterns of seasonal variation in egg size reported in the literature for darters. Inverse seasonal shifts in egg size and CS in the brighteye darter may represent adaptive phenotypic plasticity that allows females to produce larger, competitively superior offspring early in the reproductive season when there is low supply of food for them (parental investment hypothesis) or to produce larger eggs early in the reproductive season to ensure that each egg is adequately provisioned in the face of uncertainty (bet‐hedging hypothesis) if the food available for the young is unpredictable early in the season. Consistent with theoretical predictions, egg size showed less phenotypic variability than CS.
Melatonin reduces cholesterol accumulation and prooxidant state induced by high cholesterol diet in the plasma, the liver and probably in the aorta of C57BL/6J mice
Authors: Şener Göksel , Balkan Jale , Çevikbaş Uǧur , Keyer‐Uysal Meral , Uysal Müjdat
Published: November 2004

Abstract:  We examined the hypolipidemic and antioxidative effects of melatonin in plasma, liver and aorta of C57BL/6J mice fed on a high cholesterol (HC) diet. Mice were fed normal mice chow containing 1.5% cholesterol and 0.5% cholic acid for 4 months with or without melatonin (10 mg/L in drinking water) treatment. HC diet was observed to increase cholesterol, triglyceride and diene conjugate (DC) levels in plasma and liver. There was a tendency towards an increase in cholesterol level in the aorta following HC diet. In addition, aortic DC levels were higher than those of control group. No fatty streaks or plaques developed in the aorta of mice following HC diet, but in some sections, derangement of the endothelial layer was detected. Melatonin treatment was found to reduce plasma, liver cholesterol and DC levels as well as liver triglyceride levels in hypercholesterolemic mice. Aortic cholesterol and DC levels were also reduced in hypercholesterolemic mice when given melatonin, although not statistically significant. There were no differences in aortic histopathological findings of mice fed on a HC diet with and without melatonin treatment. In conclusion, our results indicate that melatonin reduces HC diet‐induced cholesterol accumulation and prooxidant state in the plasma, liver and probably in the aorta.
P‐3  Changes on pro‐inflammatory cytokine responses in peripheral blood during normal human pregnancy
Authors: Anna Tani , Ayako Nakajima , Dan Kinoshita , Yuka Kasai , Satoshi Yamamoto , Kazuhisa Maeda , Masahiko Maegawa , Masaharu Kamada , Minoru Irahara
Published: November 2004

Reference 1. Masahiko M, Anna T, Ayako N, Dan K, Yuka K, Satoshi Y, Kazuhisa M, Masahiko M, Masaharu K, Minoru I: Changes on pro‐inflammatory cytokine responses in peripheral blood during normal human pregnancy. Am J Reprod Immunol; 52 (Suppl.1); abstract P‐3.
Symptoms of craniomandibular disorders in elderly Brazilian wearers of complete dentures
Authors: Santos Jarbas F. F. , Marchini Leonardo , Campos Marcia S. , Damião Carlos F. , Cunha Vicente P. P. , Barbosa Célia M. R.
Published: November 2004

Objective:  Investigate the incidence of symptoms of craniomandibular disorder in elderly Brazilian wearers of full dentures.

Design:  In this cross‐sectional study, a questionnaire based on Helkimo's anamnestic index was applied to a group of 65‐year‐olds or older individuals who wear a set of full dentures.

Setting:  Interviews were carried out at the dental clinics of the University of Taubaté and the University of Vale do Paraíba, Brazil.

Subjects:  From a total of 384 patients, 84 elderly wearers of full dentures were interviewed.

Main outcome measures:  The questionnaire identified the most commonly related symptoms of craniomandibular disorders.

Results:  The patient's average age was 73.5 years (ranging from 65 to 89 years), 81% of them females. Only 5% reported pain when opening their mouths, and the same percentage complained of temporomandibular joint luxation and a sensation of tired muscles during mastication. Similar rates were found for pain in the temporomandibular joint area (6%), pain in the temporal muscle area (7%), difficulty to move the mandible in the morning (4%) and pain during excursive (protrusive and lateral) movements (8%). The highest rates were found for pain in the masseter muscle area (39%) and articular noises (24%).

Conclusion:  The incidence of craniomandibular disorder symptoms was low in this group of elderly wearers of full dentures, except for pain in the masseter (39%) and articular noises (24%).
Impact of socio‐demographic variables, oral hygiene practices, oral habits and diet on dental caries experience of Indian elderly: a community‐based study
Authors: Shah Naseem , Sundaram Karimassery R.
Published: November 2004

A number of factors influence the caries experience and the pattern of restorative care especially in the older age group.

Objective:  To evaluate the dental caries experience and restorative treatment needs of an elderly Indian population and to study the impact of socio‐demographic variables, oral hygiene practices, oral habits and dietary practices on them.

Design:  A community‐based study.

Setting:  An urban area in the south zone of Delhi and a cluster of four villages in its neighbourhood.

Subjects:  A total of 1240 elderly subjects, 716 urban and 524 rural, were included in the study.

Results:  Of the 1052 dentate elderly subjects, 676 (64.2%) had decayed teeth (66.7% root caries and 33.3% coronal caries), 69 (6.6%) had filled teeth and 17 (1.6%) had recurrent decay. Restorations were indicated in 233 (22.2%) subjects, endodontic treatment in 51 (4.8%) and extractions in 424 (40.3%). Urban–rural differences in caries experience were statistically significant. Multivariate regression analysis showed that dental caries was associated with literacy level, oral hygiene practices, oral health perception and diet, while previous restorative treatment was correlated only with location (urban–rural) and presence or absence of systemic diseases.

Conclusion:  Dental caries prevalence was high amongst the studied elderly population and significant differences were observed in those living in a rural compared with an urban setting. Only a small percentage of elderly had evidence of previous restorative treatment whereas their unmet treatment need was significant.
Priapism as a presentation of T‐cell acute lymphoblastic leukaemia in a child
Authors: Werther Rebecca , Oakley Edward , Heath John A
Published: November 2004

We report a case of a child who presented to the ED with priapism. This was the initial presentation of T‐cell acute lymphoblastic leukaemia (ALL). To our knowledge, this is the first report of a child with T‐cell ALL presenting with priapism. This case demonstrates the importance of identifying the underlying cause of priapism, as it directly impacts on both initial and ongoing management.
Specific training in clinical forensic medicine is useful to ACEM trainees
Authors: Young Simon , Wells David , Summers Ian
Published: November 2004

Objective:  To assess the effectiveness of a 6‐month rotation in forensic medicine in developing medicolegal and forensic skills for doctors training for a fellowship with the Australasian College for Emergency Medicine (ACEM).

Methods:  Over a period of 6 years 12 trainees undertook a 6‐month rotation with the Victorian Institute of Forensic Medicine (VIFM) as a clinical forensic registrar. These 12 trainees were surveyed and asked structured questions regarding their perception of the usefulness of the training and the impact of the rotation on their professional development.

Results:  Twelve replies were received (100% response rate). All respondents felt that the term had a major positive influence on their ability to examine victims of physical and sexual assault, obtain forensic specimens and prepare a medicolegal report.

Conclusions:  A 6‐month rotation in clinical forensic medicine improves ACEM trainees perceived ability to perform a number of medicolegal tasks without interfering with other areas of professional development.
Effects of Anticancer Chemotherapeutic Drugs on the Acetylcholine Receptor‐Operated Potassium Current in Guinea Pig Atrial Myocytes
Authors: Hara Yukio , Kizaki Keiichiro , Temma Kyosuke , Chugun Akihito , Kondo Hiroshi
Published: November 2004

Abstract: The effects of 7 anticancer chemotherapeutic drugs on the muscarinic acetylcholine receptor‐operated potassium current (IK.ACh) in guinea pig atrial myocytes were investigated using the whole cell patch clamp technique. Doxorubicin, pirarubicin, and mitoxantrone inhibited the carbachol‐induced IK.ACh in a concentration‐dependent manner in atrial cells at a holding potential of −40 mV. IC50 values of doxorubicin, pirarubicin, and mitoxantrone for the carbachol‐induced IK.ACh were 7.7 μM, 3.7 μM, and 9.1 μM, respectively. Pirarubicin inhibited the adenosine‐induced and the GTPγS‐induced IK.ACh in a concentration‐dependent manner (IC50=6.0 and 5.1 μM, respectively). Doxorubicin and mitoxantrone up to 100 μM did not have an influence on the adenosine‐induced IK.ACh. Doxorubicin did not affect the GTPγS‐induced IK.ACh. Mitoxantrone 100 μM inhibited the current only by 25%. For concentrations up to 100 μM, anticancer drugs that have chemical structures entirely different from that of doxorubicin, i.e., 5‐fluorouracil, 6‐mercaptopurine, cyclophosphamide, and actinomycin D, did not have an influence on the carbachol‐induced IK.ACh. Doxorubicin and chemically related compounds possess anticholinergic effects mediated via an inhibitory action on IK.ACh by different underlying molecular mechanisms. Doxorubicin and mitoxantrone may inhibit IK.ACh by the blockade of muscarinic receptors, whereas pirarubicin may inhibit the current not only via blocking the muscarinic receptors but also by depressing the functions of the K+ channel itself and/or GTP‐binding proteins.
Observation of Femtosecond Laser-Induced Ablation in Crystalline Silicon
Authors: Choi Tae Y. , Grigoropoulos Costas P.
Published: November 2004

The ablation of crystalline silicon by ultrashort laser pulses is studied experimentally. A pump-and-probe experiment is implemented in a collinear arrangement, utilizing a time-delayed frequency-doubled probe beam for in situ reflectance measurement and ultrafast microscopy observation. Enhanced surface reflectivity in sub-picosecond time scale at the center of the irradiated spot indicates nonthermal liquid layer formation. A short-lived nonthermal liquid phase was detected at fluence of 1.5J/cm2. In addition to this observation, the reflected images for pump beam fluences ranging from 1.5 to 4.6J/cm2 provide evidence of plasma expansion above the irradiated target.
Thermal Characteristics of Microscale Fractal-Like Branching Channels
Authors: Alharbi Ali Y. , Pence Deborah V. , Cullion Rebecca N.
Published: November 2004

Heat transfer through a fractal-like branching flow network is investigated using a three-dimensional computational fluid dynamics approach. Results are used for the purpose of assessing the validity of, and providing insight for improving, assumptions imposed in a previously developed one-dimensional model for predicting wall temperature distributions through fractal-like flow networks. As currently modeled, the one-dimensional code fairly well predicts the general wall temperature trend simulated by the three-dimensional model; hence, demonstrating its suitability as a tool for design of fractal-like flow networks. Due to the asymmetry in the branching flow network, wall temperature distributions for the proposed branching flow network are found to vary with flow path and between the various walls forming the channel network. Three-dimensional temperature distributions along the various walls in the branching channel network are compared to those along a straight channel. Surface temperature distributions on a heat sink with a branching flow network and a heat sink with a series of straight, parallel channels are also analyzed and compared. For the same observed maximum surface temperature on these two heat sinks, a lower temperature variation is noted for the fractal-like heat sink.
Feasibility of High Speed Furnace Drawing of Optical Fibers
Authors: Cheng Xu , Jaluria Yogesh
Published: November 2004

The domain of operating conditions, in which the optical fiber-drawing process is successful, is an important consideration. Such a domain is mainly determined by the stresses acting on the fiber and by the stability of the process. This paper considers an electrical resistance furnace for fiber drawing and examines conditions for process feasibility. In actual practice, it is known that only certain ranges of furnace temperature and draw speed lead to successful fiber drawing. The results obtained here show that the length of the heated zone and the furnace temperature distribution are other important parameters that can be varied to obtain a feasible process. Physical behavior close to the boundary of the feasible domain is also studied. It is found that the iterative scheme for neck-down profile determination diverges rapidly when the draw temperature is lower than that at the acceptable domain boundary due to the lack of material flow. However, the divergence rate becomes much smaller as the temperature is brought close to the domain boundary. Additional information on the profile determination as one approaches the acceptable region is obtained. It is found that it is computationally expensive and time-consuming to locate the exact boundary of the feasible drawing domain. From the results obtained, along with practical considerations of material rupture, defect concentration, and flow instability, an optimum design of a fiber-drawing system can be obtained for the best fiber quality.
Teichoic Acid Is an Essential Polymer in
Bacillus subtilis
That Is Functionally Distinct from Teichuronic Acid
Authors: Bhavsar Amit P. , Erdman Laura K. , Schertzer Jeffrey W. , Brown Eric D.
Published: November 2004

Wall teichoic acids are anionic, phosphate-rich polymers linked to the peptidoglycan of gram-positive bacteria. In
Bacillus subtilis
, the predominant wall teichoic acid types are poly(glycerol phosphate) in strain 168 and poly(ribitol phosphate) in strain W23, and they are synthesized by the
tag
and
tar
gene products, respectively. Growing evidence suggests that wall teichoic acids are essential in
B. subtilis
; however, it is widely believed that teichoic acids are dispensable under phosphate-limiting conditions. In the work reported here, we carefully studied the dispensability of teichoic acid under phosphate-limiting conditions by constructing three new mutants. These strains, having precise deletions in
tagB
,
tagF
, and
tarD
, were dependent on xylose-inducible complementation from a distal locus (
amyE
) for growth. The
tarD
deletion interrupted poly(ribitol phosphate) synthesis in
B. subtilis
and represents a unique deletion of a
tar
gene. When teichoic acid biosynthetic proteins were depleted, the mutants showed a coccoid morphology and cell wall thickening. The new wall teichoic acid biogenesis mutants generated in this work and a previously reported
tagD
mutant were not viable under phosphate-limiting conditions in the absence of complementation. Cell wall analysis of
B. subtilis
grown under phosphate-limited conditions showed that teichoic acid contributed approximately one-third of the wall anionic content. These data suggest that wall teichoic acid has an essential function in
B. subtilis
that cannot be replaced by teichuronic acid.
Rubrerythrin from the Hyperthermophilic Archaeon
Pyrococcus furiosus
Is a Rubredoxin-Dependent, Iron-Containing Peroxidase
Authors: Weinberg Michael V. , Jenney Francis E. , Cui Xiaoyuan , Adams Michael W. W.
Published: November 2004

Rubrerythrin was purified by multistep chromatography under anaerobic, reducing conditions from the hyperthermophilic archaeon
Pyrococcus furiosus
. It is a homodimer with a molecular mass of 39.2 kDa and contains 2.9 ± 0.2 iron atoms per subunit. The purified protein had peroxidase activity at 85°C using hydrogen peroxide with reduced
P. furiosus
rubredoxin as the electron donor. The specific activity was 36 μmol of rubredoxin oxidized/min/mg with apparent

K
m

values of 35 and 70 μM for hydrogen peroxide and rubredoxin, respectively. When rubrerythrin was combined with rubredoxin and
P. furiosus
NADH:rubredoxin oxidoreductase, the complete system used NADH as the electron donor to reduce hydrogen peroxide with a specific activity of 7.0 μmol of H
2
O
2
reduced/min/mg of rubrerythrin at 85°C. Strangely, as-purified (reduced) rubrerythrin precipitated when oxidized by either hydrogen peroxide, air, or ferricyanide. The gene (PF1283) encoding rubrerythrin was expressed in
Escherichia coli
grown in medium with various metal contents. The purified recombinant proteins each contained approximately three metal atoms/subunit, ranging from 0.4 Fe plus 2.2 Zn to 1.9 Fe plus 1.2 Zn, where the metal content of the protein depended on the metal content of the
E. coli
growth medium. The peroxidase activities of the recombinant forms were proportional to the iron content.
P. furiosus
rubrerythrin is the first to be characterized from a hyperthermophile or from an archaeon, and the results are the first demonstration that this protein functions in an NADH-dependent, hydrogen peroxide:rubredoxin oxidoreductase system. Rubrerythrin is proposed to play a role in the recently defined anaerobic detoxification pathway for reactive oxygen species.
Vibrio cholerae
Strains with Mutations in an Atypical Type I Secretion System Accumulate RTX Toxin Intracellularly
Authors: Boardman Bethany Kay , Fullner Satchell Karla J.
Published: November 2004

This study shows that the
Vibrio cholerae
RTX toxin is secreted by a four-component type I secretion system (TISS) encoded by
rtxB
,
rtxD
,
rtxE
, and
tolC
. ATP-binding site mutations in both RtxB and RtxE blocked secretion, demonstrating that this atypical TISS requires two transport ATPases that may function as a heterodimer.
The Chemical Chaperone Proline Relieves the Thermosensitivity of a
dnaK
Deletion Mutant at 42°C
Authors: Chattopadhyay Madhab K. , Kern Renée , Mistou Michel-Yves , Dandekar Abhaya M. , Uratsu Sandra L. , Richarme Gilbert
Published: November 2004

Since, like other osmolytes, proline can act as a protein stabilizer, we investigated the thermoprotectant properties of proline in vitro and in vivo. In vivo, elevated proline pools in
Escherichia coli
(obtained by altering the feedback inhibition by proline of γ-glutamylkinase, the first enzyme of the proline biosynthesis pathway) restore the viability of a
dnaK
-deficient mutant at 42°C, suggesting that proline can act as a thermoprotectant for
E. coli
cells. Furthermore, analysis of aggregated proteins in the
dnaK
-deficient strain at 42°C by two-dimensional gel electrophoresis shows that high proline pools reduce the protein aggregation defect of the
dnaK
-deficient strain. In vitro, like other “chemical chaperones,” and like the DnaK chaperone, proline protects citrate synthase against thermodenaturation and stimulates citrate synthase renaturation after urea denaturation. These results show that a protein aggregation defect can be compensated for by a single mutation in an amino acid biosynthetic pathway and that an ubiquitously producible chemical chaperone can compensate for a defect in one of the major chaperones involved in protein folding and aggregation.
A NEW MODEL OF NEURAL ASSOCIATIVE MEMORIES
Authors: HAO JIANBIN , VANDEWALLE JOOS
Published: November 2004

In this paper, we present a new model of discrete neural associative memories and its design rule. The most important feature of this new model is that a static mapping instead of the dynamic convergent process is used to retrieve the stored messages. The new model features a two-layer structure, with feedforward connections only and uses two kinds of neurons which implement different output functions. Another important feature is that this new model employs an extremely simple weight setup rule and all the resulted weights can only assume two different values, −1 and +1, which facilitates the VLSI implementation. Compared to the famous discrete Hopfield model designed with the well-known Hebbian rule or any other rule, the new model can guarantee all the given patterns to be stored as fixed points. Moreover, each fixed point is surrounded by an attraction basin (which is a ball in the Hamming distance sense) with the maximal possible radius. The performances of the new model are compared through some illustrative examples with those of the Hopfield associative memory designed using different methods.
LEARNING TEMPORAL SEQUENCES FROM EXAMPLES IN A LOCAL FEEDBACK NEURAL NETWORK
Authors: BRESSLOFF PAUL C.
Published: November 2004

Statistical-mechanical techniques are used to study temporal sequence association in a local feedback neural network consisting of an input layer of context units and a single output unit. Each context unit has a feedback connection onto itself such that it accumulates an exponentially decaying moving average or trace of previous inputs to that unit. The formation of these traces allows the network to extract temporal information over an interval δ, where δ=1/|ln γ| and γ is the decay-rate of the moving average. The particular problem of learning a rule from examples is considered where the rule is generated by a teacher local feedback network. The replica method and other mean-field theory techniques are used to determine how the resulting generalization error of the network varies as a function of sequence length M and decay-rate γ.
MODEL REFERENCE DIRECT ADAPTIVE CONTROL OF NONLINEAR PLANTS USING NEURAL NETWORKS
Authors: BAHRAMI MOHAMMAD , TAIT KEITH E.
Published: November 2004

A learning scheme for multilayer feedforward neural networks used as direct adaptive controllers of nonlinear plants is suggested. This scheme is a supervised steepest descent one that does not require backpropagation of the error. Using a neural network controller trained with this method does not require the identification stage and this makes it superior to the other methodologies. Methods for using neural networks in plant control suggested in the literature are discussed and compared with the proposed system. The structure of the network and the training method used are explained. Simulations based on model reference control of some nonlinear plants show satisfactory performance.
GELFAND-TSETLIN PRINCIPLE OF MINIMAL AFFERENTATION AND BISTABILITY OF DENDRITES
Authors: GUTMAN ARON
Published: November 2004

Neurons with bistable dendrites may fire persistently without persistent synaptic excitation while transient afferentation shifts the frequency of the persistent firing. These neurons change the firing frequency until they minimize their afferential input in a properly designed network. The afferentation minimum in this network is a stable state. The concept of the stable afferentation minimum generalizes Feldman’s spring model of muscle control. An oversimplified network imitating the γ-loop demonstrates the above statements.
Letter to the Editor: A STORAGE ALGORITHM FOR TWO-LAYERED NEURAL NETWORKS
Authors: MONASSON R.
Published: November 2004

A learning algorithm for the two-layered committee machine is proposed. The proof of its convergence in a finite time is given. Its efficiency is compared to the simple exhaustive enumeration of the internal representations of the training set.
SUPERVISED TRAINING OF DYNAMICAL NEURAL NETWORKS FOR ASSOCIATIVE MEMORY DESIGN AND IDENTIFICATION OF NONLINEAR MAPS
Authors: SUDHARSANAN SUBRAMANIA I. , SUNDARESHAN MALUR K.
Published: November 2004

Complexity of implementation has been a major difficulty in the development of gradient descent learning algorithms for dynamical neural networks with feedback and recurrent connections. Some insights from the stability properties of the equilibrium points of the network, which suggest an appropriate tailoring of the sigmoidal nonlinear functions, can however be utilized in obtaining simplified learning rules, as demonstrated in this paper. An analytical proof of convergence of the learning scheme under specific conditions is given and some upper bounds on the adaptation parameters for an efficient implementation of the training procedure are developed. The performance features of the learning algorithm are illustrated by applying it to two problems of importance, viz., design of associative memories and nonlinear input-output mapping. For the first application, a systematic procedure is given for training a network to store multiple memory vectors as its stable equilibrium points, whereas for the second application, specific training rules are developed for a three-layer network architecture comprising a dynamical hidden layer for the identification of nonlinear input-output maps. A comparison with the performance of a standard backpropagation network provides an illustration of the capabilities of the present network architecture and the learning algorithm.
STORAGE CAPACITY BOUNDS IN MULTILAYER NEURAL NETWORKS
Authors: WENDEMUTH ANDREAS
Published: November 2004

General analytic expressions are given for the lower and upper storage capacity bounds of multilayer neural networks which have variable weights between input layer and first hidden layer, and a fixed output function implemented between first hidden and output layer. The special cases of committee and parity machines as well as the limiting cases of networks with minimum and maximum storage capacities are discussed. The results are compared with replica calculations and simulations. An explanation is given as to why the latter have a storage capacity just slightly above the lower limit and how this can be improved.
CONSTRAINED POTTS MEAN FIELD SYSTEMS AND THEIR ELECTRONIC IMPLEMENTATION
Authors: URAHAMA KIICHI , YAMADA TADASHI
Published: November 2004

The Potts mean field approach for solving combinatorial optimization problems subject to winner-takes-all constraints is extended for problems subject to additional constraints. Extra variables corresponding to the Lagrange multipliers are incorporated into the Potts formulation for the additional constraints to be satisfied. The extended Potts equations are solved by using constrained gradient descent differential systems. This gradient system is proven theoretically to always produce a legal local optimum solution of the constrained combinatorial optimization problems. An analog electronic circuit implementing the present method is designed on the basis of the previous Potts electronic circuit. The performance of the present method is theoretically evaluated for the constrained maximum cut problems. The lower bound of the cut size obtained with the present method is proven to be the same as that of the basic Potts scheme for the unconstrained maximum cut problems.
Letter to the Editor: RESPONSE CLASSIFICATION IN PSYCHOLOGICAL TESTING USING A NEURAL NETWORK
Authors: SAMS THOMAS , LAURSEN PETER , ESKELINEN LEENA
Published: November 2004

A feedforward neural network with error backpropagation has been designed to recognize hand-drawn patterns in a cognitive test. The architecture uses both position and direction sensitivity in the input layer. The training set consisted of 659 icons which were shifted horizontally and vertically to give a total training set of 5931 icons. In testing on an independent set of 31,192 icons produced by 557 subjects from a Danish standard population sample, the rate of misclassification was 0.12% compared with an average rate of sequence errors of 1.6%.
TRIO LEARNING: A NEW STRATEGY FOR BUILDING HYBRID NEURAL TREES
Authors: D’ALCHÉ-BUC FLORENCE , ZWIERSKI DIDIER , NADAL JEAN-PIERRE
Published: November 2004

Neural trees are constructive algorithms which build decision trees whose nodes are binary neurons. We propose a new learning scheme, “trio-learning,” which leads to a significant reduction in the tree complexity. In this strategy, each node of the tree is optimized by taking into account the knowledge that it will be followed by two son nodes. Moreover, trio-learning can be used to build hybrid trees, with internal nodes and terminal nodes of different nature, for solving any standard tasks (e.g. classification, regression, density estimation). Significant results on a handwritten character classification are presented.
RELATIONSHIP BETWEEN A FUZZY LOGIC AND A STEEPEST DESCENT APPROACH TO OPTIMIZE A FEEDFORWARD ARTIFICIAL NEURAL NETWORK CONFIGURATION
Authors: SHARPE ROBERT N. , CHOW MO-YUEN
Published: November 2004

The neural network designer must take into consideration many factors when selecting an appropriate network configuration. The performance of a given network configuration is influenced by many different factors such as: accuracy, training time, sensitivity, and the number of neurons used in the implementation. Using a cost function based on the four criteria mentioned previously, the various network paradigms can be evaluated relative to one another. If the mathematical models of the evaluation criteria as functions of the network configuration are known, then traditional techniques (such as the steepest descent method) could be used to determine the optimal network configuration. The difficulty in selecting an appropriate network configuration is due to the difficulty involved in determining the mathematical models of the evaluation criteria. This difficulty can be avoided by using fuzzy logic techniques to perform the network optimization as opposed to the traditional techniques. Fuzzy logic avoids the need of a detailed mathematical description of the relationship between the network performance and the network configuration, by using heuristic reasoning and linguistic variables. A comparison will be made between the fuzzy logic approach and the steepest descent method for the optimization of the cost function. The fuzzy optimization procedure could be applied to other systems where there is a priori information about their characteristics.
DISCRIMINATIVE NONLINEAR DIMENSIONALITY REDUCTION FOR IMPROVED CLASSIFICATION
Authors: DOLSON MARK
Published: November 2004

Multi-Layer Perceptron (MLP) neural networks have been used extensively for classification tasks. Typically, the MLP network is trained explicitly to produce the correct classification as its output. For speech recognition, however, several investigators have recently experimented with an indirect approach: a unique MLP predictive network is trained for each class of data, and classification is accomplished by determining which predictive network serves as the best model for samples of unknown speech. Results from this approach have been mixed.

In this report, we compare the direct and indirect approaches to classification from a more fundamental perspective. We show how recent advances in nonlinear dimensionality reduction can be incorporated into the indirect approach, and we show how the two approaches can be integrated in a novel MLP framework. We further show how these new MLP networks can be usefully viewed as generalizations of Learning Vector Quantization (LVQ) and of subspace methods of pattern recognition. Lastly, we show that applying these ideas to the classification of temporal trajectories can substantially improve performance on simple tasks.