bluuebunny/crossref_metadata_2025 huggingface dataset:
Transscleral red‐laser cyclophotocoagulation combined with limited anterior retinal cryocoagulation in neovascular glaucoma
Authors: Raivio Virpi E. , Immonen Ilkka J. R. , Puska Päivi M.
Published: September 2006

Purpose:  To evaluate transscleral contact red‐laser cyclophotocoagulation (CPC), using a visible red 647‐nm krypton or 670‐nm diode laser and limited transscleral anterior retinal cryocoagulation in neovascular glaucoma.

Methods:  In a retrospective case series, 35 eyes of 35 consecutive patients treated during a period of 6 years were included in the study. Inclusion was dependent on follow‐up of at least 1 month. Patients who had undergone previous cyclodestructive procedures and patients who received an additional glaucoma operation in conjunction with CPC were excluded. In the combined procedure, the power per CPC application was 370–450 mW and exposure time was 10 seconds. One to two rows of cryoapplications were given to 360 degrees of the anterior retina.

Results:  The success rate in terms of intraocular pressure (IOP of 8–21 mmHg or a decrease in IOP > 30%) was 89% at the last follow‐up (17 ± 15 months). Iris neovascularization regressed in 51% of eyes. Hypotonia developed in one (3%) eye (IOP of 5 mmHg). No cases of phthisis bulbi were seen. Visual acuity (VA) declined in 49% of eyes.

Conclusions:  A combination of transscleral contact red‐laser CPC with limited anterior retinal cryocoagulation is efficient in lowering IOP in neovascular glaucoma and is well tolerated. During follow‐up, a decrease in VA occurs in a significant proportion of patients.
The Wnt‐signaling pathway is not implicated in tumorigenesis of Merkel cell carcinoma
Authors: Liu Shuang , Daa Tsutomu , Kashima Kenji , Kondoh Yoshiyuki , Yokoyama Shigeo
Published: September 2006

Background:  The Wnt‐signaling pathway, involving β‐catenin, apc, and axin, plays a critical role in numerous developmental events. Alterations in the Wnt‐signaling pathway have been detected in a wide variety of neoplasms. However, similar aberrations have not been described in Merkel cell carcinoma (MCC). The aim of this study was to determine the status of the Wnt‐signaling pathway in MCC.

Methods:  Twelve cases of MCC were tested for the expression of β‐catenin and mutational status of CTNNB1 (gene for β‐catenin), APC, AXIN1, and AXIN2. Genomic DNA extracted from paraffin blocks was subjected to a polymerase chain reaction/single‐strand conformation polymorphism analysis and sequencing.

Results:  Nuclear accumulation of β‐catenin was observed in only one case (8.3%), as determined by immunochemistry. No mutations were found in CTNNB1, APC, and AXIN2 in all cases, although silent mutations in AXIN1 were detected in three cases.

Conclusions:  We conclude that the Wnt‐signaling pathway does not play an important role in tumorigenesis in MCC.
Changes of epidermodysplasia verruciformis in benign skin lesions: the EV acanthoma
Authors: Ko Christine J. , Iftner Thomas , Barr Ronald J. , Binder Scott W.
Published: September 2006

Abstract:  Foci of histological changes of epidermodysplasia verruciformis (EV) were noted in five benign skin lesions. These skin lesions included an intradermal nevus, a pigmented seborrheic keratosis, an isolated papule on the forearm, a perianal lesion, and an acantholytic acanthoma. Because the changes resembled true EV so strongly despite the absence of clinical EV in these patients, we searched for EV‐human papilloma virus (HPV) types in these skin lesions. Polymerase chain reaction (PCR) analysis on the formalin‐fixed, paraffin‐embedded blocks was performed. As a positive control, we included tissue from two HIV‐positive patients with clinical EV proven by biopsy. Studies were also performed on five other archived biopsies that did not show changes of EV on multiple tissue sections. A nested PCR method detected EV‐HPV types in three of the five benign skin lesions showing EV changes as well as in the positive controls. EV changes and EV‐HPV can be found incidentally on biopsy in the absence of clinical EV; when such changes are the major histopathological finding in an isolated skin lesion, the lesion should be termed an EV acanthoma.
Congenital linear unilateral basal cell nevus: a case report with patched gene molecular studies
Authors: Brailey L. L. , Davis T. , Kolker S. E. , Murry T. C. , Thomas D. , Bale A. E. , Ruhoy S. M.
Published: September 2006

Background:  Linear unilateral basal cell nevus represents a linear collection of macules and papules histologically similar to basal cell carcinoma but with benign clinical behavior. We describe a patient who initially presented at the age of 6 months with a unilateral linear basal cell nevus on the right flank. The differential diagnosis included the nevoid basal cell carcinoma syndrome. Constitutional PTCH mutations are causative of the nevoid basal cell carcinoma syndrome, and somatic PTCH mutations are found in the vast majority of basal cell carcinomas. Somatic SMO mutations have also been found in some basal cell carcinomas.

Methods:  Histologic examination of the lesions is performed. Short tandem‐repeat molecular analysis at the PTCH locus and sequencing of PTCH and SMO genes is performed.

Results:  Histologic examination revealed features initially indistinguishable from basal cell carcinoma. Short tandem‐repeat DNA analysis did not reveal loss of heterozygosity at the PTCH locus. DNA sequencing of both the PTCH and the SMO genes from the patient’s lesions revealed neither inactivating mutations of PTCH nor activating mutations of SMO.

Conclusion:  Molecular examination indicates that the PTCH and SMO genes are not involved in the pathogenesis of the patients’ congenital linear unilateral basal cell nevus. Furthermore, we discuss the relationship between linear basal cell nevus and basaloid follicular hamartoma.
Inflammatory cytokines induce the transformation of human dermal microvascular endothelial cells into myofibroblasts: a potential role in skin fibrogenesis
Authors: Chaudhuri V. , Zhou L. , Karasek M.
Published: September 2006

Background:  The myofibroblast plays a central role in wound contraction and in the pathology of fibrosis. The origin(s) of this important cell type in skin has not been firmly established.

Methods:  Human epithelioid dermal microvascular endothelial cells (HDMEC) were isolated from foreskin tissue and maintained in cell culture. The transformation of epithelioid HDMEC into myofibroblasts (EMT) was induced by the inflammatory cytokines interleukin‐1β (IL‐1β) or tumour necrosis factor‐α (TNF‐α), and the transformed cells were characterized by electron microscopy, immunohistochemistry and quantitative RT‐PCR.

Results:  After short‐term exposure to IL‐1β or TNF‐α (<3 days), EMT was reversible; after long‐term exposure (>10 days), EMT was permanent. The transformed cells were identified as myofibroblasts by cytoplasmic microfilaments with dense bodies and attachment plaques, by the expression of α‐smooth muscle actin, type I collagen and calponin, and by quantitative RT‐PCR gene expression of type I collagen and α‐smooth muscle actin.

Conclusions:  Long‐term exposure to TNF‐α or IL‐1β induced the permanent transformation of HDMEC into myofibroblasts in cell culture. A similar transformation following chronic inflammatory stimulation in vivo may explain one source of myofibroblasts in skin fibrogenesis.
P63 expression pattern during rat epidermis morphogenesis and the role of p63 as a marker for epidermal stem cells
Authors: Kai‐Hong Ji , Jun Xiong , Kai‐Meng Hu , Ying Wang , Hou‐Qi Liu
Published: September 2006

Background:  Recent evidence has suggested that p63 plays a particular role in maintaining the population of epidermal stem cells (ESCs), but the expression pattern of p63 during normal rat epidermis development is still unknown. We investigated the expression of p63 during development and differentiation of rat epidermis and identified whether p63 is a specific marker of rat ESCs cultured in vitro.

Methods:  Skin biopsies were obtained from embryonic day (E) 12 rat embryo, newborn, and 4‐week‐old rats. Immunohistochemistry was used to monitor the expression profile of p63. ESCs were isolated from newborn rat epidermis by rapid adhesion to IV collagen and examined by immunofluorescence staining to detect p63 and k14 expression.

Results:  P63 expression was first observed at E12 when the epidermis was only a simple‐layer surface ectoderm. P63 continued to be expressed as the epidermis matured but restricted to the basal layer. In adult trunk epidermis, p63 was expressed in both the hair follicle and the sebaceous glands. Immunofluorescence staining for ESCs was double positive for p63 and k14.

Conclusions:  These expression data suggest a role of p63 in the development of rat epidermis. P63 transcription factor may be a specific marker of keratinocyte progenitor cells.
Dermatopathic lymphadenitis of the head and neck
Authors: Winter Leslie K. , Spiegel Jeffrey H. , King Thomas
Published: September 2006

Abstract:  Dermatopathic lymphadenitis is a histopathologic diagnosis of patients with enlarged lymph nodes classically in the setting of a variety of inflammatory erthrodermas without known malignancy. While considered a benign histopathologic finding, differentiation of this disorder from mycosis fungoides or lymphoma can be difficult.
Effect of PUVA, narrow‐band UVB and cyclosporin on inflammatory cells of the psoriatic plaque
Authors: Erkin Gul , Uğur Yeşim , Gürer Cansel Köse , Aşan Esin , Korkusuz Petek , Şahin Sedef , Kölemen Fikret
Published: September 2006

Background:  Because antigen presenting is necessary for T‐cell activation, antigen‐presenting cells should be involved in the pathogenesis of psoriasis. In this study, our purpose was to evaluate and compare effects of PUVA, cyclosporine A and narrow‐band UVB on dendritic cells and activated lymphocytes in the psoriatic lesions.

Methods:  Forty‐five volunteered patients (15 patients in each treatment group as PUVA, cyclosporin A and narrow‐band UVB) were enrolled in this study. Lesional skin biopsies were taken from each patient before and after treatments. Fresh frozen biopsies were studied for the expressions of CD1a, CD68, CD86, CD4, CD8 and HLA‐DR proteins by immunohistochemistry.

Results:  There was no correlation between severity of the lesions and expressions of the antigens. Only PUVA significantly decreased CD1a+ epidermal Langerhans cells' (LCs) counts. Treatment modalities decreased expression of costimulator CD86, and most of them decrease antigen‐presenting capacity of skin by decreasing HLA class‐II expression.

Conclusions:  All treatment modalities equally reduce lymphocytes, macrophages and dendritic cells. PUVA is the only treatment that decreases epidermal LCs. All treatments effectively diminish expression of CD86 and inhibit this step of inflammation.
Habitat and food choice of Arctic charr in Linnévatn on Spitsbergen, Svalbard: the first year‐round investigation in a High Arctic lake
Authors: Svenning M.‐A. , Klemetsen A. , Olsen T.
Published: September 2006

Abstract –  Habitat and diet of Arctic charr Salvelinus alpinus (L.) were studied by monthly sampling from late autumn to early summer in Linnévatn, Svalbard (78°3′N, 13°50′E). This is the first year‐round study of a population of charr in the High Arctic, with samples being taken every 5–7 weeks. The ice cover lasted for more than 9 months, from mid‐October to late July, with the greatest thickness in mid‐May. Although most charr occupied the littoral zone during winter, the highest densities in April and October were found in the deeper areas (20 m) of the lake. The fish fed at all times of the year, but the number of stomachs with food and the stomach‐filling indices were lowest during the darkest part of the season. The diet of smaller charr (<15 cm) varied strongly with season, showing a dominance of zooplankton in late autumn and chironomids in winter (larvae) and summer (pupae). The food choice was in accordance with the density of food items available. Larger fish (≥15 cm) were mostly cannibalistic during the entire year.
Mixed testicular germ cell tumor presenting as metastatic pure choriocarcinoma involving the maxillary gingiva
Authors: Scolozzi P. , Marret N. , Bouzourene H. , Luthi F. , Bauer J. , Jaques B. , Lombardi T.
Published: September 2006

Gingival metastases are infrequent and invariably associated with a widespread disease and a poor prognosis. Because of their unremarkable clinical appearance, they can be difficult to distinguish from more common gingival hyperplastic or reactive lesions, such as pyogenic granuloma, peripheral giant cell granuloma, and peripheral ossifying granuloma. We are reporting here an unusual case of a 36‐year‐old man with a mixed testicular germ cell tumor presenting as a metastatic pure choriocarcinoma involving the maxillary gingiva, extending from the first left premolar to the left second maxillary molar, mimicking a ‘benign looking’ gingival mass. Gingival metastases may be the first manifestation of a widespread metastatic disease and therefore particular attention must be paid to gingival lesions associated with atypical clinical symptoms and/or signs.
Synchronous ameloblastoma and orthokeratinized odontogenic cyst of the mandible
Authors: Fregnani Eduardo Rodrigues , Da Cruz Perez Danyel Elias , Soares Fernando Augusto , Alves Fábio Abreu
Published: September 2006

The simultaneous occurrence of ameloblastomas with odontogenic cysts or other non‐odontogenic lesions have already been described as combined lesions. However, we are unaware of any report in the English literature of simultaneous occurrence of ameloblastoma and orthokeratinized odontogenic cyst (OOC) occurring as completely distinct lesions. This report shows a case of synchronous ameloblastoma and OOC, located on posterior regions of the mandible, but in distinct sides.
Matrix metalloproteinase‐7, ‐8, ‐9, ‐25, and ‐26 and CD43, ‐45, and ‐68 cell‐markers in HIV‐infected patients’ saliva and gingival tissue
Authors: Mellanen Liisa , Lähdevirta Juhani , Tervahartiala Taina , Meurman Jukka H. , Sorsa Timo
Published: September 2006

Background:  Matrix metalloproteinases (MMPs) process the extracellular matrix and act in tissue remodelling in many physiological and pathological conditions. Certain MMPs can also exert protective anti‐inflammatory properties. The levels and expression of MMPs and tissue inhibitors of MMPs (TIMPs) in saliva and gingival tissues of human immunodeficiency virus‐seropositive (HIV+) patients are unclear.

Methods:  Enzyme‐linked immunosorbent assay methods and Western blots were used to study levels and molecular forms of MMP‐7, ‐8, ‐9, ‐25, and ‐26 and TIMP‐1 from salivary samples of HIV+ patients (n = 55) and healthy controls (n = 10). The expression of MMPs was also studied by immunohistochemical means in gingival tissue specimens (n = 11, HIV+ patients; n = 10, healthy controls).

Results:  The HIV+ patients’ MMP‐8 levels in saliva were statistically significantly higher only in the acquired immunodeficiency syndrome (AIDS)‐phase. MMP‐9 levels in ASX‐ and AIDS‐phases showed increased expression. TIMP‐1 levels were significantly decreased in lymphadenopathy syndrome (LAS)‐ and AIDS‐related complex (ARC)‐phases, while MMP‐8/TIMP‐1 and MMP‐9/TIMP‐1 molar ratios were increased in all phases in comparison with controls. The molecular forms of MMP‐7, ‐25, and ‐26 were different between patients and controls as assessed by Western blot. Immunohistochemical studies showed slightly enhanced MMP‐7, ‐8, ‐9, ‐25, and ‐26 staining in HIV+ gingival tissue samples in comparison with controls.

Conclusions:  This study confirmed and further demonstrated differences in salivary amounts and molecular forms of MMPs and TIMP‐1 in HIV+ patients. The results may reflect alterations in host defence reactions associated with HIV infection.
Oral shedding of herpes simplex virus type 1 in immunocompetent persons
Authors: Gilbert Stanley C.
Published: September 2006

Background:  Reactivation of herpes simplex virus‐1 (HSV‐1) can result in recurrent herpes labialis lesions (RHL) and in oral shedding of virus. This study utilized polymerase chain reaction (PCR) to document the frequency and quantity of such shedding.

Methods:  Thirty adults with greater than three RHL episodes per year were followed through one recurrence. They collected swabs for PCR every 12 h starting at prodrome and for 10 days thereafter. Shedding was analyzed with regard to frequency, timing and quantity.

Results:  HSV‐1 was detectable in 87% of participants for a mean of 4 days. Shedding occurred most frequently during the vesicle/ulcer stage (91% of subjects), but was common in both clinical and subclinical stages (50% vs. 23%, average log DNA copy number/ml2 2.6 vs. 1.4).

Conclusion:  The majority of RHL patients shed viral DNA. Shedding occurred before and after the appearance of clinical lesions. Such findings may be useful in designing methods to reduce viral shedding and prevent transmission.
Expression of complement restriction factors (CD46, CD55 & CD59) in head and neck squamous cell carcinomas
Authors: Ravindranath Naren M. H. , Shuler Charles
Published: September 2006

Background:  Tumor cells can escape complement‐dependent cytotoxicity (CDC) by expressing complement restriction factors (CRFs), CD46, CD55 and CD59. CRF‐expression in non‐neoplastic mucosa of the head and neck was compared with biopsies of the head and neck squamous cell carcinoma (HNSCC) and cell lines derived from oral squamous cell carcinomas (OSCC).

Methods:  Normal mucosa and HNSCC tumor tissue (poor, moderate, or well differentiated) specimens were immunostained with anti‐CRF monoclonal antibodies. Immunostaining of the OSCC cell lines (SCC12 and SCC71) was examined under laser scan fluorescence microscopy.

Results:  CD46, CD55 and CD59 were highly expressed in HNSCC cells including T1/T2N0M0 stages. The CRF expression was much lower or absent in non‐neoplastic squamous epithelia or in the submucosa of both normal and tumor tissues.

Conclusions:  Enhanced staining of tumor tissues at stages T1/T2 indicates that the CRFs are overexpressed by primary tumors before metastasis to either lymph nodes or organs (N0M0 stage) suggesting that CRFs are formed early during tumorigenesis.
An oral health promotion program for the prevention of complications following avulsion: the effect on knowledge of physical education teachers
Authors: Holan Gideon , Cohenca Nestor , Brin Ilana , Sgan‐Cohen Harold
Published: September 2006

Abstract –  The aim was to assess the knowledge levels of physical education teachers before and after a seminar, presented by dental faculty as part of a community outreach program, in which the need for immediate treatment because of avulsion of permanent teeth has been emphasized, and to compare knowledge levels of teachers who attended the seminar with those who did not. Physical education teachers attended a seminar presented by senior faculty of the Hebrew University–Hadassah School of Dental Medicine as part of an educational campaign in the community. The seminar included clear instructions on the appropriate treatment of avulsed permanent teeth, which were appropriate for physical education teachers. The teachers completed two multiple‐choice self‐administered anonymous questionnaires related to immediate treatment they could provide in cases of permanent teeth avulsion. One hundred and twenty‐six teachers completed the first questionnaire, 2 months before the seminar. One hundred teachers completed the second questionnaire 10 months after the seminar. Of these, 70 attended the seminar and 30 did not. Thirty‐two teachers who attended the seminar had completed both questionnaires. The percentage of teachers who provided expected ‘correct’ answers in the first questionnaire (11% and 16%) was significantly lower than that in the second questionnaire (23% and 68%). The percentage of teachers who provided correct answers in the second questionnaire among those who attended the seminar (24% and 69%) was not significantly different from those who did not attend the seminar (20% and 66%). An educational campaign in the community with a seminar targeted towards a cohort of physical education teachers can improve the knowledge of the teachers, even those who did not attend the seminar, probably by means of a contamination effect. Despite the improvement, which was found, the level of knowledge after the campaign remained low and more public health promotion efforts are indicated.
Dental trauma and associated factors in Brazilian preschoolers
Authors: Granville‐Garcia Ana Flávia , De Menezes Valdenice Aparecida , De Lira Pedro Israel Cabral
Published: September 2006

Abstract –  This study aims to determine the prevalence of dental trauma and its relation to associated factors among preschool children in both private and state schools in the city of Recife, Brazil. A cross‐sectional study was conducted in which a total of 2651 preschool children were examined; out of this total, 1313 were enrolled in private schools and 1338 in state schools. The associated factors analyzed were: type of school, gender, age group and nutritional status. After a dental exam, the anthropometric measurements of weight and height were registered. Children that presented weight values above two Z scores were considered overweight/obese. The total prevalence of trauma was 36.8%. The most frequent type of trauma was enamel fractures (58.1%); the most affected subjects were the overweight/obese children; the males and the children in private schools. With regard to age group, the risk of trauma increases as children get older (P < 0.001). The high prevalence of dental trauma in preschoolers and its possible harm for permanent dentition, suggest that public health policies need to be implemented with a view to its prevention.
DIFFERENTIAL THRESHOLD AND PSYCHOPHYSICAL POWER FUNCTION OF SWEETNESS SENSATION: APPLIED PSYCHOPHYSICS AND PROSPECT THEORY ON FORMULATING BAKING PRODUCTS
Authors: CHANG MING HSU , CHIOU WEN BIN
Published: September 2006

The main purpose of this project was to develop the optimal sweetness sensation framework for baking products. Phase 1 was designed to measure consumers' differential thresholds of sweetness sensation when the sweetener contents of various sweetener‐leveled products were increased and lowered by using the constant stimuli method. Results indicated that the consumers' differential thresholds increased when the initial sweetener levels of products increased. Phase 2 was designed to establish the psychophysical power function of sweetener‐content changes and consumers' psychological sensation of products with different sweetener levels by adopting the magnitude estimation method. Regardless of the initial sweetener levels of products, the results showed that consumers perceived the products as less sweet immediately after the sweetener contents of products dropped by even a small amount; however, consumers perceived products as sweeter only when products dramatically increased in contents of sweetener.
THURSTONIAN MODELS AND VARIANCE II: EXPERIMENTAL CONFIRMATION OF THE EFFECTS OF VARIANCE ON THURSTONIAN MODELS OF SCALING
Authors: KIM HEE‐JIN , KIM KWANG‐OK , JEON SEON YOUNG , KIM JUNG‐MI , O'MAHONY MICHAEL
Published: September 2006

Subjects rated taste intensities using category scales under a variety of experimental protocols, which induced differences in computed values of d′. These were explained in a Thurstonian/signal detection context, by variation in the effects of adaptation changing perceived intensities (perceptual variance), by the effects of forgetting (memory variance) and by differences in the idiosyncratic ways that subjects use category‐rating scales (boundary variance).
Taxonomy of Listrodromini (Hymenoptera: Ichneumonidae: Ichneumoninae) from Korea
Authors: JEONG Jong‐Chul , LEE Jong‐Wook
Published: September 2006

We record a new species, Anisobas prominens n. sp., as well as two known species, Neotypus coreensis Uchida and Neotypus nobilitator orientalis Uchida. The genus Anisobas Wesmael is newly included in the Korean fauna. An illustrated key of species and genera, a description of new species, and diagnosis and photographs of each species are provided.
Fine structure of the antennal sensilla of the millipedeOrthomorphella pekuensis(Polydesmida: Paradoxosomatidae)
Authors: CHUNG Kyung‐Hwun , MOON Myung‐Jin
Published: September 2006

The fine structural characteristics of various sensory receptors on the antenna of a millipede,Orthomorphella pekuensis, were observed with field emission scanning electron microscopy. The antenna of this millipede has eight segments, called articles. On the surface of the antenna, there are a variety of sensory receptors, including olfactory and mechanical receptors. According to their morphological and fine structural characteristics, we could identify four basic types of antennal sensillum: chaetiform sensilla (CS), trichoid sensilla (TS), basiconic sensilla (BS) and apical cone sensilla (AS). The BS are divided further into three subtypes: large basiconic sensilla (BS1) on the 5th and 6th articles; small basiconic sensilla (BS2) on the 5th article; and a distinct type of basiconic spiniform sensilla (BS3) on the 7th article. The most prominent sensilla are four large AS on the distal tip of the 8th segment. Based on our results, we conclude that the main function of the CS and TS are related to mechanical reception, and that the BS and AS are likely to function in olfactory reception of volatile odors of plants, as these sensilla have base and apex pores, respectively.
Molecular phylogeny of the KoreanRivelliaspecies (Diptera: Tephritoidea: Platystomatidae) based on 16S rDNA sequences: Testing morphological hypotheses using molecular data
Authors: BYUN Hye‐Woo , HAN Ho‐Yeon
Published: September 2006

The phylogeny of the genusRivelliaRobineau‐Desvoidy was inferred from mitochondrial 16S ribosomal (r)DNA gene sequences of 13 KoreanRivelliaspecies and six species representing other platystomatid genera and the family Tephritidae. We compared the inferred molecular phylogeny with the previously published morphological cladogram. As a result, the following phylogenetic relationships were recognized: (i) monophyly of the genusRivellia; (ii) monophyly of theR. syngenesiaespecies group; (iii)R. depictaandR. apicalis(which were not previously placed in any species group) were recognized as a sister group of theR. syngenesiaespecies group; and (iv) monophyly of theR. basilarisspecies group was recognized to a limited extent. These results, even though geographically limited, provide a new insight into the phylogeny of the genusRivellia. They clearly show the utility of 16S rDNA for phylogenetic analysis of the genusRivellia. Additional study involving samples from different geographical areas will be needed to gain a better understanding of the adaptive radiation of this species‐rich genus.
Constructing Green functions of the Schrödinger equation by elementary transformations
Authors: Tsaur Gin-yih , Wang Jyhpyng
Published: September 2006

The initial value problem in quantum mechanics is most conveniently solved by the Green function method. Instead of the conventional methods of eigenfunction expansion and path integration, we present a new method for constructing the Green functions systematically. By using suitable elementary transformations, one of the conjugate variables in the Hamiltonian can be eliminated and the Green function for the simplified Hamiltonian can be easily derived. We then obtain the Green function for the original Hamiltonian by the reverse sequence of the elementary transformations. The method is illustrated for the linear potential, the harmonic oscillator, the centrifugal potential, and the centripetal barrier oscillator.
Inversion of Gamow’s formula and inverse scattering
Authors: Gandhi Sohang C. , Efthimiou Costas J.
Published: September 2006

Gamow’s tunneling formula is inverted and the issue of the uniqueness of the solution is compared with the solution obtained by the method of Gel’fand and Levitan. Some insight is gained into the key differences between classical and quantum inverse scattering, which account for the fact that a potential can be uniquely determined in the latter but only to within a symmetry family in the former.
Popper’s experiment and communication
Authors: Gerjuoy Edward , Sessler Andrew M.
Published: September 2006

We comment on an analysis by Qureshi of an experiment proposed by Popper and show that an analysis based solely on conventional nonrelativistic quantum mechanics is sufficient to exclude the possibility of subluminal or superluminal communication. That is, local operations cannot be employed to transmit information.
A study of the longitudinal laser modes of a semiconductor laser using optical coherence tomography
Authors: Poddar R. , Sharma S. R. , Bose K. , Sen P. , Andrews J. T.
Published: September 2006

Optical coherence tomography is used to demonstrate the modes of a semiconductor laser used in supermarkets. The experiment is low cost and can be adopted for an undergraduate or graduate physics laboratory. The results enable students to understand the voltage-current and optical power characteristics of a semiconductor laser, and provide insight into the nature of radiation below and above the lasing regions.
The semiconductor diode as a rectifier, a light source, and a solar cell: A simple explanation
Authors: Herrmann F. , Würfel P.
Published: September 2006

An explanation of the principles of a pn junction is proposed without recourse to the band model, the space charge of the junction, and the charge carrier depletion at the interface. The explanation assumes that the processes in a pn junction can be considered as a chemical reaction between electrons, holes, and photons and that an n-type material is a conductor for electrons and an insulator for holes, and a p-type material is a conductor for holes and an insulator for electrons. We give a simple and concise explanation of rectification, light emission, and current generation by pn junctions.
Analysis of the shape of a sheet of paper when two opposite edges are joined
Authors: Colom Antoni Amengual
Published: September 2006

The profiles of the edge of rectangular sheets of paper folded so as to join opposite edges were measured and compared with the profiles calculated with the theory of elasticity. I show how the calculation can be accomplished by using the aspect ratio of the loops as the only input parameter.
Active mass under pressure
Authors: Ehlers Jürgen , Ozsváth István , Schucking Engelbert L.
Published: September 2006

After a historical introduction to Poisson’s equation in Newtonian gravity, we review its analog for static gravitational fields in Einstein’s theory. The source of the potential, which we call the active mass density, comprises not only all possible sources of energy, but also the pressure term 3P∕c2. In the Hamburg seminar on relativity in the 1950s we discussed whether this term due to Fermi pressure in different atomic nuclei could be detected in Cavendish-type experiments. Our reasoning contained an instructive mistake that we are now able to resolve. We conclude that this term should not lead to discrepancies for different materials in a Cavendish-type experiment, although it is important in the early universe and collapsing stellar cores.
Optical band gaps as a result of destructive superposition of scattered waves
Authors: Guo Wei
Published: September 2006

Light transmission through a finite one-dimensional photonic crystal is formulated using the theory of multiple scattering. It is shown that optical band gaps of the crystal are created by destructive superposition of waves multiply scattered from the dielectric slabs that constitute the crystal. The effects of the number of slabs and the lattice constant on the band gaps are also studied.
Revealing the blaze angle: A simple experiment for visualizing diffraction effects using microscopic and macroscopic gratings
Authors: Vandervoort K. G. , Adams S. L. , Hyder A. M.
Published: September 2006

We describe a diffraction grating experiment for visible and microwave optics. The groove spacing for the visible-optics grating is determined through atomic force microscopy, so that an additional feature, the blaze angle, is revealed. From the blaze angle, students calculate the theoretical shift in the diffraction pattern and are then able to visualize this shift through measurements of a microwave diffraction pattern produced using a macroscopic grating. The experiment demonstrates the utility of an atomic force microscope in an engineering application and allows separation of diffraction pattern effects associated with slit width and slit spacing.
Theoretical comparisons of average normalized gain calculations
Authors: Bao Lei
Published: September 2006

Since its introduction, the normalized gain or the g-factor has been widely used in assessing students’ performance in pre- and post-tests. The average g-factor can be calculated using either the average scores of the class or individual student’s scores. In general, these two calculations produce different results. The nature of these two results is explored for several idealized situations. The results suggest that we may be able to utilize the difference between the two results to extract information on how the population may have changed as a result of instruction.
An accurate formula for the period of a simple pendulum oscillating beyond the small angle regime
Authors: Lima F. M. S. , Arun P.
Published: September 2006

A simple approximate expression is derived for the dependence of the period of a simple pendulum on the amplitude. The approximation is more accurate than other simple relations. Good agreement with experimental data is verified.
Einstein and the existence of atoms
Authors: Bernstein Jeremy
Published: September 2006

The background of Einstein’s 1905 Brownian motion paper is discussed, including the work of people like Brown, Boltzmann, and Bachelier. The paper is discussed as is its aftermath. The question is raised as to whether atoms exist.
SELF-ORGANIZATION OF SPIKING NEURAL NETWORK THAT GENERATES AUTONOMOUS BEHAVIOR IN A REAL MOBILE ROBOT
Authors: ALNAJJAR FADY , MURASE KAZUYUKI
Published: September 2006

In this paper, we propose self-organization algorithm of spiking neural network (SNN) applicable to autonomous robot for generation of adoptive and goal-directed behavior. First, we formulated a SNN model whose inputs and outputs were analog and the hidden unites are interconnected each other. Next, we implemented it into a miniature mobile robot Khepera. In order to see whether or not a solution(s) for the given task(s) exists with the SNN, the robot was evolved with the genetic algorithm in the environment. The robot acquired the obstacle avoidance and navigation task successfully, exhibiting the presence of the solution. After that, a self-organization algorithm based on a use-dependent synaptic potentiation and depotentiation at synapses of input layer to hidden layer and of hidden layer to output layer was formulated and implemented into the robot. In the environment, the robot incrementally organized the network and the given tasks were successfully performed. The time needed to acquire the desired adoptive and goal-directed behavior using the proposed self-organization method was much less than that with the genetic evolution, approximately one fifth.
A NEURAL NETWORK MODEL FOR THE SIMULATION OF WORD PRODUCTION ERRORS OF FINNISH NOUNS
Authors: JÄRVELIN ANTTI , JUHOLA MARTTI , LAINE MATTI
Published: September 2006

We constructed a connectionist model with multilayer perceptron networks for the simulation of word production errors in the Finnish language. Such errors occur as slips of the tongue in healthy subjects and even more often in aphasic patients suffering from brain damage. Word production errors are of theoretical interest as they open an avenue to inner workings of the language production system. Here we present our coding schemes for semantic and phoneme information of words, investigate the general properties of the model, and compare the results of the model against empirical naming error data from ten aphasic patients. The model was reasonable in simulating word production errors in this heterogeneous group of aphasic patients.
POSE ESTIMATION IN AUTOMATED VISUAL INSPECTION USING GENETIC ALGORITHM
Authors: HATI S. , CHAUDHURY K. , IBRAHIM A.
Published: September 2006

In this paper, we propose a genetic algorithm based approach to determine the pose of an object in Automated Visual Inspection having three degrees of freedom. We have investigated the effect of noise at 20 dB SNR and also mismatch resulting from incorrect correspondences between the object space points and the image space points, on the estimation of pose parameters. The maximum error in translation parameters is less than 0.45 cm and rotational error is less than 0.2 degree at 20 dB SNR. The error in parameter estimation is insignificant upto 7 pairs of mismatched points out of 24 points in object space and the results skyrockets when 8 or more pairs of points are mismatched. We have compared our result with that obtained by least square technique and it shows that GA based method outperform the gradient based technique when the number of vertices of the object to be inspected is small. These results have clearly established the robustness of GA in estimating the pose of an object with small number of vertices in automated visual inspection.
PRUNING AND MODEL-SELECTING ALGORITHMS IN THE RBF FRAMEWORKS CONSTRUCTED BY SUPPORT VECTOR LEARNING
Authors: HAO PEI-YI , CHIANG JUNG-HSIEN
Published: September 2006

This paper presents the pruning and model-selecting algorithms to the support vector learning for sample classification and function regression. When constructing RBF network by support vector learning we occasionally obtain redundant support vectors which do not significantly affect the final classification and function approximation results. The pruning algorithms primarily based on the sensitivity measure and the penalty term. The kernel function parameters and the position of each support vector are updated in order to have minimal increase in error, and this makes the structure of SVM network more flexible. We illustrate this approach with synthetic data simulation and face detection problem in order to demonstrate the pruning effectiveness.
DYNAMIC OUTPUT FEEDBACK STABILIZATION FOR NONLINEAR SYSTEMS BASED ON STANDARD NEURAL NETWORK MODELS
Authors: LIU MEIQIN
Published: September 2006

A neural-model-based control design for some nonlinear systems is addressed. The design approach is to approximate the nonlinear systems with neural networks of which the activation functions satisfy the sector conditions. A novel neural network model termed standard neural network model (SNNM) is advanced for describing this class of approximating neural networks. Full-order dynamic output feedback control laws are then designed for the SNNMs with inputs and outputs to stabilize the closed-loop systems. The control design equations are shown to be a set of linear matrix inequalities (LMIs) which can be easily solved by various convex optimization algorithms to determine the control signals. It is shown that most neural-network-based nonlinear systems can be transformed into input-output SNNMs to be stabilization synthesized in a unified way. Finally, some application examples are presented to illustrate the control design procedures.
HADAMARD TYPE OPERATIONS FOR QUBITS
Authors: MAITRA ARPITA , PARASHAR PREETI
Published: September 2006

We obtain the most general ensemble of qubits for which it is possible to design a universal Hadamard gate. These states, when geometrically represented on the Bloch sphere, give a new trajectory. We further consider some Hadamard "type" operations and find ensembles of states for which such transformations hold. The unequal superposition of a qubit and its orthogonal complement is also investigated.
INFORMATION TRANSFER IN LEAKY ATOM–CAVITY SYSTEMS
Authors: GHOSH B. , MAJUMDAR A. S. , NAYAK N.
Published: September 2006

We consider a system of two enatangled cavities and a single two-level atom passing through one of them. A "monogamy" inequality for this tripartite system is quantitatively studied and verified in the presence of cavity leakage. Next, we consider the simultaneous passage of two-level atoms through both the cavities. Entanglement swapping is observed between the the two-cavity and the two-atom system. Cavity dissipation leads to the quantitative reduction of information transfer though preserving the basic swapping property.
WHAT IS QUANTUM INFORMATION?
Authors: HESS KARL , PHILIPP WALTER , ASCHWANDEN MANUEL
Published: September 2006

The main purpose of this review is to deal with questions related to the nature of quantum information and particularly with quantum entanglement as an important component of quantum information and computing. We will not discuss here quantum computer algorithms, like the algorithm by Shor, or their advantages and disadvantages. We only cover the material that lies at the foundations of quantum information and computing and epistemological questions. We attempt to connect the famous debate between Einstein and Bohr on quantum entanglement to some of the latest work on qubits and quantum computing and to the mathematical theorems that form the basis of these discussions, particularly the theorem of Bell. We present a critical analysis of this material and hope that this will give the reader a better understanding of what can be said with certainty about the nature of quantum information.
BELL'S INEQUALITY AND CONTEXTUAL INFORMATION
Authors: SAFINEJAD F. , SHAFIEE A. , MALEEH R.
Published: September 2006

The properties of the Shannon entropy (concavity and strong additivity) are satisfied in both classical and quantum experiments, if the context of experiment is considered appropriately. We show that these properties hold true in a classical model with the feature of being contextual, where a correlation is observed between events. Our results show that the classical example is similar to an entangled singlet state for spin-½ particles. But, contrary to general opinion, [Formula: see text] is not a necessary and sufficient condition for violating Bell's inequality, since it has been obtained on the basis of a common cause pattern. In other words, it is possible to reconstruct the amount of information contained in a quantum entangled state according to the common cause criterion satisfying local realism.
EFFICIENT TELEPORTATION OF UNKNOWN ATOMIC ENTANGLED STATES
Authors: ZHAO YAN , YANG MING , CAO ZHUO-LIANG
Published: September 2006

We propose a scheme for teleporting unknown atomic entangled states in cavity QED. With the assistance of a strong classical field, the photon number dependent parts in the effective Hamiltonian are canceled. Thus, the scheme is insensitive to both the cavity decay and the thermal field. In addition, our scheme does not require the Bell-state measurement directly and the success probability can reach 1.0 in our scheme.
Diseases Caused by Defects in the Visual Cycle: Retinoids as Potential Therapeutic Agents
Authors: Travis Gabriel H. , Golczak Marcin , Moise Alexander R. , Palczewski Krzysztof
Published: September 2006

Absorption of a photon by an opsin pigment causes isomerization of the chromophore from 11-cis-retinaldehyde to all-trans-retinaldehyde. Regeneration of visual chromophore following light exposure is dependent on an enzyme pathway called the retinoid or visual cycle. Our understanding of this pathway has been greatly facilitated by the identification of disease-causing mutations in the genes coding for visual cycle enzymes. Defects in nearly every step of this pathway are responsible for human-inherited retinal dystrophies. These retinal dystrophies can be divided into two etiologic groups. One involves the impaired synthesis of visual chromophore. The second involves accumulation of cytotoxic products derived from all-trans-retinaldehyde. Gene therapy has been successfully used in animal models of these diseases to rescue the function of enzymes involved in chromophore regeneration, restoring vision. Dystrophies resulting from impaired chromophore synthesis can also be treated by supplementation with a chromophore analog. Dystrophies resulting from the accumulation of toxic pigments can be treated pharmacologically by inhibiting the visual cycle, or limiting the supply of vitamin A to the eyes. Recent progress in both areas provides hope that multiple inherited retinal diseases will soon be treated by pharmaceutical intervention.
Epistemological issues in omics and high-dimensional biology: give the people what they want
Authors: Mehta Tapan S. , Zakharkin Stanislav O. , Gadbury Gary L. , Allison David B.
Published: September 2006

Gene expression microarrays have been the vanguard of new analytic approaches in high-dimensional biology. Draft sequences of several genomes coupled with new technologies allow study of the influences and responses of entire genomes rather than isolated genes. This has opened a new realm of highly dimensional biology where questions involve multiplicity at unprecedented scales: thousands of genetic polymorphisms, gene expression levels, protein measurements, genetic sequences, or any combination of these and their interactions. Such situations demand creative approaches to the processes of inference, estimation, prediction, classification, and study design. Although bench scientists intuitively grasp the need for flexibility in the inferential process, the elaboration of formal supporting statistical frameworks is just at the very start. Here, we will discuss some of the unique statistical challenges facing investigators studying high-dimensional biology, describe some approaches being developed by statistical scientists, and offer an epistemological framework for the validation of proffered statistical procedures. A key theme will be the challenge in providing methods that a statistician judges to be sound and a biologist finds informative. The shift from family-wise error rate control to false discovery rate estimation and to assessment of ranking and other forms of stability will be portrayed as illustrative of approaches to this challenge.