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1

Solitary median maxillary central incisor (SMMCI) syndrome  

Microsoft Academic Search

Solitary median maxillary central incisor syndrome (SMMCI) is a complex disorder consisting of multiple, mainly midline defects of development resulting from unknown factor(s) operating in utero about the 35th–38th day(s) from conception. It is estimated to occur in 1:50,000 live births. Aetiology is uncertain. Missense mutation in the SHH gene (I111F) at 7q36 may be associated with SMMCI. The SMMCI

Roger K Hall

2006-01-01

2

Concomitant solitary median maxillary central incisor and fused right mandibular incisor in primary dentition  

PubMed Central

Solitary median maxillary central incisor (SMMCI) is a unique developmental anomaly in primary dentition. It involves central incisor tooth germs and may or may not be associated with other anomalies. Its presence, concomitant with fusion of right mandibular incisors has not previously been reported. A 5-year-old girl was presented with a single symmetrical primary maxillary incisor at the midline, with the absence of labial frenulum, an indistinct philtrum and a prominent midpalatal ridge. There was an associated fused tooth in the right incisor region and radiographic examination confirmed only one maxillary central incisor in both the dentitions. Family history revealed that the father of the girl also had a similar anomaly providing probable evidence of etiological role for heredity in SMMCI.

Shilpa, G.; Nuvvula, Sivakumar; Gokhale, Niraj; Yamini, V.

2012-01-01

3

Maxillary Central Incisor With Two Root Canals: A Case Report  

Microsoft Academic Search

The success of endodontic therapy requires a knowledge of the internal and external dental anatomy and its variations in presentation. The internal anatomy of the maxillary central incisor is well known and usually presents with one root and one radicular canal system. This case report describes an endodontic treatment of a maxillary central incisor with two roots and two canal

Emílio Carlos Sponchiado; Hanan Awwad Abdel Qader Ismail; Márcia Raquel Lima Braga; Fabrício Kitazono de Carvalho; Cláudia Andréa Correa Garcia Simões

2006-01-01

4

Solitary median maxillary central incisor (SMMCI) syndrome  

PubMed Central

Solitary median maxillary central incisor syndrome (SMMCI) is a complex disorder consisting of multiple, mainly midline defects of development resulting from unknown factor(s) operating in utero about the 35th–38th day(s) from conception. It is estimated to occur in 1:50,000 live births. Aetiology is uncertain. Missense mutation in the SHH gene (I111F) at 7q36 may be associated with SMMCI. The SMMCI tooth differs from the normal central incisor, in that the crown form is symmetric; it develops and erupts precisely in the midline of the maxillary dental arch in both primary and permanent dentitions. Congenital nasal malformation (choanal atresia, midnasal stenosis or congenital pyriform aperture stenosis) is positively associated with SMMCI. The presence of an SMMCI tooth can predict associated anomalies and in particular the serious anomaly holoprosencephaly. Common congenital anomalies associated with SMMCI are: severe to mild intellectual disability, congenital heart disease, cleft lip and/or palate and less frequently, microcephaly, hypopituitarism, hypotelorism, convergent strabismus, oesophageal and duodenal atresia, cervical hemivertebrae, cervical dermoid, hypothyroidism, scoliosis, absent kidney, micropenis and ambiguous genitalia. Short stature is present in half the children. Diagnosis should be made by eight months of age, but can be made at birth and even prenatally at 18–22 weeks from the routine mid-trimester ultrasound scan. Management depends upon the individual anomalies present. Choanal stenosis requires emergency surgical treatment. Short stature may require growth hormone therapy. SMMCI tooth itself is mainly an aesthetic problem, which is ideally managed by combined orthodontic, prosthodontic and oral surgical treatment; alternatively, it can be left untreated.

Hall, Roger K

2006-01-01

5

Age estimation using maxillary central incisors: A radiographic study  

PubMed Central

Background: In the field of forensic dentistry, secondary changes in teeth with advancing age have been used as reliable predictors of age in various studies. Aim: The purpose of the present study was to present a method for assessing the chronological age based on the relationship between age and morphological parameters of maxillary central incisors. Materials and Methods: Fifty subjects between 20-70 years of age were included in the study. Intraoral periapical radiographs were taken in relation to maxillary central incisors using paralleling technique. The following measurements were recorded: lengths of tooth, pulp, root and width of root and pulp at three different points. Regression formulas were used to calculate the dental age. Results: The mean estimated age showed no statistically significant difference from the actual mean age (P > 0.05). Also, maximum difference was seen for root length variable (-1.035 ± 1.86 years).

Agarwal, Nitin; Ahuja, Parul; Sinha, Abhishek; Singh, Anil

2012-01-01

6

Prosthetic considerations in the restoration of orthodontically treated maxillary lateral incisors to replace missing central incisors: A clinical report  

Microsoft Academic Search

The treatment of young patients with missing maxillary incisors poses a challenge to prosthodontists and orthodontists. The 2 principal treatment options are (1) the reopening or maintenance of space for future autotransplantation and\\/or prosthodontic restoration of the missing teeth, or (2) total orthodontic space closure, followed by prosthodontic modification of the lateral incisors to simulate the central incisors. This article

Stella Chaushu; Adrian Becker; Maya Zalkind

2001-01-01

7

Orthodontically induced eruption of a horizontally impacted maxillary central incisor.  

PubMed

This case report presents the clinical features and periodontal findings in a patient with a horizontally impacted maxillary central incisor that had been exposed and aligned after a closed-eruption surgical technique. By combining 3 treatment stages-maxillary expansion, crown exposure surgery, and induced eruption-the horizontally impacted incisor was successfully moved into proper position. The patient finished treatment with a normal and stable occlusion between the maxillary and mandibular arches, and an adequate width of attached gingiva, even in the area surrounding the crown. The 5-year follow-up of stability and periodontal health demonstrated esthetic and functional outcomes after orthodontically induced tooth eruption. Clinical evaluation showed that the treated central incisor had periodontal clinical variables related to visible plaque, bleeding on probing, width of attached gingiva, and crown length that resembled the contralateral incisor. PMID:23810053

Rizzatto, Susana Maria Deon; de Menezes, Luciane Macedo; Allgayer, Susiane; Batista, Eraldo Luiz; Freitas, Maria Perpétua Mota; Loro, Raphael Carlos Drumond

2013-07-01

8

[Esthetic IMZ implant for a central incisor].  

PubMed

Replacement of a missing incisor with an osseo-integrated implant, presents a difficult prosthetic problem for the practitioner because of the obliqueness of the implant and its diameter smaller than the tooth to be reconstructed. Therefore, a topographic and aesthetic pre-estimation is highly desirable. The patient whose treatment is described hereafter, presents large diastemas permitting to set the missing tooth in several locations. The various options are simulated on a study model and recorded by a silicone or resin index. This index is cut out so that the implant site is clearly defined and it presents a guide rod indicating the direction of the alveolar bone. The optimal site is selected during the surgical procedure with the most favorable index depending on the residual bone. After the implant is released, the location impression, is taken using asymmetric transfer allowing a strict positioning of the implant's replica and its thread. In order to prevent the making of a triangular-shaped crown, a false transfixed core removable is built over the intramobile component of the IMZ as well as pa periodontal ring. The latter is independent and maintained by the intramobile component. It compensates the difference in diameter between the implant and the natural tooth to be reconstructed. Its finely polished but asymmetric internal aspect prevents the rotation of the device. The volume of this device is controlled by a silicone index made on the preestimation model. Both pieces are cast in gold and assembled on the implant with a positioning indes. Parallel proximal grooves increase the friction of the core and a ceramo-metal crown is built in the conventional fashion. It is temporally cemented, and periodically removed and cleansed. The absence of gingical sulcus provides an aesthetic result similar to a bridge component. PMID:2638613

Brabant, A; Lejuste, P; Andriessens, J

1989-12-01

9

The Aesthetic Management of a 180 Degree Rotated Maxillary Central Incisor With Two Root Canals- A Case Report  

PubMed Central

The success of the root canal treatment is based on a thorough knowledge of the normal tooth, the root and the root canal morphology, which include variations. Tooth rotation is a common finding in the premolar-molar region, but a 180 degree rotation of the maxillary central incisor is extremely rare and it has not documented anywhere in the dental literature. This case report describes the aesthetic correction of a maxillary central incisor with a 180 degree rotation and two root canals.

Jain, Shweta; Narang, Praful; Sharma, Rohit; Agarwal, Vijay

2013-01-01

10

Orthodontic, genetic, and periodontal considerations in the treatment of impacted maxillary central incisors: A study of twins  

Microsoft Academic Search

Treatment of twins each with one impacted maxillary central incisor and a mesiodens is described. Treatment included rapid expansion, extraction of the mesiodens, surgical exposure of the impacted central incisor, and its forced eruption. The impacted incisor was brought into functional position in one patient but was lost in the other because of insufficient root length and high mobility. Orthodontic,

Adam Brand; Mojdah Akhavan; Hongsheng Tong; Y. A. Kook; Joseph H. Zernik

2000-01-01

11

Avulsed Immature Permanent Central Incisors Obturated With Mineral Trioxide Aggregate: A Case Report  

PubMed Central

The endodontic management of immature permanent incisors in young children can be challenging. This case reported an avulsed immature maxillary central incisors that underwent complete endodontic obturation using mineral trioxide aggregate. A 10-year-old male who suffered a fall injury avulsed both his central incisors. The revascularization process was not possible due to patient compliance and geographic reasons. Mineral trioxide aggregate was utilized as a novel endodontic treatment. After one year post-injury, the teeth remained symptom-free, the clinical and radiographic follow-up showed evidence of healthy periodontium. How to cite this article: Al-Kahtani A. Avulsed Immature Permanent Central Incisors Obturated With Mineral Trioxide Aggregate: A Case Report. J Int Oral Health 2013; 5(3):88-96.

Al-Kahtani, Ahmed

2013-01-01

12

Directions of orthodontic tooth movements associated with external apical root resorption of the maxillary central incisor  

Microsoft Academic Search

External apical root resorption is a multifactorial problem encountered in all disciplines of dentistry, but it is most commonly seen in cases treated orthodontically. Specific tooth movements that are most likely to exacerbate external apical root resorption are poorly understood. Purpose of the present investigation was twofold: (1) to quantify apical and incisal movements of the maxillary central incisor in

Robert J. Parker; Edward F. Harris

1998-01-01

13

Multiple supernumerary teeth associated with an impacted maxillary central incisor: Surgical and orthodontic management  

PubMed Central

Various anomalies in the size, shape, number, structure and eruption of the teeth are often observed clinical conditions. Supernumerary teeth can be found in almost any region of the dental arch, and most of the times they are asymptomatic, and are routinely found during radiographic evaluation. The most common cause of impacted maxillary incisors is the presence of the supernumerary teeth. This paper describes a case of multiple supernumerary teeth associated with an impacted permanent maxillary central incisor in an 11-year old child along with its surgical and orthodontic management.

Yeluri, Ramakrishna; Hegde, Manjunath; Baliga, Sudhindra; Munshi, Autar Krishen

2012-01-01

14

Delayed eruption of maxillary permanent central incisors as a consequence of mesiodens: a surgical re-treatment approach.  

PubMed

The presence of mesiodens can cause some clinical problems. This paper reports a case of delayed eruption of permanent central incisors in a nine-year-old male as a consequence of a mesiodens and three surgical approaches prior to the eruption of incisors, which occurred after the third surgery when the crown was exposed and submitted to a gentle luxation. PMID:15163146

Moraes, Renata Simões; Farinhas, João Alfredo; Gleiser, Rogerio; Primo, Laura Guimarães

2004-01-01

15

Correction of a severely rotated maxillary central incisor with the Whip device  

PubMed Central

Objective The aim of this case report was to introduce an appliance that can be used for correcting severe rotation of anterior teeth in pre-adolescent children. Appliance design and testing This is a case report of an 11-year-old Iranian boy with a mixed dentition Class I malocclusion defined by a severe rotation of upper left central incisor and a mesiodens between the centrals. The supernumerary tooth was first extracted, and then a Whip device including removable appliance, a cantilever spring and bonded tube on rotated tooth was inserted into his mouth. After 8 months, the upper left central incisor was orthodontically brought into proper alignment. Circumferential supracrestal fibrotomy was done next to overcorrection of the tooth and one week after surgery, the device was removed and the retention was started. Conclusion The whip device, a removable appliance can be very effective for correcting severe rotation of anterior teeth.

Jahanbin, Arezoo; Baghaii, Bahareh; Parisay, Iman

2009-01-01

16

A three-dimensional finite-element stress analysis of an endodontically prepared maxillary central incisor.  

PubMed

This study is an application of a three-dimensional Finite-Element Method to investigate the changes in stress characteristics of a prepared maxillary central incisor. The purpose of this study was to analyze stress distributions in this tooth after simulated canal preparation and static loading. A maxillary central incisor was embedded in acrylic, sectioned, photographed, and digitized. A three-dimensional finite-element model was generated by a computer and appropriately modified to simulate canal preparation. Data identified the highest stress magnitudes to be located between the middle and coronal thirds of the root; an area clinically observed to be prone to fracture during treatment. In addition, the magnitude of generated stresses was directly correlated with the simulated prepared canal diameter. The development of a validated three-dimensional finite-element method could identify areas that may predispose a tooth to structural failure during condensation loads. PMID:7499976

Ricks-Williamson, L J; Fotos, P G; Goel, V K; Spivey, J D; Rivera, E M; Khera, S C

1995-07-01

17

Stress Distribution of Post–Core Applications in Maxillary Central Incisors  

Microsoft Academic Search

The purpose of this study was to evaluate the stress distribution in a maxillary central incisor restored with various post–core applications.The study used a three-dimensional finite element method. The tooth was assumed to be endodontically treated with a porcelain crown. Two different sizes of Flexi-post, Cera-post, and Composipost were compared for 200 N palatal and incisal loads.It was determined that,

Sis Darendeliler Yaman; Özgül Karacaer

2004-01-01

18

Simultaneous Replacement of Maxillary Central Incisors with CEREC Biogeneric Reference Technique: A Case Report  

PubMed Central

Biogeneric Reference Technique (BRT) of the CEREC 3D v.3.8 software is an effective technique for single anterior ceramic crowns because it provides computer-controlled match of the tooth form to the contralateral tooth. BRT also enables the fabrication of two or more anterior all-ceramic crowns simultaneously. This clinical report demonstrates the clinical application of BRT for designing and milling two central incisors in one appointment using a single optical impression. After completing the virtual design of the first central incisor, it was copied and a mirror image was created. The second central incisor was designed using this replicated image and therefore a computer-controlled symmetry was obtained. The crowns were milled from monolithic feldspathic ceramic blocks and adhesively luted with dual-cured resin cement following dentin conditioning. At the two-year follow-up appointment, the restorations were intact, no adverse effects were noted, and the resultant appearance was highly satisfactory for the patient. A step-by-step protocol is described from design to cementation of these restorations.

Akgungor, Gokhan; Sen, Deniz; Bal, Eray; Ozcan, Mutlu

2013-01-01

19

Orthodontic-restorative treatment as an option for biologic replacement of a maxillary central incisor: 5-year follow-up.  

PubMed

The maxillary central incisor is the tooth most often affected by trauma, especially in the age range of 7 to 10 years, when high-impact sports are prevalent. The options for conservative treatment should be prioritized in these patients, aiming to achieve a biologic response that might provide continuity of growth of the alveolus, to provide functional and esthetic development of the affected region. This case report describes a patient with a history of trauma during the deciduous dentition with consequent intrusion, root dilaceration, and retention of the maxillary left central incisor. The treatment involved extraction of the traumatized tooth and mesial movement of the lateral incisor and posterior segments. PMID:22920706

Rizzatto, Susana Maria Deon; Closs, Luciane Quadrado; Freitas, Maria Perpétua Mota; Rizzatto, Laura Escobar

2012-09-01

20

[Central incisor and individualizing treatment of the smile due to orthodontics].  

PubMed

The objectives of the orthodontic treatment that we provide are to re-establish functional occlusion and a harmonious facial appearance, taking the individual anatomic features of each patient into account as well the potential changes that will come with ageing. As a pre-treatment first step we analyze the position of the incisor teeth within the face. Next we pose several questions. Should we preserve a slight bi-maxillary protrusion or correct it? Should we decide to voluntarily maintain a slight supraclusion? When should we correct a gummy smile? What should we do about black holes? In this article we propose treatment approaches, illustrating them with clinical situations and focus on the critical role played by the central incisor in establishing smiles that are suitable for each patient, integrating them with the ageing patterns that we know the future will bring. PMID:22717111

Rozencweig, Sophie; Muller, Christine

2012-06-21

21

Analysis of stress distribution in a maxillary central incisor subjected to various post and core applications.  

PubMed

In this study, stress distribution in a maxillary central incisor that was subjected to endodontic treatment and various post and core applications was determined by using a three-dimensional finite-element method. Cast gold post and gold core and different combinations of prefabricated stainless steel post, or a prefabricated titanium post with amalgam or composite cores were considered. In all cases, the tooth was assumed to have a porcelain crown. The primary purpose of the study was to evaluate the stress distribution due to simulated biting forces and thus investigate the reliability of different post and core applications. It was found that, within the limitations of the study, the cast gold post and gold core application yielded the best result. The second purpose of the study was to highlight the importance of using a unique stress value, which contains the effects of all the possible stress components existing upon loading in the determination of a possible failure. A resultant stress value and all the constituent components were shown in detail, and it was proved that an estimation independently based on an individual component might lead to erroneous results. PMID:9641141

Yaman, S D; Alaçam, T; Yaman, Y

1998-02-01

22

Solitary median maxillary central incisor syndrome: clinical case with a novel mutation of sonic hedgehog.  

PubMed

Solitary median maxillary central incisor (SMMCI) is a rare dental anomaly. It is usually considered as a minor manifestation of holoprosencephaly (HPE). Some reported families had severe cases of HPE in some members and SMMCI in others. Mutations of Sonic Hedgehog (SHH) have been documented in these families. SMMCI has also been found as an isolated finding or together with other anomalies such as microcephaly, short stature, endocrine pathology, and choanal atresia. We describe a patient with SMMCI and a novel SHH mutation: Val332Ala. PMID:15103725

Garavelli, Livia; Zanacca, C; Caselli, G; Banchini, G; Dubourg, C; David, V; Odent, S; Gurrieri, F; Neri, G

2004-05-15

23

Mandibular midline supernumerary tooth associated with agenesis of permanent central incisors: a diagnostic conundrum.  

PubMed

Concomitant hypo-hyperdontia is a rare mixed numeric anomalous condition. The presence of this condition in the same area of dental arch and specifically in the mandibular anterior region is reported very infrequently. This case report presents a case of 20 years old male with congenitally missing permanent mandibular central incisors in conjunction with a mandibular midline supernumerary tooth. Only 3 cases have been documented in English literature till date. The article focuses on the review of mandibular mesiodens and the clarity regarding the usage of the terminology "mesiodens". PMID:23037785

Marya, Charu Mohan; Sharma, Gaurav; Parashar, Vijay P; Dahiya, Vandana; Gupta, Anil

2012-01-01

24

Esthetic and endodontic management of a deep crown-root fracture of a maxillary central incisor.  

PubMed

Treatment of trauma to anterior teeth should aim at preserving the affected teeth so as to restore function and esthetic appearance. Recently, patients have come to expect adequate esthetics immediately after trauma. In the present case, a deep crown-root fracture compromised the pulp and extended subgingivally on the palatal aspect. After using the fractured fragment as a provisional crown, the patient received conventional root canal treatment, which provided immediately satisfactory esthetic results and reliable short-term restoration of the crown-root fractured tooth. Rehabilitation of the fractured central incisor was performed with a post-core-supported prosthetic restoration. PMID:23221163

Tsurumachi, Tamotsu; Matsumoto, Sakurako; Kobayashi, Yoshimi; Ohara, Kinuyo; Suzuki, Yusuke; Ogiso, Bunnai

2012-01-01

25

Multidisciplinary management of impacted central incisors due to supernumerary teeth and an associated dentigerous cyst  

PubMed Central

Supernumerary teeth are the most common developmental dental anomaly resulting from hyperactivity of dental lamina, dichotomy, environmental factor, or polygenetic process of atavism. Supernumerary teeth present classical oral complication such as impaction of adjacent teeth, crowding, diastema formation, rotation, displacement of teeth, and occlusal interference. A dentigerous cyst associated with anterior supernumerary teeth (mesiodens) is rare and accounts for 5% of all dentigerous cysts. The present case reports describe the successful management of the impacted permanent maxillary central incisor positioned high in the vestibule. A combination of surgical and orthodontic techniques was employed to improve treatment outcome with greater hard and soft tissue preservation and to prevent psychological problems. In the surgical phase, supernumerary teeth and dentigerous cyst were removed. Subsequently traction was employed by bonding bracket on the labial surface using closed and open eruption techniques. Successively, fixed orthodontic treatment was started to align permanent maxillary central incisors in an occlusal plane. Thus, combination of surgical and orthodontic method can be the treatment of choice over surgical extraction, implant placement, and surgical repositioning.

Kalaskar, Ritesh R.; Kalaskar, Ashita R.

2011-01-01

26

Multidisciplinary management of impacted central incisors due to supernumerary teeth and an associated dentigerous cyst.  

PubMed

Supernumerary teeth are the most common developmental dental anomaly resulting from hyperactivity of dental lamina, dichotomy, environmental factor, or polygenetic process of atavism. Supernumerary teeth present classical oral complication such as impaction of adjacent teeth, crowding, diastema formation, rotation, displacement of teeth, and occlusal interference. A dentigerous cyst associated with anterior supernumerary teeth (mesiodens) is rare and accounts for 5% of all dentigerous cysts. The present case reports describe the successful management of the impacted permanent maxillary central incisor positioned high in the vestibule. A combination of surgical and orthodontic techniques was employed to improve treatment outcome with greater hard and soft tissue preservation and to prevent psychological problems. In the surgical phase, supernumerary teeth and dentigerous cyst were removed. Subsequently traction was employed by bonding bracket on the labial surface using closed and open eruption techniques. Successively, fixed orthodontic treatment was started to align permanent maxillary central incisors in an occlusal plane. Thus, combination of surgical and orthodontic method can be the treatment of choice over surgical extraction, implant placement, and surgical repositioning. PMID:22114457

Kalaskar, Ritesh R; Kalaskar, Ashita R

2011-01-01

27

A morphometric analysis of maxillary central incisor on the basis of facial appearance in Korea  

PubMed Central

PURPOSE We aimed to identify a more esthetic width-to-length ratio by analyzing maxillary central incisor of Korean adult population. Information regarding tooth ratio in the Korean population may be useful to clinicians when restoring anterior teeth. MATERIALS AND METHODS A total of 40 men and 40 women were included in this study. The NON-MEDIA group included 40 non-celebrities, who were healthy and 25 to 39 years old, with normal dentofacial appearance. The MEDIA group consisted of 40 celebrities selected only on the basis of their soft-tissue facial appearance. The facial photographs of 40 celebrities were collected from the Internet websites. The width and length of the maxillary central incisor were measured using Adobe Photoshop® 7.0, a software for analysis, measurement and edition of photographs. Data were analyzed statistically using the Independent t-test at 5% statistical significance level. RESULTS The mean ratio for the MEDIA group was 0.77, whereas that of the NON-MEDIA group was 0.88. The difference between the two groups was statistically significant. No significant gender differences were found in the width-to-length ratio in MEDIA group. In NON-MEDIA group, however, there were significant differences between female and male. CONCLUSION After analyzing maxillary anterior teeth of Korean adults, our results were in accordance with the general Western standards of esthetics. A dentist restoring the natural look and beauty of teeth will have to consider those standards.

Ku, Ji-Eun; Yang, Hong-So

2012-01-01

28

Stress Analysis of a Maxillary Central Incisor Restored with Different Posts  

PubMed Central

Objectives To evaluate the effects of different post materials on the stress distribution in an endodontically treated maxillary incisor. Materials and Methods A pseudo 3-dimensional finite element model was created in a labiolingual cross-sectional view of a maxillary central incisor and modified according to five posts with different physical properties consisting stainless steel, titanium, gold alloy, glass fiber (Snowpost), and carbon fiber (Composipost). A 200 N force was then applied from two different directions; a) vertical load on the incisal edge, b) 45 degree diagonal load above the cingulum location. Stress distribution and values were then calculated by considering the pseudo three dimensional von Mises stress criteria. Results Under two loading conditions, post made of steel showed greatest stress concentration at the post/dentin interface followed by titanium, gold alloy, Snowpost and Composipost. However, Composipost, which elastic modulus was closer to the dentin, produced highest stress values at 1/3 cervical area. Conclusions Within the limitation of this simulated mechanical analysis, we can conclude that the physical characteristics of posts were important on stress distributions in post and core applications. Glass fiber post revealed more balanced stress distribution under functional forces.

Adanir, Necdet; Belli, Sema

2007-01-01

29

Conservative management of an intruded immature maxillary permanent central incisor with healing complication of pulp bone.  

PubMed

Traumatic intrusion injury of permanent teeth is serious with multiple complications possible associated with the pulp, periodontal ligament, alveolar bone and Hertwig's epithelial root sheath. The optimal treatment for the management of an intrusion injury has not yet been determined. A case is presented involving the conservative management of an immature maxillary permanent central incisor intrusively luxated by allowing for re-eruption and orthodontic extrusion two weeks later. After a follow-up period of ten months, the intruded tooth continued to show a mobility of grade one, without metallic percussion tone or infra-occlusion, which confirmed periodontal ligament healing. Although the intruded tooth failed to respond to dry ice testing, no other signs of pulp necrosis were evident and the colour of the intruded tooth was within normal limits throughout the follow-up period. However, complications of healing of Hertwig's epithelial root sheath occurred, causing in-growth of bone and periodontal ligament into the root canal. PMID:11481877

Roberts, J; Olsen, C; Messer, H

2001-04-01

30

Minimally invasive restoration of a maxillary central incisor with a partial veneer.  

PubMed

Minimally invasive treatment modalities allow for the preservation of sound tooth substance. However, by limiting the preparation to the extent of a defect, the transition between restoration and natural tooth may be moved to more visible areas. The materials available for the restoration of a limited defect in the anterior area are either resin composite materials or porcelain. A patient was presented who asked for the replacement of a discolored filling on the maxillary right central incisor. Tooth preparation was limited to the extent of the old filling, and a porcelain partial veneer restoration was fabricated. Despite the horizontal finish line in the middle of the clinical crown, a result could be achieved that was regarded as a success by the patient. This type of restoration proves to be a suitable alternative to direct composite restorations in the anterior area for the reconstruction of a limited defect, eg, due to a dental trauma. PMID:22319761

Horvath, Sebastian; Schulz, Claus-Peter

2012-01-01

31

Multidisciplinary Approach in Management of Fractured Central Incisor through Composite Plug Stabilization - A Case Report  

PubMed Central

Crown fracture is the most frequent type of traumatic injury in permanent dentition. Traumatized anterior teeth requires quick functional and esthetic repair. Traditionally such injuries have been restored with conventional post-core and crown techniques after endodontic treatment. This article presents an innovative technique of managing a complicate crown fracture of anterior tooth where plain orthodontic band was used for stabilization and post endodontic restoration was done with adhesively luted fiber reinforced composite post through fragment and composite plug stabilization. How to cite this article: Sushil K C, Rao A, Sheila K, Hanumanth R G. Multidisciplinary Approach in Management of Fractured Central Incisor through Composite Plug Stabilization - A Case Report. J Int Oral Health 2013; 5(1):79-82.

C, Sushil Kumar; Rao, Amit; K, Sheila; G, Hanumanth Reddy

2013-01-01

32

An endo-aesthetic management of crown dilaceration in a permanent mandibular central incisor.  

PubMed

Traumatic injuries to primary dentition may result in a wide range of developmental disturbances to succedaneous permanent teeth. The prevalence of morphological disturbances, secondary to dental injuries in the primary dentition, ranges from 12% to 69%. One of the morphological disturbances are crown dilacerations which are defined as the displacement of a portion of the developing crown at an angle to the longitudinal axis of the tooth. The prevalence of crown dilaceration constitutes 3% of the total injuries in developing teeth and is usually because of intrusion or avulsion of their primary predecessors. The present article narrates a case of crown dilaceration of a permanent mandibular right central incisor with open apex and large periradicular pathosis and its endo-aesthetic management with 2 years of follow-up. PMID:23417377

Wankhade, Abhijit D; Pandey, Ramesh Kumar; Singh, Rajeev Kumar; Naphade, Milind V

2013-02-14

33

Effects of post-core design and ferrule on fracture resistance of endodontically treated maxillary central incisors  

Microsoft Academic Search

Statement of Problem. Studies concerning the effects of post-core design and ferrule on the fracture resistance of endodontically treated teeth remain controversial. Purpose. The purpose of this study was to investigate in vitro the effects of post-core design and ferrule on the fracture resistance of root canal treated human maxillary central incisors restored with metal ceramic crowns. Material and Methods.

Lu Zhi-Yue; Zhang Yu-Xing

2003-01-01

34

Moving an ankylosed central incisor using orthodontics, surgery and distraction osteogenesis.  

PubMed

When a dentist replants an avulsed tooth, the repair process sometimes results in the cementum of the root and the alveolar bone fusing together, with the replanted tooth becoming ankylosed. When this occurs, the usual process of tooth movement with bone deposition and bone resorption at the periodontium cannot function. If dental ankylosis occurs in the maxillary incisor of a growing child, the ankylosed tooth also cannot move vertically with the subsequent vertical growth of the alveolar process. This results in the ankylosed tooth leaving the plane of occlusion and often becoming esthetically objectionable. This report describes a 12-year-old female with a central incisor that was replanted 5 years earlier, became ankylosed, and left the occlusal plane following subsequent normal vertical growth of the alveolar process. When growth was judged near completion, the tooth was moved back to the occlusal plane using a combination of orthodontics, surgical block osteotomy, and distraction osteogenesis to reposition the tooth at the proper vertical position in the arch. This approach had the advantage of bringing both the incisal edge and the gingival margin of the clinical crown to the proper height in the arch relative to their antimeres. Previous treatment procedures for ankylosed teeth have often involved the extraction of the affected tooth. When this is done, a vertical defect in the alveolar process results that often requires additional bone surgery to reconstruct the vertical height of the alveolar process. If the tooth is then replaced, the replacement tooth must reach from the final occlusal plane to the deficient ridge. This results in an excessively long clinical crown with a gingival height that does not match the adjacent teeth. PMID:11605877

Isaacson, R J; Strauss, R A; Bridges-Poquis, A; Peluso, A R; Lindauer, S J

2001-10-01

35

Surgical management of multiple supernumerary teeth and an impacted maxillary permanent central incisor.  

PubMed

Hyperdontia is the condition of having supernumerary teeth, or teeth which appear in addition to the regular number of teeth. It is a developmental anomaly and has been argued to arise from multiple aetiologies. The most common site is the maxillary incisor region; but the prevalence of more than three teeth supernumerary tooth is less than 1%. A case of 13 year male patient is reported with a multiple impacted supernumerary tooth in maxillary anterior region hindering the eruption of right permanent central incisor. The supernumerary tooth was treated via surgical approach followed by an interim prosthesis for permanent central incisor which later on erupted in due course of time. Background Supernumerary teeth may be defined as any teeth or tooth substance in excess of the usual configuration of 20 deciduous and 32 permanent teeth. The presence of supernumerary teeth in the premaxillary region often poses unique diagnostic and managerial concerns for the practitioner. Rarely is the surplus number compensated by an absence or deficiency of other teeth. Therefore, the dysfunctional nature of supernumerary teeth and their ability to create a variety of pathological disturbances in the normal eruption and position of adjacent teeth warrants their early detection and prudent management. Approximately 76-86% of cases represent single-tooth hyperdontia, with two supernumerary teeth noted in 12-23% and three or more extra teeth noted in less than 1% of cases. Multiple supernumerary teeth are also associated with many syndromes like cleidocranial dysplasia and Gardner’s syndrome etc. However, it is rare to find multiple supernumeraries in individuals with no other associated disease or syndrome. In such cases, the maxillary anterior region is the common site of occurrence. The exact aetiology is not clearly understood. The supernumerary teeth result from any disturbance in the initiation and proliferation stages of odontogenesis. There are several theories regarding the development of a supernumerary tooth-phylogenetic reversion (atavism) theory, dichotomy of tooth germ theory and hyperactivity of the dental lamina. The latter being the most accepted theory, states that the remnants of dental lamina or palatal offshoots of active dental lamina are induced to develop into an extra tooth bud, which results in the formation of a supernumerary tooth. Genetics is also considered to contribute to the development of supernumerary teeth, as these have been diagnosed in twins, siblings and sequential generations of a family. Classification of supernumerary teeth may be on the basis of position or form. Positional variations include mesiodens, paramolars, distomolars and parapremolars. Variations in form consist of conical types, tuberculate types, supplemental teeth and odontomes. Supernumerary teeth may, therefore, vary from a simple odontome, through a conical or tuberculate tooth to a supplemental tooth which closely resembles a normal tooth. Also, the site and number of supernumeraries can vary greatly. This report presents a case of a non-syndromic male patient with multiple supernumerary teeth and a permanent impacted tooth in the maxillary anterior region. PMID:23704467

Rallan, Mandeep; Rallan, Neelakshi Singh; Goswami, Mousumi; Rawat, Kamini

2013-05-22

36

Unique CAD/CAM three-quarter crown restoration of a central incisor: a case report.  

PubMed

Computer-aided design and computer-aided manufacturing (CAD/CAM) dentistry has been in use for more than 2 decades. Recent improvements in this technology have made CAD/CAM restorations a viable alternative for routine dental care. This technology is being taught in dental schools to prepare students for contemporary dental practice and is particularly useful in unique restorative situations that allow conservation of tooth structure. This case report describes the restoration of a central incisor that was previously restored with an unesthetic three-quarter gold crown. The tooth exhibited recurrent caries and an unaffected labial wall of supported enamel. A CAD/CAM three-quarter crown was planned to conserve tooth structure. After preparation, the tooth was scanned for a CAD/CAM crown in order to fabricate a ceramic restoration, which was then milled and bonded, producing an esthetic result. Typically, in cases of esthetic enhancement, a labial laminate restoration is fabricated, but in this situation, a different approach was necessary to make a design for the lingual surface of an anterior tooth. PMID:23823342

Goldberg-Quieroz, Marvin B; Siegel, Sharon C; Rezakani, Niloufar

2013-07-01

37

Finite element analysis of stress concentration in three popular brands of fiber posts systems used for maxillary central incisor teeth  

PubMed Central

Aims and Objectives: To study the stress concentrations in endodontically treated maxillary central incisor teeth restored with 3 different fiber post systems subjected to various oblique occlusal loads. Materials and Methods: FEM analysis was used to analyze stress concentrations generated in maxillary anterior teeth. Computer aided designing was used to create a 2-D model of an upper central incisor. Post systems analyzed were the DT Light Post (RDT, Bisco), Luscent Anchor (Dentatus) & RelyX (3M-ESPE). The entire design assembly was subjected to analysis by ANSYS for oblique loading forces of 25N, 80N & 125 N Results: The resultant data showed that the RelyX generated the least amount of stress concentration. Conclusions: Minimal stress buildups contribute to the longevity of the restorations. Thus RelyX by virtue of judicious stress distribution is the better option for restoration of grossly decayed teeth.

Aggarwal, Shalini; Garg, Vaibhav

2011-01-01

38

Nonlinear finite element analysis of the vibration characteristics of the maxillary central incisor related to periodontal attachment  

Microsoft Academic Search

The vibration characteristics of a maxillary central incisor were investigated by using the finite element method (FEM) according\\u000a to nonlinear behavior of the human periodontal ligament (PDL). The effect of alveolar bone loss was also studied to obtain\\u000a the relationship between the vibration property of the tooth in the periodontal system and the level of periodontal attachment\\u000a for assessing the

Haitao Xin; Yulong Li; Lingcheng Zhao; Weiguo Guo

2009-01-01

39

Treatment of class II malocclusion with open bite and absence of central maxillary incisor lost by trauma aided by use of orthodontic mini-implants.  

PubMed

The aim of this article is to report the clinical case of non-surgical treatment of a Class II malocclusion with anterior open bite, associated with absence of a maxillary central incisor avulsed due to trauma. Treatment proceeded with the use of orthodontic mini-implants as an anchorage device for intrusion of the maxillary molars and for mesial movement of the lateral incisor to replace the central incisor. Treatment resulted in good occlusion, with anterior and lateral guides, enhancement of the facial profile, and good dental esthetic appearance without the need for prosthetic treatment. The treatment outcome was satisfactory but needs long-term or permanent retention. PMID:23331427

Pithon, Matheus Melo

2013-01-17

40

Treatment of class 2 division 1 malocclusion with severe short roots of upper central incisors  

PubMed Central

The average amount of resorption per root of examined maxillary incisors or anterior teeth is < 1.5 mm during comprehensive orthodontic treatment. About 5% of adults and 2% of adolescents are likely to have at least one tooth with resorption of more than 5 mm during active treatment. Although resorption stops once the active appliances are removed, fortunately, truly severe resorption that threatens the longevity of the tooth or forces a halt to treatment is rare. The fact is, however that orthodontic tooth movement does directly cause irreversible resorption of the root. As the movers of the teeth, it is incumbent for us to know as much as possible about the causes, effects and prevention of this phenomenon.

Chandrasekar, Ramaswamy; Sridevi, Kondety Sambamoorthy

2013-01-01

41

Orthodontic movement of a maxillary central incisor with a horizontal root fracture treated using an intra-radicular fibre splint  

PubMed Central

This paper reports the case of a 15-year-old boy with a horizontal root fracture in the left maxillary central incisor along with class II division 1 malocclusion for whom a fixed orthodontic treatment was planned. The fracture was present at the junction of apical and middle-third as a result of trauma 2 years back. No splinting was carried out at that time and the tooth was found to be vital, asymptomatic and showed a type-1 repair pattern. An intentional root canal treatment was carried out for placement of an intra-radicular fiber splint, nearly 3 mm beyond the fracture line. Orthodontic treatment was initiated after a month; to which the fractured and splinted tooth responded successfully. This report highlights the successful use of an intra-radicular splint for horizontally fractured tooth requiring orthodontic treatment.

Kapur, Aditi; Utreja, A.; Goyal, A.; Pankaj, P.

2013-01-01

42

A rare case of dilated invaginated odontome with talon cusp in a permanent maxillary central incisor diagnosed by cone beam computed tomography  

PubMed Central

It has been a challenge to establish the accurate diagnosis of developmental tooth anomalies based on periapical radiographs. Recently, three-dimensional imaging by cone beam computed tomography has provided useful information to investigate the complex anatomy of and establish the proper management for tooth anomalies. The most severe variant of dens invaginatus, known as dilated odontome, is a rare occurrence, and the cone beam computed tomographic findings of this anomaly have never been reported for an erupted permanent maxillary central incisor. The occurrence of talon cusp occurring along with dens invaginatus is also unusual. The aim of this report was to show the importance of cone beam computed tomography in contributing to the accurate diagnosis and evaluation of the complex anatomy of this rare anomaly.

Mohan Kumar, Rangarajan Sundaresan; Srinivasan, Ramasamy

2013-01-01

43

The restoration of a maxillary central incisor fracture with the original crown fragment using a glass fiber-reinforced post: a clinical report.  

PubMed

This report describes an esthetic, conservative, and economical alternative restoration technique for a fractured central incisor using the patient's own tooth crown piece and a bondable reinforcement glass fiber. Although the long-term durability of this adhesive post core restoration remains unknown, it remains successful after 1 year. PMID:19021643

Durkan, Rukiye Kaplan; Ozel, M Birol; Celik, Davut; Ba?i?, Bora

2008-12-01

44

A new syndrome with overlapping features of Townes-brocks syndrome and single median maxillary central incisor syndrome  

PubMed Central

A 14-month-old boy with overlapping features of Townes-Brocks syndrome (TBS) and single median maxillary incisor syndrome (SMMCIS) is being reported with brief review of the above syndromes and possible differential diagnosis.

Babu, Thirunavukkarasu Arun; Chandrasekaran, Venkatesh; Balachandran, Sathish

2012-01-01

45

Age estimation by pulp/tooth ratio in lateral and central incisors by peri-apical X-ray.  

PubMed

Since 2004, several papers on the analysis of the apposition of secondary dentine have been published. The aim of this paper was to study a sample of peri-apical X-ray images of upper and lower incisors, both lateral and medial, to examine the application of pulp/tooth area ratio as an indicator of age. A sample of 116 individuals, 62 men and 54 women, aged between 18 and 74 years, was studied. Data were fitted with age as a linear function of the pulp/tooth ratio of incisors. The total variance explained by the regression equation ranged from 51.3% of age, when lower lateral incisors were used as explanatory variable, to 81.6% when upper lateral incisors were used. The accuracy of the corresponding regression model yielded ME = 8.44 and 5.34 years, respectively. These results show that, although incisors are less reliable than canines or lower premolars, they can be used to estimate age-at-death when the latter are absent. PMID:23756528

Cameriere, R; Cunha, E; Wasterlain, S N; De Luca, S; Sassaroli, E; Pagliara, F; Nuzzolese, E; Cingolani, M; Ferrante, L

2013-04-06

46

Acute treatment of a concomitant horizontal root fracture and luxation of the coronal fragment of the right upper central incisor: a case report.  

PubMed

We report a case of a horizontal intra-alveolar root fracture between the middle and apical third of the upper right central incisor associated with an extrusive luxation of the coronal fragment, in a 24-year-old male patient. Twenty minutes after being accidentally hit by a metallic device, the patient's coronal portion was repositioned and splinted under local anesthesia. After that, we lost sight of the patient. One year later, the patient showed up. The splint was lost, the tooth showed physiological mobility and responded to pulp testing. Radiographs showed healing of the horizontal fracture and normal periodontal ligament. PMID:20455916

Berrezouga, Latifa; Belkhir, Chems; Jbir, Ridha; Belkhir, Mohamed Semir

2010-04-27

47

Management of recently traumatized maxillary central incisors by partial pulpotomy using MTA: Case reports with two-year follow-up  

PubMed Central

In traumatized, young, permanent teeth, pulpotomy is classically undertaken to promote apexogenesis. The objective is to promote root development and apical closure. Once root end development and apical closure is achieved, the root canal treatment is completed. However, it has been suggested that mere pulp exposure does not cause pulpitis in the absence of bacteria. Recent studies have proposed that as long as a good seal is ensured, root canal treatment may not be necessary following pulpotomy. In this article we report two cases of traumatized, fully matured, maxillary permanent central incisors, which have been treated with mineral trioxide aggregate following partial pulpotomy, with a two-year follow-up.

Abarajithan, M.; Velmurugan, N.; Kandaswamy, D

2010-01-01

48

Solitary median maxillary central incisor syndrome (SMMCI) with congenital nasal puriform aperture stenosis: literature review and case report with comprehensive dental treatment and 14 years follow-up.  

PubMed

BACKGROUND: Solitary median maxillary central incisor syndrome [SMMCI] is an extremely rare anomaly, especially when no other abnormalities are present. The defect is often found together with various nasal abnormalities and short stature with or without decreased levels of growth hormone. In more severe cases, SMMCI has been associated with holoprosencephaly, the CHARGE and the VACTERL association. Also, published sporadic cases have been related with rare variants of ectodermal dysplasia, chromosomal abnormalities, precocious puberty, hypothalamic hamartoma, congenital heart defects, physical/mental retardation, genital hypoplasia and ear abnormalities. For these reasons when the initial diagnosis is made by the paediatric dentist, ENT, neurological and paediatric evaluations are essential. CASE REPORT: A 4-year-old boy with SMMCI was referred for dental treatment. Clinical/radiographic examination revealed a symmetrical primary and permanent SMMCI, a skeletal Class I and a unilateral crossbite. Medical history indicated respiratory distress and surgery soon after birth due to congenital nasal puriform aperture stenosis. Gradual orthodontic treatment started at the age of 4 years and completed at the age of 13 years. Following maxillary expansion, upper lateral segments were moved backwards and anterior space was created for accommodating a second central incisor. Retainers with a supplementary acrylic incisor were provided for aesthetic and functional replacement until the age of 16 years, when a fixed Maryland ceramic bridge was placed. FOLLOW-UP: Two years recall, at the age of 18 years, revealed a satisfactory and stable aesthetic and functional result. CONCLUSION: Successful dental management of SMMCI patients is possible, following a detailed long-lasting treatment plan requiring multidisciplinary paediatric dental, orthodontic and prosthetic approach. PMID:23775592

Lygidakis, N N; Chatzidimitriou, K; Petrou, N; Lygidakis, N A

2013-06-18

49

Influence of Implant Position on Clinical Crown Length and Peri-implant Soft Tissue Dimensions at Implant-Supported Single Crowns Replacing Maxillary Central Incisors.  

PubMed

The aims of this study were to evaluate the influence of implant position on clinical crown length and marginal soft tissue dimensions at implant-supported single crowns of maxillary central incisors and to validate the papilla index score (PIS). Twenty-five patients were included. Standardized and clinical photographs and periapical radiographs from baseline were used to assess three-dimensional positional parameters. The contralateral central incisors were used as controls. Paired sample t test and Pearson correlation analysis were used to analyze implant position, dimension of crown, and papilla fill. Cohen ? and Spearman correlation were used to validate the PIS. The implant-supported crown was statistically significantly longer than the contralateral tooth, and there was significant correlation between the orofacial position of the implant and the crown length difference. The distal papilla was significantly shorter than the mesial papilla at implant-supported crowns, but this difference was not significant at the contralateral tooth. A significant relationship between the PIS and papilla fill was found. An implant protruding the mucosa in a buccal position will result in an increased implant crown length compared to the contralateral tooth. Minor buccal angulations of the implant could be corrected with customized angulated abutments and did not necessarily result in an increased crown length. The distal implant papilla height was obviously shorter, although the mesial papilla height was similar to that of the healthy dentition. The PIS was found to be a valid index for papilla fill. PMID:24116357

Peng, Min; Fei, Wei; Hosseini, Mandana; Gotfredsen, Klaus

50

Evaluation of the mineralization degree of the vestibular surface of the upper central incisors with a 655-nm diode laser in mouth breathers: preliminary results  

NASA Astrophysics Data System (ADS)

Mouth breathing unbalances the physiological mechanisms of the dental surface hydration by compromising lip closure, and, very often, causing the vestibular positioning of upper incisors. That variance leads to the interruption of the dental demineralization and remineralization feedback, prevailing a demineralized condition of the dental surface which increases caries risk. The laser fluorescence examination allows an early demineralization diagnosis, thus it makes possible through preventive measures to minimize the risk factor dental mineral structure loss in the bacterial infection of the demineralized area, and hence, preventing invasive therapeutical procedures. A DIAGNOdent® apparatus was used to evaluate the mineralization degree of the upper central incisors in 40 patients twenty of them with a mouth breathing diagnosis; the remaining twenty were nasal breathers (control group). Age ranging from 6 to 12 years, both male and female. To measure the vestibular surface of the incisors, it was divided into 3 segments: cervical, medial and incisal. The average of the results pertaining to the mouth breathing patients was as follows: tooth 11 cervical third - 5.45, medial third - 7.15, incisal third - 7.95, and tooth 21 - cervical third - 5.95, medial third - 7.25, incisal third - 8.15. The control patients, nasal breathers, presented the following results: tooth 11 cervical third - 1.75, medial third - 2.30, incisal third - 1.85, and tooth 21 - cervical third - 1.80, medial third - 2.20, incisal third - 2.15. The mouth breathing patients showed demineralization in the teeth examined at the initial stage, subclinical, comparing with the control patients, nasal breathers, who did not present any mineral deficit in these teeth.

Pinheiro Ladalardo, Thereza C. C. G.; Cappellette, Mário, Jr.; Zanin, Fátima A. A.; Brugnera, Aldo, Jr.; Anthero de Azevedo, Ramiro; Pignatari, Shirley; Weckx, Luc L. M.

2003-06-01

51

[The role of the maxillary incisors in the development of the base of the nose. Applications in dento-facial orthopedics].  

PubMed

The neonatal respiratory distress observed in the event of a solitary median maxillary central incisor compels us to reconsider some of the traditional concepts relative to the transverse growth of the nasal level of the face. The "container-contents" connections associating maxillary incisor odontogenesis with the development of the premaxillary and facial envelopes draw the attention to the significant geometrical and mechanical expression of this morphogenesis. They require attributing to the maxillary incisors an important motor role in this development. They lead to granting the ontogenetic bonds, between malocclusions and disturbed nasal breathing, the place they deserve, taking into account the morphological integration combining them. They eventually open a new therapeutic prospect: the optimization of the development of the growing face, with regard to the various tissue mechanics and physiologies, becoming the best guarantor for the prevention of relapse after dentofacial orthopedics. PMID:16708654

Talmant, J; Deniaud, J

2006-03-01

52

Ex vivo fracture resistance of endodontically treated maxillary central incisors restored with fiber-reinforced composite posts and experimental dentin posts  

PubMed Central

Aim: To compare the fracture resistance of teeth restored with fiber-reinforced composite (FRC) posts and experimental dentin posts milled from human root dentin. Materials and Methods: Thirty maxillary central incisors were divided into three groups of ten each. Twenty teeth were restored with FRC posts and solid dentin posts and numbered as Groups 2 and 3 respectively while Group 1 acted as the control, without any post. The teeth were loaded at 135° angle to their long axes after core build-up and the failure loads were recorded. Results: One-way Analysis of Variance (ANOVA) and Bonferroni multiple comparisons revealed a significant difference among test groups with the control group showing the highest fracture resistance, followed by the dentin post group and lastly the FRC post group. Conclusions: Teeth restored with dentin posts exhibited better fracture resistance than those restored with FRC posts.

Kathuria, Ambica; Kavitha, M; Khetarpal, Suchit

2011-01-01

53

Identical unerupted maxillary incisors in monozygotic twins.  

PubMed

Mesiodens is the most common type of supernumerary tooth found in the premaxilla. It might be discovered by the orthodontist by chance on a radiograph or as the cause of an unerupted maxillary central incisor. The genetic transmission of supernumerary and impacted teeth is poorly understood. The occurrence of identical unerupted maxillary central incisors and mesiodentes in monozygotic twins suggests that genetic factors might influence the etiology of this problem. In this case report, we discuss the treatment of unerupted maxillary permanent incisors caused by mesiodentes in monozygotic twins. PMID:20889057

Babacan, Hasan; Öztürk, F?rat; Polat, Hidayet Burak

2010-10-01

54

Macrodontic maxillary incisor in alagille syndrome  

PubMed Central

This case report describes the surgical-orthodontic guided-eruption of a deeply impacted macrodontic maxillary central incisor in a 10-year-old patient with Alagille syndrome (ALGS). In the first stage, orthodontic treatment with fixed appliance on deciduous teeth allowed to create enough space for the eruption of the maxillary right central incisor. The second stage included closed surgical exposure and vertical traction. After impacted tooth erupted in the proper position, accessory periodontal treatment and dental reshaping procedures may be indicated to camouflage macrodontic incisor with the adjacent teeth. This is the first report that presents a patient with ALGS undergoing orthodontic and surgical treatment.

Cozzani, Mauro; Fontana, Mattia

2012-01-01

55

Retreatodontics in maxillary lateral incisor with supernumerary root  

PubMed Central

Familiarity with the intricacies and variations of root canal morphology is essential for successful endodontic treatment. Maxillary central and lateral incisors are known to be single rooted with one canal. This case report describes endodontic retreatment of maxillary lateral incisors with two root canals, one of which was missed during the initial treatment.

Dexton, Antony Johns; Arundas, D; Rameshkumar, M; Shoba, K

2011-01-01

56

Proton microprobe assessment of the distribution of fluoride in the enamel and dentine of developing central incisors of sheep and changes induced by daily fluoride supplements.  

PubMed

Ten sheep were given 0.5 mg fluoride (F) and 10 sheep 0.2 mg F/kg body wt orally for periods of 1-6 months while 8 sheep received no additional F. One incisor from each sheep was sectioned longitudinally in the midline and, using the proton microprobe, multiple scans for calcium and F were made across the enamel and dentine. F was determined by proton-induced gamma-ray emission and calcium by X-ray emission. Tooth length and hence the stage of ameloblast activity for each of the 28 teeth at the start of the experiment was determined using a tetracycline marker. In addition, the stage of enamel development of the eight control teeth (no dietary F) at the time of their extraction was assessed from their macroscopic appearance. Continuous changes in F levels occurred in both enamel and dentine throughout tooth development and also in the mature enamel and associated dentine after ameloblast regression. All scans for all stages of tooth development and all F treatments showed a high F concentration at the enamel surface. Early in the secretory phase, a wide-based F peak occupied the entire width of the enamel with a similar F peak in the dentine. In the control teeth, no consistent increase in F concentration occurred at the enamel surface during later development. When F supplements were started early in the maturation phase an increase in F concentration only at the enamel surface was recorded. When F supplements were also given during the secretory phase, higher F concentrations were recorded not only at the enamel surface but also for the inner enamel and dentine plateau. These findings, based on a small number of sheep, indicate that further research is needed to clarify the method and control of F uptake and to determine the changes in these processes during the different stages of tooth development. PMID:7639647

Suckling, G; Coote, G E; Cutress, T W; Gao, J

1995-05-01

57

Case report: endodontic and surgical treatment of an upper central incisor with external root resorption and radicular cyst following a traumatic tooth avulsion.  

PubMed

In the age group between 6 and 12 years, trauma to the upper incisors happens frequently. In the case of avulsion, a replantation is the state-of-the-art treatment; however, it may lead to several complications, particularly if suitable posttraumatic management is not carried out. External cervical resorptions as well as apical granuloma and cysts due to microbial contamination of the root canal are common complications. In the presented trauma case, a conservative approach was chosen to treat a large cystic lesion combined with cervical and apical resorptions. After initial placement of Ledermix and calcium hydroxide into the root canal, a marsupialization with the temporary insertion of an obturator was performed. The gradual reduction led to a fast recovery of the bony defect and a root canal filling was placed. The 2-year follow-up showed an improved condition. All adjacent teeth remained vital during the course of the treatment. PMID:20692191

Lux, Hans-Christian; Goetz, Falko; Hellwig, Elmar

2010-08-09

58

Apexogenesis and revascularization treatment procedures for two traumatized immature permanent maxillary incisors: a case report  

PubMed Central

Traumatic injuries to an immature permanent tooth may result in cessation of dentin deposition and root maturation. Endodontic treatment is often complicated in premature tooth with an uncertain prognosis. This article describes successful treatment of two traumatized maxillary central incisors with complicated crown fracture three months after trauma. The radiographic examination showed immature roots in maxillary central incisors of a 9-year-old boy with a radiolucent lesion adjacent to the right central incisor. Apexogenesis was performed for the left central incisor and revascularization treatment was considered for the right one. In 18-month clinical and radiographic follow-up both teeth were asymptomatic, roots continued to develop, and periapical radiolucency of the right central incisor healed. Considering the root development of these contralateral teeth it can be concluded that revascularization is an appropriate treatment method in immature necrotic teeth.

Forghani, Maryam; Maghsoudlou, Amir

2013-01-01

59

The influence of varying maxillary lateral incisor dimensions on perceived smile aesthetics  

Microsoft Academic Search

Objective The aim of this study was to determine the influence of varying the dimensions of the maxillary lateral incisors on perceived smile aesthetics.Design Clinical study.Setting Postgraduate dental teaching hospital.Methods A photograph of a female smile displaying only the lips and teeth was digitally altered. First, the width of the maxillary lateral incisors, in proportion to the central incisor, was

S. M. N. Bukhary; D. S. Gill; D. R. Moles; C. J. Tredwin

2007-01-01

60

Development of ankylosis in permanent incisors following delayed replantation and severe intrusion.  

PubMed

Ankylosis is a predictable outcome for replanted incisors and for most severely intruded incisors. There is no treatment to arrest or reverse this periodontal ligament complication. Ankylosis of the incisors of preadolescents alters local alveolar growth and eventually produces tooth loss subsequent to resorption. Currently, clinical methods used to diagnose ankylosis in the early postinjury period include subjective assessments of percussion sound and mobility and quantitative devices such as the Periotest. This paper describes the progression of ankylosis in two preadolescent patients that sustained severe trauma to their maxillary central incisors. A number of clinical assessments for diagnosis of ankylosis were compared for their usefulness, reliability and suitability. PMID:17355290

Campbell, Karen M; Casas, Michael J; Kenny, David J

2007-06-01

61

Case studyRetention of permanent incisors by mesiodens: a family affair  

Microsoft Academic Search

The term mesiodens refers to a supernumerary tooth that is present in the midline of the maxilla between the two central incisors. One or two mesiodentes may be present. We present a rare case of two sisters, in both of whom a pair of mesiodentes caused the retention of permanent incisors. They were referred to our hospital with asymptomatic delayed

A García; Ma Mercedes Gallas

2000-01-01

62

Permanent mandibular incisor with multiple anomalies - report of a rare clinical case.  

PubMed

Permanent mandibular central incisor is rarely affected by tooth shape anomalies of crown and root. Co-occurrence of multiple anomalies in a permanent mandibular central incisor is extremely rare. This paper reports an unusual concurrent combination of multiple dental anomalies affecting both the crown and root of a permanent mandibular left central incisor - talon cusp, dens invaginatus, short root anomaly and macrodontia -, which has not previously been reported together. Case management is described and implications are discussed. The dentist should be aware of these rare entities in order to provide an accurate diagnosis and management for which detailed examination of the tooth both clinically and radiographically is very important. PMID:21861037

Nagaveni, Nayaka Basavanthappa; Umashanikara, Kagathur Veerbadrapa; Vidyullatha, B G; Sreedevi, Sreedevi; Radhika, Nayaka Basavanthappa

2011-01-01

63

Inverted Impacted Primary Maxillary Incisors: A Case Report  

PubMed Central

Tooth impaction rarely occurs in primary dentition. Most of the primary teeth impactions are seen in second molars. The purpose of this article is to present a 4-year-old girl with bilateral impaction of inverted primary maxillary central incisors which trauma had displaced their tooth germ before erupting.

Seraj, B.; Ghadimi, S.; Mighani, G.; Zare, H.; Rabbani, M.

2012-01-01

64

Middle Paleolithic human deciduous incisor from Khudji, Tajikistan  

Microsoft Academic Search

In 1997 a human mandibular second deciduous incisor was discovered during excavations at the central Asian Middle Paleolithic site of Khudji, Tajikistan. The specimen was associated with a late Middle Paleolithic assemblage in a minimally disturbed cultural layer. The specimen is average in size for Late Pleistocene archaic human di2s and differs from many late archaic human di2s in having

Erik Trinkaus; Vadim A. Ranov; Stanislav Lauklin

2000-01-01

65

Familial aggregation of maxillary lateral incisor agenesis (MLIA).  

PubMed

Agenesis of maxillary lateral incisors and mandibular second premolars is the most frequent form of hypodontia. Its prevalence varies across population from 0.8% to 4.5%. Genetic aberrations and environmental factors may cause agenesis of one or more teeth. The management of child having such a problem is very important since diastema in teeth especially in upper anteriors not only affects child's physical appearance but also its psychological development as the child wants to look like other children. In this article is presented a case of non-syndromic agenesis of maxillary lateral incisors (MLIA) and mandibular central incisors in a 10-year-old boy (patient) in permanent dentition with its management along with the radiographic investigations and photographic presentations of the other members of his family affected with this condition. PMID:23536620

Pandey, Pallavi; Ansari, Afroz Alam; Choudhary, Kartik; Saxena, Aditya

2013-03-26

66

Management of intrusive luxation of maxillary incisors with dens in dente: a case report.  

PubMed

Intrusive luxation is one of the most severe types of dental traumatic injuries. The risk of occurrence of pulpal necrosis and inflammatory or replacement resorption is high. In an attempt to prevent or delay the appearance of such lesions, endodontic intervention is required soon after the occurrence of trauma. A 17-year-old boy reported to the Department of Conservative dentistry and Endodontics, KLE VK Institute of Dental Sciences, Belgaum, 2 days after a fall from a bicycle. Clinical and radiographic examination revealed an intrusive luxation of the left maxillary central incisor and lateral incisor. There were complicated crown fracture with the right maxillary central incisor and uncomplicated crown fracture with the left maxillary central incisor. Also, all the incisors showed the presence of Oelhers type II Dens-in-dente. The management was hence challenging. Immediate surgical repositioning was performed and the teeth were stabilized with a composite resin splint. Endodontic therapy was initiated with the right maxillary central incisor, and the canal was sealed with calcium hydroxide dressing. After 3 weeks, pulp sensitivity was repeated with the maxillary left central and lateral incisors. The result was negative. Considering the incidence of pulp necrosis and root resorption in intruded teeth with complete root formation, they also were dealt in a similar manner as the maxillary right central incisor. The splint was removed after 1 month. After 6 months of calcium hydroxide therapy, there was a satisfactory apical and periodontal healing. At this stage, the teeth were obturated and the fractures were restored with composite resin. A 1-year follow up revealed a satisfactory clinical and radiographic outcome. PMID:20636362

Patil, Anand C; Patil, Rajesh R

2010-10-01

67

Mandibular talon cusp in primary lateral incisor: a rare case report.  

PubMed

A talon cusp is a dental anomaly commonly occurring in the permanent dentition compared to the primary dentition. It commonly affects the maxillary anterior teeth. In primary dentition, the most commonly affected tooth is the maxillary central incisors. This is a rare case report of a 5-year-old male patient with a talon cusp affecting the mandibular primary lateral incisor. Recognition and treatment of this anomaly at early stages is important to avoid complications. PMID:23320201

Kavitha, Swaminathan; Selvakumar, Haridoss; Barathan, Rajendran

2012-12-25

68

Mandibular Talon Cusp in Primary Lateral Incisor: A Rare Case Report  

PubMed Central

A talon cusp is a dental anomaly commonly occurring in the permanent dentition compared to the primary dentition. It commonly affects the maxillary anterior teeth. In primary dentition, the most commonly affected tooth is the maxillary central incisors. This is a rare case report of a 5-year-old male patient with a talon cusp affecting the mandibular primary lateral incisor. Recognition and treatment of this anomaly at early stages is important to avoid complications.

Kavitha, Swaminathan; Selvakumar, Haridoss; Barathan, Rajendran

2012-01-01

69

Actor Centrality Correlates to Project Based Coordination  

Microsoft Academic Search

In this study, we draw on network centrality concepts and coordination theory to understand how project team members interact when working towards a common goal. A text-mining application based on the constructs of coordination theory was developed to measure the coordinative activity of each employee. Results show that high network centrality is correlated with the ability of an actor to

Liaquat Hossain; Andre Wu; Kon Shing Kenneth Chung

2006-01-01

70

Comparison of the Physiological Properties of Human Periodontal-Masseteric Reflex Evoked by Incisor and Canine Stimulation  

PubMed Central

Introduction: The present study was designed to clarify whether the bilateral cooperation in the human periodontal-masseteric reflex (PMR) differs between central incisors and canines. Methods: Surface array electrodes were placed on the bilateral masseter muscles to simultaneously record the firing activities of single motor units from both sides in seven healthy adults. During light clenching, mechanical stimulation was applied to the right maxillary central incisor and canine to evoke the PMR. Unitary activity was plotted with respect to the background activity and firing frequency. The slope of the regression line (sRL) and the correlation coefficient (CC) between the central incisor and canine and the lateral differences between these values were compared. Results: There were significant differences in the sRL and CC, as well as lateral differences, between the central incisor- and canine-driven PMR. Discussion: These results suggest that the PMR differs depending on both the tooth position and laterality.

Ohmori, Hiroko; Kirimoto, Hiroaki; Ono, Takashi

2012-01-01

71

Alveolar ridge width and height changes after orthodontic space opening in patients congenitally missing maxillary lateral incisors.  

PubMed

The purpose of this study was to evaluate the dimensional changes of the alveolar ridge in patients with congenitally missing maxillary lateral incisors. The width and height of the alveolar ridge were compared before and after opening space for an endosseous dental implant between the central incisor and canine. Pre- and post-treatment dental stone models of 31 patients (8 males, 23 females; mean age 15.1 ± 7.9 years pre-treatment, 17.6 ± 8 years post-treatment) with unilaterally or bilaterally, congenitally missing maxillary lateral incisors were used in this study. Pre- and post-treatment measurements included: the space between the maxillary central incisor and canine, the depth of the labial concavity, and the width and height of the lateral incisor alveolar ridge. Two different techniques were used to measure the ridge width. Student's paired samples t-test was used to test for significance. The alveolar ridge underwent statistically significant width loss (Method 1: 4-8 per cent, Method 2: 13-15 per cent) during the course of orthodontic treatment. A 6-12 per cent loss in ridge height was also noted. The depth of the labial concavity between the maxillary central incisor and canine nearly doubled. There was a significant decrease in the width and height of the alveolar ridge in patients congenitally missing a maxillary lateral incisor who received orthodontic treatment to create space for an endosseous dental implant. PMID:21750237

Uribe, Flavio; Chau, Vincent; Padala, Soumya; Neace, William P; Cutrera, Alice; Nanda, Ravindra

2011-07-12

72

Revascularization of immature permanent incisors after severe extrusive luxation injury.  

PubMed

Pulp necrosis is an uncommon sequel to extrusive luxation in immature teeth with incomplete apical closure. In this report, we describe the management of severely extruded immature maxillary incisors and the outcome of revascularization to treat subsequent pulp necrosis. An 8.5-Year-old boy with severe dentoalveolar trauma to the anterior maxillary region as a result of a fall was provided emergency treatment consisting of reduction of the dislodged labial cortical bone and repositioning of the central incisors, which had suffered extrusive luxation. When he presented with spontaneous pain involving the traumatized incisors a week later, the teeth were treated via a revascularization protocol using sodium hypochlorite irrigation followed by 3 weeks of intracanal calcium hydroxide, then a coronal seal of mineral trioxide aggregate and resin composite. Complete periradicular healing was observed after 3 Months, followed by progressive thickening of the root walls and apical closure. Follow-up observations confirmed the efficacy of the regenerative treatment as a viable alternative to conventional apexification in endodontically involved, traumatized immature teeth. PMID:22322021

Cehreli, Zafer C; Sara, Sezgi; Aksoy, Burak

2012-01-01

73

Revascularization of immature permanent incisors after severe extrusive luxation injury.  

PubMed

Pulp necrosis is an uncommon sequel to extrusive luxation in immature teeth with incomplete apical closure. In this report, we describe the management of severely extruded immature maxillary incisors and the outcome of revascularization to treat subsequent pulp necrosis. An 8.5-year-old boy with severe dentoalveolar trauma to the anterior maxillary region as a result of a fall was provided emergency treatment consisting of reduction of the dislodged labial cortical bone and repositioning of the central incisors, which had suffered extrusive luxation. When he presented with spontaneous pain involving the traumatized incisors a week later, the teeth were treated via a revascularization protocol using sodium hypochlorite irrigation followed by 3 weeks of intracanal calcium hydroxide, then a coronal seal of mineral trioxide aggregate and resin composite. Complete periradicular healing was observed after 3 months, followed by progressive thickening of the root walls and apical closure. Follow-up observations confirmed the efficacy of the regenerative treatment as a viable alternative to conventional apexification in endodontically involved, traumatized immature teeth. PMID:22916525

Cehreli, Zafer C; Sara, Sezgi; Aksoy, Burak

2012-07-01

74

Impacted maxillary incisors: diagnosis and predictive measurements  

PubMed Central

Summary Background When the incisors do not erupt at the expected time, it is crucial for the clinician to determine the etiology and formulate an appropriate treatment plan. Aim The aim of this report is to provide useful information for immediate diagnosis and management of impacted maxillary incisors using the interceptive treatment: removal of obstacles and rapid maxillary expansion (RME). Design An accurate diagnosis may be obtained with clinical and radiographic exam such as panoramic radiograph, computerized tomography (CT) and cone beam computerized tomography (CBCT). It’s important to know the predictive measurements of eruption evaluated on panoramic radiograph: distance from the occlusal plane, maturity, angulation and vertical position of the unerupted incisors. Early diagnosis is important and interceptive orthodontic treatment, such as removal of obstacles and orthopedic rapid maxillary expansion (RME), may correct disturbances during the eruption through recovering space for the incisors and improving the intraosseus position of delayed teeth. Results RME treatment following the surgical removal of the obstacle to the eruption of maxillary incisors leads to an improvement of the intraosseus position of the tooth. Conclusions The angulation and the vertical position of the delayed tooth appear to be important in trying to predict eruption. The improvement of the intraosseus position of the unerupted incisor, obtained by removal of the odontoma and rapid maxillary expansion, permits a conservative surgery and the achievement of an excellent esthetics and periodontal result.

Pavoni, Chiara; Mucedero, Manuela; Lagana, Giuseppina; Paoloni, Valeria; Cozza, Paola

2012-01-01

75

[Segmented arch technique and incisor intrusion for deep overbite correction].  

PubMed

The mechanisms which will be selected for the correction of deep overbite depend exclusively on the choice of the clinician for: 1. Gennine anterior teeth intrusion. 2. Eruption of posterior teeth. 3. Combination of anterior intrusion and posterior extrusion. Principles of incisor intrusion have been presented as well as the use of intrusive springs in the segmented arch technique. Six principles must be considered in incisor intrusion: 1) the use of forces of optimal magnitude and constancy, 2) the use of a single point contact in the anterior region, 3) selection of the point of force application with respect to the center of resistance of the anterior segment, 4) selective intrusion based on anterior tooth geometry, 5) control over the reactive units and 6) inhibition of eruption of the posterior teeth and avoidance of undesirable eruptive mechanics. PMID:2486320

Toutountzakis, N; Mavreas, D

1989-12-01

76

Network centrality based Nk contingency scenario generation  

Microsoft Academic Search

To investigate and evaluate the mechanics of how failures spread in power grids, this paper introduces a methodology for a credible list of critical N-k contingencies that would threaten the grids. The methodology is based on the concept of delta centrality. The list of critical contingencies will provide the look-ahead situation awareness for operators on any impending large power grid

Rodel D. Dosano; Hwachang Song; Byongjun Lee

2009-01-01

77

Removable orthodontic appliance with nickel-titanium spring to reposition the upper incisors in an autistic patient.  

PubMed

A newly designed removable appliance with a shape-memory wire was used for the orthodontic treatment of the anterior teeth in an 11-year-old child who had autism and intellectual disability. The device was designed to reduce the lateral incisor crossbite and the central incisors' labial rotation. The child was treated for 1 year with this removable appliance. Tooth movement was analyzed using cephalograms and surface data were derived from study models. This device proved to be very durable. The lateral incisor crossbite was corrected, and the inclination of the upper central incisors and the interincisal angle were improved. This appliance exerts light and continuous orthodontic force, without requiring any adjustments of the spring wire. The appliance also facilitated orthodontic treatment in a child with intellectual disability in whom treatment with a standard orthodontic device would be unsuitable. PMID:23278147

Saito, Kan; Jang, Insan; Kubota, Kazumi; Hoshino, Tomonori; Hotokezaka, Hitoshi; Yoshida, Noriaki; Fujiwara, Taku

2012-11-12

78

Two hominin incisor teeth from the middle Pleistocene site of Boxgrove, Sussex, England.  

PubMed

In 1995-1996 two isolated hominin lower incisors were found at the middle Pleistocene site of Boxgrove in England, with Lower Palaeolithic archaeology. Boxgrove 2 is a permanent lower right central incisor and Boxgrove 3 a permanent lower left lateral incisor. They were found separately, but close to one another and appear to belong to the same individual. The Boxgrove 1 tibia discovered in 1993 came from a different stratigraphic context and is thus believed to represent a different individual. This paper describes the morphology of the incisors, which is similar to other middle Pleistocene hominin specimens and, as with the tibia, suggests that they could be assigned to Homo heidelbergensis (recognising that the taxonomic status of this species is still a matter of debate). The incisors show substantial attrition associated with secondary dentine deposition in the pulp chamber and clearly represent an adult. They also show extensive patterns of non-masticatory scratches on the labial surfaces of both crown and root, including some marks which may have been made postmortem. The roots were exposed in life on their labial sides by a large dehiscence, extending almost to the root apex. This is demonstrated by deposits of calculus, polishing, and scratching on the exposed surfaces. The dehiscence may have been caused by repeated trauma to the gingivae or remodelling of the tooth-supporting tissues in response to large forces applied to the front of the dentition. PMID:20828787

Hillson, S W; Parfitt, S A; Bello, S M; Roberts, M B; Stringer, C B

2010-09-09

79

Strong Genetic Control of Emergence of Human Primary Incisors  

Microsoft Academic Search

Our understanding of tooth eruption in humans remains incomplete. We hypothesized that genetic factors contribute significantly to phenotypic variation in the emergence of primary incisors. We applied model-fitting to data from Australian twins to quantify contributions of genetic and environmental factors to variation in timing of the emergence of human primary incisors. There were no significant differences in incisor emergence

T. E. Hughes; M. R. Bockmann; K. Seow; T. Gotjamanos; N. Gully; L. C. Richards; G. C. Townsend

2010-01-01

80

Molars and incisors: show your microarray IDs  

PubMed Central

Background One of the key questions in developmental biology is how, from a relatively small number of conserved signaling pathways, is it possible to generate organs displaying a wide range of shapes, tissue organization, and function. The dentition and its distinct specific tooth types represent a valuable system to address the issues of differential molecular signatures. To identify such signatures, we performed a comparative transcriptomic analysis of developing murine lower incisors, mandibular molars and maxillary molars at the developmental cap stage (E14.5). Results 231 genes were identified as being differentially expressed between mandibular incisors and molars, with a fold change higher than 2 and a false discovery rate lower than 0.1, whereas only 96 genes were discovered as being differentially expressed between mandibular and maxillary molars. Numerous genes belonging to specific signaling pathways (the Hedgehog, Notch, Wnt, FGF, TGF?/BMP, and retinoic acid pathways), and/or to the homeobox gene superfamily, were also uncovered when a less stringent fold change threshold was used. Differential expressions for 10 out of 12 (mandibular incisors versus molars) and 9 out of 10 selected genes were confirmed by quantitative reverse transcription-PCR (qRT-PCR). A bioinformatics tool (Ingenuity Pathway Analysis) used to analyze biological functions and pathways on the group of incisor versus molar differentially expressed genes revealed that 143 genes belonged to 9 networks with intermolecular connections. Networks with the highest significance scores were centered on the TNF/NF?B complex and the ERK1/2 kinases. Two networks ERK1/2 kinases and tretinoin were involved in differential molar morphogenesis. Conclusion These data allowed us to build several regulatory networks that may distinguish incisor versus molar identity, and may be useful for further investigations of these tooth-specific ontogenetic programs. These programs may be dysregulated in transgenic animal models and related human diseases leading to dental anomalies.

2013-01-01

81

Finite element sub-modeling analyses of damage to enamel at the incisor enamel\\/adhesive interface upon debonding for different orthodontic bracket bases  

Microsoft Academic Search

This study investigates the micro-mechanical behavior associated with enamel damage at an enamel\\/adhesive interface for different bracket bases subjected to various detachment forces using 3-D finite element (FE) sub-modeling analysis. Two FE macro-models using triangular and square bracket bases subjected to shear, tensile and torsional de-bonding forces were established using ?CT images. Six enamel\\/adhesive interface sub-models with micro- resin tag

Chun-Li Lin; Shao-Fu Huang; Hui-Chin Tsai; Wen-Jen Chang

2011-01-01

82

Inadvertent MTA extrusion in an immature traumatized permanent incisor.  

PubMed

This report describes the 24-month clinical and radiographic outcome of an unintentionally extruded mineral trioxide aggregate (MTA) apical plug. A 9 year old boy presented with a previously traumatized, immature central incisor; associated with a large periradicular lesion. During placement of MTA in the treatment of wide open apex, the material was inadvertently extruded into the periapical region upon a sudden movement of the child. No intervention was made, except for obturation of the remaining root canal two weeks later. The radiographic follow up at 12 and 24 months confirmed successful management through the non surgical approach, as evidenced by advanced healing of the periapical lesion and regeneration of the periradicular tissue in the absence of clinical symptoms. PMID:21417115

Tezel, Bahar; Uysal, Serdar; Turgut, Melek D; Cehreli, Zafer C

2010-01-01

83

Methods to find community based on edge centrality  

NASA Astrophysics Data System (ADS)

Divisive algorithms are of great importance for community detection in complex networks. One algorithm proposed by Girvan and Newman (GN) based on an edge centrality named betweenness, is a typical representative of this field. Here we studied three edge centralities based on network topology, walks and paths respectively to quantify the relevance of each edge in a network, and proposed a divisive algorithm based on the rationale of GN algorithm for finding communities that removes edges iteratively according to the edge centrality values in a certain order. In addition, we gave a comparison analysis of these measures with the edge betweenness and information centrality. We found the principal difference among these measures in the partition procedure is that the edge centrality based on walks first removes the edge connected with a leaf vertex, but the others first delete the edge as a bridge between communities. It indicates that the edge centrality based on walks is harder to uncover communities than other edge centralities. We also tested these measures for community detection. The results showed that the edge information centrality outperforms other measures, the edge centrality based on walks obtains the worst results, and the edge betweenness gains better performance than the edge centrality based on network topology. We also discussed our method's efficiency and found that the edge centrality based on walks has a high time complexity and is not suitable for large networks.

Sun, Peng Gang; Yang, Yang

2013-05-01

84

Mandibular incisor extraction: indications and long-term evaluation  

Microsoft Academic Search

SUMMARY The extraction of a lower incisor constitutes a therapeutic alternative limited to certain occlusal situations, i.e. supernumerary incisors, tooth size anomalies (peg-shaped upper laterals), ectopic eruption and anterior crossbites. The effect of the extraction of a single incisor on the out of retention alignment of lower anterior teeth was studied in 26 treated cases. Initial (T1), final (T2) and

Jose-Antonio Canut

1996-01-01

85

Reinforcement of bonded crown fractured incisors with porcelain veneers.  

PubMed

A method is described by which porcelain laminate veneers are used to reinforce crown-fractured incisors which have been restored by reattachment of enamel-dentin fragments using enamel etching and a dentin bonding system. In an experimental model using sheep incisors, it was found that fracture strength equal to that of intact incisors could be achieved by employing this method. This is in contrast to fracture strengths of reattached enamel-dentin tooth fragments without porcelain laminates which were only 50% of intact incisors. It is suggested that porcelain laminate veneers may be used to supplement fragment bonding, thereby enhancing dental esthetics and function. PMID:1782899

Andreasen, F M; Daugaard-Jensen, J; Munksgaard, E C

1991-04-01

86

Apexification of wide-open apices in nonvital, immature permanent incisors: a case report.  

PubMed

Apexification is the accepted procedure to form an apical stop in nonvital teeth with incomplete root formation. A case is presented in which apexification with calcium hydroxide was performed on two permanent central incisors with immature roots and wide-open apices; treatment concluded with gutta-percha root canal restoration. Spontaneous apical seal had probably been initiated before the calcium hydroxide was inserted, but it was weak and nonhomogenous. PMID:20830893

Peretz, B

1993-11-01

87

Bilateral fusion of permanent mandibular incisors with Talon's cusp: A rare case report  

PubMed Central

Whenever nature diverts from the “normal or usual” it gives rise to something called “abnormal or unusual,” which we call “a Disorder”. Fusion of two teeth is a common developmental disorder that is seen by a clinician. However, bilateral fusion along with Talon's cusp is very rarely seen and reported in literature. This article describes a rare case of the bilateral fusion of permanent mandibular central and lateral incisors, along with presence of Talon's cusp on the left fused teeth.

Prabhakar, Attiguppe Ramasetty; Kaur, Taranjot; Nadig, Basappa

2009-01-01

88

Fracture strength and survival rate of endodontically treated maxillary incisors with approximal cavities after restoration with different post and core systems: an in-vitro study  

Microsoft Academic Search

Objectives: This study compared the fracture strength and survival rate of endodontically treated crowned maxillary incisors with approximal class III cavities and different core build-ups.Methods: Sixty-four caries free human maxillary central incisors were selected for standardized size and quality, endodontically treated and prepared with approximal cavities 3mm in diameter. Group 1 was restored with titanium posts, group 2 received zirconia

Guido Heydecke; Frank Butz; Jörg R. Strub

2001-01-01

89

Cytotoxicity of cyclophosphamide in the rat incisor.  

PubMed Central

Three of the 4 groups of 3 Wistar rats each were given 40 mg, 80 mg and 120 mg cyclophosphamide/kg respectively by single intraperitoneal injections. The fourth group was given 2 ml of normal saline as control. One animal from each group was killed after 1, 4 and 8 days. The incisor teeth of all experimental animals showed evidence of cytotoxic injury, which appeared to be more severe with increasing dosage, to the undifferentiated mesenchymal cells in the proliferating zone of the pulp close to the basal odontogenic epithelium, cessation of root growth and relative acellularity of the basal area of the pulp. Evidence of cytotoxicity to the odontogenic epithelium was seen only in the groups given 80 mg/kg and 120 mg/kg. Resolution of the cytotoxic injury and re-establishment of normal basal odontogenesis were seen in the 40 mg dose group by the eighth day but appeared to be slower with increasing dosage. It would seem that of the rapidly proliferating epithelial and mesenchymal odontogenic cells in the basal area of the rat incisor those in the mesenchyme may be most susceptible to the cytotoxicity of cyclophosphamide. The odontogenic epithelium may be resistant to the cytotoxicity of 40 mg cyclophosphamide/kg. The results may be of significance in the investigation of the mechanism of cytotoxicity of this cancer chemotherapeutic agent. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7

Adatia, A. K.

1975-01-01

90

Correlation of asymmetric Notch2 expression and mouse incisor rotation  

Microsoft Academic Search

Notch signaling defines an evolutionarily conserved cell communication mechanism, which enables neighboring cells to adopt different fates. Furthermore, Notch signaling may create boundaries that direct both the growth and patterning of the developing organs. Here we report on the expression of Notch receptors during the development of rodent incisors. Before the aquisition of their characteristic shape, incisors rotate antero–posteriorly and

Marie-Laurence Mucchielli; Thimios A. Mitsiadis

2000-01-01

91

Using Composite Resin Inclined Plane for the Repositioning of a Laterally Luxated Primary Incisor: A Case Report  

PubMed Central

This case report describes the repositioning of a laterally luxated primary central incisor with occlusal interference, using a composite inclined plane. The patient was a 4-year-old girl who applied to our clinic three days after the injury. Because of the time delay between injury and presentation, it was not possible to reposition the tooth with pressure. Following a root-canal treatment, an inclined plane was prepared on the lower primary incisors, using composite resin. The tooth was repositioned in two weeks, and the inclined plane was then removed. After 1 year of follow-up, the treatment was found to be successful, both clinically and radiographically. The use of a composite inclined plane, accompanied by careful follow-up, is an effective alternative to extraction for laterally luxated primary incisors with occlusal interference.

Arikan, Volkan; Sari, Saziye

2011-01-01

92

United States Military Presence in Central Asia: Implications of United States Basing for Central Asian Stability.  

National Technical Information Service (NTIS)

This thesis examines the United States policy for establishing overseas military bases, particularly in Central Asia. The major transformational trends in improving U.S. military capabilities over the past two decades and the changing international securi...

J. L. Dockery

2006-01-01

93

A report of an impacted primary maxillary central incisor tooth.  

PubMed

- Primary tooth impaction is a rare phenomenon when compared to permanent teeth impaction. The purpose of this report is to present a 5-year-old Chinese girl who exhibited impaction of tooth 51, its unusual consequence on the permanent successor tooth and its comprehensive management. Her parents revealed that at 6 months of age, the patient had fallen from her bed and struck her face on the floor; however, there were no teeth present in the oral cavity. The intraoral examinations identified a bony-like projection on the buccal aspect of the alveolus in the 51 region. Radiographic examination revealed that tooth 51 exhibited an unfavourable orientation, with the crown directed towards the palate. Therefore, the impacted tooth 51 was surgically removed, and two years later tooth 11 erupted into the oral cavity with an indentation on its incisal aspect, which resembled the crown of the primary teeth, thus giving the appearance of a tooth within a tooth or 'dens in dente'. Subsequently, enameloplasty and composite resin build-up was performed on tooth 11 for aesthetic reasons. It is very unusual to have the clinical crowns of both primary and permanent teeth in such close proximity within the alveolar bone, and the present case is a good example to emphasize that trauma to the primary teeth is of considerable importance due to the close proximity of the primary teeth to permanent tooth germs. PMID:23305157

Anthonappa, Robert P; Ongtengco, Kristine L; King, Nigel M

2013-01-10

94

An Identification Key to Rodent Prey in Owl Pellets from the Northwestern and Southeastern United States: Employing Incisor Size to Distinguish among Genera  

ERIC Educational Resources Information Center

We present an identification key to the common rodent prey found in owl pellets from the Northwestern (NW) and Southeastern (SE) United States that is based on differences in incisor size (arc diameter) among genera.

Hager, Stephen B.; Cosentino, Bradley J.

2006-01-01

95

View east; interior view of central bay Naval Base ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View east; interior view of central bay - Naval Base Philadelphia-Philadelphia Naval Shipyard, Foundry-Propeller Shop, North of Porter Avenue, west of Third Street West, Philadelphia, Philadelphia County, PA

96

View west; interior view of central bay Naval Base ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

View west; interior view of central bay - Naval Base Philadelphia-Philadelphia Naval Shipyard, Foundry-Propeller Shop, North of Porter Avenue, west of Third Street West, Philadelphia, Philadelphia County, PA

97

Fitness consequences of centrality in mutualistic individual-based networks  

PubMed Central

The relationships among the members of a population can be visualized using individual networks, where each individual is a node connected to each other by means of links describing the interactions. The centrality of a given node captures its importance within the network. We hypothesize that in mutualistic networks, the centrality of a node should benefit its fitness. We test this idea studying eight individual-based networks originated from the interaction between Erysimum mediohispanicum and its flower visitors. In these networks, each plant was considered a node and was connected to conspecifics sharing flower visitors. Centrality indicates how well connected is a given E. mediohispanicum individual with the rest of the co-occurring conspecifics because of sharing flower visitors. The centrality was estimated by three network metrics: betweenness, closeness and degree. The complex relationship between centrality, phenotype and fitness was explored by structural equation modelling. We found that the centrality of a plant was related to its fitness, with plants occupying central positions having higher fitness than those occupying peripheral positions. The structural equation models (SEMs) indicated that the centrality effect on fitness was not merely an effect of the abundance of visits and the species richness of visitors. Centrality has an effect even when simultaneously accounting for these predictors. The SEMs also indicated that the centrality effect on fitness was because of the specific phenotype of each plant, with attractive plants occupying central positions in networks, in relation to the distribution of conspecific phenotypes. This finding suggests that centrality, owing to its dependence on social interactions, may be an appropriate surrogate for the interacting phenotype of individuals.

Gomez, Jose M.; Perfectti, Francisco

2012-01-01

98

Fitness consequences of centrality in mutualistic individual-based networks.  

PubMed

The relationships among the members of a population can be visualized using individual networks, where each individual is a node connected to each other by means of links describing the interactions. The centrality of a given node captures its importance within the network. We hypothesize that in mutualistic networks, the centrality of a node should benefit its fitness. We test this idea studying eight individual-based networks originated from the interaction between Erysimum mediohispanicum and its flower visitors. In these networks, each plant was considered a node and was connected to conspecifics sharing flower visitors. Centrality indicates how well connected is a given E. mediohispanicum individual with the rest of the co-occurring conspecifics because of sharing flower visitors. The centrality was estimated by three network metrics: betweenness, closeness and degree. The complex relationship between centrality, phenotype and fitness was explored by structural equation modelling. We found that the centrality of a plant was related to its fitness, with plants occupying central positions having higher fitness than those occupying peripheral positions. The structural equation models (SEMs) indicated that the centrality effect on fitness was not merely an effect of the abundance of visits and the species richness of visitors. Centrality has an effect even when simultaneously accounting for these predictors. The SEMs also indicated that the centrality effect on fitness was because of the specific phenotype of each plant, with attractive plants occupying central positions in networks, in relation to the distribution of conspecific phenotypes. This finding suggests that centrality, owing to its dependence on social interactions, may be an appropriate surrogate for the interacting phenotype of individuals. PMID:22158957

Gómez, José M; Perfectti, Francisco

2011-12-07

99

Therapeutic extraction of lower incisor for orthodontic treatment.  

PubMed

Lower incisor extraction in orthodontic treatment was very rare modality of orthodontic treatment because there are few patients who meet the standards for such treatment. Proper diagnosis and treatment planning should be done to achieve good occlusion and facial esthetics. Criteria for lower incisor extraction included degree of crowding, tooth size discrepancy, pathologic condition, vertical overbite, sagittal incisal relationship, skeletal growth pattern and age of the patient. This article comprises of a case of class I malocclusion treated with lower incisor extraction, with comprehensive analysis, diagnosis and treatment planning, treatment results were satisfactory. Clinical significance: Mandibular incisor extraction can be an effective treatment option in borderline cases with mild crowding in lower arch. Minimal alteration of mandibular arch form is key factor for success and stable results. PMID:23151713

Raju, Dandu Sitarama; Veereshi, A S; Naidu, D Lakshmayya; Raju, B H V Ramakrishnan; Goel, Manish; Maheshwari, Amit

2012-07-01

100

[Light reflection zone on the incisors' surface--a new parameter for smile esthetics evaluation].  

PubMed

The light reflection zone (LRZ) is a bright white dot or area that appears on the surface of the maxillary central incisors and/or the gingiva of the front teeth, visible in intra-oral and smile extra-oral photographs. Previously, a positive correlation between the location of the LRZ as observed in intra-oral frontal photographs and the inclination of the upper central incisors as measured on lateral headfims was found. The purpose of this study was to find whether this LRZ location can serve as a new parameter influencing the level of smile esthetics. Twelve pairs of facial photographs, including 10 of ordinary smiling persons and 2 of smiling models, were presented to 138 participants. The only difference between each pair was the location of the LRZ that was moved, compared to the original photograph, gingivally or incisally respectively, using Photoshop (Adobe). Each participant was asked to mark whether he/she noticed a difference between the 2 pictures, and if so, to score the nicer smile. Data analysis was carried out using Chi square test and Fisher's exact test (SPSS v17). The results showed that most of the participants did not recognize the differences between the pairs however, when differences were recognized, most of the participants pointed on the smile where the LRZ was located gingivally as the nicer one. This result was with statistical significance for the 2 models (p < 0.05), In conclusion, the LRZ is a new, yet unrecognized, parameter that can serve as a tool for the diagnosis of esthetic smile. The general population defines a nicer smile when the LRZ is located in the gingival area of the upper central incisors' surface rather than the incisal third. The LRZ should probably be studied not only in Orthodontics but also in other branches of dentistry. PMID:23256396

Brezniak, N; Wasserstein, A; Shmuli, T

2012-07-01

101

3D model simplification algorithm based on degree centrality  

Microsoft Academic Search

Based on the edge-collapse algorithm and Degree Centrality theory, a mesh simplification method with closeness is proposed. This method could successfully preserve appearance and closeness of the original mesh during the simplification process. The experimental results support the conclusion obviously.

Tang Yan; Fu Xin; Chen Qiang

2009-01-01

102

Localized periodontal defect associated with unusual furcation involvement on a mandibular incisor.  

PubMed

A localized periodontal defect associated with an unusual furcation on a mandibular central incisor and its treatment sequences are presented. A 54-year-old woman presented with a persistent localized periodontal defect, which was not responsive to nonsurgical periodontal therapy. An exploratory surgery revealed complete through and through furcation involvement on the right mandibular central incisor, resulting in a three-walled infrabony defect. Following thorough mechanical debridement and root planing, the infrabony aspect of the defect was grafted with freeze-dried bone allograft combined with the recombinant human platelet-derived growth factor-BB. The flaps were positioned to enable patient's home care and professional dental cleaning. Follow-up examination revealed uneventful healing and resolution of the infrabony periodontal defect. Clinicians should be aware of this unusual condition and consider it as a potential etiology when dealing with a persistent localized periodontal defect in the mandibular anterior sextant, which may not respond to the conventional nonsurgical periodontal therapy. Eliminating the active disease as well as enabling careful maintenance and oral hygiene may prevent further deterioration and result in a stable long-term outcome preserving the compromised tooth. PMID:23878844

Kwon, TaeHyun; Intini, Giuseppe; Kim, David M; Levin, Liran

2013-10-01

103

Three-dimensional evaluation of upper anterior alveolar bone dehiscence after incisor retraction and intrusion in adult patients with bimaxillary protrusion malocclusion*  

PubMed Central

Objective: The purpose of this study was to evaluate three-dimensional (3D) dehiscence of upper anterior alveolar bone during incisor retraction and intrusion in adult patients with maximum anchorage. Methods: Twenty adult patients with bimaxillary dentoalveolar protrusion had the four first premolars extracted. Miniscrews were placed to provide maximum anchorage for upper incisor retraction and intrusion. A computed tomography (CT) scan was performed after placement of the miniscrews and treatment. The 3D reconstructions of pre- and post-CT data were used to assess the dehiscence of upper anterior alveolar bone. Results: The amounts of upper incisor retraction at the edge and apex were (7.64±1.68) and (3.91±2.10) mm, respectively, and (1.34±0.74) mm of upper central incisor intrusion. Upper alveolar bone height losses at labial alveolar ridge crest (LAC) and palatal alveolar ridge crest (PAC) were 0.543 and 2.612 mm, respectively, and the percentages were (6.49±3.54)% and (27.42±9.77)%, respectively. The shape deformations of LAC-labial cortex bending point (LBP) and PAC-palatal cortex bending point (PBP) were (15.37±5.20)° and (6.43±3.27)°, respectively. Conclusions: Thus, for adult patients with bimaxillary protrusion, mechanobiological response of anterior alveolus should be taken into account during incisor retraction and intrusion. Pursuit of maximum anchorage might lead to upper anterior alveolar bone loss.

Guo, Qing-yuan; Zhang, Shi-jie; Liu, Hong; Wang, Chun-ling; Wei, Fu-lan; Lv, Tao; Wang, Na-na; Liu, Dong-xu

2011-01-01

104

Cluster Analysis Based on the Central Tendency Deviation Principle  

Microsoft Academic Search

Our main goal is to introduce three clustering functions based on the central tendency deviation principle. According to this\\u000a approach, we consider to cluster two objects together providing that their similarity is above a threshold. However, how to\\u000a set this threshold ? This paper gives some insights regarding this issue by extending some clustering functions designed for\\u000a categorical data to

Julien Ah-pine

2009-01-01

105

Characteristics of Incisor-Premolar Hypodontia in Families  

Microsoft Academic Search

Nonsyndromic tooth agenesis is a genetically and phenotypically heterogenous condition. It is generally assumed that different phenotypic forms are caused by different mutated genes. We analyzed inheritance and phenotype of hypodontia and dental anomalies in 214 family members in three generations of 11 probands collected for genetic linkage study on incisor-premolar hypodontia (IPH). Our analysis confirms the autosomal-dominant transmission with

S. Arte; P. Nieminen; S. Apajalahti; K. Haavikko; I. Thesleff; S. Pirinen

2001-01-01

106

Treatment of congenitally missing maxillary lateral incisors: an interdisciplinary approach.  

PubMed

Dentists have several treatment options when restoring patients with congenitally missing maxillary lateral incisors. Endosseous implant therapy combined with orthodontics can achieve predictable outcomes while meeting patient expectations. This case report exhibits an interdisciplinary approach involving orthodontics, implant surgery, and prosthodontics to resolve this common dental concern. PMID:23611678

Jackson, Brian J; Slavin, Mark R

2013-04-01

107

Continuous and Short Fiber Reinforced Composite in Root Post-Core System of Severely Damaged Incisors  

PubMed Central

Purpose: The aim of this study was to determine the static load-bearing capacity of endodontically treated maxillary incisors restored with post-core complex made of experimental fiber composite resin (FC) and complete crown made of particulate filler composite (PFC). Further aim was to evaluate the effect of FC resin on the failure mode of the restoration. Material and Methods: The experimental composite resin (FC) was prepared by mixing 22.5 wt% of short E-glass fibers (3 mm in length) and 22.5 wt% of semi-interpenetrating polymer network (IPN) resin with 55 wt% of silane treated silica fillers. Thirty extracted sound upper central incisors were used. Twenty teeth were prepared by cutting the clinical crown 2 mm above the cemento-enamel junction horizontally. Restorations were made by two techniques (n=10). Group A (control group) contained samples of sound incisor teeth. Group B had teeth restored using glass fiber post (everStick, Stick- Teck) and PFC (Filtek Z250, 3M-ESPE) to build up core and complete crown. In Group C, the teeth were restored with FC as post-core and complete crown of PFC. The root canals were prepared and posts were cemented with a dual cure resin cement. The restorations were polymerized with a hand-light curing unit. All restored teeth were stored in water at room temperature for 24 h before they were statically loaded with speed of 1.0 mm/min until fracture. Data were analyzed using ANOVA (p=0.05). Failure modes were visually examined. Results: ANOVA revealed that restored incisors (Group B and C) had a statistically significantly lower load-bearing capacity (p<0.05) than the control group. Restorations made from FC post-core and PFC coverage (Group C) gave force value of 363 N (112 SD), which was higher than the value of Group B (211 N, 50 SD). Conclusions: Within the limitations of this study, the teeth restored with experimental fiber composite post-core demonstrated higher load bearing capacity than those with fiber post and PFC core.

Garoushi, Sufyan; Vallittu, Pekka K; Lassila, Lippo V.J

2009-01-01

108

Repair of perforating inflammatory root resorption in a previously traumatized incisor: 36-month follow-up.  

PubMed

Inflammatory root resorption is a serious complication of dental trauma, which leads to progressive loss of the root structure. The purpose of this report was to present a case of perforating inflammatory root resorption in a previously traumatized young incisor tooth with incomplete root development. A 12-year-old girl, who had suffered a traumatic dental injury 4 years earlier, was referred with symptoms of pain and swelling in a permanent maxillary central incisor. The tooth had been root-filled and had thin dentinal walls and a wide open apex. During retreatment, a perforating resorption site was observed on the root's distal aspect. Because the entire root canal filling could not be removed, the resorption site was repaired with white mineral trioxide aggregate in the presence of the remaining gutta-percha. Clinical and radiographic follow-up was conducted for 36 months, demonstrating arrest of the resorptive process, regeneration of the periradicular tissues, and re-establishment of the periodontal space. PMID:22828765

Cehreli, Zafer C; Guzeler, Irem; Uysal, Serdar

109

The Response of the Rabbit Mandibular Incisor to Experimental Shortening and to the Prevention of Its Eruption  

Microsoft Academic Search

Measurements have been made of the eruption rates of the mandibular incisors of domestic rabbits, to examine the effects of shortening one or both incisors for a period of three weeks. Concomitant measurements were made of the rate of wear and the length of the incisors, and of a number of other values defining the occlusion of the lower incisors

A. R. Ness

1956-01-01

110

Measurement of the transmitted-light through human upper incisors  

Microsoft Academic Search

\\u000a The light transmission through the human upper incisors was examined using infrared and green laser light in vivo. Both light\\u000a simultaneously illuminated the labial surface of the tooth crown and the transmitted-light through the tooth crown was collected\\u000a from the palatal surface. The intensities of transmitted infrared light and the transmitted green light (TGL) were smaller\\u000a when the lights were

Motohide Ikawa

111

Restoration of congenitally missing maxillary lateral incisors using mini implants.  

PubMed

In this author's opinion, the advent of mini implants, or small diameter implants (SDIs) as they are more frequently being called, are becoming in many situations a viable alternative to the more traditional root form implants. They offer advantages of less cost, a more simplified placement technique, usually faster healing times, and generally less post-operative complications. A case presentation is given to demonstrate their usage for a narrow ridge application to restore congenitally missing maxillary lateral incisors. PMID:24015452

Collins, Ron

2013-07-01

112

Phosphophoryns—major noncollagenous proteins of rat incisor dentin  

Microsoft Academic Search

Summary Freshly excised rat incisors were immediately cleaned and demineralized in 0.5M ethylene diaminetetracetic acid at pH 7.5. The extracts were freed of calcium, diffusible phosphate and low molecular weight polypeptide components by dialysis in membranes with cut-off of 3500 molecular weight. The extract was resolved into at least 7 protein components by chromatography on DEAE-cellulose at pH 8.2. The

M. T. Dimuzio; A. Veis

1978-01-01

113

Bizarre cause for avulsion of permanent maxillary lateral incisor tooth.  

PubMed

A 9-year-old boy presented with a missing upper front tooth after an accident involving kite flying. Diagnosis of avulsion of the upper right lateral incisor (22) was made after examination of his socket as well as by radiological investigations. A removable partial denture was given for the aesthetic purpose. The patient is under follow-up. The present case illustrates the management of avulsion. PMID:23978496

Kiran, Shital; Bargale, Seema Dinesh; Sikligar, Smit; Shanthraj, Srinivas L

2013-08-26

114

Replantation of an Avulsed Maxillary Incisor after 12 Hours: Three-Year Follow-Up  

PubMed Central

Tooth avulsion is defined as the complete displacement of the tooth out of its alveolar socket. The treatment of choice is immediate replantation or if that is not possible, placement of the tooth in an appropriate storage media. This report presents replantation of an avulsed maxillary central incisor after 12 hours of storage in milk. The tooth was replanted and splinted. One week later, it was treated endodontically and calcium hydroxide dressing was placed for 1 month; subsequently, the tooth was obturated with gutta-percha. During three years of follow-up, no evidence of ankylosis or inflammatory resorption was observed. After three years, the tooth was stable and remained functional and esthetically acceptable.

Moradian, Hamid; Badakhsh, Samaneh; Rahimi, Mehran; Hekmatfar, Somayeh

2013-01-01

115

Molar Incisor Hypomineralization: A Study of Prevalence and Etiology in a Group of Iranian Children  

PubMed Central

Objective The aim of this study was to investigate the prevalence of molar incisor hypomineralization (MIH) and its relationship with systemic conditions in a group of Iranian children. Methods The study population comprised of 433 7-9 year olds, from four schools in Zahedan, Iran. Subjects were evaluated clinically by one examiner, and at a separate session, their mothers completed a coded medical history questionnaire. Hypo-mineralized molars and incisors were recorded based on DDE (developmental defects of enamel) index and DMFT (number of decayed, filled and missing teeth) was determined. Statistical analyses were performed using Chi-square and independent sample t-tests. Findings Fifty-five (12.7%) children showed MIH. The overall mean number of affected teeth was 0.2. The mean value of DMFT in MIH children was greater than in normal children. Demarcated opacities were the most frequent (76%) enamel defect. Mother's and child's medical problems during prenatal, perinatal and post natal period were significantly remarkable in MIH children. Conclusion The prevalence of MIH in a group of Iranian children was 12.7%. Prenatal, perinatal and post natal medical conditions were more prevalent in children affected by MIH.

Ahmadi, Rahil; Ramazani, Nahid; Nourinasab, Rahmatollah

2012-01-01

116

Disproportionate eruption of maxillary and mandibular incisors in the long-tailed ground squirrel  

Microsoft Academic Search

The surface of the maxillary and mandibular incisors of Spermophilus undulatus long-tailed ground squirrels, including those born in the current year and those that have hibernated (trapped one month\\u000a or later after hibernation) is studied. The presence of daily growth increments on the incisors’ surface allows the evaluation\\u000a of the eruption rate of the incisors; a specific change in the

G. A. Klevezal’; E. G. Potapova

2010-01-01

117

Molar and incisor changes with Wilson rapid molar distalization.  

PubMed

The purpose of this study was to determine the magnitude and direction of maxillary and mandibular first molar and incisor changes that occur during Class II molar correction with Wilson "rapid molar distalization." Nineteen patients (13 females, 6 males) were selected from the clinic at Loma Linda University Department of Orthodontics. All patients received maxillary bimetric distalizing arches (BDA), and either a mandibular three-dimensional lingual arch, with or without a passive 0.016 x 0.016-inch utility arch, or a traditional edgewise full banded and bonded arch. The arches were activated with open coil spring and Class II intermaxillary elastics. A total of five activations were completed or until visual inspection revealed a Class I molar relation. Prestudy and poststudy lateral cephalometric radiographs were taken with molar bands cemented. Dental changes were determined, with Ricketts superimpositions. The mean change in molar relation measured at the occlusal plane was 4.1 mm. The mean maxillary molar distalization was 2.16 mm, with 7.8 degrees of tip. The rate of maxillary molar movement was 0.56 mm per month. The mean mandibular molar mesial movement was 1.38 mm. The maxillary incisors protruded a mean of 0.3 mm, and extruded a mean of 1.6 mm. Except for the edgewise sample, all mandibular molars moved mesially further than the incisors, reducing the mandibular arch length. The presence of erupted maxillary second molars did not correlate with the rate of maxillary first molar movement, magnitude of movement, or amount of tipping that occurred. PMID:8249931

Muse, D S; Fillman, M J; Emmerson, W J; Mitchell, R D

1993-12-01

118

The mandibular incisor: rethinking guidelines for post and core design.  

PubMed

In post and core research, little attention has been given to the tooth with minimal bulk and mesialdistal width. The purpose of this in vitro study was to investigate retention and fracture characteristics of lower incisors restored with variable dowel designs. Fifty freshly extracted mandibular incisors were endodontically treated. Four groups of 10 teeth, decoronalized and dowel- and core-restored, were tested for retention characteristics and fracture resistance. One group of 10 teeth restored with composite resin in intact natural crown acted as controls. Dowel variables included a prefabricated round cross-sectional design and a morphologic dowel that reproduced the canal space. A universal testing machine created tensile and transverse loads, and failure was measured and recorded. Results showed no difference in resistance to transverse loading between morphological and standardized dowels (p > 0.05). However, when analyzing modes of failure, ferruled morphological post and core design was less likely to result in a catastrophic root or post fracture. In addition, morphological dowels were significantly more retentive than standardized round dowels in teeth with narrow cross-sections (p = 0.007). This study also reaffirmed the findings of previous investigations, that the intact natural crown of an endodontically treated tooth provides maximum resistance to root fracture. PMID:7714432

Gluskin, A H; Radke, R A; Frost, S L; Watanabe, L G

1995-01-01

119

Control of mandibular incisors with the combined Herbst and completely customized lingual appliance - a pilot study  

Microsoft Academic Search

BACKGROUND: The traditional Herbst appliance induces mandibular incisor proclination independent of the anchorage system used. The dental effects of the Herbst appliance as an element of a completely customized lingual orthodontic (LO) appliance (Incognito, 3 M) has not been analyzed yet and the aim of this paper was to measure the effect of mandibular incisor proclination using this Herbst-LO device.

Dirk Wiechmann; Rainer Schwestka-Polly; Hans Pancherz; Ariane Hohoff

2010-01-01

120

Fracture resistance of composite resin restorations and porcelain veneers in relation to residual tooth structure in fractured incisors.  

PubMed

The aim of the present study was to investigate whether there is a direct correlation between the amount of residual tooth structure in a fractured maxillary incisor and the fracture resistance of composite resin restorations or porcelain veneers after cyclic loading. Sixty human-extracted maxillary central and lateral incisors were mounted in an acrylic block with the coronal aspect of the tooth protruding from the block surface. The teeth were assigned to two groups: 2-mm incisal fracture and 4-mm incisal fracture. Then, the teeth were further divided into two different restoration subgroups, porcelain laminate veneer and composite resin restoration, therefore obtaining four groups for the study (n=15). The specimens were subjected to 1000 cycles of thermocycling and were mechanically tested with a custom-designed cyclic loading apparatus for 2×106 cycles or until they failed. The specimens that survived the cyclic loading were loaded on the incisal edge along the long axis of the tooth with a flat stainless steel applicator until they fractured using a universal testing machine to measure the failure load. Two-way anova was used to assess the significance of restoration, amount of fracture, and interaction effect (?=0.05). During the cyclic loading, for the composite resin group, two specimens with 2-mm fracture and three specimens with 4-mm fracture failed. For the porcelain veneer group, two specimens with 2-mm fracture and one specimen with 4-mm fracture failed. The 2-way anova did not show statistical significance for restoration (P=0.584), amount of fracture (P=0.357), or interaction effect (P=0.212). A composite resin restoration and a porcelain veneer could perform similarly for replacing a fractured incisor edge up to 4mm. Other factors such as esthetic and/or cost would be considerations to indicate one treatment over the other. PMID:21752192

Batalocco, Guido; Lee, Heeje; Ercoli, Carlo; Feng, Changyong; Malmstrom, Hans

2011-07-14

121

The Single-tooth Implant Treatment of Congenitally Missing Maxillary Lateral Incisors Using Angled Abutments: A Clinical Report  

PubMed Central

The maxillary lateral incisor is the second most common congenitally absent tooth. There are several treatment options for replacing the missing maxillary lateral incisor, including canine substitution, tooth-supported restoration, or single-tooth implant. Dental implants are an appropriate treatment option for replacing missing maxillary lateral incisor teeth in adolescents when their dental and skeletal development is complete. This case report presents the treatment of a patient with congenitally missing maxillary lateral incisors using dental implants with angled abutments.

Tuna, Suleyman Hakan; Keyf, Filiz; Pekkan, Gurel

2009-01-01

122

Analysis of crystallite shape in rat incisor enamel.  

PubMed

The hydroxyapatite crystallites of mammalian enamel appear as hexagons when seen in cross-sections examined with the transmission electron microscope. Using goniometric transmission electron microscopy, stereo-pair electron micrographs and freeze-fracture replicas, two models have been proposed to explain the hexagonal crystallite profile. The "hexagonal ribbon" model proposes that hexagonal profiles are true cross-sections of elongated hexagonal ribbons. The "rectangular ribbon"model proposes that crystallite profiles are three-dimensional rectangular segments (parallelepipeds), which are contained in the Epon sections and project as opaque hexagons in routine transmission electron micrographs. Morphological observations together with predictions from models indicate that the crystallites in rat incisor enamel are flat ribbons with rectangular cross-sectional profiles. The hexagonal images seen in electron micrographs of thin sections of enamel result from viewing parallelepiped-shaped segments of these crystallites as two-dimensional shadows. PMID:3662041

Warshawsky, H; Bai, P; Nanci, A

1987-08-01

123

Correction of palatally displaced maxillary lateral incisors without brackets.  

PubMed

This article describes the orthodontic treatment of a 25-year-old Korean female patient with anterior crowding, including palatally displaced lateral incisors. Her facial profile was satisfactory, but 3.5 mm of maxillary anterior crowding was observed. To correct this crowding, we decided to minimize the use of the conventional fixed orthodontic appliances and employed a less bulky and more aesthetic appliance for applying light continuous force. We determined the final positions of the maxillary teeth via a working model for diagnostic set up and achieved space gaining and alignment with simple Ni-Ti spring and stainless steel round tubes. Tooth alignment was achieved efficiently and aesthetically without the conventional brackets. PMID:24015390

Choi, Kyung-Hee; Lee, Yoonjung; Kim, Minji; Chun, Youn-Sic

2013-08-22

124

Nanobiotechnology-Based Drug Delivery to the Central Nervous System  

Microsoft Academic Search

Background: Drug delivery across the blood-brain barrier (BBB) is a major limitation in the treatment of central nervous system (CNS) disorders. Several approaches are being investigated to improve drug delivery across the BBB. Objective\\/Methods: This review deals with the role of nanobiotechnology in CNS drug delivery. The small size of the nanoparticles enables them to penetrate the BBB and facilitate

K. K. Jain

2007-01-01

125

Enamel-free teeth: Tbx1 deletion affects amelogenesis in rodent incisors  

PubMed Central

TBX1 is a principal candidate gene for DiGeorge syndrome, a developmental anomaly that affects the heart, thymus, parathyroid, face, and teeth. A mouse model carrying a deletion in a functional region of the Tbx1 gene has been extensively used to study anomalies related to this syndrome. We have used the Tbx1 null mouse to understand the tooth phenotype reported in patients afflicted by DiGeorge syndrome. Because of the early lethality of the Tbx1?/? mice, we used long-term culture techniques that allow the unharmed growth of incisors until their full maturity. All cultured incisors of Tbx1?/? mice were hypoplastic and lacked enamel, while thorough histological examinations demonstrated the complete absence of ameloblasts. The absence of enamel is preceded by a decrease in proliferation of the ameloblast precursor cells and a reduction in amelogenin gene expression. The cervical loop area of the incisor, which contains the niche for the epithelial stem cells, was either severely reduced or completely missing in mutant incisors. In contrast, ectopic expression of Tbx1 was observed in incisors from mice with upregulated Fibroblast Growth Factor signalling and was closely linked to ectopic enamel formation and deposition in these incisors. These results demonstrate that Tbx1 is essential for the maintenance of ameloblast progenitor cells in rodent incisors and that its deletion results in the absence of enamel formation.

Caton, Javier; Luder, Hans-Ulrich; Zoupa, Maria; Bradman, Matthew; Bluteau, Gilles; Tucker, Abigail S.; Klein, Ophir; Mitsiadis, Thimios A.

2010-01-01

126

Esthetic considerations when replacing missing maxillary incisors with implants: a clinical report.  

PubMed

Restoring missing maxillary incisors with implants is both challenging and demanding for the clinician. Decisions concerning the number, position, and diameter of implants are crucial to achieve an optimal esthetic result, especially in patients with increased vertical and horizontal overlap. This clinical report presents a treatment where 2 narrow implants, placed in the maxillary lateral incisor positions of the maxilla, support the restoration of the 4 missing incisors. Despite meticulous surgical and restorative treatment procedures, the use of gingiva-colored veneering material was required to achieve a satisfactory esthetic outcome. PMID:23522361

Petropoulou, Aikaterini; Pappa, Eftychia; Pelekanos, Stavros

2013-03-01

127

Multidisciplinary approach for the aesthetic treatment of maxillary lateral incisors agenesis: thinking about implants?  

PubMed

Missing maxillary lateral incisors create an esthetic problem with specific orthodontic and prosthetic considerations. Implants are commonly used to replace congenitally missing lateral incisors in adolescent orthodontic patients. However, an interdisciplinary approach should be observed during the diagnosis, prognosis, and treatment plan to provide a result with good predictability and meet the esthetic and functional expectations of the patient. The present study describes a case of a young patient with tooth agenesis of maxillary lateral incisors, which was conducted with an integrated planning. After 5-year follow-up of 2 fixed implant-supported prostheses, clinical and radiographic examination showed the treatment to be successful. PMID:23083483

de Avila, Érica Dorigatti; de Molon, Rafael Scaf; de Assis Mollo, Francisco; de Barros, Luiz Antonio Borelli; Capelozza Filho, Leopoldino; de Almeida Cardoso, Mauricio; Cirelli, Joni Augusto

2012-04-25

128

Management of traumatic intrusive luxation of incisors in a patient with Down's syndrome.  

PubMed

Special needs individuals are children or adults who are prevented by a physical or mental condition from full participation in the normal range of activities of their age groups. They usually exhibit high treatment needs because of an increased prevalence and severity of trauma. This paper presents a case report and review of treatment strategy of repositioning, splinting of permanent incisors in a 13-year-old boy with Down's syndrome sustaining trauma led to intrusive luxation of maxillary incisors. The intruded incisors were immediately repositioned and splinted with composite within hours. PMID:22669989

Sarkar, Priyanka Airen; Shigli, Anand

2011-12-20

129

Relationship Between the Number of Rat Littermates per Dam and Mandibular Incisor Growth  

Microsoft Academic Search

The relationship between the number of littermates per dam and tooth growth of the mandibular incisor taken out of occlusion by experimental shortening was investigated. The variation in eruptive growth was statistically significant.

Miguel C. Madeira; Sebastião Hetem; Mauro A. Rulli

1974-01-01

130

[Multi-bed & multi-parameter central monitoring system based on TCP/IP protocol].  

PubMed

Communication is one of the key problems to a central monitoring system. In this paper we put forward a central monitoring system using TCP/IP as the network protocol, Windows NT4.0 as the platform, forming a Intranet in a hospital. We also discussed the communication problem between the bed-side monitoring station and the central monitoring station in detail and then put forward a new protocol--Hospital Central Monitor Protocol (HCMP) based on TCP/IP to transfer monitoring data. It is easy to achieve tele-monitoring through the current communication subsystem. PMID:12583091

Lian, S J; Hu, D K; Zhao, M H; Tang, L H

2000-02-01

131

GaN-based photonic crystal surface emitting lasers with central defects  

NASA Astrophysics Data System (ADS)

The GaN-based photonic crystal surface emitting lasers (PCSELs) with different central defects were fabricated and investigated. The threshold energy densities increased from 3.23 to 3.51 mJ/cm2 when the central defect size increased. In addition, lasing wavelengths decreased from 400 nm to 390 nm due to the guided mode shifting phenomenon for the PCSEL cavities with larger central defects. The tendency of threshold gain and resonance wavelength for PCSELs with different central defects were calculated by the multiple scattering method and well matched to the experimental results.

Wu, Tzeng-Tsong; Weng, Peng-Hsiang; Hou, Yen-Ju; Lu, Tien-Chang

2011-11-01

132

An efficient community detection method based on rank centrality  

NASA Astrophysics Data System (ADS)

Community detection is a very important problem in social network analysis. Classical clustering approach, K-means, has been shown to be very efficient to detect communities in networks. However, K-means is quite sensitive to the initial centroids or seeds, especially when it is used to detect communities. To solve this problem, in this study, we propose an efficient algorithm K-rank, which selects the top-K nodes with the highest rank centrality as the initial seeds, and updates these seeds by using an iterative technique like K-means. Then we extend K-rank to partition directed, weighted networks, and to detect overlapping communities. The empirical study on synthetic and real networks show that K-rank is robust and better than the state-of-the-art algorithms including K-means, BGLL, LPA, infomap and OSLOM.

Jiang, Yawen; Jia, Caiyan; Yu, Jian

2013-05-01

133

Does orthodontic proclination of lower incisors in children and adolescents cause gingival recession?  

Microsoft Academic Search

In this investigation we sought to assess the effect of orthodontic proclination of lower incisors in children and adolescents with respect to the possible development of gingival recession. Ninety-eight children with a mean ± SD start-of-treatment age of 12.8 ± 1.4 years, treated with the Herbst appliance, were surveyed, for a total of 392 lower incisors. Lateral head films, dental

Sabine Ruf; Ken Hansen; Hans Pancherz

1998-01-01

134

Effects of Accelerated Eruption On the Enamel of the Rat Lower Incisor  

Microsoft Academic Search

The effect of accelerated eruption of the rat lower incisor on enamel was studied in a series of segments obtained when the incisor was cut repeatedly out of occlusion over a five-week period. The segments were ground, cleaned, acid-etched, observed with SEM, and analyzed with EDX. Pigmentation was lost within 11 days. Pigmented superficial enamel was more acid-resistant than the

S. Risnes; C. B. Møinichen; D. Septier; M. Goldberg

1996-01-01

135

Non-invasive management of fused upper incisors  

PubMed Central

The union of two different dental sprouts which can happen in any phase of dental development is commonly called fusion. This developmental anomaly may cause clinical problems including esthetic impairment, which are mainly treated by endodontic and surgical treatments. There are a few reports of conservative not invasive treatment of fused incisors teeth through restorative or prosthetic techniques. They are rarely reported in mandibular posterior teeth. This paper presents an unusual case of fusion of 7 and 8, and also 9 and 10 teeth which was treated with a nonendodontic and nonsurgical conservative approach. Patient was a healthy18-year-old female with chief complaint of bad-looking teeth that in intraoral examination revealed the fusion of 7 and 8, and also 9 and 10 teeth. The space between the mesial of the 6 and 11 teeth was reconstructed. Diastema between the fused teeth was closed. A new lateral tooth was replaced between the fused teeth (7 and 8) and 6 tooth with direct fiber-reinforced composite. The space between the fused teeth (9 and 10) and also tooth 11 was partially closed. Gingival papillas were reconstructed using pink composite. The mandibular anterior missing teeth were replaced with rochett bridge. At the end of treatment the esthetic of the patient was improved. As the treatment was not invasive, major complications are not expected; however, there is potential for eventual long-term periodontal problems due to poor oral hygiene. Debonding of the rochett bridge may happen as well.

Samimi, Pouran; Shirban, Mohammad-Reza; Arbabzadeh-Zavareh, Farahnaz

2012-01-01

136

Comparisons of nipple attachment and incisor growth among four species of voles (Microtus).  

PubMed

Patterns of nipple attachment and incisor growth were compared between four species of voles (Microtus). Offspring of two highly social species, prairie voles (M. ochrogaster) and pine voles (M. pinetorum), were shown to cling tightly to the nipples of their dams on Days 2, 6, and 10. This pattern contrasted to weak nipple attachment displayed by two less-social species, meadow voles (M. pennsylvanicus) and montane voles (M. montanus). Lengths of the upper (maxillary) and lower (mandibular) incisors of the four species were recorded throughout the first 10 days of age and in adults. Incisors of the pine and prairie voles typically erupted earlier and grew longer than those of the meadow or montane voles during the first few days of development. Incisors grew at a substantial rate in the latter two species, such that they equalled or surpassed the incisor lengths of the former two species as Day 10 and weaning approached. Patterns of incisor growth, in part, reflected those for nipple attachment, but do not appear to account substantially for differences in nipple attachment. PMID:7926283

Salo, A L; Shapiro, L E; Dewsbury, D A

1994-07-01

137

Cross-sectional study of correlation between mandibular incisor crowding and third molars in young Brazilians  

PubMed Central

Objectives: The aim of this study was to evaluate transversally the clinical correlation between lower incisor crowding and mandible third molar. Study Design: Three hundred healthy volunteers (134 male and 166 female), aged 20.4 (±2.4) years-old were submitted to a complete clinical examination and filled up a questionnaire about gender, age, total teeth number and presence or absence of superior and inferior third molar. After a recent panoramic radiography were evaluated. The multiple logistic regression showed that none of the studied factors influenced the mandibular incisor crowding. Results: The proportion of both molars present or both absent was higher than the other conditions (Chi-square, p<.0001). The multiple logistic regression showed that any of the studied factors, influenced (p>.05) the mandibular incisor crowding. Despite the statistical significance, wear orthodontics appliances showed a little correlation (odds ratios < 1.0) in the mandibular incisor crowding. Conclusion: Presence of maxillary and/or mandibular third molars has no relation with the lower incisor crowding. Key words:Malocclusion, third molars, lower incisor crowding, mandible.

Karasawa, Lilian H.; Groppo, Francisco C.; Prado, Felippe B.; Caria, Paulo H F.

2013-01-01

138

Extraction of the lateral incisors to treat maxillary protrusion: quantitative evaluation of the stomatognathic functions.  

PubMed

To treat morphological abnormalities, impaction, and severe malposition of the teeth, the lateral incisors are sometimes extracted, followed by orthodontic space closure. This procedure often requires special consideration, not only with regard to esthetics but also for functional issues. However, thus far, few reports that have performed a functional evaluation in such cases. The purpose of this article is to report the successful treatment of an adult patient with a Class II division 1 malocclusion who was treated with extraction of the upper lateral incisors. The female patient, aged 23 years and 6 months, had a chief complaint of maxillary incisal protrusion and crooked teeth. In this patient, the upper lateral incisors were extracted to fulfill the patient's strong request, followed by orthodontic treatment using edgewise appliances. A high-pull J-hook headgear on the lower dental arch was used to prevent further labial inclination of the lower incisors. The total active treatment period was 37 months. The resulting occlusion and a satisfactory facial profile were maintained during a 4-year retention period. Additionally, this treatment did not affect the stomatognathic functions as assessed by the following criteria: range of the incisal path or condylar motion during maximal open-close movement, protrusive excursion, lateral excursion, and the chewing test. In conclusion, extraction of the upper lateral incisors can be an effective treatment choice when the upper lateral incisors are dwarfed, are nonvital, or demonstrate severe malposition. PMID:22908948

Ishihara, Yoshihito; Kuroda, Shingo; Sumiyoshi, Kumi; Takano-Yamamoto, Teruko; Yamashiro, Takashi

2012-08-22

139

A role for suppressed incisor cuspal morphogenesis in the evolution of mammalian heterodont dentition  

PubMed Central

Changes in tooth shape have played a major role in vertebrate evolution with modification of dentition allowing an organism to adapt to new feeding strategies. The current view is that molar teeth evolved from simple conical teeth, similar to canines, by progressive addition of extra “cones” to form progressively complex multicuspid crowns. Mammalian incisors, however, are neither conical nor multicuspid, and their evolution is unclear. We show that hypomorphic mutation of a cell surface receptor, Lrp4, which modulates multiple signaling pathways, produces incisors with grooved enamel surfaces that exhibit the same molecular characteristics as the tips of molar cusps. Mice with a null mutation of Lrp4 develop extra cusps on molars and have incisors that exhibit clear molar-like cusp and root morphologies. Molecular analysis identifies misregulation of Shh and Bmp signaling in the mutant incisors and suggests an uncoupling of the processes of tooth shape determination and morphogenesis. Incisors thus possess a developmentally suppressed, cuspid crown-like morphogenesis program similar to that in molars that is revealed by loss of Lrp4 activity. Several mammalian species naturally possess multicuspid incisors, suggesting that mammals have the capacity to form multicuspid teeth regardless of location in the oral jaw. Localized loss of enamel may thus have been an intermediary step in the evolution of cusps, both of which use Lrp4-mediated signaling.

Ohazama, Atsushi; Blackburn, James; Porntaveetus, Thantrira; Ota, Masato S.; Choi, Hong Y.; Johnson, Eric B.; Myers, Philip; Oommen, Shelly; Eto, Kazuhiro; Kessler, John A.; Kondo, Takashi; Fraser, Gareth J.; Streelman, J. Todd; Pardinas, Ulyses F. J.; Tucker, Abigail S.; Ortiz, Pablo E.; Charles, Cyril; Viriot, Laurent; Herz, Joachim; Sharpe, Paul T.

2009-01-01

140

Mineralized deposits in pulps of incompletely developed permanent monkey incisors after pulpotomy with tungsten carbide fissure burs.  

PubMed

The exposed pulp of incompletely developed permanent incisors of nine monkeys were treated with partial pulpotomy with tungsten carbide fissure burs on an air turbine equipment. The pulps were capped with calcium hydroxide (Dycal) followed by insertion of conventional amalgam. The results were studied by conventional light microscopy after 1 and 6 months. Rod-like mineralized pulpal deposits were seen in five of the nine animals, in 9 out of 67 teeth, evenly distributed at the two observation times. Also the lengths of the deposits appeared similar, while the thickness had increased markedly after 6 months. After 1 month the presence of a central vessel lumen was observed in the deposits. The results seemed to indicate that the mechanism of formation was an initial pathologic mineralization of the vessel wall, and a growth of the deposits by the elaboration of fibrous, atubular dentin on to the outside of this wall. PMID:7995242

Heide, S; Koppang, H S

1994-06-01

141

A histological study of root-resected and root-transected rat incisors when eruption ceases, shortly before they are exfoliated from the socket  

Microsoft Academic Search

Resection of the odontogenic region or root transection of normal (impeded) rat lower incisors showed that eruption ceased from 1 to 13 weeks when the base of the resected teeth (87.5%) or of the distal segment of the transected ones (86%) reached the alveolar-crest region. When the operated teeth reached the crestal region, the enamel-related periodontal tissues were absent and

Jose Merzel; Pedro Duarte Novaes; Silvana Furlan

2000-01-01

142

A diagnostic dilemma of central skull base osteomyelitis mimicking neoplasia in a diabetic patient.  

PubMed

We present a case which illustrates the diagnostic difficulty in distinguishing between osteomyelitis of the central skull base and base of skull tumours. A woman in her early forties presented with seizures and multiple cranial nerve palsies. She also had a background of chronic otalgia and poorly controlled diabetes mellitus. The clinical diagnosis of skull base osteomyelitis (SBO) was made, but both MRI and bone scans were unable to distinguish this from a skull base malignancy on imaging criteria. Eventually biopsies were required to exclude the diagnosis of malignancy and the patient was treated for central SBO. PMID:23355560

Ganhewa, Aparna Dasunmalee; Kuthubutheen, Jafri

2013-01-25

143

A WebGIS-based system model of vehicle monitoring central platform  

Microsoft Academic Search

The vehicle monitoring central platform is establishing a uniform information portal on vehicle monitoring in China. Rather than elaborating sophisticated vehicle monitoring and management approaches, the WebGIS-based system model is striving to develop a technical umbrella for the distributed and Web-based vehicle management systems, which employs several technologies, including communication technology - SMS (short message services), vehicle position technology -

Yong Wang; Dafang Zhuang; Runhe Shi; Su Li

2005-01-01

144

Amelin extracellular processing and aggregation during rat incisor amelogenesis.  

PubMed

Amelin (also known as ameloblastin and sheathlin) is a recently described protein that is secreted by ameloblasts during enamel formation. Here, the extracellular distribution and processing of amelin during rat incisor amelogenesis were investigated by Western blot probing using anti-recombinant rat amelin antibodies. In addition, the solubility behaviour and aggregative properties of rat amelin were investigated using a sequential extraction procedure involving (1) extraction with simulated enamel fluid to extract proteins most likely to be soluble in vivo; (2) extraction with phosphate buffer to desorb proteins bound to enamel crystal surfaces; (3) extraction with sodium dodecyl sulphate (SDS) to extract proteins present as insoluble aggregates; followed by (4) a final acid demineralization step to release any remaining proteins. Proteins immunoreactive to the anti-amelin antibodies were detectable in secretory- and transition-stage enamel. Maturation-stage enamel appeared devoid of amelin. The largest immunoreactive protein detected migrated at 68 kDa on SDS gels, corresponding to the M(r) of nascent amelin. Other immunoreactive bands at 52, 40, 37, 19, 17, 16, 15, 14 and 13 kDa were presumably amelin processing products. The sequential extraction procedure revealed that the 68-, 52-, 40-, 37- and 13-kDa amelins were completely extracted under solution conditions similar to those reported to exist in vivo. In contrast, the 19-, 17- and 16-kDa amelins were only partially extracted, whilst the 15- and 14-kDa amelins could not be extracted with simulated enamel fluid. A proportion of the remaining 17- and 16-kDa amelins was desorbed from the enamel crystals with phosphate buffer and appeared to have been mineral-bound. The 15- and 14-kDa amelins and the remainder of the 17- and 16-kDa amelins were extracted with SDS only, suggesting that these species were present in vivo as an insoluble aggregate. The results provide additional information on amelin processing and degradation, and on how such processing influences the solubility and aggregative properties of amelin-derived proteins. PMID:11165565

Brookes, S J; Kirkham, J; Shore, R C; Wood, S R; Slaby, I; Robinson, C

2001-03-01

145

Sex determination using mesiodistal dimension of permanent maxillary incisors and canines  

PubMed Central

Background: Sexual dimorphism refers to the differences in size, shape, etc., between males and females. The dentition's use in sex assessment has been explored and advocated owing to its strength and resistance to peri- and post-mortem insults. Objectives: The study evaluated permanent maxillary incisors and canines for sexual dimorphism and estimated the level of accuracy with which they could be used for sex determination. Materials and Methods: The study was conducted on 100 subjects (50 males, 50 females). The mesiodistal dimension of permanent maxillary incisors and canines was measured and the data were subjected to statistical analysis. Result: Univariate analysis revealed that all permanent maxillary incisors and canines exhibited larger mean values of mesiodistal dimension in males compared to females but only canines were found to be statistically significant for sexual dimorphism. Conclusion: The study showed maxillary canines exhibiting significant sexual dimorphism and can be used for sex determination along with other procedures.

Khangura, Rajbir Kaur; Sircar, Keya; Singh, Sanjeet; Rastogi, Varun

2011-01-01

146

Cone-beam computed tomography evaluation of relationship between tongue volume and lower incisor irregularity.  

PubMed

The aim of this study was to evaluate the relationship between the tongue volume and lower incisor irregularity, using cone-beam computed tomography (CBCT), and to identify the possible gender differences. CBCT images of 60 patients between 16 and 36 years of age were selected from 1400 sets of images in the database. Tomography was carried out using iCAT® (Imaging Sciences International, Hatfield, Pennsylvania, USA) and segmentation was carried out by using Mimics 10.1 software (Materialise NV, Leuven, Belgium). The tongue volume was calculated by using the volume of the voxels from the scan and the number of voxels selected for a given mask. Lower incisor crowding was measured with the Little's irregularity index and divided into three groups: mild, moderate, and severe. Independent samples t-test, analysis of variance (ANOVA), and Tukey test were used at P < 0.05 level. Pearson correlation coefficients and linear regression model were calculated to determine the correlation between tongue volume and incisor irregularity. No significant gender dimorphism was found for the tongue volume (females: 28.13 ± 8.54 cm(3) and males: 31.02 ± 9.75 cm(3)). According to ANOVA, there was statistically significant difference in the tongue volume measurements among subjects with different levels of irregularity. Tukey analysis indicated that mild irregularity group (33.97 cm(3)) showed higher values for tongue volume than severe irregularity group (26.60 cm(3); P = 0.025). The relationship between incisor irregularity and tongue volume was evaluated for both genders and significant inverse correlation (r = -0.429; P = 0.029) was determined between lower incisor irregularity and tongue volume in males. In female group, no significant correlation was determined between tongue volume and incisor irregularity. PMID:21734255

Uysal, Tancan; Yagci, Ahmet; Ucar, Faruk Izzet; Veli, Ilknur; Ozer, Torun

2011-07-06

147

Unconventional prosthodontics for the aesthetic rehabilitation of discoloured rotated maxillary central incisor.  

PubMed

Orthodontics is always the first choice treatment for aesthetic and functional rehabilitation of malaligned teeth but in some exceptionally rare cases, the unwillingness of the patient for orthodontic correction poses a tough challenge to the dentist. In such cases, the only other option for aesthetic restoration is the change in angulation with custom cast post and core followed by the placement of an aesthetic crown. PMID:23893280

Singh, Kunwarjeet; Kumar, Narendra; Choudhary, Nisha; Gupta, Nidhi

2013-07-26

148

Endodontic management of an unusual foreign body in a maxillary central incisor  

PubMed Central

The discovery of foreign bodies in the teeth is often diagnosed accidentally. It is commonly seen in children. These foreign objects may act as a potential source of infection and may later lead to a painful condition. Detailed case history, clinical and radiographic examinations are necessary to come to a conclusion about the nature, size, and location of the foreign body, and the difficulty involved in its retrieval. This paper discusses the types of foreign objects found in and around the teeth and reports an unusual case of a stapler pin in the root canal of a tooth, its retrieval, and associated management of the involved teeth.

Chand, Keerthi; Joesph, Sam; Varughese, Jolly Mary; Nair, Mali G; Prasanth, Santhosh

2013-01-01

149

[Dental trauma: coronal fractures of permanent incisors. A new technique of bonding fragments].  

PubMed

The coronal fractures of the upper incisors for traumatic injuries represent the 8% of the total dental trauma. The use of new dentinal adhesive have permitted to obtain new interesting development in dental traumatology and dental esthetic, like the possibility of the utilisation of the dental fragment, of the incisor broken for a trauma. The new dentinal adhesive is the Gluma (Bayer). The Authors describe the technique, the times, some particulars and step by step all the method to obtain good final results. Finally are presented all the advantages compared to the traditional methods with the composites materials. PMID:2126960

Caprioglio, D; Cenzato, M; Caprioglio, C; Falconi, A

150

Palatally impacted maxillary canine with congenitally missing lateral incisors and midline diastema.  

PubMed

Multiple treatment options are available for patients who have impacted canines in addition to congenitally missing lateral incisors. This article describes the treatment of a 13-year-old postpubertal girl with bilaterally impacted permanent maxillary canines, missing lateral incisors, retained deciduous canines, and a midline diastema. The orthodontic treatment plan included extraction of the deciduous canines. A lingual and labial approach (1-couple force system) was used to move the permanent canines into the arch. Through a collaborative team effort, including an orthodontist and a periodontist, the outcome was excellent esthetically and functionally. PMID:23810055

Yadav, Sumit; Upadhyay, Madhur; Uribe, Flavio; Nanda, Ravindra

2013-07-01

151

An examination of the effects of levelingwith nickel titanium rectangular arch wires combined with torqued incisor brackets  

Microsoft Academic Search

Leveling the curve of Spee with sequential round cross-section arch wires characteristically results in incisor proclination. To prevent this, the use of low modulus, rectangular cross-section arch wires combined with torqued incisor brackets has been recommended by some clinicians. Clinical data were analyzed to determine whether this is the case. It showed that proclination does occur at a lesser angle

Stanley Braun

2001-01-01

152

Light and electron microscopic analysis of the somata and parent axons innervating the rat upper molar and lower incisor pulp  

Microsoft Academic Search

The morphology of intradental nerve fibers of permanent teeth and of continuously growing rodent incisors has been studied in detail but little information is available on the parent axons that give rise to these fibers. Here we examined the axons and somata of trigeminal neurons that innervate the rat upper molar and lower incisor pulp using tracing with horseradish peroxidase

S. K. Paik; K. P. Park; S. K. Lee; S. K. Ma; Y. S. Cho; Y. K. Kim; I. J. Rhyu; D. K. Ahn; A. Yoshida; Y. C. Bae

2009-01-01

153

Autotransplantation of a Supernumerary Tooth to Replace a Misaligned Incisor with Abnormal Dimensions and Morphology: 2-Year Follow-Up  

PubMed Central

Autotransplantation is a viable treatment option to restore esthetics and function impaired by abnormally shaped teeth when a suitable donors tooth is available. This paper describes the autotransplantation and 2-year follow-up of a supernumerary maxillary incisor as a replacement to a misaligned maxillary incisor with abnormal crown morphology and size. The supernumerary incisor was immediately autotransplanted into the extraction site of the large incisor and was stabilized with a bonded semirigid splint for 2 weeks. Fixed orthodontic therapy was initiated 3 months after autotransplantation. Ideal alignment of the incisors was accomplished after 6 months along with radiographic evidence of apical closure and osseous/periodontal regeneration. In autogenous tooth transplantation, a successful clinical outcome can be achieved if the cases are selected and treated properly.

Tirali, R. Ebru; Sar, Cagla; Ates, Ufuk; Kizilkaya, Metin; Cehreli, S. Burcak

2013-01-01

154

Evaluation of the Central Heating Plant Operation at Malmstrom Air Force Base, MT.  

National Technical Information Service (NTIS)

In 1983, a new coal-fired central heating plant was built for Malmstrom Air Force Base (MAFB), MT, to replace the existing poorly operating system and provide for increased heating requirements. Although the generators had been fired intermittently with c...

M. J. Savoie J. Davidson J. Northrup T. Ask C. Schmidt

1995-01-01

155

Halogens in water from the crystalline basement of the Gotthard rail base tunnel (central Alps)  

Microsoft Academic Search

Drilling of the new Gotthard rail base tunnel (central Alps) opened a large number of water-conducting fractures in granite and gneiss of the crystalline basement. The overburden reaches locally more than 2000m and water and rock temperature is up to 45°C. The tunnel crosses a series of steeply dipping fractured rock units that also crop out at the surface above

Ulrike Seelig; Kurt Bucher

2010-01-01

156

Ethernet-based remote distributed control system for central air conditioner  

Microsoft Academic Search

This paper develops a remote distributed control system (DCS) for central air conditioner based on the Ethernet. The system architecture and function are described in detail in this paper. The DCS control system presents a control-platform that can realize the configuration of the controlled objects in different regions at the same time. In any place with access to the internet,

Chunhua Zhang; Zhenhua Li; Huayi Wang; Bin Song; Yunta Xiong

2010-01-01

157

An Agent-Based Model of Centralized Institutions, Social Network Technology, and Revolution  

Microsoft Academic Search

Recent uprisings in the Arab world consist of individuals revealing vastly different preferences than were expressed prior to the uprisings. This paper sheds light on the general mechanisms underlying large-scale social and institutional change. We employ an agent-based model to test the impact of authority centralization and social network technology on preference revelation and falsification, social protest, and institutional change.

Michael D. Makowsky; Jared Rubin

2011-01-01

158

A plant-based index of biological integrity (IBI) for headwater wetlands in central Pennsylvania  

Microsoft Academic Search

Vascular plants are quickly emerging as one of the best indicators of human-mediated disturbances in the environment. We developed a plant-based index of biological integrity (IBI) to evaluate headwater wetland condition in response to anthropogenic disturbances in the Ridge and Valley Physiographic Province of central Pennsylvania. To construct the IBI, we evaluated 50 attributes of the plant community, including species

Sarah J. Miller; Denice H. Wardrop; Wendy M. Mahaney; Robert P. Brooks

2006-01-01

159

Centralized content-based Web filtering and blocking: how far can it go?  

Microsoft Academic Search

To an organisation, centralized Internet filtering and blocking is very important. Educators and parents would like to block offensive materials from children. Companies also want to reduce the amount of work time that employees spend on non-productive Web surfing. Current blocking and filtering mechanisms can roughly be classified into two approaches: URL-based and content filtering. In the URL-based approach, a

Chen Ding; Chi-Hung Chi; Jing Deng; Chun-Lei Dong

1999-01-01

160

Iodopolatinate visualization of phospholipids in rat incisor predentine and dentine, compared with malachite green aldehyde  

Microsoft Academic Search

The iodoplatinate (IP) reaction, a selective method for visualization of phospholipids, was applied to the predentine and dentine of rat incisors and compared with malachite green aldehyde (MG) fixation\\/staining. Spot tests indicated (1) that IP specifically stains phospholipids, but not amino acids, displaying as do phospholipids, quaternary ammonium groups; and (2) phosphatidylserine and sphingomyelin were also stained by MGA. Although

L. Vermelin; D. Septier; M. Goldberg

1994-01-01

161

Histology of primary incisor enamel in children with early onset celiac disease  

Microsoft Academic Search

The manifestations of celiac disease are a result of nutri- tional malabsorption. An early onset of such malabsorption may jeopardize the primary enamel which is not mineralized. Prepared sections of 10 primary incisors from 10 children with early onset celiac disease were examined using polarized light microscopy to determine if enamel defects were present. Study of the tooth sections dry

Daniel Raether

1988-01-01

162

The MMP activity in developing rat molar roots and incisors demonstrated by in situ zymography  

Microsoft Academic Search

Matrix metalloproteinases (MMPs) have been expressed during root development and periodontal tissue formation, whereas it is not known if these MMP molecules are enzymatically active to degrade the extracellular matrices (ECMs). The present study was designed to investigate the gelatinolytic and collagenolytic activity in rat molar root and incisor development. Three-week old rat mandibles were frozen and cut without fixation

Ichiro Sakuraba; Junko Hatakeyama; Yuji Hatakeyama; Ichiro Takahashi; Hideaki Mayanagi; Yasuyuki Sasano

2006-01-01

163

Evaluation of Canal Morphology at Different Levels of Root Resection in Mandibular Incisors.  

National Technical Information Service (NTIS)

One hundred randomly selected mandibular incisors were examined to assess the prevalence and location of two canals and to describe the canal anatomy that may be encountered during apical surgery. The roots were resected at 1, 2, and 3mm apical sections s...

M. J. Mauger

1997-01-01

164

No Correlation between Primary Mandibular Anterior Crowding and Vertical Craniofacial Configuration or Lower Incisor Inclination  

Microsoft Academic Search

The aim of the present study was to evaluate the correlation between primary mandibular anterior crowding and vertical cranofacial configuration or sagittal lower incisor inclination. The collective comprised 100 consecutive patients (50 males, 50 females) subject to 4 selection criteria: mandibular anterior crowding S 1.0 mm, no provious orthodontic therapy, completely preserved deciduous canines and molars, and lateral cephalograms of

Rainer-Reginald Miethke

2000-01-01

165

Molar-incisor hypomineralisation: prevalence and defect characteristics in Iraqi children.  

PubMed

BACKGROUND.? Little prevalence data relating to molar incisor hypomineralisation (MIH) exist for Middle East populations. AIM.? To evaluate the prevalence and the clinical features of MIH in school-aged children residing in Mosul City, Iraq. DESIGN.? A cluster sample of 823 7- to 9-year-old children had their first permanent molars and incisors (index teeth) evaluated using the European Academy of Paediatric Dentistry (EAPD) criteria for MIH. The examinations were conducted at schools by a calibrated examiner. RESULTS.? Of the children examined, 177 (21.5%) had hypomineralisation defects in at least one index tooth, 153 (18.6%) had at least one affected first molar or first molars and incisors and were considered as having MIH. The most commonly affected teeth were maxillary molars. Demarcated creamy white opacities were the most frequent lesion type. Dental restorations and tooth extraction because of MIH were uncommon. Children with three or more affected teeth were 3.7 times more likely to have enamel breakdown when compared with those children having only one or two affected teeth. CONCLUSIONS.? Molar incisor hypomineralisation was common amongst Iraqi children. Demarcated opacities were more prevalent than breakdown. The severity of the lesions increased with the number of affected teeth. The more severe the defect, the greater the involved tooth surface area. PMID:21689174

Ghanim, Aghareed; Morgan, Michael; Mariño, Rodrigo; Bailey, Denise; Manton, David

2011-06-20

166

Minimizing upper lip and incisor teeth paresthesias in approaches to transsphenoidal surgery  

Microsoft Academic Search

Currently popular transsphenoidal approaches to the pituitary include sublabial, external rhinoplasty, alotomy, and transnasal techniques. The conventional sublabial approach remains the workhorse method despite postoperative lip edema, potential difficulty for denture wearers, and troublesome persistent upper lip and incisor teeth numbness. We traced the courses of the nasopalatine, infraorbital, and anterior superior alveolar nerves in 41 cadaveric half-head dissections to

SCOTT R. SCHOEM; ANJUM KHAN; WILLIAM R. WILSON; EDWARD R. LAWS

1997-01-01

167

Nano-mechanical properties profiles across dentin–enamel junction of human incisor teeth  

Microsoft Academic Search

Understanding how load is transferred from enamel to dentin and how the two tissues function as a single mechanical unit during mastication requires studies of micromechanics in relation to microstructure of the dentin–enamel junction (DEJ) zone. In this investigation, nano-hardness and elastic modulus of human incisor teeth were studied across the DEJ. It was found that, over a length scale

Hanson Fong; Mehmet Sarikaya; Shane N White; Malcolm L Snead

2000-01-01

168

Organic and inorganic content of fluorotic rat incisors measured by FTIR spectroscopy  

NASA Astrophysics Data System (ADS)

Details on how fluoride interferes in enamel mineralization are still controversial. Therefore, this study aimed at analyzing the organic contents of fluorosis-affected teeth using Fourier Transformation Infrared spectroscopy. To this end, 10 male Wistar rats were divided into two groups: one received 45 ppm fluoride in distilled water for 60 days; the other received distilled water only. Then, the lower incisors were removed and prepared for analysis by two FTIR techniques namely, transmission and micro-ATR. For the first technique, the enamel was powdered, whereas in the second case one fluorotic incisor was cut longitudinally for micro-ATR. Using transmission and powdered samples, FTIR showed a higher C-H content in the fluorotic enamel compared with control enamel ( p < 0.05, n = 4 in the flurotic, and n = 5 in the control group). Results from the micro-ATR-FTIR spectroscopic analysis on one longitudinally cut incisor carried out at six points reveal a higher C-H bond content at the surface of the enamel, with values decreasing toward the dentine-enamel junction, and reaching the lowest values at the subsuperficial enamel. These results agree with the morphological data, which indicate that in the rat incisor the fluorotic lesion is superficial, rather than subsuperficial, as in the case of human enamel. The results also suggest that the increased C-H bond content may extend toward the more basal enamel (intraosseous), indicating that fluorotic enamel may intrinsically contain more protein. Finally, particularly when coupled to ATR, FTIR is a suitable tool to study the rat incisor enamel, which is a largely used model of normal and abnormal amelogenesis. Further studies along this line may definitely answer some questions regarding protein content in fluorotic enamel as well as their origin.

Porto, Isabel Maria; Saiani, Regina Aparecida; Chan, K. L. Andrew; Kazarian, Sergei G.; Gerlach, Raquel Fernanda; Bachmann, Luciano

2010-09-01

169

Chemical and structural composition of Atlantic Canadian moose (Alces alces) incisors with patterns of high breakage.  

PubMed

Analysis of mammalian teeth can provide information regarding local environmental conditions. For example, a high incidence of breakage and wear within a population may indicate poor food quality. Individuals consuming a diet causing high mechanical stress on their teeth, and/or lacking the appropriate minerals for proper development, could experience degradation of tooth condition. Previously, we documented a high rate of incisor tooth breakage, with age, in two genetically distinct moose populations in Atlantic Canada. In this study, multi-element (11B, 63Cu, 64Zn, 75As, 85Rb, 88Sr, 111Cd, 118Sn, 137Ba, 208Pb, 232Th, and 238U) analyses using laser ablation ICP-MS were performed on moose incisors from multiple North American regions. The purpose was to determine whether the elemental composition of moose incisors varies among regions, and whether that variation is related to tooth degradation among Atlantic Canadian populations. A principal components analysis revealed that nearly 50% of the elemental variation in the inner enamel matrix of moose teeth was explained by three groupings of elements. The element groupings revealed differences among geographic regions, but did not explain the variation between incisors that were broken and those that were not. Regression models indicate that the elemental group which includes Cu, Pb, and Zn is related to decreases in incisal integrity. It is likely that other environmental factors contribute to the occurrence of increased incisor breakage in affected populations. The relationship between food resource quantity and quality, as a function of moose density, is hypothesized to explain loss of tooth integrity. PMID:21945187

MacKenzie, Cynthia S Kendall; Clough, Michael J; Broders, Hugh G; Tubrett, Mike

2011-09-26

170

Bacterial penetration of the root canal of intact incisor teeth after a simulated traumatic injury.  

PubMed

One of the aims in treating traumatised teeth is to maintain the vitality of the pulp or allow conditions favourable for pulp revascularisation. However, infection of the pulp and root canal system may prevent this. A number of pathways have been proposed that allow bacteria to invade the root canal system, however most of these pathways cannot account for pulp infection in teeth that did not sustain injury to the periodontal attachment. Enamel/dentine cracks have been proposed as a portal for bacterial invasion of seemingly intact teeth and the aim of this study was to determine if bacteria could invade the root canal system after a simulated traumatic episode. Twenty intact and sound upper central incisors were chosen and prepared. One tooth was selected as a sterility control and the external crown surface of the remaining 19 teeth was subjected to infection with Streptococcus gordonii in a bacterial microleakage model. Over 7 days samples of growth media from the root canal system were taken and tested for bacteria. Sixteen of the teeth did not demonstrate bacterial invasion over the time frame. These teeth were then prepared for testing in a pendulum impact device and were subjected to a blow which did not fracture the crowns or dislodge the tooth from its simulated alveolus. The teeth were then prepared and tested in the bacterial microleakage model. After impact seven of the teeth demonstrated bacterial invasion of the root canal system (P = 0.002). These teeth were then reprepared for testing in the bacterial microleakage model. The crowns of five teeth, selected at random, were coated with two layers of light cured unfilled resin, the remaining two were used as positive controls. All the teeth coated with resin did not demonstrate bacterial invasion (P = 0.00), while the positive controls demonstrated invasion. The results suggested that enamel/dentine infractions were pathways for bacterial invasion of the root canal system of traumatised teeth. The application of unfilled resin to the anatomical crown prevented infection. PMID:9206377

Love, R M

1996-12-01

171

Management of macular edema secondary to central retinal vein occlusion: an evidence-based  

Microsoft Academic Search

Retinal vein occlusions are common retinal vascular disorders with the potential for significant vision-related morbidity.\\u000a Retinal vein occlusions are classified as either branch retinal vein occlusion (BRVO), central retinal vein occlusion (CRVO),\\u000a or hemiretinal vein occlusion (HRVO) based on the specific occlusion site. Decreased vision in patients afflicted with CRVO\\u000a may result from retinal ischemia and\\/or the accumulation of fluid

Ahmad A. Aref; Ingrid U. Scott

2011-01-01

172

Bioenergy and economic analysis of soybean-based crop production systems in central India  

Microsoft Academic Search

The study examines the energy requirement and energy input–output relationship of soybean-based crop production systems viz., soybean (Glycine max (L.) Merr.)–wheat (Triticum aestivum L.), soybean–mustard (Brassica juncea (L.) Czern & Coss.) and soybean–chickpea (Cicer arietinum L.) in central India. Using a pre-tested questionnaire, 135 farmers were selected through a multi-stage stratified random sampling technique. Results revealed that manures and chemical

K. G Mandal; K. P Saha; P. K Ghosh; K. M Hati; K. K Bandyopadhyay

2002-01-01

173

Deformations in Central Europe: finite element approach and comparison with GPS-based strain determinations  

NASA Astrophysics Data System (ADS)

From a geological point of view, the area of Central Europe is very complex. At the same time Europe is being affected by the forces associated with tectonic Africa, as well as Atlantic (ridge) push. In our study the general strain pattern of Central Europe was determined from two different approaches. The first one was finite element approach (FEM). The area of Europe was subdivided into more than 50 elements corresponding to the main geological units and the two-dimensional model of strain field in Central Europe was developed. In order to model a diverse nature of geological structures two approaches were investigated: elastic and more sophisticated made by adding some viscosity properties. Various parameters (Young's modulus, Poisson's ratio, lithosphere thickness, etc.) with the use of the ABAQUS software were implemented. The second approach was based on the method using sites' velocities determined by continuous GPS measurements. EPN network as well as ASG-EUPOS Polish system were utilised. More than 300 European sites with the precisely known velocities in global ITRF2008 reference frame formed the basis for these determinations by using GRID_STRAIN software. This geometrical method allows determining the magnitude and the main strain directions as well. The presentation describes results of numerical calculations and their comparison on the area of Central Europe.

Bogusz, Janusz; Jarosinski, Marek; Araszkiewicz, Andrzej; Figurski, Mariusz; Klos, Anna; Kontny, Bernard

2013-04-01

174

Continued root development of a surgically repositioned human incisor tooth germ.  

PubMed

Conventional orthodontic traction may not be the treatment of choice in cases of inverted impaction of a maxillary incisor, especially when located near the alveolar crest. Poor prognosis is associated with the limited space for proper root development, resulting in a root too short for normal function and/or a severely dilacerated root interrupting the force-induced positioning. The surgical repositioning of ectopic impacted toothgerm before the development of root could be a valuable alternative choice of treatment before the decision of extraction. In this case report, an impacted immature incisor toothgerm in complete inversion was surgically repositioned using a closed-flap technique in a boy who was 6 years 8 months old. Continued root formation and spontaneous eruption were observed after surgery over the 51-month follow-up period, without pulpal or periodontal complications. PMID:22771411

Kim, Seunghye; Kim, Junhewk; Song, Je Seon; Choi, Hyung-Jun; Choi, Byung-Jai; Kim, Seong-Oh

2012-07-07

175

Reattachment of fractured maxillary incisors using fiber-reinforced post: Two case reports  

PubMed Central

Objective: The reattachment of the crown fragment to a fractured tooth is a conservative treatment that should be considered for young patients with crown-root fractures to the maxillary incisors if the subgingival fracture can be exposed to provide isolation. Gingivectomy, the surgical or orthodontic extrusion of the apical fragment is necessary to expose the subgingival fracture. This report demonstrates the treatment of two cases with the combination of gingivectomy or resective osseous surgery, reattachment of coronal fracture and fiber-reinforced polymer posts and shows three years long term follow-up. Subgingivally extended crown-root fractures of maxillary incisors were restored with a combination of chemically cured resin material, light cured resin material and polyethylene fiber. Conclusion: Within the limitations of this case report, it was demonstrated that reattachment of tooth fragments can successfully benefit periodontal health, aesthetic needs and normal functioning after three years.

Tosun, Gul; Yildiz, Esma; Elbay, Mesut; Sener, Yagmur

2012-01-01

176

Non-Syndromic Bilateral Supplemental Maxillary Lateral Incisors: A Rare Case  

PubMed Central

Supernumerary teeth or hyperdontia are defined as the teeth that exceeds the normal dental formula, regardless of their location and morphology. A supernumerary tooth is a developmental anomaly and it has been argued to arise from multiple aetiologies. Supernumerary teeth with orthodox shapes and sizes, that resemble the normal dentition are called ‘supplemental teeth’. The supplemental teeth are often overlooked because of their normal shapes and sizes. Supplemental lateral incisors are rare and bilateral cases are even rarer, with only two cases being reported in the literature till date. Therefore, we are describing a rare case of non–syndromic, bilateral, supplemental, maxillary, lateral incisors and we have discussed the management of supernumerary teeth.

Nagpal, Ajay; Hans, Manoj Kumar; Shetty, Shashit; Kaur, Navpreet; Kumar, Sunil

2013-01-01

177

Treatment of severe inflammatory root resorption in a young permanent incisor with mineral trioxide aggregate.  

PubMed

Inflammatory root resorption is a pathologic condition caused by several etiologic factors including traumatic dental injury. In this case report, we describe treatment of a maxillary lateral incisor affected by severe, perforating inflammatory root resorption. An 11-year-old patient presented with a previously traumatized, root-filled maxillary lateral incisor associated with pain, mobility and a sinus tract. Radiographic examination revealed a large periradicular lesion involving pathologic resorption of the apical region of the root. After removal of the root canal filling, the tooth was treated with intracanal calcium hydroxide for 2 weeks. The calcium hydroxide dressing was then removed and the entire root canal was filled with mineral trioxide aggregate. The endodontic access cavity was restored with composite resin. After 1 year, advanced osseous healing of the periradicular region had occurred and no clinical symptoms were apparent. PMID:21846458

Guzeler, Irem; Uysal, Serdar; Cehreli, Zafer C

2011-01-01

178

[Extended subfrontal approach to the central cranial base - analysis of the surgical technique in cadaver simulation].  

PubMed

The aim of the study was to present consecutive stages of the extended subfrontal approach (ESA). Eight simulations of ESA were performed on non-fixed human cadavers without any known pathologies in the head and neck. The consecutive stages of the procedure were documented with photographs and schematic diagrams. The starting point for ESA is a bifrontal craniotomy and osteotomy including the base of the nose and superior parts of the orbits. If the anterior cranial base is not invaded by the tumour, an attempt to partially preserve olfaction is possible. Wound closure after removal of the tumour with ESA requires reconstruction of the tissue barrier between the cranial cavity, paranasal sinuses and nasopharynx. The extended subfrontal approach is a reproducible technique which provides surgical penetration of the central skull base. This approach is particularly useful in the surgical treatment of tumours expanding along the midline, superiorly and inferiorly to the skull base. PMID:19353445

Ladzi?ski, Piotr; Maliszewski, Mariusz

179

Lipid detection by malachite green-aldehyde in the dental basement membrane in the rat incisor  

Microsoft Academic Search

Developing rat incisors were treated with malachite green-aldehyde fixative solution (MGA), which retains and stains lipids. We observed positive staining occurring as dots in the basement membrane. Most of these dots (2–3.5 nm in diameter) were grouped in the lamina densa but some were also present in the lamina lucida and the lamina fibroreticularis. These data provide evidence for the

M. Goldberg; S. Lecolle; J. V. Ruch; A. Staubli; D. Septier

1988-01-01

180

Cultured incisors display major modifications in basal lamina deposition without further effect on odontoblast differentiation  

Microsoft Academic Search

Matrix-mediated epithelio-mesenchymal interactions play a crucial role in the control of dental cytodifferentiations. Ultrastructural observation of the epithelio-mesenchymal junction in cultured embryonic mouse molars showed discrete zones with duplicated or multilayered basal laminae. The use of synthetic peptides demonstrated that the process was RGD*-independent, did not involve the YIGSR* sequence present on laminin and could occur spontaneously. Cultured incisors showed

Jean-Marie Meyer; Jean Victor Ruch; Marie Dominique Kubler; Christian Kupferle; Hervé Lesot

1995-01-01

181

Histology of enamel organ and chemical composition of adjacent enamel in rat incisors  

Microsoft Academic Search

Summary  By avoiding chemical fixation and using a freeze-drying technique, it proved possible to examine the enamel organ of rat mandibular\\u000a incisors histologically while retaining the adjacent enamel of the same tooth for chemical analysis. The dramatic alterations\\u000a which occur in enamel organ histology, such as ameloblast shortening and the development of the papillary layer, could then\\u000a be compared directly with

C. Robinson; H. D. Briggs; P. J. Atkinson

1981-01-01

182

Rat incisor dentin formed under low plasma calcium concentration: Relation of phosphophoryns to the affected dentin  

Microsoft Academic Search

:   When parathyroidectomized (PTX) rats were maintained on a diet containing 0.3% calcium and lacking vitamin D, the forming\\u000a incisor dentin consisted of two distinct layers that differed in their degree of mineralization. The two layers could be distinguished\\u000a by hematoxylin staining and by contact microradiography. The layer near the dental pulp was the hypomineralized dentin, different\\u000a from a predentin,

Makoto Fukae; Takako Tanabe; Michitsugu Arai; Shinji Shimoda; Masahito Yamaguchi; Yasuo Yamakoshi; Akifumi Togari; Kenzo Kawasaki; Marie Yamada; Shosei Matsumoto

1998-01-01

183

[Lip angle and the position of the maxillary lateral incisor--post orthodontics retention considerations].  

PubMed

The relations between the soft tissues draping, the dentoskeletal structure and teeth position have been thoroughly investigated. Nevertheless, it is still unclear to point on the primary underlying cause for pathology if exists, is it the frame or the content, the chicken or the egg. Those relations are of an utmost importance in the process of determining the retention procedure and length in post orthodontic treatment patients. This paper discusses the issue which, as far as we know, has never been examined - the upper lip angle, (the angle created by 3 points - the two intersections between the lip cupid arch and the lip philtrum columns and the lip commissural point in either side), as it related to the maxillary lateral incisors position. Long term clinical observations were behind our hypothesis that lips with acute angles go along with palatally positioned maxillary lateral incisors, one or two. The lips angel of both the study group (37 orthodontic patients ages 15.7+/-6.8, with at least one maxillary lateral incisor in palatal position), and the control group (37 orthodontic patients ages 16.5+/-8.7 with no mal-aligned maxillary teeth) were measured and compared. It was found that the lip angle of the control group was 152.256+/-5.52 degrees while for the study group it was 149.23+6.68. This result is with statistical difference (p=0.001). It was further found that the more acute the lip angle; the more the lateral maxillary tooth or teeth are palatally positioned. The results of this study and the clinical observations suggest long term fixed retention of the maxillary incisors, following orthodontic treatment especially in patients with acute lip angle. PMID:23697299

Coval, M; Wasserstein, A; Brezniak, N

2013-01-01

184

Endodontic treatment of immature maxillary lateral incisor with two canals: type 3 dens invaginatus.  

PubMed

Dens invaginatus is a developmental anomaly. The nonsurgical endodontic treatment of a type 3 dens invaginatus with a large periradicular lesion in a maxillary left lateral incisor of a 10-year-old girl is presented. In spite of difficult diagnosis and treatment of type 3 dens invaginatus, nonsurgical treatment was performed successfully. Resolution of the periradicular lesion and apical closure was observed after 1-year follow-up. PMID:20580274

Altunta?, Alev; C?nar, Ca?da?; Akal, Ne?e

2010-07-02

185

Alveolar bone loss around incisors in Class I bidentoalveolar protrusion patients: a retrospective three-dimensional cone beam CT study  

PubMed Central

Objectives The aim of this study was to test the null hypothesis that there is no difference in the alveolar bone thickness, bone loss or incidence of fenestrations between upper and lower incisors in skeletal Class I bidentoalveolar protrusive patients before orthodontic treatment. Methods Three-dimensional (3D) cone beam CT (CBCT) images were taken of 24 patients from the Republic of Korea (17 females and 7 males). Reformatted CBCT images were used to measure labial and lingual alveolar bone thickness (ABT) of the 4 upper incisors and 4 lower incisors of the 24 patients (total n = 192 incisors) at every 1/10 of root length (Level 0, cementoenamel junction (CEJ) area; Level 10, root apex area) as well as alveolar bone area (ABA) and alveolar bone loss (%BL) rate to dental root length. The numbers of fenestration teeth were also tallied. Results All anterior teeth were supported by <1 mm of ABT on the labial surfaces up to root length Level 8. ABA was statistically greater on the lingual aspect than the labial aspect in lower incisors. The %BL was 26.98% in the lower labial region, 19.27% in upper labial aspect and most severe on the lower lingual plate 31.25% compared with the labial plate. There were no significant differences in %BL between subgroups when categorized by sex or age. Fenestrations were 1.37 times more frequent on lower incisors (37) than upper incisors (27). Conclusion The null hypothesis was rejected, confirming that incisor periodontal support is poor and alveolar bone loss is severe even prior to the start of orthodontic treatment. Careful diagnosis using 3D CBCT images is needed to avoid iatrogenic degeneration of periodontal support around anterior teeth, particularly in the lower lingual bone plate region.

Nahm, K-Y; Kang, J-H; Moon, S-C; Choi, Y-S; Kook, Y-A; Kim, S-H; Huang, JC

2012-01-01

186

Assessing the ecological base and peak flow of the alpine streams in Central Taiwan  

NASA Astrophysics Data System (ADS)

The ecological base and peak flow are crucial for the assessment and design for habitat rehabilitation and recovery. The amount of discharge affects the aquatic creatures and may severely damage the existence and balance of the community under extreme conditions. Aquatic insects are selected as the target species in this study to evaluate the influence of the discharge and to estimate the ecological base and peak flow. The distribution of the number of species and abundance (density) versus discharge is assessed to define the critical discharge. Two streams located at the alpine area in central Taiwan are selected as the study area to evaluate the base and peak flow. From the preliminary data (Aug 2008 to Dec 2008) collected from one stream Creek C originating from Sitou Area in Central Taiwan shows that the abundance of several species varies with the discharge. The dominate family and genus of aquatic insects is Baetidae (Order Ephemeroptera) and Baetis spp. that accounts for 32.47% and 31.11%, respectively. The Hilsenhoff family biotic index (FBI) shows that the water quality is classified to "Good" and "Very Good" level while the river pollution index (RPI) indicates that the stream is non-polluted. The discharge of base flow interpreted from the 95% curve of duration for the daily discharge is 0.0234 cms. Consistent observations are yet to be collected to yield more accurate result and ecological peak flow in rainy and typhoon seasons.

Wei, C.; Yang, P. S.; Tian, P. L.

2009-04-01

187

Ankylosis of traumatized permanent incisors: pathogenesis and current approaches to diagnosis and management.  

PubMed

Ankylosis is a known complication of replanted or severely intruded permanent incisors and can be diagnosed by the characteristic sound emitted when the tooth is tapped. The ankylosed incisor demonstrates a lack of physiologic mobility and, later, radiographic evidence of replacement resorption. If the patient is pre-adolescent or adolescent at the time of trauma, infraocclusion relative to adjacent teeth will become apparent during jaw growth. Despite considerable knowledge about the pathogenesis of ankylosis garnered from animal studies and observation of human replanted teeth, there is no known treatment to arrest this condition. Management techniques and rehabilitation options for addressing ankylosis and its consequences are supported by little evidence, do not appear to be widely adopted and do not offer any proven long-term benefit. Avulsion and severe intrusion of permanent incisors are rare injuries. Should the decision be made to intervene by replantation or reduction of the intrusion, the clinician must be prepared to diagnose ankylosis, identify its negative consequences and develop treatment plans accordingly. PMID:16324230

Campbell, Karen M; Casas, Michael J; Kenny, David J

2005-11-01

188

Periostin is an extracellular matrix protein required for eruption of incisors in mice  

SciTech Connect

A characteristic tooth of rodents, the incisor continuously grows throughout life by the constant formation of dentin and enamel. Continuous eruption of the incisor is accompanied with formation of shear zone, in which the periodontal ligament is remodeled. Although the shear zone plays a role in the remodeling, its molecular biological aspect is barely understood. Here, we show that periostin is essential for formation of the shear zone. Periostin {sup -/-} mice showed an eruption disturbance of incisors. Histological observation revealed that deletion of periostin led to disappearance of the shear zone. Electron microscopy revealed that the disappearance of the shear zone resulted from a failure in digestion of collagen fibers in the periostin {sup -/-} mice. Furthermore, immunohistochemical analysis using anti-periostin antibodies demonstrated the restricted localization of periostin protein in the shear zone. Periostin is an extracellular matrix protein, and immunoelectron microscopy showed a close association of periostin with collagen fibrils in vivo. These results suggest that periostin functions in the remodeling of collagen matrix in the shear zone.

Kii, Isao [Department of Biological Information, Tokyo Institute of Technology, Yokohama 226-8501 (Japan); Amizuka, Norio [Center for Transdisciplinary Research, Niigata University, Niigata 951-8514 (Japan); Minqi, Li [Center for Transdisciplinary Research, Niigata University, Niigata 951-8514 (Japan); Kitajima, Satoshi [Division of Cellular and Molecular Toxicology, National Institute of Health Science, Tokyo 158-8501 (Japan); Saga, Yumiko [Division of Mammalian Development, National Institute of Genetics, Mishima 411-8540 (Japan); Kudo, Akira [Department of Biological Information, Tokyo Institute of Technology, Yokohama 226-8501 (Japan)]. E-mail: akudo@bio.titech.ac.jp

2006-04-14

189

Rapid decrease of malaria morbidity following the introduction of community-based monitoring in a rural area of central Vietnam  

Microsoft Academic Search

BACKGROUND: Despite a successful control programme, malaria has not completely disappeared in Vietnam; it remains endemic in remote areas of central Vietnam, where standard control activities seem to be less effective. The evolution of malaria prevalence and incidence over two and half years in a rural area of central Vietnam, after the introduction of community-based monitoring of malaria cases, is

Ngo Duc Thang; Annette Erhart; Le Xuan Hung; Le Khanh Thuan; Nguyen Xuan Xa; Nguyen Ngoc Thanh; Pham Ky; Marc Coosemans; Nico Speybroeck; Umberto D'Alessandro

2009-01-01

190

Structural analysis of the central Columbia Plateau utilizing radar, digital topography, and magnetic data bases  

SciTech Connect

Interest in the Hanford site (Washington) as a nuclear production, power, and waste disposal site has led to generation of a vast quantity of geophysical and remote sensing data sets of the central Columbia Plateau. To data, these various studies, including at least 13 independent magnetic linear and image lineament studies, have not been adequately correlated. Therefore, these studies provide a unique opportunity to compare and contrast the viability of the different geophysical and remote sensing techniques. The geology of the central Columbia Plateau is characterized by subdued topography and limited outcrop, with most of the exposure concentrated in localized folded/faulted mountains (the Yakima folds) and along river canyons. In order to efficiently compare lineament data bases, we have written an automated computer routine that correlated lineaments that are within a user specified distance of each other. The angle between their trends has to be less than an input maximum separation angle. If more than two lineament maps exist for the area, the analyst may also specify the minimum number of times each structure must be seen. The lineament correlation routine was applied to data bases of all aeromagnetic linears as well as lineaments seen on radar and a digital elevation model DEM image. Geologic structures align with a set of three-dimensional planar structures identified with our Geologic Spatial Analysis (GSA) system. The GSA analysis is based upon computer automated detection of valley bottoms as defined by a DEM.

Thiessen, R.L.; Eliason, J.R.; Johnson, L.K.; Brougher, C.W. [Washington State Univ., Pullman, WA (United States). Dept. of Geology; Foley, M.G.; Beaver, D.E. [Pacific Northwest Lab., Richland, WA (United States)

1991-08-01

191

Central obesity in Yemeni children: A population based cross-sectional study  

PubMed Central

AIM: To establish percentile curves and to explore prevalence and correlates of central obesity among Yemeni children in a population based cross-sectional study. METHODS: A representative sample of 3114 Yemeni children (1564 boys, 1550 girls) aged 6-19 years participating in the HYpertension and Diabetes in Yemen study was studied. Data collection was conducted at home by survey teams composed of two investigators of both genders. Study questionnaire included questions about demographics, lifestyle, and medical history. Anthropometric measurements included body weight, height, waist circumference (WC) and hip circumferences. Waist to hip ratio (WHR) and waist-to-height ratio (WHtR) were then calculated. Age and gender specific smoothed percentiles of WC, WHR, and WHtR were obtained using lambda-mu-sigma parameters (LMS method). The independent predictors of central obesity defined as (1) WC percentile ? 90th; (2) WHtR ? 0.5; or (3) WC percentile ? 90th and WHtR ? 0.5, were identified at multivariate logistic regression analysis adjusted for age, gender, urban/rural location, years of school education, sedentary/active life-style. RESULTS: Percentile curves for WC, WHR and WHtR are presented. Average WC increased with age for both genders. Boys had a higher WC than girls until early adolescence and thereafter girls had higher values than boys. WHR decreased both in boys and girls until early adolescence. Thereafter while in boys it plateaued in girls it continued to decrease. Mean WHtR decreased until early adolescence with no gender related differences and thereafter increased more in girls than in boys towards adult age. Prevalence of central obesity largely varied according to the definition used which was 10.9% for WC ? 90th percentile, 18.3% for WHtR ? 0.5, and 8.6% when fulfilling both criteria. At adjusted logistic regression WC ? 90th percentiles and WHtR ? 0.5 were less prevalent in rural than in urban areas (OR = 0.52, 95%CI: 0.41-0.67 and 0.66, 0.54-0.79 respectively), being more prevalent in children with sedentary lifestyle rather than an active one (1.52, 95%CI: 1.17-1.98 and 1.42, 95%CI: 1.14-1.75, respectively). CONCLUSION: Yemeni children central obesity indices percentile curves are presented. Central obesity prevalence varied according to the definition used and was more prevalent in urban sedentary subjects.

Bamoshmoosh, Mohamed; Massetti, Luciano; Aklan, Hameed; Al-Karewany, Mahdi; Goshae, Husni Al; Modesti, Pietro Amedeo

2013-01-01

192

Management of macular edema secondary to central retinal vein occlusion: an evidence-based.  

PubMed

Retinal vein occlusions are common retinal vascular disorders with the potential for significant vision-related morbidity. Retinal vein occlusions are classified as either branch retinal vein occlusion (BRVO), central retinal vein occlusion (CRVO), or hemiretinal vein occlusion (HRVO) based on the specific occlusion site. Decreased vision in patients afflicted with CRVO may result from retinal ischemia and/or the accumulation of fluid within the center of the retina (macular edema). The Central Vein Occlusion Study (CVOS) Group demonstrated that grid laser photocoagulation is not an effective treatment for decreased vision due to CRVO-related macular edema. Since publication of that report, the standard of care for patients with decreased vision due to CRVO-associated macular edema was observation. However, in the past 5 years, several major randomized controlled clinical trials have investigated new therapeutic modalities for the treatment of macular edema secondary to CRVO. This article aims to provide insight into current evidence-based approaches to the management of macular edema secondary to CRVO. A companion article reviews approaches for the management of macular edema secondary to BRVO. PMID:21153510

Aref, Ahmad A; Scott, Ingrid U

2010-12-09

193

The Central Simulation Committee (CSC): a model for centralization and standardization of simulation-based medical education in the U.S. Army healthcare system.  

PubMed

In this report, we describe the organizational framework, operations and current status of the Central Simulation Committee (CSC). The CSC was established in 2007 with the goals of standardizing simulation-based training in Army graduate medical education programs, assisting in redeployment training of physicians returning from war, and improving patient safety within the Army Medical Department. Presently, the CSC oversees 10 Simulation Centers, controls over 21,000 sq ft of simulation center space, and provides specialty-specific training in 14 medical specialties. In the past 2 years, CSC Simulation Centers have trained over 50,000 Army medical students, residents, physician assistants, nurses, Soldiers and DoD civilian medical personnel. We hope this report provides simulation educators within the military, and our civilian simulation colleagues, with insight into the workings of our organization and provides an example of centralized support and oversight of simulation-based medical education. PMID:22808890

Deering, Shad; Sawyer, Taylor; Mikita, Jeffrey; Maurer, Douglas; Roth, Bernard J

2012-07-01

194

[MR-based methods of the functional imaging of the central nervous system].  

PubMed

This review presents the basic principles of functional imaging of the central nervous system utilizing magnetic resonance imaging. The focus is set on visualization of different functional aspects of the brain and related pathologies. Additionally, clinical cases are presented to illustrate the applications of functional imaging techniques in the clinical setting. The relevant physics and physiology of contrast-enhanced and non-contrast-enhanced methods are discussed. The two main functional MR techniques requiring contrast-enhancement are dynamic T1- and T2*-MRI to image perfusion. Based on different pharmacokinetic models of contrast enhancement diagnostic applications for neurology and radio-oncology are discussed. The functional non-contrast enhanced imaging techniques are based on "blood oxygenation level dependent (BOLD)-fMRI and arterial spin labeling (ASL) technique. They have gained clinical impact particularly in the fields of psychiatry and neurosurgery. PMID:15871087

Giesel, F L; Wüstenberg, T; Bongers, A; Weber, M A; Zechmann, C; Baudendistel, K T; von Tengg-Kobligk, H; Hahn, H K; Essig, M; Kauczor, H-U

2005-05-01

195

[Central wavelength shift analysis between laboratory and field spectral calibrations of grating based imaging spectrometer].  

PubMed

Spectral calibration must be carried out in order to determine its central wavelength and half-wave band width of each pixel before the usage of imaging spectrometer. But it was found out that these parameters vary as environment changes. The present paper studies the effect based on test field data. The authors analyzed the optical structure and compared the working environmental parameters. Then a theoretical model is established and the influences of vibration, distortion and temperature parameters are evaluated. The theoretical model and the caculation results are in good consistency, which testifies the theoretical model. This research will shed some light on the high accuracy spectral calibration of the grating based imaging spectrometer and its manufacture. PMID:24159894

Wang, Ming-Zhi; Yan, Lei; Yang, Bin; Gou, Zhi-Yang

2013-08-01

196

An Innovative Approach to Treat Incisors Hypomineralization (MIH): A Combined Use of Casein Phosphopeptide-Amorphous Calcium Phosphate and Hydrogen Peroxide--A Case Report  

PubMed Central

Molar Incisor Hypomineralization (MIH) is characterized by a developmentally derived deficiency in mineral enamel. Affected teeth present demarcated enamel opacities, ranging from white to brown; also hypoplasia can be associated. Patient frequently claims aesthetic discomfort if anterior teeth are involved. This problem leads patients to request a bleaching treatment to improve aestheticconditions.Nevertheless, hydrogen peroxide can produce serious side-effects, resulting from further mineral loss. Microabrasion and/or a composite restoration are the treatments of choice in teeth with mild/moderate MIH, but they also need enamel loss. Recently, a new remineralizing agent based on Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) has been proposed to be effective in hypomineralized enamel, improving also aesthetic conditions. The present paper presents a case report of a young man with white opacities on incisors treated with a combined use of CPP-ACP mousse and hydrogen peroxide gel to correct the aesthetic defect. The patient was instructed to use CPP-ACP for two hours per day for three months in order to obtain enamel remineralization followed by a combined use of CPP-ACP and bleaching agent for further two months. At the end of this five-month treatment, a noticeable aesthetic improvement of the opacities was observed.

Mastroberardino, Stefano; Campus, Guglielmo; Strohmenger, Laura; Villa, Alessandro; Cagetti, Maria Grazia

2012-01-01

197

Total capital cost data base: 10MWe Solar Thermal Central Receiver Pilot Plant  

SciTech Connect

This report describes the total capital cost data base of the 10 MWe Solar Thermal Central Receiver Pilot Plant. This Solar One cost data base was created using the computer code ''Cost Data Management System (CDMS)''. The cost data base format was developed to be used as a common method of presentation of capital costs for power plants. The basic format is a plant system cost breakdown structure. Major accounts are land; structures and improvements; collector, receiver, thermal transport, thermal storage, and stream generation systems; turbine plant; electrical plant; miscellaneous plant systems and equipment; and plant-level indirect costs. Each major account includes subaccounts to as many as nine level of detail. The data base can be accessed to provide elements-of-work costs at any subaccount level or at the plant level. The elements-of-work include sitework/earthwork; concrete work; metal work; architectural; process equipment; piping; electrical; and miscellaneous work. Each of these elements-of-work can be or are broken into finer detail and costs can be accumulated to identify more specific needs, e.g., pipe insulation or heat exchangers. The cost data base can be accessed and various reports can be generated. These vary from a single page summary to detailed listings of costs and notes. Reported costs can be stated in dollars, dollars per kilowatt or percentage of the total plant cost. Reports or samples of reports for the pilot plant capital cost are included.

Norris, H.F. Jr.

1986-05-01

198

[Central neurobiological mechanism of liver depression and spleen deficiency syndrome based on chronic stress: a review].  

PubMed

Some researchers focus on research of the nature of syndromes. The methods of combining traditional Chinese medicine syndrome and diseases and the correspondence between formulas and syndromes may be used in research of the nature of syndromes. According to combined theories of zang-organ state and seven emotions in traditional Chinese medicine with stress theory in modern medicine, the authors applied the methods of chronic immobilization stress to induce liver depression and spleen deficiency syndrome in rats based on the thinking of relativity on formula and syndrome. The research showed that the central neurobiology mechanism of liver depression and spleen deficiency syndrome closely correlates to the hypothalamic-pituitary-adrenal axis, brain-gut axis, myriad central neurotrophic factors, neurotransmitters, neuropeptides and hormones and their receptors, involving in many encephalic regions such as the hypothalamus, hippocampus, cortex, amygdale, etc. The authors will combine their previous work with multi-disciplinary research, such as genomics, proteomics, metabolomics and bioinformatics in future studies, to reveal the scientific connotations of liver depression and spleen deficiency syndrome. PMID:22237267

Li, Xiao-hong; Li, Jing-jing; Liu, Yue-yun; Chen, Jia-xu

2012-01-01

199

Indirect usage of miniscrew anchorage to intrude overerupted mandibular incisors in a Class II patient with a deep overbite.  

PubMed

Vertical dentoalveolar discrepancies are a common problem in orthodontic patients but are often difficult to treat with traditional mechanics. This case report illustrates the successful treatment of overerupted mandibular incisors via the indirect use of miniscrew anchorage. A woman (age, 22 years 9 months) had chief complaints of maxillary incisor protrusion and crooked teeth. An excessive curve of Spee caused by elongation of the mandibular incisors was also found. The patient was diagnosed with a severe Class II Division 1 malocclusion and a deep overbite. After extraction of the mandibular first premolars and the subsequent leveling phase, the elongated incisors were intruded with a novel method, which involved the combined use of sectional archwires and miniscrews placed in the premolar areas. After the procedure, the mandibular incisors had been intruded by 6.5 mm with no undesirable side effects. The total active treatment period was 42 months. The resultant occlusion and satisfactory facial profile were maintained after 30 months of retention. Our novel intrusion approach shows potential for correcting a deep overbite. PMID:23540627

Ishihara, Yoshihito; Kuroda, Shingo; Sugawara, Yasuyo; Balam, Tarek A; Takano-Yamamoto, Teruko; Yamashiro, Takashi

2013-04-01

200

Early Diagnosis of Bilateral Supplemental Primary and Permanent Maxillary Lateral Incisors: A Case Report  

PubMed Central

Supernumerary teeth occur frequently in permanent dentition, but they are rarely found in primary dentition. Supernumerary teeth of orthodox shape and size that resemble normal dentition are called ‘supplemental teeth’. Supplemental teeth are less common than supernumerary teeth and are often overlooked because of their normal shape and size. Supplemental teeth may cause esthetic problems, delayed eruption and crowding, and they require early diagnosis and treatment to prevent complications. The case reported here is one of bilateral supplemental teeth impeding the eruption of permanent maxillary lateral incisors, and it emphasizes the importance of early diagnosis and treatment during early mixed dentition.

Yildirim, Gozde; Bayrak, Sule

2011-01-01

201

Implant rehabilitation of canines in case of bilaterally missing maxillary lateral incisors.  

PubMed

This article reports the successful treatment of a patient with a malocclusion and missing maxillary lateral incisors with an unusual implant-prosthetic rehabilitation in place of the canines. A man, 25 years 5 months of age, was referred by his general dentist with the chief complaint of retained maxillary deciduous canines. He had a skeletal Class I and an Angle Class I malocclusion with an open-bite tendency and prolonged retention of both deciduous canines. The malocclusion was treated with extraction of the maxillary deciduous canines, a fixed edgewise appliance, and implant-prosthesis rehabilitation in place of the canines. A functional and an esthetic occlusion was achieved. PMID:23810052

Bizetto, Murilo Sérgio Principe; Tessarollo, Fábio Rafael; Jimenez, Emigdio Enrique Orellana; Guariza-Filho, Odilon; Camargo, Elisa Souza; Tanaka, Orlando Motohiro

2013-07-01

202

A case of Ekman-Westborg-Julin trait: endodontic treatment of a macrodontic incisor.  

PubMed

A case of Ekman-Westborg and Julin trait and endodontic treatment of a macrodontic lateral incisor with a necrotic pulp and periradicular pathosis presented in a 21-year-old woman. Clinical and radiological findings suggesting the Ekman-Westborg and Julin trait included multiple macrodontia, multituberculism, and single conical molar roots. Orthodontic problems such as mandibular prognatism and anterior and posterior cross-bite and other minor dental morphological changes were also found. Periradicular healing after endodontic treatment was followed by standardized periapical x-ray series, and signs of healing were observed at the 9 months postoperative control. PMID:19426915

Peker, Ilkay; Kayaoglu, Guven

2009-05-01

203

Research and Realization of a Centralized Document Management Model Based on ASP.NET  

Microsoft Academic Search

Centralized document management is a prevalent model used by electronic document processing system on B\\/S mode. The paper firstly analyzes disadvantages of general centralized document management systems, then brings forward a new centralized document management model by combing the advantage of relational database system and file system. The model adopts different storage modes according to the security classification of documents,

Zhu Ai-hong; He Hai-yan

2009-01-01

204

Investigation of the maxillary lateral incisor agenesis and associated dental anomalies in an orthodontic patient population  

PubMed Central

Objectives: The aim of this study was to investigate the prevalence of maxillary lateral incisor (MLI) agenesis and associated dental anomalies as well as skeletal patterns in an orthodontic population, and then to compare it with the prevalence of these anomalies in the general population. Study Design: The material of the present study included the records of the 3872 orthodontic patients. The followings were recorded for each subject with the agenesis of MLI: Age, sex, unilateral or bilateral absence, anterior-posterior skeletal relationship of the maxilla and mandible, and presence of associated dental anomalies. The occurrence of these anomalies was compared with data previously reported for the general populations. Results: Of the 3872 patients examined, 94 were found to have agenesis of the MLI, representing a prevalence of 2.4 per cent, with females being more frequently observed. The most commonly found associated anomalies were ectopic eruption of maxillary canines and reduced or peg- shaped contralateral incisor with the frequencies of 21.3 per cent and 20.2 per cent respectively. Conclusions: Patients with agenesis of MLI showed a significantly higher prevalence of skeletal Class III malocclusion compared with the general population. The prevalence of ectopic eruption, transposition, and transmigration of the maxillary canine and reduced or peg- shaped MLIs were significantly increased. Key words:Hypodontia, missing laterals, associated dental anomalies.

Kamak, Hasan; Yildirim, Hanifi; Ceylan, Ismail

2012-01-01

205

Adaptive diversity of incisor enamel microstructure in South American burrowing rodents (family Ctenomyidae, Caviomorpha)  

PubMed Central

The aim of this study was to analyse the morphofunctional and adaptive significance of variation in the upper incisor enamel microstructure of South American burrowing ctenomyids and other octodontoid taxa. We studied the specialized subterranean tooth-digger †Eucelophorus chapalmalensis (Pliocene – Middle Pleistocene), and compared it with other fossil and living ctenomyids with disparate digging adaptations, two fossorial octodontids and one arboreal echimyid. Morphofunctionally significant enamel traits were quite similar among the species studied despite their marked differences in habits, digging behaviour and substrates occupied, suggesting a possible phylogenetic constraint for the Octodontoidea. In this context of relative similarity, the inclination of Hunter–Schreger bands, relative thickness of external index (EI) and prismless enamel zone were highest in †Eucelophorus, in agreement with its outstanding craniomandibular tooth-digging specialization. Higher inclination of Hunter–Schreger bands reinforces enamel to withstand high tension forces, while high external index provides greater resistance to wear. Results suggest increased frequency of incisor use for digging in †Eucelophorus, which could be related to a more extreme tooth-digging strategy and/or occupancy of hard soils. Higher external index values as recurring patterns in distant clades of tooth-digging rodents support an adaptive significance of this enamel trait.

Vieytes, Emma C; Morgan, Cecilia C; Verzi, Diego H

2007-01-01

206

Studying Geology of Central Texas through Web-Based Virtual Field Trips  

NASA Astrophysics Data System (ADS)

Each year over 2500 students, mainly non-science majors, take introductory geology classes at the University of Houston. Optional field trips to Central Texas for these classes provide a unique learning opportunity for students to experience geologic concepts in a real world context. The field trips visit Enchanted Rock, Inks Lake, Bee Cave Road, Lion Mountain, and Slaughter Gap. Unfortunately, only around 10% of our students participate in these field trips. We are developing a web-based virtual field trip for Central Texas to provide an additional effective learning experience for students in these classes. The module for Enchanted Rock is complete and consists of linked geological maps, satellite imagery, digital elevation models, 3-D photography, digital video, and 3-D virtual reality visualizations. The ten virtual stops focus on different geologic process and are accompanied by questions and answers. To test the efficacy of the virtual field trip, we developed a quiz to measure student learning and a survey to evaluate the website. The quiz consists of 10 questions paralleling each stop and information on student attendance on the Central Texas field trip and/or the virtual field trip. From the survey, the average time spent on the website was 26 minutes, and overall the ratings of the virtual field trip were positive. Most noticeably students responded that the information on the website was relevant to their class and that the pictures, figures, and animations were essential to the website. Although high correlation coefficients between responses were expected for some questions (i.e., 0.89 for "The content or text of the website was clear" and "The information on the website was easy to read"), some correlations were less expected: 0.77 for "The number of test questions was appropriate" and "The information on the website was easy to read," and 0.70 for "The test questions reinforced the material presented on the website" and "The information on the website is relevant to my class." These virtual field trips provide an alternative for students who cannot attend the actual field trips. They also allow transfer students to experience these sites before attending upper level field trips, which often return to study these sites in more detail. These modules provide a valuable supplementary experience for all students, as they emphasize skills for which we are presently unable to provide sufficient practice in lecture, fieldtrips, or laboratory. Public access to the field trips is available at: http://geoinfo.geosc.uh.edu/VR/

Chan, C.; Khan, S. D.; Wellner, J. S.

2007-12-01

207

Characteristics and composition of atmospheric aerosols in Phimai, central Thailand during BASE-ASIA  

NASA Astrophysics Data System (ADS)

Comprehensive measurements of atmospheric aerosols were made in Phimai, central Thailand (15.183°N, 102.565°E, elevation: 206 m) during the BASE-ASIA field experiment from late February to early May in 2006. The observed aerosol loading was sizable for this rural site (mean aerosol scattering: 108 ± 64 Mm-1; absorption: 15 ± 8 Mm-1; PM10 concentration: 33 ± 17 ?g m-3), and dominated by submicron particles. Major aerosol compounds included carbonaceous (OC: 9.5 ± 3.6 ?g m-3; EC: 2.0 ± 2.3 ?g m-3) and secondary species (SO42-: 6.4 ± 3.7 ?g m-3, NH4+: 2.2 ± 1.3 ?g m-3). While the site was seldom under the direct influence of large forest fires to its north, agricultural fires were ubiquitous during the experiment, as suggested by the substantial concentration of K+ (0.56 ± 0.33 ?g m-3). Besides biomass burning, aerosols in Phimai during the experiment were also strongly influenced by industrial and vehicular emissions from the Bangkok metropolitan region and long-range transport from southern China. High humidity played an important role in determining the aerosol composition and properties in the region. Sulfate was primarily formed via aqueous phase reactions, and hygroscopic growth could enhance the aerosol light scattering by up to 60%, at the typical morning RH level of 85%. The aerosol single scattering albedo demonstrated distinct diurnal variation, ranging from 0.86 ± 0.04 in the evening to 0.92 ± 0.02 in the morning. This experiment marks the first time such comprehensive characterization of aerosols was made for rural central Thailand. Our results indicate that aerosol pollution has developed into a regional problem for northern Indochina, and may become more severe as the region's population and economy continue to grow.

Li, Can; Tsay, Si-Chee; Hsu, N. Christina; Kim, Jin Young; Howell, Steven G.; Huebert, Barry J.; Ji, Qiang; Jeong, Myeong-Jae; Wang, Sheng-Hsiang; Hansell, Richard A.; Bell, Shaun W.

2013-10-01

208

Assessing the ecological base flow in an experimental watershed of Central Taiwan  

NASA Astrophysics Data System (ADS)

The ecological base flow is crucial for the assessment and design for habitat rehabilitation and recovery. The amount of discharge affects the aquatic creatures and may damage the existence and balance of the community under extreme low conditions. Aquatic insect is selected as the target species in this study to evaluate the influence of the discharge and to estimate the ecological base flow. The distribution of the number of species and abundance (density) versus discharge is assessed to define the critical discharge. A stream located at the alpine area in central Taiwan is selected as the study area to evaluate the base flow. From the preliminary data (Aug 2008 to May 2009) collected from Creek C of Sitou watershed (area: 1.3 km^2) shows that the abundance of several species varies with the discharge. The dominate family and genus of aquatic insects is Baetidae (Order Ephemeroptera) and Baetis spp. that accounts for 26.3 and 17.2 %, respectively. The Hilsenhoff family biotic index (FBI) shows that the water quality is classified to "Excellent" and "Good" level while the EPT Index (Index of three orders: Ephemeroptera, Plecoptera, and Trichoptera) indicates that the stream is non-polluted. The discharge of base flow interpreted from the 90%, 95% and 96% curve of duration for the daily discharge is 0.1582, 0.0476 and 0.0378 cms; the threshold value evaluated by curve of abundance vs. discharge is 0.0154 cms. Consistent observations are yet to be collected to yield more accurate results.

Wei, Chiang; Yang, Ping-Shih; Tian, Pei-Ling

2010-05-01

209

The PCR-Based Diagnosis of Central Nervous System Tuberculosis: Up to Date  

PubMed Central

Central nervous system (CNS) tuberculosis, particularly tuberculous meningitis (TBM), is the severest form of Mycobacterium tuberculosis (M.Tb) infection, causing death or severe neurological defects in more than half of those affected, in spite of recent advancements in available anti-tuberculosis treatment. The definitive diagnosis of CNS tuberculosis depends upon the detection of M.Tb bacilli in the cerebrospinal fluid (CSF). At present, the diagnosis of CNS tuberculosis remains a complex issue because the most widely used conventional “gold standard” based on bacteriological detection methods, such as direct smear and culture identification, cannot rapidly detect M.Tb in CSF specimens with sufficient sensitivity in the acute phase of TBM. Recently, instead of the conventional “gold standard”, the various molecular-based methods including nucleic acid amplification (NAA) assay technique, particularly polymerase chain reaction (PCR) assay, has emerged as a promising new method for the diagnosis of CNS tuberculosis because of its rapidity, sensitivity and specificity. In addition, the innovation of nested PCR assay technique is worthy of note given its contribution to improve the diagnosis of CNS tuberculosis. In this review, an overview of recent progress of the NAA methods, mainly highlighting the PCR assay technique, was presented.

Takahashi, Teruyuki; Tamura, Masato; Takasu, Toshiaki

2012-01-01

210

Fully automated 3D prostate central gland segmentation in MR images: a LOGISMOS based approach  

NASA Astrophysics Data System (ADS)

One widely accepted classification of a prostate is by a central gland (CG) and a peripheral zone (PZ). In some clinical applications, separating CG and PZ from the whole prostate is useful. For instance, in prostate cancer detection, radiologist wants to know in which zone the cancer occurs. Another application is for multiparametric MR tissue characterization. In prostate T2 MR images, due to the high intensity variation between CG and PZ, automated differentiation of CG and PZ is difficult. Previously, we developed an automated prostate boundary segmentation system, which tested on large datasets and showed good performance. Using the results of the pre-segmented prostate boundary, in this paper, we proposed an automated CG segmentation algorithm based on Layered Optimal Graph Image Segmentation of Multiple Objects and Surfaces (LOGISMOS). The designed LOGISMOS model contained both shape and topology information during deformation. We generated graph cost by training classifiers and used coarse-to-fine search. The LOGISMOS framework guarantees optimal solution regarding to cost and shape constraint. A five-fold cross-validation approach was applied to training dataset containing 261 images to optimize the system performance and compare with a voxel classification based reference approach. After the best parameter settings were found, the system was tested on a dataset containing another 261 images. The mean DSC of 0.81 for the test set indicates that our approach is promising for automated CG segmentation. Running time for the system is about 15 seconds.

Yin, Yin; Fotin, Sergei V.; Periaswamy, Senthil; Kunz, Justin; Haldankar, Hrishikesh; Muradyan, Naira; Turkbey, Baris; Choyke, Peter

2012-02-01

211

Ring1a/b polycomb proteins regulate the mesenchymal stem cell niche in continuously growing incisors.  

PubMed

Rodent incisors are capable of growing continuously and the renewal of dental epithelium giving rise to enamel-forming ameloblasts and dental mesenchyme giving rise to dentin-forming odontoblasts and pulp cells is achieved by stem cells residing at their proximal ends. Although the dental epithelial stem cell niche (cervical loop) is well characterized, little is known about the dental mesenchymal stem cell niche. Ring1a/b are the core Polycomb repressive complex1 (PRC1) components that have recently also been found in a protein complex with BcoR (Bcl-6 interacting corepressor) and Fbxl10. During mouse incisor development, we found that genes encoding members of the PRC1 complex are strongly expressed in the incisor apical mesenchyme in an area that contains the cells with the highest proliferation rate in the tooth pulp, consistent with a location for transit amplifying cells. Analysis of Ring1a(-/-);Ring1b(cko/cko) mice showed that loss of Ring1a/b postnatally results in defective cervical loops and disturbances of enamel and dentin formation in continuously growing incisors. To further characterize the defect found in Ring1a(-/-);Ring1b(cko/cko) mice, we demonstrated that cell proliferation is dramatically reduced in the apical mesenchyme and cervical loop epithelium of Ring1a(-/-);Ring1b(cko/cko) incisors in comparison to Ring1a(-/-);Ring1b(fl/fl)cre- incisors. Fgf signaling and downstream targets that have been previously shown to be important in the maintenance of the dental epithelial stem cell compartment in the cervical loop are downregulated in Ring1a(-/-);Ring1b(cko/cko) incisors. In addition, expression of other genes of the PRC1 complex is also altered. We also identified an essential postnatal requirement for Ring1 proteins in molar root formation. These results show that the PRC1 complex regulates the transit amplifying cell compartment of the dental mesenchymal stem cell niche and cell differentiation in developing mouse incisors and is required for molar root formation. PMID:22562112

Lapthanasupkul, Puangwan; Feng, Jifan; Mantesso, Andrea; Takada-Horisawa, Yuki; Vidal, Miguel; Koseki, Haruhiko; Wang, Longlong; An, Zhengwen; Miletich, Isabelle; Sharpe, Paul T

2012-05-04

212

Comparison of Central Dimmer Systems Based on Multiple-Tapped Autotransformer and High-Frequency Switching Converter  

Microsoft Academic Search

This paper compares two central dimmer system technologies used in street lighting. These dimmers are utilized in adaptive lighting systems based on high-intensity-discharge lamps and magnetic ballasts. The first technology is based on a multiple-tapped autotransformer which is commonly used for these types of installations. The second technology is based on a high-frequency switch converter (more specifically in a single-

Guillermo Velasco-Quesada; Manuel Roman-Lumbreras; Alfonso Conesa-Roca

2012-01-01

213

Base of Principal Aquifer for the Elkhorn-Loup Model Area, North-Central Nebraska  

USGS Publications Warehouse

In Nebraska, the water managers in the Natural Resources Districts and the Nebraska Department of Natural Resources are concerned with the effect of ground-water withdrawal on the availability of surface water and the long-term effects of ground-water withdrawal on ground- and surface-water resources. In north-central Nebraska, in the Elkhorn and Loup River Basins, ground water is used for irrigation, domestic supply, and public supply; surface water is used in this area for irrigation, recreation, and hydropower production. In recognition of these sometimes competing ground- and surface-water uses in the Elkhorn and Loup River Basins, the U.S. Geological Survey, the Lewis and Clark Natural Resources District, the Lower Elkhorn Natural Resources District, the Lower Loup Natural Resources District, the Lower Niobrara Natural Resources District, the Lower Platte North Natural Resources District, the Middle Niobrara Natural Resources District, the Upper Elkhorn Natural Resources District, and the Upper Loup Natural Resources District agreed to cooperatively study water resources in the Elkhorn and Loup River Basins. The goals of the overall study were to construct and calibrate a regional ground-water flow model of the area and to use that flow model as a tool to assess current and future effects of ground-water irrigation on stream base flow and to help develop long-term water-resource management strategies for this area, hereafter referred to as the Elkhorn-Loup model area. The Elkhorn-Loup model area covers approximately 30,800 square miles, and extends from the Niobrara River in the north to the Platte River in the south. The western boundary of the Elkhorn-Loup model area coincides with the western boundary of the Middle Niobrara, Twin Platte, and Upper Loup Natural Resources Districts; the eastern boundary coincides with the approximate location of the western extent of glacial till in eastern Nebraska. The principal aquifer in most of the Elkhorn-Loup model area is the High Plains aquifer; the principal aquifer in the remaining part of the Elkhorn-Loup model area is an unnamed alluvial aquifer. The upper surface of the geologic units that directly underlie the aquifer is called the 'base of aquifer' in this report. The geologic unit that forms the base of aquifer in the Elkhorn-Loup model area varies by location. The Tertiary-age Brule Formation generally is the base of aquifer in the west; the Cretaceous-age Pierre Shale generally is the base of aquifer in the east. The purpose of this report is to update the altitude and configuration of the base of the principal aquifer in the Elkhorn-Loup model area and a 2-mile buffer area around the Elkhorn-Loup model area, using base-of-aquifer data from test holes, registered water wells, and oil and gas wells within the Elkhorn-Loup model area and a 20-mile buffer area around the Elkhorn-Loup model area that have become available since the publication of earlier maps of the base of aquifer for this area. The base-of-aquifer map is important for the Elkhorn-Loup ground-water flow model because it defines the model's lower boundary. The accuracy of the Elkhorn-Loup ground-water flow model and the accuracy of the model's predictions about the effects of ground-water irrigation on stream base flow are directly related to the accuracy of the model's lower boundary.

McGuire, V. L.; Peterson, S. M.

2008-01-01

214

Coal-based stratigraphy for upper Fort Union Group (Paleocene), west-central North Dakota  

SciTech Connect

On the basis of an evaluation of lithologic and geophysical logs from 2500 shallow drill holes and information from a limited number of natural outcrops and mine highwalls, a detailed stratigraphic framework was constructed for the Paleocene strata of the Sentinel Butte and upper Bullion Creek formations (upper Fort Union Group) in the Knife River area in west-central North Dakota. The study sequence was found to be characterized by at least seven major coals continuous over the 8000 km/sup 2/ (3089 mi/sup 2/) of the study area instead of a large number of locally persistent coals, as interpreted by previous investigations of surface sections. A series of geologic cross sections demonstrates the correlation of the lignite beds in the upper Bullion Creek and Sentinel Butte formations and together provide a three-dimensional picture of coal distribution in the study area. Each major lignite bed has been named and assigned both type and reference test holes. The recognition of coals continuous over the study area provides a means of correlating this complex terrestrial section. The resulting framework in turn provides a basis for (1) the development of a chronostratigraphy and biostratigraphy, (2) a more accurate evaluation of the magnitude and distribution of coal resources, and (3) an appraisal of depositional setting and history. The recognition of widespread coals in the upper Fort Union strata in other portions of the basin suggests the potential for establishing a basinwide stratigraphic framework based on these coals.

Groenewold, G.; Hemish, L.; Daly, D.J.; Schmit, C.

1986-08-01

215

Population-based study of central post-stroke pain in Rimini district, Italy  

PubMed Central

Central post-stroke pain (CPSP) is still an underestimated complication of stroke, resulting in impaired quality of life and, in addition to the functional and cognitive consequences of stroke, the presence of CPSP may be associated with mood disorders, such as depression, anxiety, and sleep disturbances. This type of pain may also impair activities of daily living and further worsen quality of life, negatively influencing the rehabilitation process. The prevalence of CSPS in the literature is highly variable (1%–12%) according to different studies, and this variability could be influenced by selection criteria and the different ethnic populations being investigated. With this scenario in mind, we performed a population-based study to assess the prevalence of CPSP and its main features in a homogeneous health district (Rimini, Italy), including five hospitals for a total population of 329,970 inhabitants. From 2008 to 2010, we selected 1,494 post-stroke patients and were able to interview 660 patients, 66 (11%) of whom reported pain with related tactile and thermal hyperesthesia, accompanied by needle puncture, tingling, swelling, and pressure sensations. Patients reported motor impairment and disability, which influenced their working ability, rehabilitation, and social life. Despite this severe pain state, there was a high percentage of patients who did not receive adequate treatment for pain.

Raffaeli, William; Minella, Cristina E; Magnani, Francesco; Sarti, Donatella

2013-01-01

216

Cardiovascular safety of central nervous system stimulants in children and adolescents: population based cohort study  

PubMed Central

Objectives To evaluate the cardiac safety of central nervous system stimulants in children and adolescents. Design Population based retrospective cohort study. Setting Automated healthcare claims data from 1?219?847 children and young people eligible for 28 state Medicaid programmes from 1999 to 2006 linked to the Social Security Death Master File and the National Death Index. Participants Children and young people age 3-18 entered the cohort at the first diagnosis of a mental health condition commonly treated with stimulants (such as attention-deficit/hyperactivity disorder) after a minimum period of six months’ eligibility and were followed until loss of eligibility, their 19th birthday, admission to hospital for longer than 30 days, or death. Exclusion criteria included transplant recipients, receipt of dialysis, or claims indicating substance misuse. We retained high risk groups with similar use of stimulants as low risk children (such as children with congenital heart disease). Sociodemographic characteristics, cardiac risk factors, and psychiatric diagnoses obtained from before the index period were summarised with a propensity score. We used discrete survival analysis to estimate the relative risk for periods of stimulant use and non-use, adjusted for propensity score and antipsychotic use for the full cohort and the high risk and low risk groups. Main outcome measures Composite endpoint of stroke, acute myocardial infarction, or sudden cardiac death; a secondary composite endpoint added ventricular arrhythmia Results A total of 66 (95 including ventricular arrhythmia) events occurred during 2?321?311 years of follow-up. The odds ratio adjusted for propensity score and antipsychotic use for current versus no stimulant use was 0.62 (95% confidence interval 0.27 to 1.44), with a corresponding adjusted incidence rate of 2.2 and 3.5 per 100?000 patient years for current stimulant and non-use, respectively. Twenty six events occurred in high risk patients (incidence rate 63 per 100?000 patient years) with an odds ratio of 1.02 (0.28 to 3.69). Odds ratios for the secondary endpoint were similar to those for the primary endpoint (0.74, 0.38 to 1.46). Conclusions Treatment of children with central nervous stimulants is not significantly associated with an increase in the short term risk of severe cardiac events. Analyses cannot be generalised to children with long term use of stimulants. Furthermore, long term effects of slight increases in heart rate or blood pressure are unknown.

2012-01-01

217

Long-term development in the mandible and incisor crowding with and without an orthodontic stabilising appliance  

Microsoft Academic Search

Summary In children with dentoalveolar Class Il malocclusion with proclined upper incisors treated with extraction of the maxillary first premolars and appliance in the upper jaw only has been reported to increase the lower arch crowding when compared with children with untreated normal occlusion. Stabilising orthodontic appliances might therefore be useful in the lower jaw. A comparison was made of

Ulrike Schütz-Fransson; Krister Bjerklin; Jüri Kurol

1998-01-01

218

Long-term effects of Herbst treatment on the mandibular incisor segment: A cephalometric and biometric investigation  

Microsoft Academic Search

The purpose of this study was to analyze mandibular incisor changes during and after Herbst treatment with respect to tooth inclination and anterior crowding. The sample consisted of 24 Class II, Division 1 subjects (15 boys and 9 girls) treated with the Herbst appliance. Dental casts and lateral head films from before and after treatment, 6 months after treatment and

Ken Hansen; Theodoros G. Koutsonas; Hans Pancherz

1997-01-01

219

The effects of intrusive loading on axial movements of impeded and unimpeded rat incisors: estimation of eruptive force.  

PubMed

Axial movements of impeded and unimpeded rat mandibular incisors were measured following application and removal of intrusive loads of 1, 2, 5, 10 and 20 mN in a stepwise order at intervals of 1h on erupting teeth. The tooth movements were recorded by a displacement detector under artificial respiration with halothane anaesthesia. The loading and unloading procedures brought about the tooth movements in two steps: an initial rapid movement immediately after application or removal of the load and a subsequent slow and gradual movement. The initial rapid intrusive or extrusive tooth movements were significantly greater in the unimpeded than in the impeded teeth at the same load. The forces to stop extrusive tooth movements, estimated from the formula of regression lines showing correlations between the intrusive loads from 0 to 5 mN and tooth movements (microm/30 min), were 4.2 mN in the impeded and 2.9 mN in the unimpeded incisors. We suggest that repeated shortenings of the rat incisor did not cause an increase in the eruptive force and that changes in the resistance of the periodontal ligament predominantly regulate the axial movement of the rat incisor. PMID:12711378

Shimada, A; Shibata, T; Komatsu, K; Chiba, M

2003-05-01

220

A river based stable isotope record of orographic precipitation: Taurus Mountains, south central Turkey  

NASA Astrophysics Data System (ADS)

Reconstructing continental precipitation and vegetation patterns has become one of the most rapidly growing fields in terrestrial paleoclimate research. Furthermore, stable isotopes in precipitation within continental plateau regions represent an increasingly important tool for reconstructing the various effects of uplift related climate change within the world's largest plateau regions. With peak elevations of more than 3,000 m the Taurus Mountains represent the southern margin of the central Anatolian plateau and must have played a pivotal role in controlling the drainage and sedimentation patterns within the plateau interior. However, their surface uplift history remains largely elusive. We sampled a series of tributaries and rivers along the Ermenek valley that crosscuts the Taurus Mountains in Southern Turkey. The aim of this study is to quantify the modern effect of orographic rainout of the Taurus Mountains on the d18O and dD values of river and spring waters and to compare these values to the d18O and dD of recent precipitation gathered by the Global Network of Isotopes in Precipitation (GNIP). Further we try to study the trends of the recent d18O and dD isotopic composition of local rivers and precipitation in the area to create a set of isotopic data that is comparable to isotopic studies on paleosoils and can therefore be used in future paleoaltimetry and paleoclimate studies. We sampled 6 individual rivers during the fall season 2008 to capture mostly groundwater runoff in the south central Taurus Mountains. All sampled rivers belong to the same local drainage system which drains into the Mediterranean Sea. The total elevation difference within the sampling area exceeds 2,000 m and we were able to collect samples over almost 1,800 m of elevation. Our measurements show that both d18O and dD values follow the same basic trend. d18O and dD values decrease systematically with increasing elevation. The lapse rate of d18O is about -2.2 per mil/km, whereas the lapse rate of dD is about -20 per mil/km. Select samples have higher d18O and dD values than expected for their respective elevations due to strong evaporative effects at the sampling sites. In areas of very steep topography (waterfalls, valley gorges) the d18O and dD values of water samples are biased towards values lower than expected for their respective elevations. However, such irregularities can be accounted for by plotting the measured isotopic compositions against the hypsometric mean elevations instead of the actual sampling elevations. Comparison with data gathered by the GNIP network at four neighboring stations (Adana, Antalya, Güzeloluk, and Kocebeyli) shows that the longer-term (1 to 18 years) isotopic composition of precipitation agrees very well with the data collected in this study. Collectively, the data presented here may serve as a modern template against which late Neogene proxy-based records of paleoprecipitation along the southern margin of the central Anatolian plateau may be calibrated.

Schemmel, Fabian; Mulch, Andreas; Mikes, Tamás.; Schildgen, Taylor

2010-05-01

221

Model-based clustering reveals vitamin D dependent multi-centrality hubs in a network of vitamin-related proteins  

PubMed Central

Background Nutritional systems biology offers the potential for comprehensive predictions that account for all metabolic changes with the intricate biological organization and the multitudinous interactions between the cellular proteins. Protein-protein interaction (PPI) networks can be used for an integrative description of molecular processes. Although widely adopted in nutritional systems biology, these networks typically encompass a single category of functional interaction (i.e., metabolic, regulatory or signaling) or nutrient. Incorporating multiple nutrients and functional interaction categories under an integrated framework represents an informative approach for gaining system level insight on nutrient metabolism. Results We constructed a multi-level PPI network starting from the interactions of 200 vitamin-related proteins. Its final size was 1,657 proteins, with 2,700 interactions. To characterize the role of the proteins we computed 6 centrality indices and applied model-based clustering. We detected a subgroup of 22 proteins that were highly central and significantly related to vitamin D. Immune system and cancer-related processes were strongly represented among these proteins. Clustering of the centralities revealed a degree of redundancy among the indices; a repeated analysis using subsets of the centralities performed well in identifying the original set of 22 most central proteins. Conclusions Hierarchical and model-based clustering revealed multi-centrality hubs in a vitamin PPI network and redundancies among the centrality indices. Vitamin D-related proteins were strongly represented among network hubs, highlighting the pervasive effects of this nutrient. Our integrated approach to network construction identified promiscuous transcription factors, cytokines and enzymes - primarily related to immune system and cancer processes - representing potential gatekeepers linking vitamin intake to disease.

2011-01-01

222

Effect of single-base substitutions in the central domain of virus-associated RNA I on its function.  

PubMed Central

Adenoviruses use virus-associated RNA I (VAI RNA) to counteract the cellular antiviral response mediated by the interferon-induced, double-stranded-RNA-activated protein kinase PKR. VAI RNA is a highly structured small RNA which consists of two long duplex regions connected at the center by a complex, short stem-loop. This short stem-loop and the adjacent base-paired regions, referred to as the central domain, bind to PKR and inactivate it. Currently it is not known whether binding of VAI RNA to PKR is dependent solely on the secondary (and tertiary) structure of the central domain or whether nucleotide sequences in the central domain are also critical for this interaction. To address this question, 54 VAI mutants with single-base substitution mutations in the central domain of the RNA were constructed, and their capacities to inhibit the autophosphoryation of PKR in vitro were determined. It was found that although about half of the mutants inhibited PKR activity as efficiently as the wild type, a significant number of mutants lost the inhibitory activity substantially, without a perceptible change in their secondary structures. These results indicate that, in addition to secondary structure, at least some nucleotides in the central domain may be critical for the efficient function of VAI RNA.

Rahman, A; Malhotra, P; Dhar, R; Kewalramani, T; Thimmapaya, B

1995-01-01

223

Preliminary Results of the Active Source Portion of the Bighorns Array Seismic Experiment (BASE), North-Central Wyoming, USA  

Microsoft Academic Search

The Bighorn Arch Seismic Experiment (BASE), is designed to image the Bighorn Arch in North Central Wyoming using active and passive seismic methods. The Bighorn Mountains formed as a basement involved foreland arch during the Laramide Orogeny. Whereas such arches are major features of both modern and ancient contractional orogens, the manifestation of arch shortening at depth has been highly

B. R. Terbush; L. L. Worthington; K. C. Miller; S. H. Harder; E. Erslev; M. L. Anderson; C. S. Siddoway

2010-01-01

224

The Most Proficient Enzyme as the Central Theme in an Integrated, Research-based Biochemistry Laboratory Course  

ERIC Educational Resources Information Center

|The enzyme orotidine-5'-monophosphate decarboxylase is an attractive choice for the central theme of an integrated, research-based biochemistry laboratory course. A series of laboratory exercises common to most instructional laboratories, including enzyme assays, protein purification, enzymatic characterization, elementary kinetics, and…

Smiley, Jeffrey A.

2002-01-01

225

New Reforms in the Management of the University: Transition from Centralized to Decentralized (University-Based Management) in Iran  

ERIC Educational Resources Information Center

|This article focuses on new reforms in Iran's higher education management system--Transition from centralized to decentralized (University-Based management--UBM). This is an important subject since Iran's Ministry of Science, Research, and Technology (MSRT) has begun to introduce new reforms for the improvement and the enhancement of Iranian…

Mehralizadeh, Y.

2005-01-01

226

Validation and Application of a Fish-Based Index of Biotic Integrity for Small Central Minnesota Lakes  

Microsoft Academic Search

We evaluated the performance of an index of biotic integrity (IBI) based on 16 fish population metrics of three types: species richness, community assemblage, and trophic composition. Two sets of central Minnesota lakes independent from the original set of lakes used to develop the IBI model were used to validate it. One set of lakes (n = 15) had physical

Melissa T. Drake; Ray D. Valley

2005-01-01

227

Long-term Effects of Traumatic Injuries to Incisors and Periodontal Tissues during Childhood  

Microsoft Academic Search

\\u000a Abstract\\u000a \\u000a \\u000a Aim:\\u000a   The purpose of this study was to investigate the incidence\\u000a of dentoalveolar growth disturbances, loss of teeth and esthetic\\u000a impairment after the end of growth following traumatic injuries\\u000a to incisors and periodontal tissues during childhood.\\u000a \\u000a \\u000a \\u000a \\u000a \\u000a Materials and Methods:\\u000a   41 patients having sustained dentoalveolar\\u000a trauma before age 10 and who were now at least aged 16\\u000a years, and a

Susanne Wriedt; Monika Martin; Bilal Al-Nawas; Heiner Wehrbein

2010-01-01

228

Expression patterns of RNAs for amelin and amelogenin in developing rat molars and incisors.  

PubMed

We have recently identified a novel RNA sequence in ameloblasts, coding for amelin (Cerny et al., 1996). In the present paper, its expression has been compared with that of amelogenin in developing incisors and molars of rats, by means of in situ hybridization of paraffin sections. The RNAs for both amelin and amelogenin were highly expressed in secretory ameloblasts. The expression of RNA for amelogenin gradually decreased in the post-secretory ameloblasts. In contrast, the RNA expression for amelin remained high in post-secretory ameloblasts up to the stage of fusion between dental and oral epithelia at the time of tooth eruption. We suggest that amelin might be involved in the mineralization of enamel or in the attachment of ameloblasts to the enamel surface. The whole-mount in situ hybridization procedure is described for the first time in dental research. It proved to be a useful method and confirmed the results of the conventional in situ hybridization. PMID:9206337

Fong, C D; Hammarström, L; Lundmark, C; Wurtz, T; Slaby, I

1996-11-01

229

An immunohistochemical study of the effects of fluoride on enamel development in the rat incisor.  

PubMed

A monoclonal antiamelogenin antibody was used to investigate the effects of fluoride on enamel development in the rat incisor. The results suggested that during secretion the enamel matrix molecules are arranged in such a way as to mask the epitope recognized by the monoclonal antibody. However, during the transition stage of development as the matrix begins to be degraded the epitope becomes exposed and labelling intensity increases to reach a maximum at the end of transition/start of maturation. The effect of fluoride is to delay the appearance of labelling within the enamel matrix until the end of transition. This suggests that the fluoride may inhibit enzymatic degradation or disaggregation of the matrix, the resulting residual matrix then inhibiting crystal growth. PMID:8368958

Shore, R C; Robinson, C; Kirkham, J; Herold, R C

1993-07-01

230

Macrodontia, shovel-shaped incisors, and multituberculism: probable Ekman-Westborg-Julin trait.  

PubMed

Multiple macrodontia is a rare finding and is defined as a condition in which a tooth is significantly larger than normal. Macrodontia may occur as an isolated finding, part of a group of dental anomalies, or as a component of a syndrome with multiple oral and systemic manifestations. The purpose of this paper was to report a case of macrodontia affecting all permanent teeth and exhibiting shovel-shaped maxillary and mandibular incisors and multituberculate molars and premolars. Some or all of this patient's characteristics have been reported in both males and females, with a ratio of 5:2. No inheritance pattern has been established, as these traits have generally occurred spontaneously. As more individuals are identified and as molecular techniques continue to advance, it is probable that a gene or genes responsible for macrodontia and the associated traits will be identified. PMID:23433627

Reardon, Gayle Tieszen; Slayton, L Rebecca; Norby, Clinton; Geneser, Teresa

231

Type III dens invaginatus in a mandibular incisor: a case report of a conventional endodontic treatment.  

PubMed

This article presents one of the few reported cases of endodontic treatment of class III dens invaginatus involving mandibular incisor. Due to invagination extending through the root, supposedly communicating laterally with the periodontal ligament space through the pseudoforamen, this case was classified as Oehlers type IIIA. The periradicular radiolucency was evident around the root apex with 5.0 × 3.0 mm diameter. The conventional chemical and mechanical preparation with hand files and 2.5% sodium hypochlorite combined with intracanal dressing with calcium hydroxide for 6 weeks was able to promote the regression of lesion noted at 1-year follow-up. This case reinforces the precept that knowledge about the biologic aspects of endodontics combined with adherence to technical standards are able to resolve complex cases without the need of additional resources. PMID:21420629

Monteiro-Jardel, C C; Alves, Flávio R F

2011-04-01

232

X-ray microtomographic study of mineral distribution in enamel of mandibular rat incisors.  

PubMed

X-ray microtomography was used to study the mineral concentrations in sequential slices of enamel of 5 mandibular incisors which showed an increase from approximately 1.0 to approximately 2.7 g cm(-3) from the apex towards the incisal end. For points at the same distance from the apex, there were differences up to 0.6 g cm(-3) between the teeth. The change of mean concentrations in the slices with distance could be modelled as (different) saturating exponentials. Under the assumption of a uniform growth rate of a mandibular incisor of 0.6 mm per day and a common time origin for the start of maturation (taken as a mineral concentration of 1 g cm(-3)), the distances were transformed to a common time frame to give a pooled data set. A single saturating exponential could be fitted to this pooled transformed data; this was: Cm = 2.84-1.94exp (-0.18d) where Cm is the mean mineral concentration (g cm(-3)) and d the time (days) from the start of maturation. This gives an asymptotic concentration of 2.84 g cm(-3) towards the incisal end, with a time constant of 7.7 days. The mineral concentration distribution functions were found to be more positively skewed closer to the apex, but more negatively skewed towards the incisal end. The difference between the higher mineral concentration in the outer enamel and the enamel near the amelodentinal junction (ADJ) was approximately 3%. The direction of maximum increase in concentration from the outer enamel surface to the ADJ meets the boundary of the ADJ at approximately 80 degrees. Three dimensional surface rendering of isodensity contours showed that the previously described C-shaped pattern of mineralisation is not solely a surface phenomenon, but extends through the depth of the enamel. PMID:10853962

Wong, F S; Elliott, J C; Davis, G R; Anderson, P

2000-04-01

233

Rock glacier analyses in the Tyrolean Central Alps based on airborne lidar-data  

NASA Astrophysics Data System (ADS)

Airborne LIDAR-datasets offer a high potential for the monitoring of surface changes within high mountain environments. Based on an analysis of rock glaciers with airborne LIDAR-datasets a rock glacier activity index is developed. The results are then compared to the classified rock glacier activities from the Tyrolean rock glacier inventory. LIDAR-data from 2006 and 2010 are used to generate bi-temporal, high-resolution DTMs, for more than 400 rock glaciers in the Tyrolean Central Alps (Austria). The differential DTMs are used to identify basic processes on rock glacier surfaces including vertical and horizontal displacement rates. In order to calculate the vertical displacement rates the DTMs from 2006 are subtracted from 2010 DTMs, whereas the velocities are calculated by image matching. Based on the DTMs the mean and standard deviation of the surface elevation changes and the surface velocities are calculated for each rock glacier. The accuracy of the results of the surface elevation change calculations is improved by applying a simple stable area approach. This approach allows to correct the systematic error between the bi-temporal DTMs, yielding a higher accuracy for the vertical displacement rates. By combining the normalized mean and standard deviation of the surface elevation changes and velocities, a rock glacier activity index is developed. The activity index ranges from values between zero and one indicating low and high activity rates for each rock glacier. A clear trend between the activity index and the rock glacier inventory is found. Most of the active classified rock glaciers show a high activity index with values exceeding 0.4 and most of the fossil classified rock glaciers show a low activity index with values around zero. Discrepancies between the two methods, the developed rock glacier activity index and the prior manual rock glacier classification, will be discussed. The activity index is in good agreement with the standard classification of an already existing rock glacier inventory. This activity index offers new possibilities in rock glacier research towards an independently reproducible and quantitative airborne lidar based classification.

Girstmair, Anna; Mitterer-Hoinkes, Susanna; Bollmann, Erik; Krainer, Karl; Sailer, Rudolf; Stötter, Johann

2013-04-01

234

Geriatric Home-and Community-Based Care Training Project for Transitional Societies from Central and Eastern Europe Through Asia  

Microsoft Academic Search

Societies from Central Europe through Asia are struggling to develop home-and community-based care programs prompted by the poor quality and limited quantities of institutional care for older adults. A three-year home-and community-based care training and program development project has provided education and training to 130 professionals from the disciplines of social work, medicine, nursing, and rehabilitation who reside in 20

Charles A. Emlet; Merl C. Hokenstad

2001-01-01

235

Halogens in water from the crystalline basement of the Gotthard rail base tunnel (central Alps)  

NASA Astrophysics Data System (ADS)

Drilling of the new Gotthard rail base tunnel (central Alps) opened a large number of water-conducting fractures in granite and gneiss of the crystalline basement. The overburden reaches locally more than 2000 m and water and rock temperature is up to 45 °C. The tunnel crosses a series of steeply dipping fractured rock units that also crop out at the surface above the tunnel. Recharge water enters the fractured rocks in the high mountainous area, migrates gravity driven to the sampling locality in the tunnel. Along its flow path it reacts with rocks exposed on the fractures where it dissolves the principal granite minerals, resulting in high-pH Na 2CO 3 waters. The tunnel waters contain unusually high concentrations of fluoride ranging from 5 to 29 mg/L. Alteration of F-bearing biotite to F-free chlorite is one of the sources of fluorine. The highest F-concentrations result from the equilibration of low-Ca waters with fluorite. Fluoride concentration is strongly lithology-dependent and sharp discontinuities in both, concentration and saturation state with respect to fluorite occur at the contacts of the different gneiss and granite slabs. Chloride concentrations vary between 1 and 1300 mg/L. In contrast, the Cl/Br mass ratio exhibits small variations and centers around 110 suggesting a common source for the Cl and Br, which is independent of the lithology. In the northern part of the tunnel, Cl and Br are chiefly derived from saline pore fluids of one lithology which is then mixed with low-salinity water along flow paths. Cl/Br ratios of the waters in the southern part of the tunnel section are similar to those measured in experimental leachates from different tunnel rocks, suggesting that leaching of metamorphic fluids in the pore space is the main source of both Cl and Br.

Seelig, Ulrike; Bucher, Kurt

2010-05-01

236

Deep sounding TEM investigation method based on a modified fixed central-loop system  

NASA Astrophysics Data System (ADS)

The central-loop TEM technology has been widely used in mineral exploration, engineering and environmental investigations and assorted geologic studies. For easy and efficient working conditions, a square (or rectangular) loop is generally employed instead of a circular one. Any position within the inner one ninth of the central part of the loop is often designated as the central survey location (within which the field is assumed to be uniform), and referred to as a modified central-loop configuration.However, the deduced field parameters at such non-central positions when calculated by a central-loop formula result in decreased accuracy and possibly erroneous interpretation. A large-fixed loop offers the advantage of being able to determine the induced potential at any point inside or outside the loop. In this study we provide the formula for the large-fixed loop and receiver positions within the modified central-loop system and solve the problem. Specifically, we compute the electromagnetic response of any field point by using an electric dipole integration method. The full time-domain apparent resistivity values are then extracted by using an iterative method. Both theoretical modeling and real data examples indicate that such a configuration not only improves the accuracy for the TEM survey, but also enlarges the exploration depth, due to a large loop used in the deployment. The method is used for locating the water enriched areas in coal mines in Yangquan region of Shanxi province and in Bin County of Shaanxi province, China. The interpreted results are tested by later drilling, which confirmed our combined method to be a reliable and efficient method for deep sounding.

Xue, Guo-Qiang; Bai, Chao-Ying; Yan, Shu; Greenhalgh, Stewart; Li, Mei-Fang; Zhou, Nan-Nan

2012-01-01

237

A Centralized, Computerized, and Relational Data Base for Student Clinical Placements.  

ERIC Educational Resources Information Center

|A centralized relational database is used to manage information on advanced practice nursing students and their preceptors at Johns Hopkins University. The system relieves faculty of time-consuming tasks and enables rapid report generation, consistent tracking, and timely communications. (SK)|

Lears, Mary Kathleen; Olsen, Sharon J.; Morrison, Candis; Vessey, Judith A.

1998-01-01

238

Sensor-based mapping of soil quality on degraded claypan landscapes of the central United States  

Technology Transfer Automated Retrieval System (TEKTRAN)

Claypan soils (Epiaqualfs) in the central USA have experienced severe erosion as a result of tillage practices of the late 1800s and 1900s. Because of the site-specific nature of erosion processes within claypan fields, research is needed to achieve cost-effective sensing and mapping of soil and lan...

239

Variability of atmospheric dust loading over the central Tibetan Plateau based on ice core glaciochemistry  

NASA Astrophysics Data System (ADS)

A Mt. Geladaindong (GL) ice core was recovered from the central Tibetan Plateau (TP) spanning the period 1940-2005 AD. High-resolution major ion (Na + , K + , Ca 2+ , Mg 2+ , Cl - , SO 4 2- , NO 3 - ) time-series are used to investigate variations in atmospheric dust loading through time. The crustal source ions vary seasonally with peaks in dust concentrations occurring during the winter and spring which are consistent with atmospheric dust observations at local meteorological stations. However, both similarities and dissimilarities are displayed between the decadal variation of atmospheric dust in the GL core and dust observation records from meteorological stations, which can be attributed to local environmental effects at the stations. This paper compares the 1980s and 1970s as case periods for low and high atmospheric dust loading, respectively, two periods reflecting shifts in spring atmospheric circulation (a weakening of zonal and meridional winds) from the 1970s (a period of enhanced dust aerosol transportation to central TP) to the 1980s (a period of diminished dust aerosol transportation to central TP), especially a significant decrease of meridional wind speeds in the 1980s. GL ice core dust proxies (Ca 2+ and K + ) are correlated with Total Ozone Mapping Spectrometer (TOMS) Aerosol Index (AI) data in spring over the TP and in the northwestern China (especially for K + ). Thus variability of crustal ions in central TP ice core provides a proxy for reconstructing a history of atmospheric dust loading not only on the TP, but also in northwestern China.

Kang, Shichang; Zhang, Yulan; Zhang, Yongjun; Grigholm, Bjorn; Kaspari, Susan; Qin, Dahe; Ren, Jiawen; Mayewski, Paul

2010-08-01

240

A Web based Telemedicine Portal for centralized access to Patient Health Records  

Microsoft Academic Search

Despite telemedicine's applications evolution to cover a wide area of users' needs, data centralization is not achieved yet. Also, access to patient data from any remote location, through a secure environment, is necessary to achieve remote data handling and doctor's collaboration. A remote access has been implemented through a Portal using only web modules, which do not require the users

G. TRIANTAFYLLOU; G. KOYTELAKIS; C. BOUKOUVALAS; G. MANDELLOS

241

Prediction of central nervous system embryonal tumour outcome based on gene expression  

Microsoft Academic Search

Embryonal tumours of the central nervous system (CNS) represent a heterogeneous group of tumours about which little is known biologically, and whose diagnosis, on the basis of morphologic appearance alone, is controversial. Medulloblastomas, for example, are the most common malignant brain tumour of childhood, but their pathogenesis is unknown, their relationship to other embryonal CNS tumours is debated, and patients'

Scott L. Pomeroy; Pablo Tamayo; Michelle Gaasenbeek; Lisa M. Sturla; Michael Angelo; Margaret E. McLaughlin; John Y. H. Kim; Liliana C. Goumnerova; Peter M. Black; Ching Lau; Jeffrey C. Allen; David Zagzag; James M. Olson; Tom Curran; Cynthia Wetmore; Jaclyn A. Biegel; Tomaso Poggio; Shayan Mukherjee; Ryan Rifkin; Andrea Califano; Gustavo Stolovitzky; David N. Louis; Jill P. Mesirov; Eric S. Lander; Todd R. Golub

2002-01-01

242

A model-based reconstruction of Holocene treeline dynamics in the Central Swiss Alps  

Microsoft Academic Search

Summary 1 We used the forest succession model F ?? C ??? to simulate Holocene treeline dynamics along an elevational transect in the Central European Alps, in order to explore the extent and cause of changes in treeline altitude and composition. 2 A temperature reconstruction independent of vegetation proxies was used to drive the model, and the simulation results were

C. HEIRI; H. BUGMANN; W. TINNER; O. HEIRI; H. LISCHKE

2006-01-01

243

Agent based modeling of national economy - centralized mode analysis of virtual economy by GA simulation  

Microsoft Academic Search

In this paper we analyze national economy as a socioeconomic multi-agent system. For the purpose we investigate the centralized bird's eye view model of small national economy across the terms. We analyze the model by hybrid approach between machine agent model and human gaming simulation model. We investigate effective growth path by genetic algorithm in machine agent model. We can

Hiroshi Deguchi; Masato Kobayashi; Hao Lee

2003-01-01

244

Central Nervous System Based Neurogenic Female Sexual Dysfunction: Current Status and Future Trends  

Microsoft Academic Search

The amount of information available regarding the impact of various central nervous system disorders on female sexual function has greatly increased. In this article, the most recent information regarding brain and spinal cord disorders in human females is reviewed. Evidence from women with spinal cord injuries (SCIs) supports findings in able-bodied females that the sympathetic nervous system provides regulation of

Marca L. Sipski

2002-01-01

245

A restorative approach to the clinical and aesthetic management of adult patients with Class II division 2 incisor malocclusions.  

PubMed

A Class II division 2 incisor malocclusion may be a cause of aesthetic and/or functional concern for some affected patients. Their particular concerns may include dark spaces around the misaligned teeth or uneven gingival contours. Orthodontic and/or orthognathic treatment can address some of these problems but frequently involves lengthy and expensive treatment in the adult dentition. Sadly, such treatment often produces an unstable result, with significant drawbacks such as the requirement for long-term retention. This article aims to describe alternative strategies for managing patients with this incisor malocclusion. Clinical Relevance: This paper outlines a quicker, pragmatic and minimally destructive restorative treatment alternative to conventional orthodontic treatment and the associated long-term retention. PMID:23367633

Ray-Chaudhuri, Arijit; Porter, Richard J; Kelleher, Martin G D

2012-12-01

246

Feasibility study for establishing a centralized geothermal data base for New Mexico. Final report, June 1, 1979-October 15, 1979  

SciTech Connect

The purpose of this work is to catalog the information available and to make recommendations toward improving its accessibility. Existing computerized and non-computerized data sources are identified at both the state and national level. The content and accessibility of each such data base are investigated, as well as its suitability for aiding geothermal development. A catalog of such information is provided for each of the following data sources: GEOTHERM, WATSORE, STORIT, RPPM, GRID, HISS, EID air quality, and EID water quality. The available computing facilities within the state are evaluated for their appropriateness as a central storage facility for the many data sources. Recommendations are made for the establishment of a centralized geothermal/environmental data base. Included are recommendations for the computing facilities to be used by such a data base. How to obtain access to a given data base is described. This includes whether the data base is accessible from within New Mexico, necessary agreements, and contact persons. A glossary of computer-related terms and a brief description of knowledge-based problem-solving are included. (MHR)

Klimowicz, G.; Martin, N.

1980-01-01

247

Development of a chironomid-based air temperature inference model for the central Canadian Arctic  

Microsoft Academic Search

Subfossil midge remains were identified in surface sediment recovered from 88 lakes in the central Canadian Arctic. These\\u000a lakes spanned five vegetation zones, with the southern-most lakes located in boreal forest and the northern-most lakes located\\u000a in mid-Arctic tundra. The lakes in the calibration are characterized by ranges in depth, summer surface-water temperature\\u000a (SSWT), average July air temperature (AJAT) and

David Porinchu; Nicolas Rolland; Katrina Moser

2009-01-01

248

Ostracode-based aminostratigraphy and aminochronology of a tufa system in central Spain  

Microsoft Academic Search

In the Priego area, central Spain, extensive tufa deposits are located in three small tributaries located at the head of the 1000km-long Tagus River. The deposits are originated after karst-origin running waters emerged from the confines of the canyons and expanded outward. Old tufa deposits of Priego are mainly present as terraced alluvial plain deposits where different autochthonous and allochthonous

T. Torres; J. E. Ortiz; M. A. García de la Morena; F. J. Llamas; G. Goodfriend

2005-01-01

249

Community-Based Study of Neurological Disorders in Rural Central Ethiopia  

Microsoft Academic Search

Between 1986 and 1988 a door-to-door survey was conducted on a stable rural population of 60,820 in central Ethiopia. Trained lay health workers made a complete census and identified cases with symptoms -and signs of neurological disorders, using specially designed questionnaires which, in a previous pilot study, were found to have a sensitivity of 91% and specificity of 85%. Neurological

Redda Tekle-Haimanot; Mekonnen Abebe; Ayele Gebre-Mariam; Lars Forsgren; Jan Heijbel; Gösta Holmgren; Jan Ekstedt

1990-01-01

250

A 750-year fire history based on lake sediment records in central Yellowstone National Park, USA  

Microsoft Academic Search

A 750-year fire history was reconstructed for the Central Plateau of Yellowstone National Park from the deep-water sediments of five lakes. The charcoal record from a large lake provided a chronology of regional fires. Data from four small lakes were used to study local and extralocal fires. The co-occurrence of abundant charcoal and high magnetic-susceptibility values at the same stratigraphic

Sarah H. Millspaugh; Cathy Whitlock

1995-01-01

251

Correlation of Champlainian (Middle Ordovician) K-Bentonite Beds in Central Pennsylvania Based on Chemical Fingerprinting  

Microsoft Academic Search

The lower Trenton Salona Formation in central Pennsylvania contains five widespread K-bentonite beds, distinguishable on the basis of chemical fingerprinting. Thirty-five samples, one from each K-bentonite bed with good stratigraphic control at seven localities, were analyzed for Na, K, Sc, Cr, Mn, Fe, Co, Zn, Ga, As, Rb, Sb, Cs, La, Ce, Sm, Eu, Tb, Dy, Yb, Lu, Hf, Ta,

Joan Cullen-Lollis; Warren D. Huff

1986-01-01

252

Seismic hazard assessment in central Ionian Islands area (Greece) based on stress release models  

Microsoft Academic Search

The long-term probabilistic seismic hazard of central Ionian Islands (Greece) is studied through the application of stress\\u000a release models. In order to identify statistically distinct regions, the study area is divided into two subareas, namely Kefalonia\\u000a and Lefkada, on the basis of seismotectonic properties. Previous results evidenced the existence of stress transfer and interaction\\u000a between the Kefalonia and Lefkada fault

Irene Votsi; George M. Tsaklidis; Eleftheria E. Papadimitriou

2011-01-01

253

Memory and Working-with-Memory: A Component Process Model Based on Modules and Central Systems  

Microsoft Academic Search

A neuropsychological model of memory is proposed that incorporates Fodor's (1983) idea of modules and central systems. The model has four essential components: (1) a non-frontal neocortical component that consists of perceptual (and perhaps interpretative semantic) modules that mediate performance on item-specific, implicit tests of memory, (2) a modular medial temporal\\/hippocampal component that mediates encoding, storage, and retrieval on explicit,

Morris Moscovitch

1992-01-01

254

Survival of resin-bonded bridgework provided for post-orthodontic hypodontia patients with missing maxillary lateral incisors  

Microsoft Academic Search

Objective To analyse the clinical performance and factors influencing the survival of resin-bonded bridgework provided for hypodontia patients with missing maxillary lateral incisors, following orthodontic treatment to open, maintain or redistribute the missing tooth space.Design A retrospective analysis of patients treated at a single centre using case notes with all patients invited for review to corroborate findings.Setting Departments of Orthodontics,

R W Wassell; N J Jepson; F S Nohl; M J Garnett

2006-01-01

255

An Unusual Type II Dens Invaginatus with Calcified Canals in a Maxillary Lateral Incisor - A Case Report  

PubMed Central

Dens invaginatus is a developmental malformation resulting from the invagination of enamel organ into the dental papilla. Management of dens invaginatus is an endodontic challenge. Presence of calcified canals in dens invaginatus makes it even more complicated. Modification of the treatment plan is required to treat such cases. This case report deals with the management of a Type II Dens Invaginatus in a lateral incisor with calcified canals.

Subbiya, Arunajatesan; Geethapriya, Nagarajan; Pradeepkumar, Angambakam Rajasekaran; Vivekanandhan, Paramasivam

2013-01-01

256

Differential staining of glycosaminoglycans in the predentine and dentine of rat incisor using Cuprolinic Blue at various magnesium chloride concentrations  

Microsoft Academic Search

Summary  Rat incisors were fixed with a solution of 0.05% Cuprolinic Blue and 2.5% glutaraldehyde in the presence of various concentrations of MgCl2 according to the critical electrolyte concentration (CEC) principle. This method allows glycosaminoglycans (GAG) to be properly preserved and visualized. Small granules were stained by the cationic dye in the predentine in the absence of MgCl2. These granules grew

M. Goldberg; D. S. Septier

1992-01-01

257

Influence of fatigue testing and cementation mode on the load-bearing capability of bovine incisors restored with crowns and zirconium dioxide posts  

Microsoft Academic Search

The aim of the study was to evaluate the influence of fatigue and cementation mode on the fracture behavior of endodontically\\u000a treated bovine incisors restored with zirconium dioxide posts and crowns. Forty-eight endodontically treated bovine primary\\u000a incisors were restored with zirconium dioxide posts (Cerapost, Brasseler), composite build-ups, and crowns cast from a chromium\\u000a cobalt alloy. In 16 teeth, each of

F. P. Nothdurft; T. Schmitt; P. J. Motter; P. R. Pospiech

2008-01-01

258

Er:YAG Laser and Fractured Incisor Restorations: An In Vitro Study  

PubMed Central

Introduction. The aim of this study was to analyse the effects of an Er:YAG laser on enamel and dentine in cases of dental restorations involving fractured teeth, utilizing the dental fragment. Materials and Methods. Seventy-two freshly extracted bovine incisors were fractured at the coronal level by using a hammer applied with a standardized method, and the fragment was reattached by using three different methods: Er:YAG laser, orthophosphoric acid, and laser plus acid. The different groups were evaluated by a test realized with the dynamometer to know the force required to successfully detach the reattached fragment and by a microinfiltration test by using a 0.5% methylene blue solution followed by the optic microscope observation. Results. The compression test showed only a slight difference between the three groups, without any statistical significance. The infiltration test used to evaluate the marginal seal between the fracture fragment and the tooth demonstrated that etching with Er:YAG laser alone or in combination with orthophosphoric acid gives better results than orthophosphoric acid alone, with a highly significant statistical result. Discussion. Reattaching a tooth fragment represents a clinically proven methodology, in terms of achieving resistance to detachment, and the aim of this work was to demonstrate the advantages of Er:YAG laser on this procedure. Conclusion. This “in vitro” study confirms that Er:YAG laser can be employed in dental traumatology to restore frontal teeth after coronal fracture.

Fornaini, C.; Petruzzella, S.; Podda, R.; Merigo, E.; Nammour, S.; Vescovi, P.

2012-01-01

259

Relapse of incisor crowding: a visit to the Prince of Salina.  

PubMed

The management of the retention period after comprehensive orthodontic treatment is of great importance, as a primary goal of clinician. Considerable controversy still surrounds the problem of stability after the retention period. Many studies analyze factors associated to the presence of crowding or incisor irregularity and find predictive features on its relapse. Most studies have reported little o no correlation between the treatment changes in the biological parameters - clinical, biometric (irregularity index, intermolar width, intercanine width, arch length, overjet, overbite), or cephalometric variables- that ocurred and the posttretament and postretention changes that may predict their future development. This article provides a bibliographical overview on the relapse of dental alignment in treated cases. In a brief historical introduction, the first studies on the long-term stability of orthodontic results are analysed. The article then goes on to assess studies that focus attention on anteroinferior alignment before finally studying relapse of upper crowding. It concludes by making some final comments in the light of the bibliography provided and the differents schools regarding retention needs and methods. PMID:23229267

López-Areal, Luis; Gandía, Jose-Luis

2013-03-01

260

One-visit RCT of Maxillary Incisors with Extensive Inflammatory Root Resorption and Periradicular Lesions: A Case Report.  

PubMed

Inflammatory external root resorption (IERR) is a pathological phenomenon of microbial origin. This study reports a case of external apical inflammatory root resorption of maxillary incisors associated with periradicular lesions in a 22 year old female, which was successfully treated by one-visit root canal therapy (RCT). Radiographic investigation revealed periapical radiolucencies in the upper incisors associated with varying degrees of external inflammatory root resorption of teeth 12, 21 and 22. One-visit RCT of all involved teeth was carried out. Access cavities were permanently restored after 1 week. Clinical and radiographic examinations at 1 day, 1 week and 14 month follow-up demonstrated complete resolution of patient's signs/symptoms. The incisors were fully functional, and complete bone healing of the apical radiolucencies had taken place. The treatment outcomes demonstrated that IERR associated with periradicular lesions can respond successfully to one-visit RCT when conducted with adequate disinfection and a satisfactory coronal seal. Hence, one-visit RCT may be a good alternative to multiple-visit RCT involving intra-canal medicaments. PMID:23130060

Asgary, Saeed; Ahmadyar, Maryam

2011-05-15

261

The design of future central receiver power plants based on lessons learned from the Solar One Pilot Plant  

SciTech Connect

The 10-MW{sub e} Solar One Pilot Plant was the world's largest solar central receiver power plant. During its power production years it delivered over 37,000 MWhrs (net) to the utility grid. In this type of electric power generating plant, large sun-tracking mirrors called heliostats reflect and concentrate sunlight onto a receiver mounted on top a of a tower. The receiver transforms the solar energy into thermal energy that heats water, turning it into superheated steam that drives a turbine to generate electricity. The Solar One Pilot Plant successfully demonstrated the feasibility of generating electricity with a solar central receiver power plant. During the initial 2 years the plant was tested and 4 years the plant was operated as a power plant, a great deal of data was collected relating to the efficiency and reliability of the plant's various systems. This paper summarizes these statistics and compares them to goals developed by the US Department of Energy. Based on this comparison, improvements in the design and operation of future central receiver plants are recommended. Research at Sandia National Laboratories and the US utility industry suggests that the next generation of central receiver power plants will use a molten salt heat transfer fluid rather than water/steam. Sandia has recently completed the development of the hardware needed in a molten salt power plant. Use of this new technology is expected to solve many of the performance problems encountered at Solar One. Projections for the energy costs from these future central receiver plants are also presented. For reference, these projections are compared to the current energy costs from the SEGS parabolic trough plants now operating in Southern California.

Kolb, G.J.

1991-01-01

262

Viral Infections of the Central Nervous System: A Case-Based Review  

PubMed Central

Three patients with viral infections of the central nervous system (CNS) were evaluated on an inpatient infectious diseases consultation service within a two-week period. These cases, caused by herpes simplex virus, varicella zoster virus and enterovirus, highlight the importance of viral pathogens in causing debilitating infections of the CNS and provide examples of the utility of molecular diagnostics in evaluating patients with encephalitis and meningitis. The importance of antiviral therapy is particularly underscored by these cases, as is the variability in response of patients to such agents.

Big, Cecilia; Reineck, Lora A.; Aronoff, David M.

2009-01-01

263

Modified nucleotides reveal the indirect role of the central base pairs in stabilizing the lac repressor-operator complex.  

PubMed Central

Guanine residues in the lac operator were replaced by 2-aminopurine or purine analogues, pairing the modified nucleotides with C. The observed equilibrium dissociation constants for lac repressor binding to substituted operators were measured in 10 mM Tris, 150 mM KCl, 0.1 mM EDTA, 0.1 mM DTE, pH 7.6 at 25 degrees C. These measurements revealed five positions that destabilized the complex when substituted with either analogue. Two positions, which are related by a 2-fold symmetry, are in the major groove of the operator thought to directly interact with the protein. Three sites were in the central region of the operator. A purine analogue at a sixth site perturbed the local DNA structure and destabilized the complex. Alkylation interference experiments of the 2-aminopurine substituted operators demonstrated that, of the five affected, two substitutions displayed altered phosphate interference patterns at the phosphate adjacent to the substituted base. For these operators, complex formation was measured in different concentrations of KCl to assess the contribution of counterion release to the bimolecular process. The results indicated that both complexes were similar to wild-type, although minor changes were observed. The Kobs of the complex was then measured when 2-aminopurine or purine analogues were paired with uracil nucleotide, a base pair that serves to stabilize the DNA. The introduction of the new base pairs revealed two effects on the bimolecular interaction. For those operator sites that are thought to perturb the interaction directly, the affinity of the complex was weakened to levels observed for the singly-substituted operators. In contrast, the nucleotides of 2-aminopurine paired with uracil positioned in the central region of the operator served to enhance the stability of the complex. The purine-uracil base pair substitution on the other hand had a significant destabilizing effect on the interaction. We propose that the central base pairs modulate binding of the complex by altering the intrinsic properties of the DNA. Two specific attributes are required to achieve the lowest free energy of interaction. The DNA must have two interstrand hydrogen bonds to stabilize the duplex and it must have properties associated with directional bending or unwinding. This analysis does not rule out contributions by direct interactions between the protein and the central region of the operator but underscores how indirect effects play a major role in complex formation in this system. Images

Zhang, X; Gottlieb, P A

1995-01-01

264

Glacier changes in the central and northern Tien Shan during the last 140 years based on surface and remote-sensing data  

Microsoft Academic Search

This research presents a precise evaluation of the recession of Akshiirak and Ala Archa glaciers, Tien Shan, central Asia, based on data of geodetic surveys from 1861-69, aerial photographs from 1943, 1963, 1977 and 1981, 1 : 25 000 scale topographic maps and SRTM and ASTER data from 2000-03. The Akshiirak glacierized massif in the central Tien Shan contains 178

Vladimir B. Aizen; Valeriy A. Kuzmichenok; Arzhan B. Surazakov; Elena M. Aizen

2006-01-01

265

Unnatural base pair systems toward the expansion of the genetic alphabet in the central dogma  

PubMed Central

Toward the expansion of the genetic alphabet of DNA, several artificial third base pairs (unnatural base pairs) have been created. Synthetic DNAs containing the unnatural base pairs can be amplified faithfully by PCR, along with the natural A–T and G–C pairs, and transcribed into RNA. The unnatural base pair systems now have high potential to open the door to next generation biotechnology. The creation of unnatural base pairs is a consequence of repeating “proof of concept” experiments. In the process, initially designed base pairs were modified to address their weak points. Some of them were artificially evolved to ones with higher efficiency and selectivity in polymerase reactions, while others were eliminated from the analysis. Here, we describe the process of unnatural base pair development, as well as the tests of their applications.

HIRAO, Ichiro; KIMOTO, Michiko

2012-01-01

266

Unnatural base pair systems toward the expansion of the genetic alphabet in the central dogma.  

PubMed

Toward the expansion of the genetic alphabet of DNA, several artificial third base pairs (unnatural base pairs) have been created. Synthetic DNAs containing the unnatural base pairs can be amplified faithfully by PCR, along with the natural A-T and G-C pairs, and transcribed into RNA. The unnatural base pair systems now have high potential to open the door to next generation biotechnology. The creation of unnatural base pairs is a consequence of repeating "proof of concept" experiments. In the process, initially designed base pairs were modified to address their weak points. Some of them were artificially evolved to ones with higher efficiency and selectivity in polymerase reactions, while others were eliminated from the analysis. Here, we describe the process of unnatural base pair development, as well as the tests of their applications. PMID:22850726

Hirao, Ichiro; Kimoto, Michiko

2012-01-01

267

Peripherally inserted central catheter: compliance with evidence-based indications for insertion in an inpatient setting.  

PubMed

A randomized, retrospective chart review was conducted at a medium-sized community hospital to verify appropriateness of peripherally inserted central catheter (PICC) use in 49 inpatient patients. Study results support the Infusion Nurses Society recommendation to use PICCs to facilitate either short- or long-term intravenous therapy of vesicants, irritants, and any medications with a pH less than 5 or greater than 9 and osmolarity greater than 600 mOsm/L. All PICC insertion criteria recommended by the Centers for Disease Control and Prevention were met except one--the intended duration of intravenous therapy of more than 6 days. Identical PICC selection criteria are needed to standardize clinical practice. PMID:23823005

Wojnar, Danuta G; Beaman, Margaret L

268

Sustainability and Cost of a Community-Based Strategy Against Aedes aegypti in Northern and Central Vietnam  

PubMed Central

We previously reported a new community-based mosquito control that resulted in the elimination of Aedes aegypti in 40 of 46 communes in northern and central Vietnam. During 2007 and 2008, we revisited Nam Dinh and Khanh Hoa provinces in northern and central Vietnam, respectively, to evaluate whether or not these programs were still being maintained 7 years and 4.5 years after formal project activities had ceased, respectively. Using a previously published sustainability framework, we compared 13 criteria from Tho Nghiep commune in Nam Dinh where the local community had adopted our community-based project model using Mesocyclops from 2001. These data were compared against a formal project commune, Xuan Phong, where our successful intervention activities had ceased in 2000 and four communes operating under the National Dengue Control Program with data available. In Khanh Hoa province, we compared 2008 data at Ninh Xuan commune with data at project completion in 2003 and benchmarked these, where possible, against an untreated control commune, Ninh Binh, where few control activities had been undertaken. The three communes where the above community-based strategy had been adopted were rated as well-sustained with annual recurrent total costs (direct and indirect) of $0.28–0.89 international dollars per person.

Kay, Brian H.; Tuyet Hanh, Tran T.; Le, Nguyen Hoang; Quy, Tran Minh; Nam, Vu Sinh; Hang, Phan V. D.; Yen, Nguyen Thi; Hill, Peter S.; Vos, Theo; Ryan, Peter A.

2010-01-01

269

Central Issues in the Use of Computer-Based Materials for High Volume Entrepreneurship Education  

ERIC Educational Resources Information Center

|This article discusses issues relating to the use of computer-based learning (CBL) materials for entrepreneurship education at university level. It considers CBL as a means of addressing the increased volume and range of provision required in the current context. The issues raised in this article have importance for all forms of computer-based

Cooper, Billy

2007-01-01

270

Centralized Monitoring of the Microsoft Windows-based computers of the LHC Experiment Control Systems  

NASA Astrophysics Data System (ADS)

The control system of each of the four major Experiments at the CERN Large Hadron Collider (LHC) is distributed over up to 160 computers running either Linux or Microsoft Windows. A quick response to abnormal situations of the computer infrastructure is crucial to maximize the physics usage. For this reason, a tool was developed to supervise, identify errors and troubleshoot such a large system. Although the monitoring of the performance of the Linux computers and their processes was available since the first versions of the tool, it is only recently that the software package has been extended to provide similar functionality for the nodes running Microsoft Windows as this platform is the most commonly used in the LHC detector control systems. In this paper, the architecture and the functionality of the Windows Management Instrumentation (WMI) client developed to provide centralized monitoring of the nodes running different flavour of the Microsoft platform, as well as the interface to the SCADA software of the control systems are presented. The tool is currently being commissioned by the Experiments and it has already proven to be very efficient optimize the running systems and to detect misbehaving processes or nodes.

Varela Rodriguez, F.

2011-12-01

271

A logic-based diagram of signalling pathways central to macrophage activation  

PubMed Central

Background The complex yet flexible cellular response to pathogens is orchestrated by the interaction of multiple signalling and metabolic pathways. The molecular regulation of this response has been studied in great detail but comprehensive and unambiguous diagrams describing these events are generally unavailable. Four key signalling cascades triggered early-on in the innate immune response are the toll-like receptor, interferon, NF-?B and apoptotic pathways, which co-operate to defend cells against a given pathogen. However, these pathways are commonly viewed as separate entities rather than an integrated network of molecular interactions. Results Here we describe the construction of a logically represented pathway diagram which attempts to integrate these four pathways central to innate immunity using a modified version of the Edinburgh Pathway Notation. The pathway map is available in a number of electronic formats and editing is supported by yEd graph editor software. Conclusion The map presents a powerful visual aid for interpreting the available pathway interaction knowledge and underscores the valuable contribution well constructed pathway diagrams make to communicating large amounts of molecular interaction data. Furthermore, we discuss issues with the limitations and scalability of pathways presented in this fashion, explore options for automated layout of large pathway networks and demonstrate how such maps can aid the interpretation of functional studies.

Raza, Sobia; Robertson, Kevin A; Lacaze, Paul A; Page, David; Enright, Anton J; Ghazal, Peter; Freeman, Tom C

2008-01-01

272

Community-based study of neurological disorders in rural central Ethiopia.  

PubMed

Between 1986 and 1988 a door-to-door survey was conducted on a stable rural population of 60,820 in central Ethiopia. Trained lay health workers made a complete census and identified cases with symptoms and signs of neurological disorders, using specially designed questionnaires which, in a previous pilot study, were found to have a sensitivity of 91% and specificity of 85%. Neurological disorders in the rural population were epilepsy, postpoliomyelitis paralysis, mental retardation, peripheral neuropathy (mainly due to leprosy), and deaf-mutism with prevalence rates (cases/100,000 population) of 520, 240, 170, 150 and 130, respectively. The prevalence rates of the other less common neurological disorders were 62 for hemiparesis (15 of which were for cerebrovascular accidents), 20 for cerebral palsy, 16 for optic atrophy, 12 for perceptive deafness, 10 for tropical spastic paraparesis, 7 for Parkinson's disease and 5 for motor neuron disease, ataxia and chorea/athetosis. Among related non-neurological conditions, blindness, locomotor disability and deafness were predominant. The significance and role of such a neuroepidemiological study in laying the strategies for the prevention of neurological disorders and rehabilitation of patients are discussed in the context of a developing country. PMID:2087251

Tekle-Haimanot, R; Abebe, M; Gebre-Mariam, A; Forsgren, L; Heijbel, J; Holmgren, G; Ekstedt, J

1990-01-01

273

Texture-based tasks are little affected by second tasks requiring peripheral or central attentive fixation.  

PubMed

Experiments are described in which observers attempted to perform concurrently two separate visual tasks. Two types of tasks were used: the identification of a T-shaped or L-shaped letter target, and the detection or localization of a texture element of unique orientation (texture target) within a dense texture. Combining these tasks to form various task pairs, performance as a function of stimulus onset asynchrony (SOA) was established separately for each task in a pair. In addition, performance was measured when each task was carried out by itself. When paired, two identification tasks (T or L) on (two) letter targets required a significantly larger SOA than either identification task by itself. This outcome suggests the involvement of serial performance and competition for a limited resource, confirming that letter identification requires attentive fixation. However, when the identification of a central letter target was paired with the localization (upper or lower hemifield) of an eccentric texture target, performance in the pair was comparable to performance of each task by itself. This suggests parallel performance and a lack of conflict over resources. The outcome was similar when the identification of an eccentric letter target was paired with the detection (present or absent) of an eccentric texture target. These results are consistent with the possibility that localization and detection of a textural singularity do not require attentive fixation. PMID:1771133

Braun, J; Sagi, D

1991-01-01

274

PHYSICS AND CONTROL OF ELMING H-MODE NEGATIVE CENTRAL SHEAR ADVANCED TOKAMAK SCENARIO BASED ON EXPERIMENTAL PROFILES FOR ITER  

SciTech Connect

A271 PHYSICS AND CONTROL OF ELMING H-MODE NEGATIVE CENTRAL SHEAR ADVANCED TOKAMAK SCENARIO BASED ON EXPERIMENTAL PROFILES FOR ITER. Key DIII-D AT experimental and modeling results are applied to examine the physics and control issues for ITER to operate in a negative central shear (NCS) AT scenario. The effects of a finite edge pressure pedestal and current density are included based on the DIII-D experimental profiles. Ideal and resistive stability analyses indicate that feedback control of resistive wall modes by rotational drive or flux conserving intelligent coils is crucial for these AT configurations to operate at attractive {beta}{sub N} values in the range of 3.0-3.5. Vertical stability and halo current analyses show that reliable disruption mitigation is essential and mitigation control using an impurity gas can significantly reduce the local mechanical stress to an acceptable level. Core transport and turbulence analyses demonstrate that control of the rotational shear profile is essential to maintain the good confinement necessary for high {beta}. Consideration of edge stability and core transport suggests that a sufficiently wide pedestal is necessary for the projected fusion performance. Heat flux analyses indicate that with core-only radiation enhancement the outboard peak divertor heat load is near the design limit of 10 MW/m{sup 2}

LAO,LL; CHAN,VS; EVANS,TE; HUMPHREYS,DA; LEUER,JA; MAHDAVI,MA; PETRIE,TW; SNYDER,PB; STJOHN,HE; STAEBLER,GM; STAMBAUGH,RD; TAYLOR,TS; TURNBULL,AD; WEST,WP; BRENNAN,DP

2002-11-01

275

Security of Business to Business and Business to Customer Software Applications based on the Central Dogma of Molecular Biology (CDMB) and evolutionary models  

Microsoft Academic Search

The development, implementation and testing for Security of Business to Business and Business to Customer Software Applications System is based on the Central Dogma of Molecular Biology (CDMB), where we derive DNA Cryptographic Keys based on evolutionary models as public-key algorithms are based on mathematical functions rather than on substitution and permutation involving the use of two separate keys, in

Tatiana Hodorogea; Ionas Szilard Otto

2011-01-01

276

Bilateral dens evaginatus (talon cusp) in permanent maxillary lateral incisors: a rare developmental dental anomaly with great clinical significance.  

PubMed

Talon cusp is an accessory cusp-like structure which projects from the cingulum area or cementoenamel junction. It is important for dentists to be aware of the potential complications that may occur with talon cusp. Early diagnosis and treatment is important, especially to prevent pulpal complications in permanent teeth which may be in developing stage in paediatric patients. The purpose of this paper is to report a case of bilateral talon cusp in permanent maxillary lateral incisors. Associated dental anomalies and clinical problems are discussed along with successful management of the case with conservative therapy. PMID:23813995

Manuja, Naveen; Chaudhary, Seema; Nagpal, Rajni; Rallan, Mandeep

2013-06-24

277

LOW COMPLEXITY SPATIAL SCHEDULING PROSCHED FOR MIMO SYSTEMS WITH MULTIPLE BASE STATIONS AND A CENTRAL CONTROLLER  

Microsoft Academic Search

Wireless communications systems with multiple antennas at the transmitter can serve multiple terminals at the same time by exploiting the spatial domain. In a transmission scheme which also uses other orthogonal resources such as time and frequency, a different subset of terminals can be assigned t o each resource element. If joint spatial processing is perfo rmed at the base

Martin Fuchs; Giovanni Del Galdo; Martin Haardt

278

Base Cation and Nitrogen Budgets for a Mixed Hardwood Catchment in South-central Ontario  

Microsoft Academic Search

There is growing concern that available base cation pools in soil are declining in eastern North America and that some forests are approaching nitrogen (N) saturation due to the combined effects of acid deposition and harvesting. To assess these concerns, elemental mass balances for calcium (Ca), magnesium (Mg), potassium (K), and N were conducted over a 17-year period in a

Shaun A. Watmough; Peter J. Dillon

2003-01-01

279

A GPS-based three-dimensional lightning mapping system: Initial observations in central New Mexico  

Microsoft Academic Search

A GPS-based system has been developed that accurately locates the sources of VHF radiation from lightning discharges in three spatial dimensions and time. The observations are found to reflect the basic charge structure of electrified storms. Observations have also been obtained of a distinct type of energetic discharge referred to as positive bipolar breakdown, recently identified as the source of

W. Rison; R. J. Thomas; P. R. Krehbiel; T. Hamlin; J. Harlin

1999-01-01

280

Knowledge-Based, Central Nervous System (CNS) Lead Selection and Lead Optimization for CNS Drug Discovery  

PubMed Central

The central nervous system (CNS) is the major area that is affected by aging. Alzheimer’s disease (AD), Parkinson’s disease (PD), brain cancer, and stroke are the CNS diseases that will cost trillions of dollars for their treatment. Achievement of appropriate blood–brain barrier (BBB) penetration is often considered a significant hurdle in the CNS drug discovery process. On the other hand, BBB penetration may be a liability for many of the non-CNS drug targets, and a clear understanding of the physicochemical and structural differences between CNS and non-CNS drugs may assist both research areas. Because of the numerous and challenging issues in CNS drug discovery and the low success rates, pharmaceutical companies are beginning to deprioritize their drug discovery efforts in the CNS arena. Prompted by these challenges and to aid in the design of high-quality, efficacious CNS compounds, we analyzed the physicochemical property and the chemical structural profiles of 317 CNS and 626 non-CNS oral drugs. The conclusions derived provide an ideal property profile for lead selection and the property modification strategy during the lead optimization process. A list of substructural units that may be useful for CNS drug design was also provided here. A classification tree was also developed to differentiate between CNS drugs and non-CNS oral drugs. The combined analysis provided the following guidelines for designing high-quality CNS drugs: (i) topological molecular polar surface area of <76 Å2 (25–60 Å2), (ii) at least one (one or two, including one aliphatic amine) nitrogen, (iii) fewer than seven (two to four) linear chains outside of rings, (iv) fewer than three (zero or one) polar hydrogen atoms, (v) volume of 740–970 Å3, (vi) solvent accessible surface area of 460–580 Å2, and (vii) positive QikProp parameter CNS. The ranges within parentheses may be used during lead optimization. One violation to this proposed profile may be acceptable. The chemoinformatics approaches for graphically analyzing multiple properties efficiently are presented.

2011-01-01

281

Spatial point analysis based on dengue surveys at household level in central Brazil  

PubMed Central

Background Dengue virus (DENV) affects nonimunne human populations in tropical and subtropical regions. In the Americas, dengue has drastically increased in the last two decades and Brazil is considered one of the most affected countries. The high frequency of asymptomatic infection makes difficult to estimate prevalence of infection using registered cases and to locate high risk intra-urban area at population level. The goal of this spatial point analysis was to identify potential high-risk intra-urban areas of dengue, using data collected at household level from surveys. Methods Two household surveys took place in the city of Goiania (~1.1 million population), Central Brazil in the year 2001 and 2002. First survey screened 1,586 asymptomatic individuals older than 5 years of age. Second survey 2,906 asymptomatic volunteers, same age-groups, were selected by multistage sampling (census tracts; blocks; households) using available digital maps. Sera from participants were tested by dengue virus-specific IgM/IgG by EIA. A Generalized Additive Model (GAM) was used to detect the spatial varying risk over the region. Initially without any fixed covariates, to depict the overall risk map, followed by a model including the main covariates and the year, where the resulting maps show the risk associated with living place, controlled for the individual risk factors. This method has the advantage to generate smoothed risk factors maps, adjusted by socio-demographic covariates. Results The prevalence of antibody against dengue infection was 37.3% (95%CI [35.5–39.1]) in the year 2002; 7.8% increase in one-year interval. The spatial variation in risk of dengue infection significantly changed when comparing 2001 with 2002, (ORadjusted = 1.35; p < 0.001), while controlling for potential confounders using GAM model. Also increasing age and low education levels were associated with dengue infection. Conclusion This study showed spatial heterogeneity in the risk areas of dengue when using a spatial multivariate approach in a short time interval. Data from household surveys pointed out that low prevalence areas in 2001 surveys shifted to high-risk area in consecutive year. This mapping of dengue risks should give insights for control interventions in urban areas.

Siqueira-Junior, Joao B; Maciel, Ivan J; Barcellos, Christovam; Souza, Wayner V; Carvalho, Marilia S; Nascimento, Nazareth E; Oliveira, Renato M; Morais-Neto, Otaliba; Martelli, Celina MT

2008-01-01

282

Developing a multimetric index of ecological integrity based on macroinvertebrates of mountain ponds in central Italy  

Microsoft Academic Search

\\u000a The lack of biological systems for the assessment of ecological quality specific to mountain ponds prevents the effective\\u000a management of these natural resources. In this article we develop an index based on macroinvertebrates sensitive to the gradient\\u000a of nutrient enrichment. With this aim, we sampled 31 ponds along a gradient of trophy and with similar geomorphological characteristics\\u000a and watershed use

Angelo G. Solimini; Marcello Bazzanti; Antonio Ruggiero; Gianmaria Carchini

283

Developing a multimetric index of ecological integrity based on macroinvertebrates of mountain ponds in central Italy  

Microsoft Academic Search

The lack of biological systems for the assessment of ecological quality specific to mountain ponds prevents the effective\\u000a management of these natural resources. In this article we develop an index based on macroinvertebrates sensitive to the gradient\\u000a of nutrient enrichment. With this aim, we sampled 31 ponds along a gradient of trophy and with similar geomorphological characteristics\\u000a and watershed use

Angelo G. Solimini; Marcello Bazzanti; Antonio Ruggiero; Gianmaria Carchini

2008-01-01

284

Task-Based Lessons: The Central Focus of a Mathematics Content Course for Future Elementary Teachers  

Microsoft Academic Search

A task-based lesson serves as the organizing principle for a university mathematics content course for future elementary teachers.\\u000a The course, which provides the first semester of a year-long sequence, covers the arithmetic of numbers. The daily classroom\\u000a activities follow a Japanese-style lesson plan and use tasks developed through a didactical phenomenological analysis. A situated\\u000a learning perspective frames an understanding of

Anne R. Teppo

285

Strike-slip induced horizontal shear at the lithosphere base: evidence from the Shear Belt of Central Brittany (France)  

NASA Astrophysics Data System (ADS)

Recent acquisition of passive seismology data have allowed the calculation of a 3D P-wave velocity model of the lithosphere beneath Central Brittany (Judenherc et al, 2002). The model displays a strong high velocity anomaly in the asthenospheric mantle which trends NW-SE, oblique to the E-W tectonic grain of the crust. This anomaly cannot be attributed to a thermal origin as neither tectonic nor volcanic major event has occurred since 250 Ma. Conversely, in the frame of the Hercynian orogeny, this anomaly seated below 130 km in the mantle, can be interpreted as a remnant of a subducted slab. A comparable anomaly also exists in the lower part of the lithosphere mantle but it trends roughly N-S. This difference in trend, above and below 130 km, suggests a rotation of the upper one by late hercynian dextral shear beneath Central Brittany. A restoration of shear strain using the model of strike-slip deformation associated to the South Armorican Shear Zone, brings the anomaly seated within the lower lithosphere into parallelism with the one located deeper into the mantle. In other terms, a slab initially dipping to the NE across the lithosphere/asthenosphere boundary has been cut by an horizontal shear along the base of the lithosphere. Judenherc S., Granet M., Brun J.P., Poupinet G., Plomerova J., Mosquet A., Achauer U.,(2002), "Images of lithospheric heterogeneities in the Armorican segment of the Hercynian Range in France.", Tectonophysics (358) 121-134

Gumiaux, C.; Brun, J. P.; Gapais, D.; Granet, M.; Judenherc, S.

2003-04-01

286

GIS-based seismic shaking slope vulnerability map of Sicily (Central Mediterranean)  

NASA Astrophysics Data System (ADS)

Earthquakes often represent very dangerouses natural events in terms of human life and economic losses and their damage effects are amplified by the synchronous occurrence of seismically-induced ground-shaking failures in wide regions around the seismogenic source. In fact, the shaking associated with big earthquakes triggers extensive landsliding, sometimes at distances of more than 100 km from the epicenter. The active tectonics and the geomorphic/morphodinamic pattern of the regions affected by earthquakes contribute to the slopes instability tendency. In fact, earthquake-induced groun-motion loading determines inertial forces activation within slopes that, combined with the intrinsic pre-existing static forces, reduces the slope stability towards its failure. Basically, under zero-shear stress reversals conditions, a catastrophic failure will take place if the earthquake-induced shear displacement exceeds the critical level of undrained shear strength to a value equal to the gravitational shear stress. However, seismic stability analyses carried out for various infinite slopes by using the existing Newmark-like methods reveal that estimated permanent displacements smaller than the critical value should also be regarded as dangerous for the post-earthquake slope safety, in terms of human activities use. Earthquake-induced (often high-speed) landslides are among the most destructive phenomena related to slopes failure during earthquakes. In fact, damage from earthquake-induced landslides (and other ground-failures), sometimes exceeds the buildings/infrastructures damage directly related to ground-shaking for fault breaking. For this matter, several hearthquakes-related slope failures methods have been developed, for the evaluation of the combined hazard types represented by seismically ground-motion landslides. The methodologies of analysis of the engineering seismic risk related to the slopes instability processes is often achieved through the evaluation of the permanent displacement potentially induced by an seismic scenario. Such methodologies found on the consideration that the conditions of seismic stability and the post-seismic functionality of engineering structures are tightly related to the entity of the permanent deformations that an earthquake can induce. Regarding the existing simplified procedures among slope stability models, Newmark's model is often used to derive indications about slope instabilities due to earthquakes. In this way, we have evaluated the seismically-induced landslides hazard in Sicily (Central Mediterranean) using the Newmark-like model. In order to determine the map distribution of the seismic ground-acceleration from an earthquake scenario, the attenuation-law of Sabetta & Pugliese has been used, analyzing some seismic recordings occurred in Italy. Also, by evaluating permanent displacements, the correlation of Ambraseys & Menu has been assumed. The seismic shaking slope vulnerability map of Sicily has been carried out using GIS application, also considering max seismic ground-acceleration peak distribution (in terms of exceedance probability for fixed time), slope acclivity, cohesion/angle of internal friction of outcropping rocks, allowing the zoning of the unstable slopes under seismic forces.

Nigro, Fabrizio; Arisco, Giuseppe; Perricone, Marcella; Renda, Pietro; Favara, Rocco

2010-05-01

287

Hypohyperdontia: Agenesis of three third molars and mandibular centrals associated with midline supernumerary tooth in mandible  

PubMed Central

Agenesis of teeth in a patient who also presents with a supernumerary tooth is one of the rare numerical anomalies in human dentition. Agenesis of third molars was shown to be associated with other missing permanent teeth. A review of literature on hypodontia including third molar agenesis, hyperdontia and a concomitant presence of these two conditions which is termed as hypohyperdontia is presented along with a case showing agenesis of three third molars, both mandibular central incisors and a midline supernumerary tooth.

Nuvvula, Sivakumar; Kiranmayi, M.; Shilpa, G.; Nirmala, S. V. S. G.

2010-01-01

288

Evidence-based practice implementation strategy: the central role of the clinical nurse specialist.  

PubMed

The Hospital of the University of Pennsylvania Model of Excellence in Nursing Professional Practice serves to fully integrate the role of the clinical nurse specialist (CNS) in the implementation of evidence-based care and the role of organizational change agent. In this role, the CNS is responsible for the identification and remedy of system-wide challenges to optimal quality care, mentorship of clinical nurses both as clinicians and as leaders, and enhancement of interdisciplinary partnerships. Integrating the CNS role as the nursing department knowledge keepers, knowledge seekers and knowledge disseminators able to proactively develop and enhance interdisciplinary partnerships required systematic educational sessions and use of outcome measurement tools. Resources have included role development seminars, individual mentoring and standardization of role expression, across service lines. Development and implementation of an outcome measurement tool has served to further quantify the contribution of the CNS and standardized role implementation across service divisions. This dedication of resources has resulted in a significant number of unit-based and system-wide CNSs, serving as a significant support to the clinical nurse's practice and leadership development. This article will describe some of the processes used to enhance the role of the CNS implementing change and practice improvement at the Hospital of the University of Pennsylvania. PMID:21403488

Muller, Anne; McCauley, Kathleen; Harrington, Paul; Jablonski, Julie; Strauss, Robyn

289

Histopathologic evaluation following chronic implantation of chromium and steel based metal alloys in the rabbit central nervous system.  

PubMed

Histopathologic evaluation of three metal alloys for chronic implantation in the central nervous system (CNS) was undertaken in rabbits. Throughout the 8 month evaluation period the inflammatory response to the alloys was bland. Two of the alloys tested (chromium based MP35N, Trademark of the Standard Pressed Steel Company, and a stainless steel alloy, BG42 VacArc, Trademark of Latrobe Steel) appeared suitable as CNS implants. The third alloy (stainless steel 440C, Carpenter Steel Company) showed more corrosion than the other alloys, and may be less suitable for implantation. While E. cuniculi infection was found in four rabbits, the infection did not directly interfere with the assessment of the histologic changes directly due to the implants. Autoantibodies to a brain constituent were not observed. PMID:3097022

Rauch, H C; Ekstrom, M E; Montgomery, I N; Parada, F; Berke, J

290

GIS-based landslide hazard assessment at regional scale in Sicily (Central Mediterranean)  

NASA Astrophysics Data System (ADS)

The presence, type and abundance of landslides in an area depend on the characteristics of the triggers and on the predisposing conditions. Natural conditions that control these factors include the local and regional morphological and lithological setting, the presence and abundance of geological discontinuities including bedding planes, faults, joints, and cleavage systems, the type and depth of the soil, the extent and type of the vegetation cover, and the mechanical and hydrological properties of the rocks and soils. In order to evaluate the landslides susceptibility requires understanding of spatial distribution of all these factors that control slope instability. They depend on intrinsic and extrinsic variables. Intrinsic variables determining hazards include bedrock geology, topography, soil depth, soil type, slope gradient, slope aspect, slope curvature, elevation, engineering properties of the slope material, land use pattern and drainage patterns. Extrinsic variables include heavy rainfall, earthquakes and volcanic activities. Although the probability of landslide occurrence depends on both intrinsic and extrinsic variables, the latter possess a temporal distribution which is more difficult to handle in modelling practice. Therefore, for landslide hazard assessment, "landslide susceptibility mapping" is often conducted in which the extrinsic variables are not considered in determining the probability of landslide occurrence. The landslide susceptibility zoning methods mainly applied are: qualitative, statistical methodologies, and geotechnical/safety factor models. Qualitative approaches are based on the judgment of those conducting the susceptibility or hazard assessment; the statistical approach uses a predictive function or index derived from a combination of weighted factors; and the deterministic, models are based on the physical laws of conservation of mass, energy, and momentum. Regarding the statistical methodologies, the combination of factors that have led to landslides in the past are determined and quantitative predictions are made for areas currently free of landslides. In these methods the use of complex statistics requires the collection of large amounts of data to produce reliable results. Instead, deterministic landslide hazard maps normally provide the most detailed results, expressing the hazard in absolute values in the form of safety factors, or the probability of failure given a set of boundary conditions for groundwater levels and seismic acceleration. A methodology for landslide susceptibility mapping of the Sicily using a GIS technology is presented, based on a weighted approach. The degree of susceptibility was weighted considering the extrinsic variable of rainfall and the prevalence of the condition of geology, elevation, slope and land cover. Finally, an overlay analysis is carried out by evaluating the layers obtained according to their weight, and the landslide susceptibility map is produced. The study area was classified into five classes of relative landslide susceptibility, namely, very low, low, moderate, high and very high.

Nigro, Fabrizio; Pisciotta, Antonino; Perricone, Marcella; Renda, Pietro; Favara, Rocco

2010-05-01

291

A preliminary study of incisor exfoliation as an estimator of the postmortem interval using accumulated degree days.  

PubMed

This research shows the exfoliation of the anterior dentition has significant potential to aid in establishing the minimum length of the post-mortem interval. Accumulated degree days (ADD) were used to quantify the decomposition of the periodontal ligament, represented by post-mortem exfoliation of the incisors. After subjects were removed subsequent to disturbance by scavengers and time limitations on the study, the final sample size was 36 incisors from the maxillae and mandibles of seven pigs (Sus scrofa). Average daily temperature was calculated using hourly temperature data recorded using DS1921G thermochrons for the duration of the project (June 14-December 17, 2008). During this period, six teeth (16.7%) were exfoliated. ADD for these six teeth ranged from 1539.7 °C to 2006.7 °C. The average ADD required for exfoliation was 1788.0 °C (SD=198.1 °C). No differences in ADD required for exfoliation were observed between the maxillary and mandibular teeth (t=2.085; p=0.128). PMID:22459202

Granrud, Michelle A; Dabbs, Gretchen R

2012-03-28

292

Mineral trioxide aggregate apical plug method for the treatment of nonvital immature permanent maxillary incisors: Three case reports  

PubMed Central

Treatment of nonvital immature permanent teeth with calcium-hydroxide is associated with some difficulties such as weakened tooth fracture, root canal reinfection and long treatment time. Mineral trioxide aggregate (MTA) apical plug method is an alternative treatment option for open apices, and has gained popularity in the recent times. In this case report, we have attempted to present successful treatment of three maxillary incisors with open apices and periapical lesions with MTA. After preparing the access cavity, the working length was determined. The root canals were irrigated with 2.5% Sodium hypochlorite (NaOCl) and disinfected with calcium-hydroxide for two weeks. MTA was then placed in the apical 3 millimeters of the root canal. The remaining part of the root canal was filled with gutta-percha and the coronal restoration was finished with composite resin. After six months the radiographic examination showed a decrease of periapical lesions. At a 1-year and 18-months follow up, radiological and clinical successful healing of the incisor teeth was seen. MTA seems as an effective material for the apical plug method for the treatment of nonvital immature permanent teeth with open apices.

Gunes, Betul; Aydinbelge, Hale Ari

2012-01-01

293

A Population-based Survey of the Prevalence and Types of Glaucoma in Central Iran: The Yazd Eye Study.  

PubMed

PURPOSE: To describe the prevalence and types of glaucoma in Yazd, central Iran. DESIGN: Population-based, cross-sectional study. PARTICIPANTS: Iranian adults aged 40 to 80 years, residing in Yazd, Iran, in 2010 and 2011. METHODS: Eligible samples were selected using cluster random sampling. Each participant underwent an interview and ophthalmologic examinations, including refraction, determination of uncorrected and best-corrected visual acuity, slit-lamp biomicroscopy, Goldmann applanation tonometry, gonioscopy, dilated fundus examination, central corneal thickness measurement, visual field testing, and stereoscopic fundus photography. MAIN OUTCOME MEASURES: Prevalence of different types of glaucoma. RESULTS: Of 2320 eligible individuals, 2098 (response rate, 90.4%) participated in the study and 1990 completed all evaluations for glaucoma diagnosis. Overall, 47 persons (2.4%) were categorized with ocular hypertension, 32 persons (1.6%) were categorized with primary angle-closure suspect (PACS), and 16 persons (0.8%) were categorized with primary angle closure (PAC). The total number of subjects with glaucoma was 87 (4.4%; 95% confidence interval, 3.3-5.4), consisting of primary open-angle glaucoma (POAG, 3.2%, including high-tension glaucoma [1.7%] and normal-tension glaucoma [NTG], 1.5%]), primary angle-closure glaucoma (PACG, 0.4%), pseudoexfoliation glaucoma (0.4%), and other secondary glaucomas (0.4%). The mean age of subjects with glaucoma was 63.3±11 years, and 57.5% of them were female. Seventy-eight individuals (89.7%) were unaware of their disease. Positive family history of glaucoma was present in 6.9% of glaucoma subjects. CONCLUSIONS: The prevalence of glaucoma in Yazd (4.4%) is comparable to that in other population-based studies in Asia, with POAG accounting for the majority of cases. Most affected subjects were unaware of their disease. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article. PMID:23664464

Pakravan, Mohammad; Yazdani, Shahin; Javadi, Mohammad-Ali; Amini, Heidar; Behroozi, Zohreh; Ziaei, Hossein; Katibeh, Marzieh; Solaimanizad, Reza; Ghahari, Elham; Yaseri, Mehdi

2013-05-01

294

Injury among a population based sample of career firefighters in the central USA.  

PubMed

BACKGROUND: Rates of occupational injuries among firefighters are high because of the physically demanding and variable tasks required by their job. While descriptive data about injuries exist, few studies have explored individual risk factors and their relationship to occupational injury. METHODS: The current study presents data from a population-based sample of 462 career firefighters from 11 randomly-selected fire departments in the Missouri Valley region of the USA (Kansas, Missouri, Iowa, North Dakota, South Dakota, Colorado, Wyoming, Nebraska) who participated in a study evaluating risks for negative cardiovascular outcomes and injury. Relationships were examined between injury and demographic characteristics, body composition, fitness, and health behaviours. RESULTS: Participants were most likely to be injured during physical exercise and those who reported regular on-duty exercise had a fourfold increase in risk for exercise-related injury compared with those who did not exercise on duty (OR=4.06, 95% CI 1.73 to 12.24). However, those who exercised were half as likely to sustain non-exercise injuries (OR=0.53, 95% CI 0.32 to 0.85). CONCLUSIONS: Findings highlight the benefit of physical training for firefighters despite the risk of injury during exercise. PMID:23504995

Jahnke, Sara A; Poston, Walker S Carlos; Haddock, Christopher Keith; Jitnarin, Nattinee

2013-03-16

295

The beaver Anchitheriomys from the Miocene of Central Europe  

SciTech Connect

New finds of teeth and mandibles of Anchitheriomys from the Hambach opencast lignite mine in Northwest Germany and the first detailed descriptions of other mandibles from South Germany and Switzerland allow a review of the Central European specimens of this rare beaver genus. The metric variation of cheek teeth and especially the great differences in dimensions of incisors can be much better assessed. The observed range in size can be attributed to ontogenetic changes, and all material is assigned to Anchitheriomys suevicus. Stratigraphically, this species is restricted to the early middle Miocene, European Mammalian Neogene biozones MN 5-6.

Stefen, C.; Mors, T. [Museum Tierkunde, Dresden (Germany)

2008-09-15

296

A new interpretation of the sedimentary cover in the western Siljan Ring area, central Sweden, based on seismic data  

NASA Astrophysics Data System (ADS)

Two new reflection seismic profiles over the Paleozoic successions of the western part of the Siljan Ring impact structure show a contrasting seismic signature. The more southerly c. 10 km long Mora profile reveals a highly disturbed structure, with only a few kilometers of relatively horizontally layered structures observed. However, interpretations of refracted arrivals in the data, that can be correlated to reflections, indicate the Silurian clastic rocks to be about 200 m thick in the central part of the profile. Weak reflections from about 600 m depth suggest a 400 m thick Ordovician limestone sequence to be present. Cores from the area show a mainly shale lithology for the Silurian and only a thin sequence of Ordovician strata, suggesting a rapid thickening of the Ordovician towards the north. On the more northern c. 12 km Orsa profile clear reflections from the Paleozoic successions are seen along the entire profile, except on the southernmost few kilometers. Based on interpretations of refracted arrivals, the Silurian succession appears to be considerably thinner here, and possibly absent at some locations. The Ordovician is also interpreted to be thinner in this area, with a maximum thickness of about 200-300 m along most of the profile. A deeper reflection from about 2 km within the crystalline basement may represent a dolerite sill. The lack of clear basement reflections on the Mora profile can be attributed to near-surface conditions and the acquisition geometry. The seismic data and recent coring in the area suggest the presence of a deeper paleo-basin towards the southwest with significantly more shales being deposited and the Paleozoic successions being severely disturbed. The shallow coring and seismic data will help form the basis for locating future boreholes for deeper drilling to study impact processes and the Paleozoic evolution of central Sweden.

Juhlin, Christopher; Sturkell, Erik; Ebbestad, Jan Ove R.; Lehnert, Oliver; Högström, Anette E. S.; Meinhold, Guido

2012-12-01

297

A comparative analysis between site-based and centralized ratings and patient self-ratings in a clinical trial of Major Depressive Disorder.  

PubMed

We compared scores from three different ratings methods in a clinical trial of patients with Major Depressive Disorder (MDD). The Quick Inventory of Depressive Symptoms (QIDS-SR16) was compared to site-based clinician and centralized (site-independent) ratings of the Inventory of Depressive Symptoms (IDSc30). An extracted QIDSc16 was used for a matched comparison with the QIDS-SR16. Patient self-ratings were more depressed at baseline than either site-based ratings (p = 0.131) or centralized ratings (p = 0.005), but significantly less depressed at the end of double-blind treatment than either site-based (p = 0.006) or centralized ratings (p = 0.014), and after 12 weeks (site-based ratings: p = 0.048; centralized ratings: p = 0.004). The matched comparisons with patient self-ratings revealed ICC of r = 0.55 (site-based raters) and r = 0.49 (centralized raters) at baseline. After baseline, the correlations between the two different clinician ratings and patient self-ratings improved to r-values between 0.78 and 0.89. At the end of double-blind treatment, site-based raters separated the combination treatment from placebo on the IDSc30 (p = 0.030) whereas neither centralized ratings nor patient self-ratings achieved statistical significance. Alternatively, patient self-ratings separated the combination treatment from buspirone (p = 0.030) whereas neither clinician rating method achieved significance. A "dual" scoring concordance range reduced the placebo response rate and increased the drug effect between the combination treatment and placebo. These findings reveal scoring variability between each of the three ratings methods and challenge the reliability of any single method to accurately assess symptom severity scores, particularly at baseline. The use of "dual" scoring criteria may help to confirm symptom severity scores and improve ratings precision, particularly prior to enrolling subjects into CNS trials. PMID:23562150

Targum, Steven D; Wedel, Pamela C; Robinson, Jill; Daniel, David G; Busner, Joan; Bleicher, Leo S; Rauh, Philip; Barlow, Carrolee

2013-04-04

298

Base surge deposits, eruption history, and depositional processes of a wet phreatomagmatic volcano in Central Anatolia (Cora Maar)  

NASA Astrophysics Data System (ADS)

Cora Maar is a Quaternary volcano located to the 20 km northwest of Mount Erciyes, the largest of the 19 polygenetic volcanic complexes of the Cappadocian Volcanic Province in central Anatolia. Cora Maar is a typical example of a maar-diatreme volcano with a nearly circular crater with a mean diameter of c.1.2 km, and a well-bedded base surge-dominated maar rim tephra sequence up to 40 m in thickness. Having a diameter/depth ratio (D/d) of 12, Cora is a relatively “mature” maar compared to recent maar craters in the world. Cora crater is excavated within the andesitic lava flows of Quaternary age. The tephra sequence is not indurated, and consists of juvenile clasts up to 70 cm, non-juvenile clasts up to 130 cm, accretionary lapilli up to 1.2 cm in diameter, and ash to lapilli-sized tephra. Base surge layers display well-developed antidune structures indicating the direction of the transport. Both progressive and regressive dune structures are present within the tephra sequence. Wavelength values increase with increasing wave height, and with large wavelength and height values. Cora tephra display similarities to Taal and Laacher See base surge deposits. Impact sags and small channel structures are also common. Lateral and vertical facies changes are observed for the dune bedded and planar bedsets. According to granulometric analyses, Cora Maar tephra samples display a bimodal distribution with a wide range of Md? values, characteristic for the surge deposits. Very poorly sorted, bimodal ash deposits generally vary from coarse tail to fine tail grading depending on the grain size distribution while very poorly sorted lapilli and block-rich deposits display a positive skewness due to fine tail grading.

Gençalio?lu-Ku?cu, Gonca; Atilla, Cüneyt; Cas, Ray A. F.; Ku?cu, Ilkay

2007-01-01

299

An Evaluation of Incisor Relapse in Premolar Extraction and Nonextraction Patients Premolar Çekimli ve Çekimsiz Hastalarda Kesici Relapsinin De?erlendirilmesi  

Microsoft Academic Search

Objective: The purpose of this study was to evaluate the short-term postretention changes in four first premolar extraction and nonextraction patients to detect relapse in maxillary and mandibular dental arches and consider the associated factors with upper and lower incisor crowding. Subjects and Method: 15 cases were treated by four first premolar extraction and 30 cases without extraction. All of

TANER DDS; Derya GERMEÇ DDS

300

Alveolar bone thickness and lower incisor position in skeletal Class I and Class II malocclusions assessed with cone-beam computed tomography  

PubMed Central

Objective To evaluate lower incisor position and bony support between patients with Class II average- and high-angle malocclusions and compare with the patients presenting Class I malocclusions. Methods CBCT records of 79 patients were divided into 2 groups according to sagittal jaw relationships: Class I and II. Each group was further divided into average- and high-angle subgroups. Six angular and 6 linear measurements were performed. Independent samples t-test, Kruskal-Wallis, and Dunn post-hoc tests were performed for statistical comparisons. Results Labial alveolar bone thickness was significantly higher in Class I group compared to Class II group (p = 0.003). Lingual alveolar bone angle (p = 0.004), lower incisor protrusion (p = 0.007) and proclination (p = 0.046) were greatest in Class II average-angle patients. Spongious bone was thinner (p = 0.016) and root apex was closer to the labial cortex in high-angle subgroups when compared to the Class II average-angle subgroup (p = 0.004). Conclusions Mandibular anterior bony support and lower incisor position were different between average- and high-angle Class II patients. Clinicians should be aware that the range of lower incisor movement in high-angle Class II patients is limited compared to average- angle Class II patients.

Ucar, Faruk Izzet; Buyuk, Suleyman Kutalmis; Ozer, Torun; Uysal, Tancan

2013-01-01

301

Type 2 dens invaginatus in a maxillary lateral incisor: a case report of a conventional endodontic treatment.  

PubMed

Dens invaginatus is a rare malformation of the teeth resulting from the invagination of the tooth crown before biological mineralization occurs. In most cases, the thin or incomplete enamel lining of the invagination cannot prevent the entry of bacteria into the pulp, which leads to pulp necrosis with an eventual periapical inflammatory response. The treatment options include preventive sealing or filling of the invagination, root canal treatment, endodontic apical surgery and extraction. The root canal treatment of such teeth is often complicated because of their anatomical complexity. This case describes a successful non-surgical endodontic treatment of a maxillary lateral incisor with type 2 dens invaginatus with a large periradicular lesion. At follow-up examinations after 6 and 12-months, the tooth was asymptomatic and the healed lesion was evident radiographically PMID:19358374

Aguiar, C M; Ferreira, J P M G; Câmara, A C; de Figueiredo, J A P

2008-01-01

302

Knowledge-based soil inference modeling for estimating soil productivity and grain yield in north-central Missouri  

Technology Transfer Automated Retrieval System (TEKTRAN)

We used ArcSIE (Soil Inference Engine) software to model soils resembling those mapped by NRCS soil survey, for eight 12-digit watersheds in the Central Claypan (MLRA113) in north-central Missouri. Our source data for modeling was the 10m USGS Digital Elevation Model. Environmental Covariates used i...

303

Late Glacial and Holocene paleoceanography of the central and northern Greenland Sea based on foraminifera, stable isotopes and sediments  

NASA Astrophysics Data System (ADS)

Micropaleontological, sedimentological and stable isotope studies of four sediment cores from the central and northern Greenland Sea are used to reconstruct the Late Glacial and Holocene paleoceanography. The chronology and correlation of the sediments were based on the absolute radiocarbon ages. The data show a typical transition from the glacial towards the interglacial, with a distinct Holocene Thermal Maximum (HTM), expressed by maximum abundances of total and subpolar foraminifera. In the southernmost record, from the southern slope of the Vesterisbanken Seamount, the HTM is interrupted by two events of significantly lower foraminiferal abundance. The cooling trend after the HTM with >95% polar specimens in the planktic foraminifer associations is reversed in the Late Holocene part of that record, which is unusual, compared to other records from the northern Nordic Seas. Both total and subpolar foraminifer abundances return rapidly to the values comparable with the HTM, which indicates a strong influence of Atlantic Water (AW). This is not observed in the northernmost record from the Greenland Fracture Zone and therefore the AW must have come from a different direction. The Greenland Fracture Zone records reveal a planktic isotope pattern similar to that found on the Western Svalbard Slope indicating a connection between the two sites. The area was strongly influenced by the AW since the Early Holocene. However, around 3 cal. ka BP the inflow of AW was reduced, resulting in a cooling and a stronger stratification of the water column due to the thickening of the cold, low-salinity surface layer.

Telesi?ski, M. M.; Spielhagen, R. F.

2012-04-01

304

GIS-based probability assessment of natural hazards in forested landscapes of Central and South-Eastern Europe.  

PubMed

We assessed the probability of three major natural hazards--windthrow, drought, and forest fire--for Central and South-Eastern European forests which are major threats for the provision of forest goods and ecosystem services. In addition, we analyzed spatial distribution and implications for a future oriented management of forested landscapes. For estimating the probability of windthrow, we used rooting depth and average wind speed. Probabilities of drought and fire were calculated from climatic and total water balance during growing season. As an approximation to climate change scenarios, we used a simplified approach with a general increase of pET by 20%. Monitoring data from the pan-European forests crown condition program and observed burnt areas and hot spots from the European Forest Fire Information System were used to test the plausibility of probability maps. Regions with high probabilities of natural hazard are identified and management strategies to minimize probability of natural hazards are discussed. We suggest future research should focus on (i) estimating probabilities using process based models (including sensitivity analysis), (ii) defining probability in terms of economic loss, (iii) including biotic hazards, (iv) using more detailed data sets on natural hazards, forest inventories and climate change scenarios, and (v) developing a framework of adaptive risk management. PMID:20535611

Lorz, C; Fürst, C; Galic, Z; Matijasic, D; Podrazky, V; Potocic, N; Simoncic, P; Strauch, M; Vacik, H; Makeschin, F

2010-06-10

305

Structural bases for the interaction of frataxin with the central components of iron-sulphur cluster assembly  

PubMed Central

Reduced levels of frataxin, an essential protein of as yet unknown function, are responsible for causing the neurodegenerative pathology Friedreich's ataxia. Independent reports have linked frataxin to iron–sulphur cluster assembly through interactions with the two central components of this machinery: desulphurase Nfs1/IscS and the scaffold protein Isu/IscU. In this study, we use a combination of biophysical methods to define the structural bases of the interaction of CyaY (the bacterial orthologue of frataxin) with the IscS/IscU complex. We show that CyaY binds IscS as a monomer in a pocket between the active site and the IscS dimer interface. Recognition does not require iron and occurs through electrostatic interactions of complementary charged residues. Mutations at the complex interface affect the rates of enzymatic cluster formation. CyaY binding strengthens the affinity of the IscS/IscU complex. Our data suggest a new paradigm for understanding the role of frataxin as a regulator of IscS functions.

Prischi, Filippo; Konarev, Petr V.; Iannuzzi, Clara; Pastore, Chiara; Adinolfi, Salvatore; Martin, Stephen R.; Svergun, Dmitri I.; Pastore, Annalisa

2010-01-01

306

A pollen-based reconstruction of summer temperature in central North America and implications for circulation patterns during medieval times  

NASA Astrophysics Data System (ADS)

We present a reconstruction of mean summer temperature for the northern Midwest of the USA based on lacustrine pollen records from three different lakes in Wisconsin. The results suggest a relatively warm period during the earlier part of the record (~ 1200-1500 CE) followed by a cooler Little Ice Age (~ 1500-1900) and a subsequent warming to modern conditions. The reconstructed modern summer mean temperature is in good agreement with observations, and the decades of the 1930s to 1950s appear to be the warmest such period in the proxy record (through 1974).Analyses of circulation features associated with the warmest summers in the recent climate record suggest a prevalence of continental ridging accompanied by generally dry conditions during these warm summers in the Midwest. Drought reconstruction using the Palmer Drought Severity Index (PDSI) and tree-ring records as predictors also yield relatively dry conditions in medieval times for the central US. As reported in a number of recent studies, possible forcing mechanisms include La Niña-like conditions in the equatorial Pacific and warmer than average waters in the tropical Indo-western Pacific Ocean possibly coupled to a positive mode of the AMO/NAO North Atlantic circulation pattern.

Wahl, Eugene R.; Diaz, Henry F.; Ohlwein, Christian

2012-03-01

307

Shovel incisors, three-rooted molars, talon cusp, and supernumerary tooth in one patient  

Microsoft Academic Search

2 Ad- ditionally, multiple dental anomalies have been re- ported in individuals and within families, without evi- dence of other systemic manifestations. Ekman-Westborg and Julin3 reported a case of macrodontia, multituberculism, central cusps and pulp invaginations in the permanent dentition. Reportedly, no hereditary factors were found. Mann et al.^ reported a variant of the Ekman-Westborg-Julin syndrome, dis- covered as part

1992-01-01

308

HIVRelated Risk Factors in a Population-Based Probability Sample of North and Central Trinidad: The Voluntary HIV1 Counseling and Testing Efficacy Study  

Microsoft Academic Search

A population-based probability sample of North and Central Trinidad collected information on 860 respondents' demographic characteristics, as well as the prevalence of sexual risk behaviors and precursors to sexual risk taking in the 2 months preceding interview. Precursors of sexual risk behavior included HIV transmission knowledge, condom possession, and alcohol and drug use prior to sexual intercourse. A 91% response

Colin Furlonge; Steven E. Gregorich; Samuel Kalibala; Olga A. Grinstead; Thomas J. Coates; Kevin R. O'Reilly

2000-01-01

309

Shallow-water and sub-storm-base deposition of Lewis Shale in Cretaceous Western interior seaway, south-central Wyoming  

Microsoft Academic Search

Shallow- and deep-water (below storm base) clastics of the Lewis Shale were deposited in south-central Wyoming during a part of the Late Cretaceous Core, log, and outcrop data indicate that the Lewis Shale consists of a thin, transgressive, marine shale overlain by a thicker, coarser, progradational interval. The sea in which the Lewis Shale was deposited opened eastward into the

R. D. Jr. Winn; M. G. Bishop; P. S. Gardner

1987-01-01

310

Preliminary Results of the Active Source Portion of the Bighorns Array Seismic Experiment (BASE), North-Central Wyoming, USA  

NASA Astrophysics Data System (ADS)

The Bighorn Arch Seismic Experiment (BASE), is designed to image the Bighorn Arch in North Central Wyoming using active and passive seismic methods. The Bighorn Mountains formed as a basement involved foreland arch during the Laramide Orogeny. Whereas such arches are major features of both modern and ancient contractional orogens, the manifestation of arch shortening at depth has been highly contested due to the absence of detailed geophysical imaging of crust and mantle beneath the arches. BASE is a component of an integrated geological-geophysical program, the Bighorns Project, focused on discovering the nature of features that accommodate shortening at depth in such orogens. The active component of BASE was conducted in two deployments during the summer of 2010 and was designed to image the crust and upper mantle of the region. During the first deployment, ca. 1800 single channel Texan seismographs were deployed at 100 and 500 m spacings along a north-south profile located on the west flank of the Bighorn Mountains and along an east-west profile that extended across the arch from near Cody, Wyoming to north of Gillette, Wyoming. The seismograph array recorded blasts at 16 locations over two nights. The second deployment recorded 8 shots on ~800 Texan seismographs deployed at 200 and 1000 m spacings along the same north-south and east-west profiles. These shots were also recorded by ~400 additional Texans seismographs with 1 km spacing on a larger grid that encompassed the entire arch. Preliminary review of the data shows that shot energy propagated to offsets as great as 270 km and that large delays and advances in first arrival times correlate with the location of basins and exposed basement rocks respectively. Early one-dimensional velocity models show that the crystalline crust has velocities of 6.1 to 6.5 km/s to depths of ca 22 km, below which velocities increase from 6.8 to 7.0 km/s Crustal thickness appears to vary between 35 and 45 km. Future work includes developing velocity models from seismic tomography that will show what type of basement structures exist beneath the mountains, and, after integration with other datasets, how their geometries change in two- and three-dimensions.

Terbush, B. R.; Worthington, L. L.; Miller, K. C.; Harder, S. H.; Erslev, E.; Anderson, M. L.; Siddoway, C. S.

2010-12-01

311

The effect of the central donor in bis(benzimidazole)-based cobalt catalysts for the selective cis-1,4-polymerisation of butadiene.  

PubMed

A series of bis(benzimidazole)-based cobalt(II) dichloride complexes containing a range of different central donors has been synthesized and characterized. The nature of the central donor affects the binding of the ligand to the cobalt centre and determines the coordination geometry of the metal complexes. All complexes have been shown to catalyse the polymerization of butadiene, in combination with MAO as the co-catalyst, to give cis-1,4-polybutadiene with high selectivity. The nature of the central donor has a marked influence on the polymerization activity of the catalysts, but does not affect the polymer microstructure. The addition of PPh(3) generally increases the polymerization activity of these cobalt catalysts and results in predominantly (60-70%) 1,2-vinyl-polybutadiene. PMID:20725692

Cariou, Renan; Chirinos, Juan J; Gibson, Vernon C; Jacobsen, Grant; Tomov, Atanas K; Britovsek, George J P; White, Andrew J P

2010-08-20

312

Validation and future predictions based on a new Non-Point Source Assessment Toolbox, applied to the Central Valley, California  

NASA Astrophysics Data System (ADS)

Groundwater is a major irrigation water source in semi-arid regions. It is also vulnerable to Non-Point Source (NPS) contamination, particularly from nitrate (NO3-) as a result of agricultural practices. To support sound policy decisions we developed a physically based flow and transport model framework to understand and predict the fate of contaminants within regional aquifer systems. In large aquifers, the total source area of pollutants typically cover several thousand square kilometers, whilst individual sources typically do not exceed a few hundred square meters. The large contrast in these scenarios result in NPS modeling tasks that are computationally demanding, and the classical 3D models that solve the Advection-Dispersion Equation (ADE) are often not applicable due to computer memory limitations, numerical dispersion and numerical instabilities. Here, we developed and employed a number of numerical techniques to assemble a Non-Point Source Assessment Toolbox (NPSAT). The NPSAT is a quasi-3D model, combining a flow model and a streamline transport model. The flow model solves the groundwater flow equation using very fine discretization. For very large groundwater basins, a simplistic decomposition method is applied, splitting the aquifer into several overlapping sub-domains and solving to produce a high resolution velocity field. This velocity field is subsequently utilized within the transport model, where backward particle tracking links contamination sources with discharge surfaces using a large number of streamlines. For each streamline the 1D ADE is solved, assuming a unit pulse loading at the source side and a free exit boundary condition at the discharge surface side. From this, a Unit Response Function (URF) is obtained at the discharge surface side. Subsequently, actual Breakthrough Curves (BTCs) can be quickly computed from actual or hypothetical loading histories, by convoluting the URFs with real loading functions. The URFs are stored into a GIS platform and can be used for efficient scenario evaluations without the need to repeat groundwater model simulations. This method is applied to the southern third part of the Central Valley Aquifer, California, which is an intensively farmed semi-arid area, where the local communities rely heavily on groundwater. To obtain a detailed velocity field, the Central Valley Hydrologic Model (CVHM) developed by the USGS was used as the coarse solution, split and refined into a large number of sub-domains. The CVHM resolution is 1 sq mi, with the stresses applied to the center of each cell. In our refined model the well stresses are spatially distributed to a large number of hypothetical wells, where the pumping rates, well depths and screen lengths are obtained from empirical probability distributions, derived from real data. The NPSAT generates a time-dependent water quality probability distribution, which express the time-dependent probability for a discharge surface (e.g., well) to exceed a threshold level of contamination across at a specific time. The model result is compared against real historic nitrate data, and used for future predictions with different scenario evaluations.

Kourakos, G.; Harter, T.

2011-12-01

313

Adapting to climate variability and change: experiences from cereal-based farming in the central rift and kobo valleys, ethiopia.  

PubMed

Small-holder farmers in Ethiopia are facing several climate related hazards, in particular highly variable rainfall with severe droughts which can have devastating effects on their livelihoods. Projected changes in climate are expected to aggravate the existing challenges. This study examines farmer perceptions on current climate variability and long-term changes, current adaptive strategies, and potential barriers for successful further adaptation in two case study regions-the Central Rift Valley (CRV) and Kobo Valley. The study was based on a household questionnaire, interviews with key stakeholders, and focus group discussions. The result revealed that about 99 % of the respondents at the CRV and 96 % at the Kobo Valley perceived an increase in temperature and 94 % at CRV and 91 % at the Kobo Valley perceived a decrease in rainfall over the last 20-30 years. Inter-annual and intraseasonal rainfall variability also has increased according to the farmers. The observed climate data (1977-2009) also showed an increasing trend in temperature and high inter-annual and intra-seasonal rainfall variability. In contrast to farmers' perceptions of a decrease in rainfall totals, observed rainfall data showed no statistically significant decline. The interaction among various bio-physical and socio-economic factors, changes in rainfall intensity and reduced water available to crops due to increased hot spells, may have influenced the perception of farmers with respect to rainfall trends. In recent decades, farmers in both the CRV and Kobo have changed farming practices to adapt to perceived climate change and variability, for example, through crop and variety choice, adjustment of cropping calendar, and in situ moisture conservation. These relatively low-cost changes in farm practices were within the limited adaptation capacity of farmers, which may be insufficient to deal with the impacts of future climate change. Anticipated climate change is expected to impose new risks outside the range of current experiences. To enable farmers to adapt to these impacts critical technological, institutional, and market-access constraints need to be removed. Inconsistencies between farmers' perceptions and observed climate trends (e.g., decrease in annual rainfall) could lead to sub-optimal or counterproductive adaptations, and therefore must be removed by better communication and capacity building, for example through Climate Field Schools. Enabling strategies, which are among others targeted at agricultural inputs, credit supply, market access, and strengthening of local knowledge and information services need to become integral part of government policies to assist farmers to adapt to the impacts of current and future climate change. PMID:23943096

Kassie, Belay Tseganeh; Hengsdijk, Huib; Rötter, Reimund; Kahiluoto, Helena; Asseng, Senthold; Van Ittersum, Martin

2013-08-14

314

A centralized supply voltage and local body bias-based compensation approach to mitigate within-die process variation  

Microsoft Academic Search

With the scaling of MOSFET dimensions and the enhancements introduced to boost its performance, variation in semiconductor manufacturing has increased. The manufactured designs are usually shifted from the intended operating point, degrading the parametric yield. In this paper, we partition the chip into multiple regions with localized sensors and introduce a centralized control system with region-specific bias control to mitigate

Amlan Ghosh; Rahul M. Rao; Richard B. Brown

2009-01-01

315

Aetiologies of Central Nervous System Infection in Viet Nam: A Prospective Provincial Hospital-Based Descriptive Surveillance Study  

Microsoft Academic Search

BackgroundInfectious diseases of the central nervous system (CNS) remain common and life-threatening, especially in developing countries. Knowledge of the aetiological agents responsible for these infections is essential to guide empiric therapy and develop a rational public health policy. To date most data has come from patients admitted to tertiary referral hospitals in Asia and there is limited aetiological data at

Nghia Ho Dang Trung; Tu Le Thi Phuong; Marcel Wolbers; Hoang Nguyen Van Minh; Vinh Nguyen Thanh; Minh Pham Van; Nga Tran Vu Thieu; Tan Le Van; Diep To Song; Phuong Le Thi; Thao Nguyen Thi Phuong; Cong Bui Van; Vu Tang; Tuan Hoang Ngoc Anh; Dong Nguyen; Tien Phan Trung; Lien Nguyen Thi Nam; Hao Tran Kiem; Tam Nguyen Thi Thanh; James Campbell; Maxine Caws; Jeremy Day; Menno D. de Jong; Chau Nguyen Van Vinh; H. Rogier Van Doorn; Hien Tran Tinh; Jeremy Farrar; Constance Schultsz

2012-01-01

316

Governmental Accounting versus National Accounts: Implications of different accounting bases on EU member-States Central Government deficit\\/surplus  

Microsoft Academic Search

The main purpose of this paper is to assess the implications on the European Union (EU) member-States Central Government deficit\\/surplus of different accounting basis adopted in Governmental Accounting (GA – microeconomic perspective) and National Accounting (NA – macroeconomic perspective). It analyses the cash to accrual basis adjustments to be made to General Government Sector (GGS) data, when converting from Governmental

Maria Antónia Jorge de Jesus; Susana Margarida Jorge

2012-01-01

317

Determination of central q and effective mass on TEXTOR based on Discrete Alfven Wave (DAW) spectrum measurements.  

National Technical Information Service (NTIS)

The use of the Discrete Alfven Wave spectrum to determine the current density profile and the effective mass density of the plasma in the TEXTOR tokamak is studied; the measurement, the validity of which is discussed, confirms independently the central q(...

P. Descamps G. Wasserhove R. Koch A. M. Messiaen P. E. Vandenplas

1989-01-01

318

The application of GIS-based logistic regression for landslide susceptibility mapping in the Kakuda-Yahiko Mountains, Central Japan  

Microsoft Academic Search

As a first step forward in regional hazard management, multivariate statistical analysis in the form of logistic regression was used to produce a landslide susceptibility map in the Kakuda-Yahiko Mountains of Central Japan. There are different methods to prepare landslide susceptibility maps. The use of logistic regression in this study stemmed not only from the fact that this approach relaxes

Lulseged Ayalew; Hiromitsu Yamagishi

2005-01-01

319

Discrepant Prevalence and Incidence of Leishmania Infection between Two Neighboring Villages in Central Mali Based on Leishmanin Skin Test Surveys  

Microsoft Academic Search

Apart from a single report, the last publication of cutaneous leishmaniasis (CL) in Mali dates back more than 20 years. The absence of information on the current status of CL in Mali led us to conduct a cohort study in Kemena and Sougoula, two villages in Central Mali from which cases of CL have been recently diagnosed by Mali's reference

Fabiano Oliveira; Seydou Doumbia; Jennifer M. Anderson; Ousmane Faye; Souleymane S. Diarra; Pierre Traoré; Moumine Cisse; Guimba Camara; Koureissi Tall; Cheick A. Coulibaly; Sibiry Samake; Ibrahim Sissoko; Bourama Traoré; Daouda Diallo; Somita Keita; Rick M. Fairhurst; Jesus G. Valenzuela; Shaden Kamhawi

2009-01-01

320

Regeneration of periodontal primary afferents of the rat incisor following injury of the inferior alveolar nerve with special reference to neuropeptide Y-like immunoreactive primary afferents  

Microsoft Academic Search

Regeneration of primary afferents and the expression of neuropeptide Y (NPY) in the lingual periodontal ligament of the rat incisor were examined following different types of injury (resection or crush) of the inferior alveolar nerve (IAN) combined with superior cervical ganglionectomy. In normal animals, protein gene product 9.5 (PGP 9.5)-like immunoreactivity (-LI) was localized in the middle areas of the

S. H. Youn; M. Sakuda; K. Kurisu; S. Wakisaka

1997-01-01

321

Multiple traumatic injury to maxillary incisors in an adolescent female: treatment outcome with two years follow-up  

PubMed Central

Summary Number, type and severity of dental injuries per patient differ according to the patient’s age and the cause of accident. The trauma group resulting from pedestrian-, bicycle-, and car-related injuries is usually dominated by multiple dental injuries, injuries to the supporting bone and soft-tissue injuries. This report describes a case of a 16.2-year-old female who suffered traumatic injuries to her permanent maxillary incisors after a car accident. Concussion of tooth 12, extrusive luxation of tooth 11, avulsion of tooth 21 and subluxation with complicated crown fracture of tooth 22 were observed at the emergency visit 75 minutes after the trauma. Tooth 21 was dry stored for 15 minutes, then in milk for 60 minutes. The treatment plan according to IADT guidelines was performed with the satisfaction of the dentists and the patient. After 1 year follow- up a replacement root resorption of tooth 21 was diagnosed; it was then considered severe at the time of the 2 year control visit. Educational programs are essential to optimize the treatment outcome both at the accident site and also at the dental office.

Biagi, Roberto; Cardarelli, Filippo; Storti, Ennio; Majorana, Alessandra; Farronato, Giampietro

2013-01-01

322

Multiple traumatic injury to maxillary incisors in an adolescent female: treatment outcome with two years follow-up.  

PubMed

Number, type and severity of dental injuries per patient differ according to the patient's age and the cause of accident. The trauma group resulting from pedestrian-, bicycle-, and car-related injuries is usually dominated by multiple dental injuries, injuries to the supporting bone and soft-tissue injuries. This report describes a case of a 16.2-year-old female who suffered traumatic injuries to her permanent maxillary incisors after a car accident. Concussion of tooth 12, extrusive luxation of tooth 11, avulsion of tooth 21 and subluxation with complicated crown fracture of tooth 22 were observed at the emergency visit 75 minutes after the trauma. Tooth 21 was dry stored for 15 minutes, then in milk for 60 minutes. The treatment plan according to IADT guidelines was performed with the satisfaction of the dentists and the patient. After 1 year follow- up a replacement root resorption of tooth 21 was diagnosed; it was then considered severe at the time of the 2 year control visit. Educational programs are essential to optimize the treatment outcome both at the accident site and also at the dental office. PMID:23991273

Biagi, Roberto; Cardarelli, Filippo; Storti, Ennio; Majorana, Alessandra; Farronato, Giampietro

2013-06-25

323

Rat wct mutation prevents differentiation of maturation-stage ameloblasts resulting in hypo-mineralization in incisor teeth.  

PubMed

A recent study provided genetic and morphological evidence that rat autosomal-recessive mutation, whitish chalk-like teeth (wct), induced tooth enamel defects resembling those of human amelogenesis imperfecta (AI). The wct locus maps to a specific interval of rat chromosome 14 corresponding to human chromosome 4q21 where the ameloblastin and enamelin genes exist, although these genes are not included in the wct locus. The effect of the wct gene mutation on the enamel matrix synthesis and calcification remains to be elucidated. This study clarifies how the wct gene mutation influences the synthesis of enamel matrix and its calcification by immunocytochemistry for amelogenin, ameloblastin and enamelin, and by electron probe micro-analysis (EPMA). The immunoreactivity for enamel proteins such as amelogenin, ameloblastin, and enamelin in the ameloblasts in the homozygous teeth was the same as that in the heterozygous teeth from secretory to transitional stages, although the homozygous ameloblasts became detached from the enamel matrix in the transitional stage. The flattened ameloblasts in the maturation stage of the homozygous samples contained enamel proteins in their cytoplasm. Thus, the wct mutation was found to prevent the morphological transition of ameloblasts from secretory to maturation stages without disturbing the synthesis of enamel matrix proteins, resulting in the hypo-mineralization of incisor enamel and cyst formation between the enamel organ and matrix. This mutation also prevents the transfer of iron into the enamel. PMID:17636316

Osawa, Masaru; Kenmotsu, Shin; Masuyama, Taku; Taniguchi, Kazuyuki; Uchida, Takashi; Saito, Chikara; Ohshima, Hayato

2007-07-17

324

The treatment of a maxillary lateral incisor with unusual morphology with long-term follow-up.  

PubMed

AIM: To report the treatment of an unusual combination of one dens evaginatus and two dens invaginatus in a single tooth and its healing outcome after 10 years. SUMMARY: The long-term outcome of a maxillary lateral incisor with dens evaginatus combined with two Oehlers type II dens invaginatus and a large periradicular lesion in an 11-year-old female treated endodontically and restoratively is described. The endodontic treatment included intracanal medication with calcium hydroxide and canal filling using a thermoplastic root canal filling technique. The crown was restored with conventional composite resin. During periodic clinical and radiographic follow-up, the patient remained symptom free, and the periradicular region was completely healed, meeting both aesthetic and functional expectations after 10 years. KEY LEARNING POINTS: The co-occurrence of dens evaginatus and two dens invaginatus in the same tooth is an unusual finding that compromises aesthetics and predisposes the patient to dental pulp infection. The complex morphology observed in this case represented both endodontic and restorative challenges. PMID:23594115

De Rossi, A; Carvalho, F K; Queiróz, A M; Silva, R A B; Nelson-Filho, P; Silva, L A B

2013-03-29

325

Distribution of non-collagenous dentin matrix proteins and proteoglycans, and their relation to calcium accumulation in bisphosphonate-affected rat incisors.  

PubMed

It has been reported that multiple injections of 1-hydroxyethylidene- 1,1-bisphosphonate (HEBP) to rats prevent mineralization of incisor dentin, thereby revealing high concentrations of calcium in the non-mineralized matrix of circumpulpal dentin. To identify the molecules responsible for calcium accumulation in circumpulpal dentin matrix, rats were injected daily with HEBP (8 mg P/kg) for 7 d, and the incisors processed for various histochemical and immunohistochemical staining of non-collagenous matrices of dentin. Cuprolinic blue reactions for proteoglycans (PGs) were equally distributed in non-mineralized matrix of mantle and circumpulpal dentin layers. Dentin sialoprotein (DSP) and osteopontin (OPN) immunoreactions were found in non-mineralized circumpulpal dentin matrix, but not in mantle dentin. In normal incisors, however, predentin matrix showing significant DSP immunoreactivity was negative for Ca-GBHA reactions. HEBP-affected, non-mineralized OPN immunopositive bone matrix was also non-reactive for calcium. From these observations, neither PGs, OPN nor DSP appear to be responsible for calcium accumulation in HEBP-affected circumpulpal dentin. Stains-all reactive component, possibly dentin phosphoprotein (DPP), only showed the same distribution as that of Ca-GBHA in both HEBP-affected and normal dentin matrix, implicating a possible contribution of DPP to calcium accumulation in circumpulpal dentin and, hence, to appositional mineralization of dentin. PMID:10872993

Ohma, N; Takagi, Y; Takano, Y

2000-06-01

326

Dopamine induces cell death, lipid peroxidation and DNA base damage in a catecholaminergic cell line derived from the central nervous system  

Microsoft Academic Search

Dopamine can be autoxidized to superoxides and quinones. Superoxides can form hydroxyl radicals that are highly reactive with\\u000a lipids, proteins and DNA leading to neuronal damage and cell death. We used a clonal catecholaminergic cell line (CATH.a)\\u000a derived from the central nervous system to evaluate the effects of dopamine on cell death, lipid peroxidation and DNA base\\u000a damage. Dopamine produces

Joseph M. Masserano; Ivory Baker; Diane Venable; Li Gong; Steven J. Zullo; Carl R. Merril; Richard Jed Wyatt

1999-01-01

327

Isoprene and monoterpene fluxes from Central Amazonian rainforest inferred from tower-based and airborne measurements, and implications on the atmospheric chemistry and the local carbon budget  

Microsoft Academic Search

We estimated the isoprene and monoterpene source strengths of a pristine tropical forest north of Manaus in the central Amazon Basin using three different micrometeorological flux measurement approaches. During the early dry season campaign of the Cooperative LBA Airborne Regional Experiment (LBA-CLAIRE-2001), a tower-based surface layer gradient (SLG) technique was applied simultaneously with a relaxed eddy accumulation (REA) system. Airborne

U. Kuhn; M. O. Andreae; C. Ammann; A. C. Araújo; E. Brancaleoni; P. Ciccioli; T. Dindorf; M. Frattoni; L. V. Gatti; L. N. Ganzeveld; B. Kruijt; J. Lelieveld; J. Lloyd; F. X. Meixner; A. D. Nobre; U. Pöschl; C. Spirig; P. Stefani; A. Thielmann; R. Valentini; J. Kesselmeier

2007-01-01

328

Predictors of central nervous system metastasis in patients with metastatic breast cancer. A competing risk analysis of 579 patients treated with epirubicin-based chemotherapy  

Microsoft Academic Search

Summary In order to identify factors predictive of central nervous system (CNS) metastasis, we reviewed the histories of 579 patients treated with epirubicin-based chemotherapy for metastatic breast cancer. Statistical analysis included Kaplan–Meier survival plots, Cox’s regression analysis and competing risk analysis using the cumulative incidence. Median follow-up-time was 137 months (range 0–183+). In this period, one hundred and twenty-four patients (21.4%)

Marianne Ryberg; Dorte Nielsen; Kell Osterlind; Per Kragh Andersen; Torben Skovsgaard; Per Dombernowsky

2005-01-01

329

Degradation of carboxylated styrene butadiene rubber based water born paints: Part 2 – Models to predict UV stability and water absorption through central composite design  

Microsoft Academic Search

Central composite experimental design methods have been used to examine the simultaneous effects of talc (Viaton Viatalc® 30), titanium dioxide (modified Rutile, Tioxide® TR92) and additional hindered phenolic stabiliser (Aquanox® L, a 50% w\\/w aqueous dispersion of Winstay® L) on the water uptake and UV stability of composite films based on a carboxylated styrene butadiene rubber (c-SBR) latex. The talc

Elena Jubete; Christopher M. Liauw; Norman S. Allen

2007-01-01

330

A mathematical model to design a lignocellulosic biofuel supply chain system with a case study based on a region in Central Texas  

Microsoft Academic Search

This study formulates a model to maximize the profit of a lignocellulosic biofuel supply chain ranging from feedstock suppliers to biofuel customers. The model deals with a time-staged, multi-commodity, production\\/distribution system, prescribing facility locations and capacities, technologies, and material flows. A case study based on a region in Central Texas demonstrates application of the proposed model to design the most

Heungjo An; Wilbert E. Wilhelm; Stephen W. Searcy

2011-01-01

331

Analysis of bacterial core communities in the central Baltic by comparative RNA-DNA-based fingerprinting provides links to structure-function relationships.  

PubMed

Understanding structure-function links of microbial communities is a central theme of microbial ecology since its beginning. To this end, we studied the spatial variability of the bacterioplankton community structure and composition across the central Baltic Sea at four stations, which were up to 450?km apart and at a depth profile representative for the central part (Gotland Deep, 235?m). Bacterial community structure was followed by 16S ribosomal RNA (rRNA)- and 16S rRNA gene-based fingerprints using single-strand conformation polymorphism (SSCP) electrophoresis. Species composition was determined by sequence analysis of SSCP bands. High similarities of the bacterioplankton communities across several hundred kilometers were observed in the surface water using RNA- and DNA-based fingerprints. In these surface communities, the RNA- and DNA-based fingerprints resulted in very different pattern, presumably indicating large difference between the active members of the community as represented by RNA-based fingerprints and the present members represented by the DNA-based fingerprints. This large discrepancy changed gradually over depth, resulting in highly similar RNA- and DNA-based fingerprints in the anoxic part of the water column below 130?m depth. A conceivable mechanism explaining this high similarity could be the reduced oxidative stress in the anoxic zone. The stable communities on the surface and in the anoxic zone indicate the strong influence of the hydrography on the bacterioplankton community structure. Comparative analysis of RNA- and DNA-based community structure provided criteria for the identification of the core community, its key members and their links to biogeochemical functions. PMID:21697960

Brettar, Ingrid; Christen, Richard; Höfle, Manfred G

2011-06-23

332

Impact of an internet-based intervention on Finnish mothers' perceptions of parenting satisfaction, infant centrality and depressive symptoms during the postpartum year.  

PubMed

OBJECTIVE: this study evaluates how an internet-based intervention affects mothers' parenting satisfaction, infant centrality and depressive symptoms. DESIGN: a quasi-experimental design and repeated measures were used. SETTINGS: this study was conducted in two Finnish public maternity hospitals (intervention/control). PARTICIPANTS: a convenience sample (N=1300) of primiparous and multiparous Finnish-speaking mothers were invited to participate. Multiple-birth and early discharge mothers receiving home visits were excluded. The analysis included 760 mothers. INTERVENTION: the intervention offered online support for parenting, breast feeding and infant care beginning from the middle of pregnancy. It consisted of an information database, a peer discussion forum and expert advice. MEASUREMENTS: Outcomes were measured by the Evaluation and Infant Centrality subscales of the What Being the Parent of a New Baby is Like-Revised, and the Edinburgh Postnatal Depression Scale after childbirth, and six weeks, six months and 12 months post partum. Age, parity, parenting self-efficacy, and perception of infant and family functioning were used as the covariates. FINDINGS: during the first postpartum year, mothers' parenting satisfaction increased significantly, whereas infant centrality and depressive symptoms decreased within groups. However, these changes were not linear. The mean difference between groups in parenting satisfaction and depressive symptoms was not significant within any of the four assessments. The mean difference in infant centrality between control and intervention mothers was significant only at six weeks post partum. Primiparas scored significantly higher in infant centrality and significantly lower in depressive symptoms than multiparas. KEY CONCLUSION AND IMPLICATIONS FOR PRACTICE: an internet-based intervention did not significantly affect mothers' perceptions of parenting satisfaction and depressive symptoms, but intervention mothers experienced higher infant centrality compared with control mothers at six weeks. Parenting self-efficacy was a significant covariate for all measures. Parity needs to be taken into account when infant centrality and depressive symptoms are used as outcome variables in intervention studies. More research is needed to study the potential of information data bank, professional, and peer online support. This study also highlights the need to pay more attention to the selection of the target population, the selection of outcome measures, and implementation issues in intervention research. PMID:23623471

Salonen, Anne H; Pridham, Karen F; Brown, Roger L; Kaunonen, Marja

2013-04-23

333

The design of future central receiver power plants based on lessons learned from the Solar One Pilot Plant  

Microsoft Academic Search

The 10-MW(sub e) Solar One Pilot Plant was the world's largest solar central receiver power plant. During its power production years it delivered over 37,000 MWhrs (net) to the utility grid. In this type of electric power generating plant, large sun-tracking mirrors called heliostats reflect and concentrate sunlight onto a receiver mounted on top of a tower. The receiver transforms

G. J. Kolb

1991-01-01

334

Seismic properties of the upper crust in the central Friuli area (northeastern Italy) based on petrophysical data  

Microsoft Academic Search

The compressional and shear wave velocities have been measured at room temperature and pressure up to 450 MPa on 5 sedimentary rock samples, representative of the most common lithologies of the upper crust in the central Friuli area (northeastern Italy). At 400 MPa confining pressure the Triassic dolomitic rock shows the highest velocities (Vp ?7 km\\/s, Vs ?3.6 km\\/s), the Jurassic and Triassic limestones samples

M. Faccenda; G. Bressan; L. Burlini

2007-01-01

335

SHORT REPORT: HIGH EFFICACY OF TWO ARTEMISININ-BASED COMBINATIONS (ARTESUNATE + AMODIAQUINE AND ARTEMETHER + LUMEFANTRINE) IN CAALA, CENTRAL ANGOLA  

Microsoft Academic Search

In April 2004, 137 children 6-59 months of age with uncomplicated Plasmodium falciparum (Pf) malaria (Caala, Central Angola) were randomized to receive either artemether-lumefantrine (Coartem) or artesunate + amo- diaquine (ASAQ). After 28 days of follow-up, there were 2\\/61 (3.2%) recurrent parasitemias in the Coartem group and 4\\/64 (6.2%) in the ASAQ group (P 0.72), all classified as re-infections after

JEAN-PAUL GUTHMANN; SANDRA COHUET; CHRISTINE RIGUTTO; FILOMENO FORTES; NILTON SARAIVA; JAMES KIGULI; JULIET KYOMUHENDO; MAX FRANCIS; FRÉDÉRIC NOËL; MARYLINE MULEMBA; SUNA BALKAN

2006-01-01

336

ecological geological maps: GIS-based evaluation of the Geo-Ecological Quality Index (GEQUI) in Sicily (Central Mediterranean)  

NASA Astrophysics Data System (ADS)

The condition of landscapes and the ecological communities within them is strongly related to levels of human activity. As a consequence, determining status and trends in the pattern of human-dominated landscapes can be useful for understanding the overall conditions of geo-ecological resources. Ecological geological maps are recent tools providing useful informations about a-biotic and biotic features worldwide. These maps represents a new generation of geological maps and depict the lithospheric components conditions on surface, where ecological dynamics (functions and properties) and human activities develop. Thus, these maps are too a fundamental political tool to plan the human activities management in relationship to the territorial/environmental patterns of a date region. Different types of ecological geological maps can be develop regarding the: conditions (situations), zoning, prognosis and recommendations. The ecological geological conditions maps reflects the complex of parameters or individual characteristics of lithosphere, which characterized the opportunity of the influence of lithosphere components on the biota (man, fauna, flora, and ecosystem). The ecological geological zoning maps are foundamental basis for prognosis estimation and nature defenses measures. Estimation from the position of comfort and safety of human life and function of ecosystem is given on these maps. The ecological geological prognosis maps reflect the spatial-temporary prognoses of ecological geological conditions changing during the natural dynamic of natural surrounding and the main-during the economic mastering of territory and natural technical systems. Finally, the ecological geological recommendation maps are based on the ecological geological and social-economical informations, aiming the regulation of territory by the regulation of economic activities and the defense of bio- and socio-sphere extents. Each of these maps may also be computed or in analytic or in synthetic way. The first, characterized or estimated, prognosticated one or several indexes of geological ecological conditions. In the second type of maps, the whole complex is reflected, which defined the modern or prognosticable ecological geological situation. Regarding the ecological geological zoning maps, the contemporary state of ecological geological conditions may be evaluated by a range of parameters into classes of conditions and, on the basis of these informations, the estimation from the position of comfort and safety of human life and function of ecosystem is given. Otherwise, the concept of geoecological land evaluation has become established in the study of landscape/environmental plannings in recent years. It requires different thematic data-sets, deriving from the natural-, social- and amenity-environmental resources analysis, that may be translate in environmental (vulnerability/quality) indexes. There have been some attempts to develop integrated indices related to various aspects of the environment within the framework of sustainable development (e.g.: United Nations Commission on Sustainable Development, World Economic Forum, Advisory Board on Indicators of Sustainable Development of the International Institute for Sustainable Development, Living Planet Index established by the World Wide Fund for Nature, etc.). So, the ecological geological maps represent the basic tool for the geoecological land evaluation policies and may be computed in terms of index-maps. On these basis, a GIS application for assessing the ecological geological zoning is presented for Sicily (Central Mediterranean). The Geo-Ecological Quality Index (GEQUI) map was computed by considering a lot of variables. Ten variables (lithology, climate, landslide distribution, erosion rate, soil type, land cover, habitat, groundwater pollution, roads density and buildings density) generated from available data, were used in the model, in which weighting values to each informative layer were assigned. An overlay analysis was carried out, allowing to classify the region into five classes

Nigro, Fabrizio; Arisco, Giuseppe; Perricone, Marcella; Renda, Pietro; Favara, Rocco

2010-05-01

337

Comparative gene expression supports the origin of the incisor and molar process from a single endite in the mandible of the red flour beetle Tribolium castaneum  

PubMed Central

Background The biting edge of the primitive arthropod mandible consists of a biting incisor process and a crushing molar process. These structures are thought to be derived from a structure known as an endite but the precise details of this are not understood. Various hypotheses concerning the number of endites present in the arthropod mandible have been proposed. In the developing embryo, the mandible has an inner and outer lobe that are likely to develop into the incisor and molar processes of the larval mandible; these two lobes are commonly held to be derived from separate endites and to be serially homologous to the galea and lacinia endites of the maxillary appendage respectively (Machida). Results We undertook a study of the development of the embryonic mandible of the beetle Tribolium castaneum using the expression of developmental genes as markers of the developing endites in the mandible and maxilla. The Tribolium ortholog of paired (Tc-prd) has expression domains in the developing maxillary and labial endites as well as the inner and outer lobes of the mandible. Following the expression of Tc-prd in the developing mandible through to late stage embryos shows that the molar and incisor process develop from the inner and outer lobes respectively. In addition to Tc-prd, we compared the expression of genes in the endites of the maxilla to the mandible to draw conclusions about the number of endites in the mandible. Homologs of dachshund are typically expressed in the endites of mandibulate gnathal appendages. Comparison of the expression of Tc-prd, Tribolium dachshund (Tc-dac) and Tribolium wingless (Tc-wg) between the endites of the maxilla and the mandible suggest that, while there are two endites in the maxilla only a single endite is present in the mandible. Conclusions Comparative gene expression suggests that the Tribolium mandible has a single endite from which both mandible lobes are derived. Our results do not support Machida’s hypothesis homologising the incisor and molar processes of the mandible to the galea and lacinia endites of the maxilla. We propose, instead, that both incisor and molar processes are derived from a single endite serially homologous to the lacinia of the maxilla.

2013-01-01

338

Measuring rodent incisors from scats can increase accuracy of predator diet studies. An illustration based on island cats and rats  

Microsoft Academic Search

Non-invasive diet studies, which are a simple but important tool to understand trophic interactions inside ecosystems, need to be as detailed as possible. Determining the precise biomass of ingested prey is a key to obtaining not only a better understanding of the amount of food really ingested but also the predator-prey interactions. It is particularly relevant in the case of

Elsa Bonnaud; Eric Vidal; Diane Zarzoso-Lacoste; Franck Torre

2008-01-01

339

Closeness Centrality on BBS Reply Network  

Microsoft Academic Search

In this paper, a reply network was constructed with the data downloaded from SINA BBS. Based on the complex network theory, we firstly studied the node closeness centrality and graph closeness centralization of the reply network, and analyzed the influence of the central figure in reply network by studying the node closeness centrality. The leadership of the central figure was

Ke Zhang; Hui Li; Lijuan Qin; Min Wu

2011-01-01

340

Study on Corporate Hereditary Central Dogma  

Microsoft Academic Search

Based on analyzing the central dogma of biology, this paper raises hypothesis, using the analogism method to set up the corporate hereditary central dogma. It analyzes the differences between the Corporate hereditary central dogma and the central dogma of biology, which explains the significance of research on Corporate hereditary central dogma; it discusses the meanings of all factors of Corporate

Li Xianbai

2010-01-01

341

Estimation of Recurrence Interval of Large Earthquakes on the Central Longmen Shan Fault Zone Based on Seismic Moment Accumulation/Release Model  

PubMed Central

Recurrence interval of large earthquake on an active fault zone is an important parameter in assessing seismic hazard. The 2008 Wenchuan earthquake (Mw 7.9) occurred on the central Longmen Shan fault zone and ruptured the Yingxiu-Beichuan fault (YBF) and the Guanxian-Jiangyou fault (GJF). However, there is a considerable discrepancy among recurrence intervals of large earthquake in preseismic and postseismic estimates based on slip rate and paleoseismologic results. Post-seismic trenches showed that the central Longmen Shan fault zone probably undertakes an event similar to the 2008 quake, suggesting a characteristic earthquake model. In this paper, we use the published seismogenic model of the 2008 earthquake based on Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) data and construct a characteristic seismic moment accumulation/release model to estimate recurrence interval of large earthquakes on the central Longmen Shan fault zone. Our results show that the seismogenic zone accommodates a moment rate of (2.7?±?0.3)?×?1017?N?m/yr, and a recurrence interval of 3900?±?400?yrs is necessary for accumulation of strain energy equivalent to the 2008 earthquake. This study provides a preferred interval estimation of large earthquakes for seismic hazard analysis in the Longmen Shan region.

Zhang, Shimin

2013-01-01

342

Estimation of recurrence interval of large earthquakes on the central Longmen Shan fault zone based on seismic moment accumulation/release model.  

PubMed

Recurrence interval of large earthquake on an active fault zone is an important parameter in assessing seismic hazard. The 2008 Wenchuan earthquake (Mw 7.9) occurred on the central Longmen Shan fault zone and ruptured the Yingxiu-Beichuan fault (YBF) and the Guanxian-Jiangyou fault (GJF). However, there is a considerable discrepancy among recurrence intervals of large earthquake in preseismic and postseismic estimates based on slip rate and paleoseismologic results. Post-seismic trenches showed that the central Longmen Shan fault zone probably undertakes an event similar to the 2008 quake, suggesting a characteristic earthquake model. In this paper, we use the published seismogenic model of the 2008 earthquake based on Global Positioning System (GPS) and Interferometric Synthetic Aperture Radar (InSAR) data and construct a characteristic seismic moment accumulation/release model to estimate recurrence interval of large earthquakes on the central Longmen Shan fault zone. Our results show that the seismogenic zone accommodates a moment rate of (2.7?±?0.3)?×?10¹??N?m/yr, and a recurrence interval of 3900?±?400?yrs is necessary for accumulation of strain energy equivalent to the 2008 earthquake. This study provides a preferred interval estimation of large earthquakes for seismic hazard analysis in the Longmen Shan region. PMID:23878524

Ren, Junjie; Zhang, Shimin

2013-06-26

343

A New PCR-Based Approach Indicates the Range of Clonorchis sinensis Now Extends to Central Thailand  

PubMed Central

Differentiation of the fish-borne trematodes belonging to the Opisthorchiidae, Heterophyidae and Lecithodendriidae is important from a clinical and epidemiological perspective, yet it is impossible to do using conventional coprological techniques, as the eggs are morphologically similar. Epidemiological investigation therefore currently relies on morphological examination of adult worms following expulsion chemotherapy. A PCR test capable of amplifying a segment of the internal transcribed spacer region of ribosomal DNA for the opisthorchiid and heterophyid flukes eggs taken directly from faeces was developed and evaluated in a rural community in central Thailand. The lowest quantity of DNA that could be amplified from individual adults of Opisthorchis viverrini, Clonorchis sinensis and Haplorchis taichui was estimated at 0.6 pg, 0.8 pg and 3 pg, respectively. The PCR was capable of detecting mixed infection with the aforementioned species of flukes under experimental conditions. A total of 11.6% of individuals in rural communities in Sanamchaikaet district, central Thailand, were positive for ‘Opisthorchis-like’ eggs in their faeces using conventional parasitological detection techniques. In comparison to microscopy, the PCR yielded a sensitivity and specificity of 71.0% and 76.7%, respectively. Analysis of the microscopy-positive PCR products revealed 64% and 23% of individuals to be infected with O. viverrini and C. sinensis, respectively. The remaining 13% (three individuals) were identified as eggs of Didymozoidae, presumably being passed mechanically in the faeces following the ingestion of infected fishes. An immediate finding of this study is the identification and first report of a C. sinensis–endemic community in central Thailand. This extends the known range of this liver fluke in Southeast Asia. The PCR developed herein provides an important tool for the specific identification of liver and intestinal fluke species for future epidemiological surveys.

Traub, Rebecca J.; Macaranas, Julie; Mungthin, Mathirut; Leelayoova, Saovanee; Cribb, Thomas; Murrell, K. Darwin; Thompson, R. C. Andrew

2009-01-01

344

A new permanent multi-parameter monitoring network in Central Asian high mountains - from measurements to data bases  

NASA Astrophysics Data System (ADS)

Long-term monitoring of water resources and climate parameters at the scale of river basins requires networks of continuously operated in-situ stations. Since 2009, GFZ and CAIAG, in cooperation with the National Hydrometeorological Services (NHMS), are establishing such a regional monitoring network in Central Asia (Kazakhstan, Kyrgyzstan, Tajikistan, Uzbekistan, and Afghanistan) which is collecting observations of meteorological and hydrological parameters and delivering them to the end-users. The network design focuses mainly on the higher elevations where the recent decline of monitoring stations and networks established in Soviet times was strongest, and the resulting observational gap hinders research on climate and hydrological change as well as operational tasks in water management such as the seasonal runoff forecast. The newly developed and installed Remotely Operated Multi-Parameter Stations (ROMPS) do not only monitor standard meteorological and hydrological parameters, but also deliver GPS data for atmospheric sounding as well as tectonic studies. The observational data from the ROMPS is transmitted at least once a day to a centralized geo-database infrastructure for long-term storage and data redistribution. Users can access the data manually using a web-interface or automatically using SOS requests; in addition, data is distributed to the NHMS through standard communication and data exchange channels.

Schöne, T.; Zech, C.; Unger-Shayesteh, K.; Rudenko, V.; Thoss, H.; Wetzel, H.-U.; Zubovich, A.

2012-06-01

345

A new permanent multi-parameter monitoring network in Central Asian high mountains - from measurements to data bases  

NASA Astrophysics Data System (ADS)

Long-term monitoring of water resources and climate parameters at the scale of river basins requires networks of continuously operated in-situ stations. Since 2009, GFZ and CAIAG, in cooperation with the National Hydrometeorological Services (NHMS) of Central Asia, are establishing such a regional monitoring network in Kazakhstan, Kyrgyzstan, Tajikistan, Uzbekistan, and lately Afghanistan to collect observations of meteorological and hydrological parameters and to deliver them to the end-users for operational tasks and scientific studies. The newly developed and installed remotely operated multi-parameter stations (ROMPS) do not only monitor standard meteorological and hydrological parameters, but also deliver Global Navigation Satellite System (GNSS) data for atmospheric sounding as well as tectonic studies. Additionally, three stations integrate seismic sensors for earthquake monitoring. The observational data from the ROMPS is transmitted nominally in near-real time, but at least once a day to a centralized geo-database infrastructure for long-term storage and data redistribution. Users can access the data manually using a web-interface or automatically using SOS requests; in addition, data is planed to be distributed to the NHMS through standard communication and data exchange channels.

Schöne, T.; Zech, C.; Unger-Shayesteh, K.; Rudenko, V.; Thoss, H.; Wetzel, H.-U.; Gafurov, A.; Illigner, J.; Zubovich, A.

2013-02-01

346

Timing of deglaciation of the Gotthard Pass area, Central Swiss Alps, based on surface exposure dating with cosmogenic 10Be  

NASA Astrophysics Data System (ADS)

Mapping of glacial trimlines in the Central Swiss Alps showed the existence of two ice domes during the Last Glacial Maximum (LGM), one in the upper Rhone catchment and one in the upper Rhine catchment [1]. Between these ice domes there was an area of major ice accumulation and through-flow at the Urseren Valley. Ice from the Rhone glacier flowed down westward along the Rhone Valley but also eastward over Furka Pass towards the Urseren area. In an LGM-paleoglaciation model Gotthard Pass is a central corridor (pathway) for mass transport from north to south. Highly polished granitic rocks, crescentic gouges and other small scale glacial erosional features show that ice flowed southward from the Urseren area over the Gotthard Pass (2106 m a.s.l.) towards the Leventina Valley and the Ticino glacier. This is also shown by the continuous decrease of the trimline elevation from north to south, from about 2600 m at the Gotthard Pass to about 2500 m in the Leventina Valley. In the pass a minimum ice thickness of 480-500 m was calculated [1]. We apply surface exposure dating using cosmogenic 10Be to determine when the southward ice flow over Gotthard Pass ceased. This will show when the elevation of ice in the Urseren accumulation area was lower than the Gotthard Pass. We will present surface exposure ages from different altitudes sampled along a transect at the western Pass area. This data will be compared to exposure ages from the nearby Grimsel Pass that indicate that this Pass was ice free no later than ~14 ka BP [2]. Radiocarbon data from the Rhone Valley also suggest a deglaciation by 14 590-14 020 cal. yr BP [3]. Only slightly older (~15 000-14 300 cal. yr BP) are radiocarbon ages from the Simplon Pass [4]. Our data will be discussed within the scope of the collapse of the LGM ice domes in the Central Swiss Alps and the timing of the initial Alpine catastrophic deglaciation after the LGM. References: [1] Florineth & Schlüchter (1998), Eclogae geol. Helv. 91, 391-407. [2] Kelly et al. (2006), Boreas 35, 634-643. [3] Welten (1982), Denkschrift Schw. Naturforsch. Ges. 95, 105 pp. [4] Müller (1984), Küng: Näfels, 205 pp.

Hippe, Kristina; Ivy-Ochs, Susan; Kober, Florian; Wieler, Rainer; Schlüchter, Christian

2010-05-01

347

Replantation of 400 avulsed permanent incisors. 4. Factors related to periodontal ligament healing.  

PubMed

400 avulsed and replanted permanent teeth were examined for periodontal ligament (PDL) healing, using standardized radiographic and clinical examination procedures (i.e. percussion test and mobility test). The effect of various clinical factors was examined, such as age and sex of the patient, type of tooth replanted, presence of crown fracture or bone fracture, stage of root development (including apical diameter and length of the pulp), type and length of extra-alveolar storage, clinical contamination of the root surface, type of root surface cleansing procedure, type and length of splinting period and antibiotic therapy. Surface resorption was generally diagnosed after 12 months; while inflammatory resorption and replacement resorption (ankylosis) were usually observed after 1 month and 1-2 months respectively. Most resorptive processes were diagnosed within the first 2-3 years. However, although rarely, even after 5 and 10 years new resorptive processes could be diagnosed. A univariate statistical analysis of 272 teeth revealed 9 factors significantly related to PDL healing. A subsequent multivariate analysis revealed that the following 4 factors had the strongest impact upon PDL healing, in descending order of significance: Stage of root development; length of the dry extra-alveolar storage period; immediate replantation and length of the wet period (saliva or saline storage). Nonphysiological storage, such as homemade saline and sterilizing solutions (chloramine and alcohol) always led to root resorption. Storage in tap water for more than 20 minutes usually led to root resorption. The common denominator for all these factors related to PDL healing appears to be survival of the PDL cells along the root surface. Based on these findings, immediate replantation is recommended irrespective of stage of root development. PMID:7641622

Andreasen, J O; Borum, M K; Jacobsen, H L; Andreasen, F M

1995-04-01

348

Effects of seasonal variability in across- and alongshore transport of anchoveta (Engraulis ringens) larvae on model-based pre-recruitment indices off central Chile  

NASA Astrophysics Data System (ADS)

An individual-based model (IBM) of anchoveta (Engraulis ringens) larvae was coupled to a climatological hydrodynamic (Regional Oceanic Modeling System, ROMS) model for central-southern Chile to answer the question as to whether or not across- and alongshore transport off central-southern Chile enhances retention in the spawning areas during the winter and summer reproductive periods, using model-based pre-recruitment indices (simulated transport success to nursery areas). The hydrodynamic model validation showed that ROMS captures the mean Seas Surface Temperature and Eddie Kinetic Energy observed in satellite-based data over the entire region. The IBM was used to simulate the transport of eggs and larvae from spawning zones in central Chile (Constitución, Dichato, Gulf of Arauco and Lebu-Corral) to historical nursery areas (HRZ, region between 35°S and 37°S). Model results corroborated HRZ as the most successful pre-recruitment zone (particles originated in the Dichato and Gulf of Arauco spawning areas), as well as identifying Lebu-Corral as a zone of high retention with a high associated pre-recruitment index (particles originated in the Lebu-Corral spawning zone). The highest pre-recruitment values were mainly found in winter. The Constitución and Dichato spawning zones displayed a typical summer upwelling velocity pattern, while the Gulf of Arauco in summertime showed strong offshore and alongshore velocity components. The Lebu-Corral region in winter presented important near-surface cross-shore transport towards the coast (associated with downwelling events), this might be one of the major mechanisms leading to high retention levels and a high pre-recruitment index for Lebu-Corral spawning zone. The limitations of the modeling approach are discussed and put into perspective for future work.

Parada, Carolina; Colas, Francois; Soto-Mendoza, Samuel; Castro, Leonardo

2012-01-01

349

Speed and eccentricity tuning reveal a central role for the velocity-based cue to 3D visual motion.  

PubMed

Two binocular cues are thought to underlie the visual perception of three-dimensional (3D) motion: a disparity-based cue, which relies on changes in disparity over time, and a velocity-based cue, which relies on interocular velocity differences. The respective building blocks of these cues, instantaneous disparity and retinal motion, exhibit very distinct spatial and temporal signatures. Although these two cues are synchronous in naturally moving objects, disparity-based and velocity-based mechanisms can be dissociated experimentally. We therefore investigated how the relative contributions of these two cues change across a range of viewing conditions. We measured direction-discrimination sensitivity for motion though depth across a wide range of eccentricities and speeds for disparity-based stimuli, velocity-based stimuli, and "full cue" stimuli containing both changing disparities and interocular velocity differences. Surprisingly, the pattern of sensitivity for velocity-based stimuli was nearly identical to that for full cue stimuli across the entire extent of the measured spatiotemporal surface and both were clearly distinct from those for the disparity-based stimuli. These results suggest that for direction discrimination outside the fovea, 3D motion perception primarily relies on the velocity-based cue with little, if any, contribution from the disparity-based cue. PMID:20881201

Czuba, Thaddeus B; Rokers, Bas; Huk, Alexander C; Cormack, Lawrence K

2010-09-29

350

Evolutionary Relationships of the Triatoma matogrossensis Subcomplex, the Endemic Triatoma in Central-Western Brazil, Based on Mitochondrial DNA Sequences.  

PubMed

Abstract. The phylogenetic relationships among species of Triatoma matogrossensis subcomplex (T. baratai, T. guazu, T. matogrossensis, T. sordida, T. vandae, and T. williami) was addressed by using fragments of cytochrome oxidase I (COI), 16S rDNA (16S), and cytochrome b (Cytb) through Bayesian and parsimony analyses. We did not recover a monophyletic T. matogrossensis subcomplex, and their members were found clustered in three strongly supported clades, as follows: i) T. jurbergi + T. matogrossensis + T. vandae + T. garciabesi + T. sordida; ii) with T. guasayana as the sister group of clade (i); and iii) T. williami + T. guazu, however not closely related to the clade formed by the previously mentioned species. The other two endemic species from Central-Western Brazil, T. baratai and T. costalimai, were not recovered with strong clade support as related to other members of this subcomplex. Results call for a further revision in the classification of the subcomplexes within the genus Triatoma. PMID:24002487

Gardim, Sueli; Rocha, Cláudia S; Almeida, Carlos E; Takiya, Daniela M; da Silva, Marco T A; Ambrósio, Daniela L; Cicarelli, Regina M B; da Rosa, João A

2013-09-03

351

Glacial-eustatic sea-level fluctuation curve for Carboniferous-Permian boundary strata based on outcrops in the North American Midcontinent and North-Central Texas  

SciTech Connect

Based on lithologic and faunal analysis of uppermost Carboniferous through Lower Permian strata (Wabaunsee through lower Chase groups) exposed from southeastern Nebraska through north-central Oklahoma, a preliminary glacial-eustatic sea-level fluctuation curve is presented herein. In addition to the sea-level curve presented for the Midcontinent region, one for coeval outcropping strata (middle and upper Cisco Group) of the Eastern Shelf of the Midland Basin is also presented based on similar criteria. This sea-level curve is derived from new field studies as well as a refinement of earlier curves presented by Harrison (1973), and Boardman and Malinky (1985). The conclusion on the nature of the Carboniferous-Permian boundary strata cyclothems in the Midcontinent is mirrored by the results of that from North-Central Texas. Each of the primary biostratigraphically-based picks for the Carboniferous-Permian boundary coincide with either intermediate of major cycles in both study areas. Utilization of a glacial-eustatic maximum transgressive event for the Carboniferous-Permian boundary should result in a more correlatable level for intercontinental correlation.

Boardman, D.R. (Oklahoma State Univ., Stillwater, OK (United States). School of Geology)

1993-02-01

352

Discrepant Prevalence and Incidence of Leishmania Infection between Two Neighboring Villages in Central Mali Based on Leishmanin Skin Test Surveys  

PubMed Central

Apart from a single report, the last publication of cutaneous leishmaniasis (CL) in Mali dates back more than 20 years. The absence of information on the current status of CL in Mali led us to conduct a cohort study in Kemena and Sougoula, two villages in Central Mali from which cases of CL have been recently diagnosed by Mali's reference dermatology center in Bamako. In May 2006, we determined the baseline prevalence of Leishmania infection in the two villages using the leishmanin skin test (LST). LST-negative individuals were then re-tested over two consecutive years to estimate the annual incidence of Leishmania infection. The prevalence of Leishmania infection was significantly higher in Kemena than in Sougoula (45.4% vs. 19.9%; OR: 3.36, CI: 2.66–4.18). The annual incidence of Leishmania infection was also significantly higher in Kemena (18.5% and 17% for 2007 and 2008, respectively) than in Sougoula (5.7% for both years). These data demonstrate that the risk of Leishmania infection was stable in both villages and confirm the initial observation of a significantly higher risk of infection in Kemena (OR: 3.78; CI: 2.45–6.18 in 2007; and OR: 3.36; CI: 1.95–5.8 in 2008; P<0.005). The absence of spatial clustering of LST-positive individuals in both villages indicated that transmission may be occurring anywhere within the villages. Although Kemena and Sougoula are only 5 km apart and share epidemiologic characteristics such as stable transmission and random distribution of LST-positive individuals, they differ markedly in the prevalence and annual incidence of Leishmania infection. Here we establish ongoing transmission of Leishmania in Kemena and Sougoula, Central Mali, and are currently investigating the underlying factors that may be responsible for the discrepant infection rates we observed between them. Trial Registration ClinicalTrials.gov NCT00344084

Anderson, Jennifer M.; Faye, Ousmane; Diarra, Souleymane S.; Traore, Pierre; Cisse, Moumine; Camara, Guimba; Tall, Koureissi; Coulibaly, Cheick A.; Samake, Sibiry; Sissoko, Ibrahim; Traore, Bourama; Diallo, Daouda; Keita, Somita; Fairhurst, Rick M.; Valenzuela, Jesus G.; Kamhawi, Shaden

2009-01-01

353

A mathematical model to design a lignocellulosic biofuel supply chain system with a case study based on a region in Central Texas.  

PubMed

This study formulates a model to maximize the profit of a lignocellulosic biofuel supply chain ranging from feedstock suppliers to biofuel customers. The model deals with a time-staged, multi-commodity, production/distribution system, prescribing facility locations and capacities, technologies, and material flows. A case study based on a region in Central Texas demonstrates application of the proposed model to design the most profitable biofuel supply chain under each of several scenarios. A sensitivity analysis identifies that ethanol (ETOH) price is the most significant factor in the economic viability of a lignocellulosic biofuel supply chain. PMID:21724388

An, Heungjo; Wilhelm, Wilbert E; Searcy, Stephen W

2011-06-13

354

Experiences from near-real-time satellite-based volcano monitoring in Central America: case studies at Fuego, Guatemala  

Microsoft Academic Search

Over the past decade, remote sensing has been used increasingly in the study of active volcanoes and their associated hazards. Ground?based remote sensing techniques, such as those aimed at the analysis of volcanic gases or fumarole temperatures, are now part of routine monitoring operations with additional satellite?based remote sensing methods. It is likely that the use of satellite?based systems will

P. W. Webley; M. J. Wooster; W. Strauch; J. A. Saballos; K. Dill; P. Stephenson; J. Stephenson; R. Escobar Wolf; O. Matias

2008-01-01

355

ATE Central  

NSDL National Science Digital Library

ATE Central is a freely available online portal and collection of materials and services that highlight the work of the Advanced Technological Education (ATE) projects and centers. These National Science Foundation funded initiatives work with educators from two-year colleges to develop and implement ideas for improving the skills of technicians and the educators who teach them. ATE Central is designed to help educators, students, and the general public to learn about, and use materials from, the entire depth and breadth of the Advanced Technological Education program.ATE Central helps direct users to a full range of high-impact ATE resources available online, including curricula, learning objects, and podcasts. The portal aggregates information about the materials developed by ATE centers and projects, and organizes them using subject taxonomies, context appropriate keywords, and other digital cataloging techniques.

2011-08-17

356

Cardiothoracic anesthesia, respiration and airway modified mallampati test, thyromental distance and inter-incisor gap are the best predictors of difficult laryngoscopy in West Africans  

Microsoft Academic Search

\\u000a Abstract\\u000a Purpose  To determine the ability to predict difficult visualization of the larynx (DVL) from the following preoperative airway predictive\\u000a indices, in isolation and combination: modified Mallampati test (MMT), thyromental distance (TMD), sternomental distance (SMD),\\u000a horizontal length of the mandible (HLM) and inter-incisor gap(IIG).\\u000a \\u000a \\u000a \\u000a Methods  Three hundred and eighty consecutive patients undergoing general anesthesia were evaluated using the MMT, TMD, SMD, HLM

Nkihu A. Merah; David T. Wong; Dorothy J. Ffoulkes-Crabbe FRCA; Olusola T. Kushimo; Christopher O. Bode

2005-01-01

357

Internal tectonic structure of the Central American Wadati-Benioff zone based on analysis of aftershock sequences  

NASA Astrophysics Data System (ADS)

Relocated Engdahl et al. (1998) global seismological data for 10 aftershock sequences were used to analyze the internal tectonic structure of the Central American subduction zone; the main shocks of several of these were the most destructive and often referenced earthquakes in the region (e.g., the 1970 Chiapas, 1983 Osa, 1992 Nicaragua, 1999 Quepos, 2001 El Salvador earthquakes). The spatial analysis of aftershock foci distribution was performed in a rotated Cartesian coordinate system (x, y, z) related to the Wadati-Benioff zone, and not in a standard coordinate system ($\\varphi$, ?, h are latitude, longitude, focal depth, respectively). Available fault plane solutions were also transformed into the plane approximating the Wadati-Benioff zone. The spatial distribution of earthquakes in each aftershock sequence was modeled as either a plane fit using a least squares approximation or a volume fit with a minimum thickness rectangular box. The analysis points to a quasi-planar distribution of earthquake foci in all aftershock sequences, manifesting the appurtenance of aftershocks to fracture zones. Geometrical parameters of fracture zones (strike, dip, and dimensions) hosting individual sequences were calculated and compared with the seafloor morphology of the Cocos Plate. The smooth character of the seafloor correlates with the aftershock fracture zones oriented parallel to the trench and commonly subparallel to the subducting slab, whereas subduction of the Cocos Ridge and seamounts around the Quepos Plateau coincides with steeply dipping fracture zones. Transformed focal mechanisms are almost exclusively (>90%) of normal character.

Špi?ák, Aleš; Hanuš, Václav; Van?k, Ji?í; B?hounková, Marie

2007-09-01

358

Long-term earthquake prediction along the western coast of South and Central America based on a time predictable model  

NASA Astrophysics Data System (ADS)

The repeat times, T, of strong shallow mainshocks in fourteen seismogenic sources along the western coast of South and Central America have been determined and used in an attempt at long-term forecasting. The following relation was determined: 24_2004_Article_BF00879409_TeX2GIFE1.gif log T = 0.22M_{min } + 0.21M_p + a between the repeat time, T, and the magnitudes, M min, of the minimum mainshock considered and M p , of the preceding mainshock. No dependence of the magnitude, M f , of the following mainshock on the preceding intervent time, T, was found. These results support the idea that the time-predictable model is valid for this region. This is an interesting property for earthquake prediction since it provides the ability to predict the time of occurrence of the next strong earthquake. A strong negative dependence of M f on M p was found, indicating that a large mainshock is followed by a smaller magnitude one, and vice versa. The probability for the occurrence of the expected strong mainshocks ( M s ?7.5) in each of the fourteen seismogenic sources during the next 10 years (1992 2002) is estimated, adopting a lognormal distribution for earthquake interevent times. High probabilities ( P 10>0.80) have been calculated for the seismogenic sources of Oaxaca, Chiapas and Southern Peru.

Papadimitriou, Eleftheria E.

1993-06-01

359

Internal tectonic structure of the Central American Wadati-Benioff zone based on analysis of aftershock sequences  

NASA Astrophysics Data System (ADS)

Relocated Engdahl et al. (1998) global seismological data for 10 aftershock sequences were used to analyze the internal tectonic structure of the Central American subduction zone; the main shocks of several of these were the most destructive and often referenced earthquakes in the region (e.g., the 1970 Chiapas, 1983 Osa, 1992 Nicaragua, 1999 Quepos, 2001 El Salvador earthquakes). The spatial analysis of aftershock foci distribution was performed in a rotated Cartesian coordinate system (x, y, z) related to the Wadati-Benioff zone, and not in a standard coordinate system (?, ?, h are latitude, longitude, focal depth, respectively). Available fault plane solutions were also transformed into the plane approximating the Wadati-Benioff zone. The spatial distribution of earthquakes in each aftershock sequence was modeled as either a plane fit using a least squares approximation or a volume fit with a minimum thickness rectangular box. The analysis points to a quasi-planar distribution of earthquake foci in all aftershock sequences, manifesting the appurtenance of aftershocks to fracture zones. Geometrical parameters of fracture zones (strike, dip, and dimensions) hosting individual sequences were calculated and compared with the seafloor morphology of the Cocos Plate. The smooth character of the seafloor correlates with the aftershock fracture zones oriented parallel to the trench and commonly subparallel to the subducting slab, whereas subduction of the Cocos Ridge and seamounts around the Quepos Plateau coincides with steeply dipping fracture zones. Transformed focal mechanisms are almost exclusively (>90%) of normal character.

Å Pi?áK, Aleš; Hanuš, VáClav; Van?K, Ji?Ã.­; B?Hounková, Marie

2007-09-01

360

Community-based study on knowledge, attitudes and perception of rabies in Gelephu, south-central Bhutan.  

PubMed

Community knowledge, attitudes and practices are important both for prevention of human deaths due to rabies and for control of the disease in animals. This study was a cross-sectional survey investigating the level of community knowledge as well as attitudes and perceptions about rabies in Gelephu, south-central Bhutan, a region endemic for rabies. A total of 615 household respondents were interviewed, of which 224 (36%) were male and 391 (64%) were female. The majority of respondents had a high level of knowledge, attitudes and perception of rabies and had a positive attitude towards the prevention and control of rabies. Multivariate logistic regression modelling showed that better knowledge of rabies was predicted by gender, educational level and dog ownership status of respondents, whilst health-seeking behaviour of animal bite injuries was predicted by dog ownership status, presence of children in the household and occupation of the respondents. The majority of respondents believed that stray dogs are a problem in the community and felt that it was important to control the dog population in Gelephu. These findings also indicate that there exists a knowledge gap about rabies in the community that could be improved by creating an awareness education programme. PMID:24029402

Tenzin; Dhand, Navneet K; Rai, Bir Doj; Changlo; Tenzin, Sangay; Tsheten, Karma; Ugyen, Pema; Singye, Karma; Ward, Michael P

2012-09-01

361

The impact of primary central nervous system lymphoma in AIDS patients: a population-based autopsy study from Oslo.  

PubMed

This study comprises the 255 adult AIDS patients treated at Ullevål hospital 1983-1995. These patients, fulfilling the Centers of Disease Control (CDC) clinical criteria for AIDS, correspond to 91% of all adult AIDS cases in Oslo. By the end of the study period, 44 patients were alive and 211 had died. Full autopsy was performed on 153 (73%) of the deceased. Supplementary analyses were carried out on the 344 patients (225 deceased) fulfilling the U.S. definition of AIDS, which includes CD4 cell counts below 200 cells/mm3. In the autopsy group, histologically verified non-Hodgkin B-cell lymphoma was found in 29 cases (19%). Nineteen of these (12%) had primary central nervous system (PCNS) lymphoma. Survival curves indicate that PCNS lymphoma constitutes a small risk early in the AIDS stage, but it has a serious impact on long-term survival. For patients not contracting other fatal diseases, one fourth are estimated to die of PCNS lymphoma within about 3 years. Comparison of clinical diagnoses and autopsy results show that PCNS lymphoma has been difficult to separate from other CNS disorders, which probably has caused marked underestimation of the incidence in previous assessments. We conclude that PCNS lymphoma is a major threat to long-term survival in AIDS victims. PMID:9111477

Goplen, A K; Dunlop, O; Liestøl, K; Lingjaerde, O C; Bruun, J N; Maehlen, J

1997-04-01

362

Moho structure of Central America based on three-dimensional lithospheric density modelling of satellite-derived gravity data  

NASA Astrophysics Data System (ADS)

The Central American isthmus hosts a highly variable Moho structure due to the diverse origin and composition of the crustal basement and the influence of large-scale neotectonic processes. Gravity data from the combined geopotential model EGM2008 were interpreted via forward modelling to outline the three-dimensional lithospheric density structure along the Middle American Trench, as well as the segmentation of the oceanic Cocos and Nazca plates and the overriding Caribbean plate. In this work, results for the depth of the Moho obtained from the density model are presented. The Quaternary volcanic arc correlates with a maximum Moho depth of 44 km in western Guatemala. To the south-east of the continental shelf, the Caribbean plate shows Moho depths between 20 and 12 km whereas to the north, values as shallow as 8 km are observed at the Cayman trough. For the oceanic Cocos plate, depths between 16 and 21 km are obtained for the Moho along the Cocos ridge, contrasting with values between 15 and 12 km for the seamount segment and 8 and 11 km for the segments of the crust that are not affected by the Galapagos hot-spot track.

Lücke, Oscar H.

2012-05-01

363

An economic feasibility analysis of distributed electric power generation based upon the natural gas-fired fuel cell: a model of a central utility plant.  

SciTech Connect

This central utilities plant model details the major elements of a central utilities plant for several classes of users. The model enables the analyst to select optional, cost effective, plant features that are appropriate to a fuel cell application. These features permit the future plant owner to exploit all of the energy produced by the fuel cell, thereby reducing the total cost of ownership. The model further affords the analyst an opportunity to identify avoided costs of the fuel cell-based power plant. This definition establishes the performance and capacity information, appropriate to the class of user, to support the capital cost model and the feasibility analysis. It is detailed only to the depth required to identify the major elements of a fuel cell-based system. The model permits the choice of system features that would be suitable for a large condominium complex or a residential institution such as a hotel, boarding school or prison. The user may also select large office buildings that are characterized by 12 to 16 hours per day of operation or industrial users with a steady demand for thermal and electrical energy around the clock.

Not Available

1993-06-30

364

Notes From the Field: Learning Cultural Humility Through Critical Incidents and Central Challenges in Community-Based Participatory Research  

Microsoft Academic Search

Cultural humility is critical in the education of community development and planning graduate students because they often work with communities—geographic and\\/or identity based—where there is a power differential based on privileges of race, income, and education. Cultural humility requires commitment to ongoing self-reflection and self-critique, particularly identifying and examining one's own patterns of unintentional and intentional racism (Israel, Eng, Schulz,

Laurie Ross

2010-01-01

365

Halloween Central  

NSDL National Science Digital Library

Halloween is coming up, and this site will help readers prepare for an evening of ghouls, goblins, and other nasties. Halloween Central is a fairly extensive metasite with links to a wide variety of Halloween resources, including costumes, clip art, recipes, haunted houses, Halloween safety, and pumpkins, among many others.

366

Seismic properties of the upper crust in the central Friuli area (northeastern Italy) based on petrophysical data  

NASA Astrophysics Data System (ADS)

The compressional and shear wave velocities have been measured at room temperature and pressure up to 450 MPa on 5 sedimentary rock samples, representative of the most common lithologies of the upper crust in the central Friuli area (northeastern Italy). At 400 MPa confining pressure the Triassic dolomitic rock shows the highest velocities (Vp ˜ 7 km/s, Vs ˜ 3.6 km/s), the Jurassic and Triassic limestones samples intermediate velocities (Vp ˜ 6.3 /s, Vs ˜ 3.5 km/s) and the Cenozoic and Paleozoic sandstones the lowest velocities (Vp ˜ 6.15 km/s, Vs ˜ 3.35 km/s). The Paleozoic sandstone sample is characterized by the strongest anisotropy (10%) and significant birefringence (0.2 km/s) is found only on the Cenozoic sandstone sample. We elaborated the synthetic profiles of seismic velocities, density, elastic parameters and reflection coefficient, related to 4 one-dimensional geological models extended up to 22 km depth. The synthetic profiles evidence high rheological contrasts between Triassic dolomitic rocks and the soft sandstones and the Jurassic limestones. The Vp profiles obtained from laboratory measurements match very well the in-situ Vp profile measured by sonic log for the limestones and dolomitic rocks, supporting our one-dimensional modelling of the calcareous-carbonatic stratigraphic series. The Vp and Vs values of the synthetic profiles are compared with the corresponding ones obtained from the 3-D tomographic inversion of local earthquakes. The laboratory Vp are generally higher than the tomographic ones with major discrepancies for the dolomitic lithology. The comparison with the depth location of seismicity reveals that the seismic energy is mainly released in correspondence of high-contrast rheological boundaries.

Faccenda, M.; Bressan, G.; Burlini, L.

2007-12-01

367

A centralized condition monitoring system for MV power cables based on on-line partial discharge detection and location  

Microsoft Academic Search

This paper presents the principles and the first results of a new and unique on-line partial discharge (PD) based diagnostic system for medium-voltage power cables, which enables monitoring the condition of complete cable connections up to several kilometers in length over a long period of time. It allows locating the weak spots along the cable connection and identifying the development

P. C. J. M. van der Wielen; E. F. Steennis

2008-01-01

368

Controls on mineralisation in the Sierra Foothills gold province, central California, USA: a GIS-based reconnaissance prospectivity analysis  

Microsoft Academic Search

The assessment of spatial relationships between the location, abundance and size of orogenic-gold deposits in the highly endowed Sierra Foothills gold province in California, via the combination of field studies and a GIS-based analysis, illustrates the power of such an approach to the characterisation of important parameters of mineral systems, and the prediction of districts likely to host economic mineralisation.

F. P. Bierlein; H. J. Northover; D. I. Groves; R. J. Goldfarb; E. E. Marsh

2008-01-01

369

Development of a Fish-Based Index of Biotic Integrity forSmall Inland Lakes in Central Minnesota  

Microsoft Academic Search

We developed a fish-based index of biotic integrity (IBI) for a set of Minnesota lakes having similar geophysical and chemical features. Fish data were collected by means of trap nets, gill nets, shoreline seines, and backpack electrofishing. Of 30 evaluated metrics, we identified 16 metrics of three types: species richness, community assemblage, and trophic composition. In contrast to lotic IBIs,

Melissa T. Drake; Donald L. Pereira

2002-01-01

370

Mammalian cell transduction and internalization properties of ? phages displaying the full-length adenoviral penton base or its central domain  

Microsoft Academic Search

In recent years a strong effort has been devoted to the search for new, safe and efficient gene therapy vectors. Phage ? is a promising backbone for the development of new vectors: its genome can host large inserts, DNA is protected from degradation by the capsid and the ligand-exposed D and V proteins can be extensively modified. Current phage-based vectors

Stefania Piersanti; Gioia Cherubini; Yuri Martina; Barbara Salone; Daniele Avitabile; Fabiana Grosso; Enrico Cundari; Giovanni Di Zenzo; Isabella Saggio

2004-01-01

371

Influence of fatigue testing and cementation mode on the load-bearing capability of bovine incisors restored with crowns and zirconium dioxide posts.  

PubMed

The aim of the study was to evaluate the influence of fatigue and cementation mode on the fracture behavior of endodontically treated bovine incisors restored with zirconium dioxide posts and crowns. Forty-eight endodontically treated bovine primary incisors were restored with zirconium dioxide posts (Cerapost, Brasseler), composite build-ups, and crowns cast from a chromium cobalt alloy. In 16 teeth, each of the posts was cemented conventionally with KetacCem (3M ESPE) or adhesively with Panavia F (Kuraray) or RelyX UniCem (3M ESPE). One-half of the specimens in each group were subjected to thermocycling with 10,000 cycles at 5-55 degrees C and mechanical aging, loading the specimens at an angle of 45 degrees in 1,200,000 cycles with 50 N. Fracture resistance was determined by loading the specimens until fracture at an angle of 45 degrees to the long axis of the teeth. The loading test showed that neither cementation mode nor fatigue testing had an influence on the load bearing capability. Most specimens fractured in a favorable way, independent from the type of cementation. PMID:18536945

Nothdurft, F P; Schmitt, T; Motter, P J; Pospiech, P R

2008-06-07

372

A search for the osteogenic factor in dentin. Rat incisor dentin contains a factor stimulating rat muscle cells in vitro to incorporate sulfate into an altered proteoglycan.  

PubMed

Demineralized dentin matrix has the capacity to induce bone formation via a chondrogenic pathway when implanted into muscle, in a fashion entirely analogous to bone matrix implants. In this work we have attempted to isolate, from rat incisor dentin, the matrix factor responsible for initiating osteogenesis. Rat incisor dentin was demineralized with EDTA plus 4.0 M guanidine. HCl. The proteins in the extracts were collected and, after a CaCl2 precipitation step, fractionated on Sephacryl S-200 in 6.0 M guanidine. HCl. The primary assay for activity was the incorporation of 35S-sulfate into proteoglycan in cultures of the fibroblast-like outgrowth cells from explants of neonatal rat muscle. Two Sephacryl S-200 fractions showed enhanced sulfate incorporating activity, but only one showed enhanced incorporation without a concomitant increase in cell number. In the presence of this fraction, the cell cultures produced a larger amount of a new small proteoglycan, as compared to controls, and a significant amount of a much larger proteoglycan. The active fraction had proteins in the Mr range from 8,000 to 15,000 as the major components. These data suggest that the fraction identified may contain the factors responsible for initiating the osteogenic response to dentin matrix upon its implantation in muscle in vivo. PMID:2630167

Veis, A; Sires, B; Clohisy, J

1989-01-01

373

Garlic Central  

NSDL National Science Digital Library

Can garlic help repel mosquitoes? Find out the answer to this question and more at Garlic Central, an all-about-garlic website created by aficionado Trevor Mendham. The site contains an introductory section--titled Garlic 101--and sections that address culinary uses, medicinal benefits, and cultivation. The site's Cooking section includes a collection of recipes; and information about storing, freezing, and crushing garlic. The site also features a brief how-to guide for planting, growing, and harvesting garlic. Garlic Central even hosts a virtual shopping mall that connects site visitors to a wide range of garlic-related websites peddling foodstuffs, kitchen implements, posters, books, and garden supplies. This site is also reviewed in the September 17, 2004 _NSDL Life Sciences Report_.

374

Central Africa  

NSDL National Science Digital Library

Begun in 1996, the International Crisis Group's (ICG) Central Africa Project analyzes political and ethnic conflict within and between the nations that straddle mid-Africa, including the Democratic Republic of Congo (DRC), Burundi, Angola, Uganda, and Rwanda. As part of that effort ICG has released over twelve full text reports in the last year (a few in French only). The two most recent in-depth reports are: "Africa's Seven-Nation War," which examines how the armies of seven African nations have been drawn into the rebellion against DRC President Laurent Dsir Kabila; and "How Kabila Lost His Way," which traces the foundation of the Kabila regime and seeks to discover why it has engendered both internal and external opposition. Well-researched and fully footnoted, yet written with a non-specialist audience in mind, these reports are a good resource for both students and general readers with an interest in the current situation in Central Africa.

1996-01-01

375

PE Central  

NSDL National Science Digital Library

The Virginia Polytechnic Institute Health and Physical Education Program developed this site, a clearinghouse of information about K-12 physical education and health. An extensive list of lesson plans and assessment ideas, arranged topically and by grade level, is the focal point of this site; the Classroom Teacher Lesson Ideas uses PE "across the curriculum" to help students learn concepts in other subjects. PE Central provides information for PE professionals on relevant journals, job announcements, and equipment purchases, among other topics.

1996-01-01

376

Discovery of the first Quaternary maar in the Bohemian Massif, Central Europe, based on combined geophysical and geological surveys  

Microsoft Academic Search

Based on results of previous investigations of tephra-tuff volcaniclastic deposits and a geophysical survey in the surroundings of the Železná h?rka Quaternary volcano, West Bohemia, we performed detailed geophysical surveys using gravimetry, magnetometry and electrical conductivity techniques. Striking anomalies were revealed in a morphological depression near Mýtina, West Bohemia, as a strong evidence of the assumed maar-diatreme structure. The sharp

J. Mrlina; H. Kämpf; C. Kroner; J. Mingram; M. Stebich; A. Brauer; W. H. Geissler; J. Kallmeyer; H. Matthes; M. Seidl

2009-01-01

377

Structure based design of iminohydantoin BACE1 inhibitors: identification of an orally available, centrally active BACE1 inhibitor.  

PubMed

From an initial lead 1, a structure-based design approach led to identification of a novel, high-affinity iminohydantoin BACE1 inhibitor that lowers CNS-derived A? following oral administration to rats. Herein we report SAR development in the S3 and F' subsites of BACE1 for this series, the synthetic approaches employed in this effort, and in vivo data for the optimized compound. PMID:22390835

Cumming, Jared N; Smith, Elizabeth M; Wang, Lingyan; Misiaszek, Jeffrey; Durkin, James; Pan, Jianping; Iserloh, Ulrich; Wu, Yusheng; Zhu, Zhaoning; Strickland, Corey; Voigt, Johannes; Chen, Xia; Kennedy, Matthew E; Kuvelkar, Reshma; Hyde, Lynn A; Cox, Kathleen; Favreau, Leonard; Czarniecki, Michael F; Greenlee, William J; McKittrick, Brian A; Parker, Eric M; Stamford, Andrew W

2012-02-16

378

Central metal ion exchange in a coordination polymer based on lanthanide ions and di(2-ethylhexyl)phosphoric acid: Exchange rate and tunable affinity.  

PubMed

In this paper the exchange of lanthanide(III) ions (Ln(3+)) between a solution and a coordination polymer (CP) of di(2-ethylhexyl)phosphoric acid (Hdehp), [Ln(dehp)3], is studied. Kinetic and selectivity studies suggest that a polymeric network of [Ln(dehp)3] has different characteristics than the corresponding monomeric complex. The reaction rate is remarkably slow and requires over 600h to reach in nearly equilibrium, and this can be explained by the polymeric crystalline structure and high valency of Ln(3+). The affinity of the exchange reaction reaches a maximum with the Ln(3+) possessing an ionic radius 7% smaller than that of the central Ln(3+), therefore, the affinity of the [Ln(dehp)3] is tunable based on the choice of the central metal ion. Such unique affinity, which differs from the monomeric complex, can be explained by two factors: the coordination preference and steric strain caused by the polymeric structure. The latter likely becomes predominant for Ln(3+) exchange when the ionic radius of the ion in solution is smaller than the original Ln(3+) by more than 7%. Structural studies suggest that the incoming Ln(3+) forms a new phase though an exchange reaction, and this could plausibly cause the structural strain. PMID:24183431

Tasaki-Handa, Yuiko; Abe, Yukie; Ooi, Kenta; Tanaka, Mikiya; Wakisaka, Akihiro

2013-09-25

379

Extension of the Najd Shear System from Saudi Arabia to the central eastern desert of Egypt based on integrated field and LANDSAT observations  

NASA Astrophysics Data System (ADS)

The Najd Shear System in Saudi Arabia extends over 1200 km in a NW-SE direction and has a width of approximately 300 km. A digital color mosaic, compiled from seven Landsat thematic mapper scenes, was used to delineate characteristic structural features of the Najd System in the Midyan region of Saudi Arabia and to search for similar features in the Egyptian Eastern Desert. The digital mosaic was generated using ratios of Landsat thematic mapper bands (bands 5/4 × 3/4, 5/1, 5/7) that are sensitive to the rock content of Fe-bearing aluminosilicates, spectrally opaque phases, and hydroxyl-bearing or carbonate minerals, respectively. The mosaic covers approximately 130,000 km² of late Proterozoic exposures of the Arabian-Nubian Shield and has the Eastern Desert and the Midyan region placed in their approximate pre-Red Sea locations. The Ajjaj Shear Zone (AJZ) marks the termination of the Najd System against the eastern margin of the Red Sea in the Midyan region. The AJZ aligns with the central Eastern Desert, based on analysis of pre-Red Sea locations. Analyses of Landsat data and field observations show that the Ajjaj Shear Zone and the central Eastern Desert exhibit the following features in common: (1) outcrops that are generally elongate in a NW-SE direction as a result of folding, with fine-scale lithologic heterogeneity at the outcrop scale related to deformation associated with faulting; (2) NW trending left-lateral faults and ductile shear zones; (3) subhorizontal, NW trending mineral lineations, and variably dipping NW trending foliations, with local changes in attitude around large competent (e.g., granitic) bodies; and (4) lithologic contacts that are generally tectonic in nature and related to faulting. These features are less common to the north and south of both the Ajjaj Shear Zone and the central Eastern Desert. Results are consistent with the Najd Shear System extending into the Eastern Desert and dominating the structural patterns within the central part of the Eastern Desert.

Sultan, Mohamed; Arvidson, Raymond E.; Duncan, Ian J.; Stern, Robert J.; El Kaliouby, Baher

1988-12-01

380

Centrality and network flow  

Microsoft Academic Search

Centrality measures, or at least popular interpretations of these measures, make implicit assumptions about the manner in which traffic flows through a network. For example, some measures count only geodesic paths, apparently assuming that whatever flows through the network only moves along the shortest possible paths. This paper lays out a typology of network flows based on two dimensions of

Stephen P. Borgatti

2005-01-01

381

Hydrological landscape classification: investigating the performance of HAND based landscape classifications in a central European meso-scale catchment  

NASA Astrophysics Data System (ADS)

This paper presents a detailed performance and sensitivity analysis of a recently developed hydrological landscape classification method based on dominant runoff mechanisms. Three landscape classes are distinguished: wetland, hillslope and plateau, corresponding to three dominant hydrological regimes: saturation excess overland flow, storage excess sub-surface flow, and deep percolation. Topography, geology and land use hold the key to identifying these landscapes. The height above the nearest drainage (HAND) and the surface slope, which can be easily obtained from a digital elevation model, appear to be the dominant topographical controls for hydrological classification. In this paper several indicators for classification are tested as well as their sensitivity to scale and resolution of observed points (sample size). The best results are obtained by the simple use of HAND and slope. The results obtained compared well with the topographical wetness index. The HAND based landscape classification appears to be an efficient method to ''read the landscape'' on the basis of which conceptual models can be developed.

Gharari, S.; Hrachowitz, M.; Fenicia, F.; Savenije, H. H. G.

2011-11-01

382

Elevated temperature dry sliding wear behavior of nickel-based composite coating on austenitic stainless steel deposited by a novel central hollow laser cladding  

NASA Astrophysics Data System (ADS)

In order to improve the high-temperature wear resistance of austenitic stainless steel, a wear resistant composite coating reinforced with hard (Cr,Fe)7C3 carbide and toughened by ductile ?-(Ni,Fe)/(Cr,Fe)7C3 eutectic matrix was fabricated by a novel central hollow laser cladding technique. The constituent phases and microstructure as well as high-temperature tribological behaviors of the Ni-based coating were investigated, respectively, and the corresponding wear mechanisms were discussed. It has been found that the composite coating exhibits superior wear resistance than substrate either at ambient or high temperatures. The coating shows better sliding wear resistance at 600 °C than 300 °C owing to high-temperature stability of the reinforced carbide and polishing effect as well as formation of continuous lubricious films, which implied it has large potential industrial applications at relatively higher temperatures.

He, Xiang-Ming; Liu, Xiu-Bo; Wang, Ming-Di; Yang, Mao-Sheng; Shi, Shi-Hong; Fu, Ge-Yan; Chen, Shu-Fa

2011-10-01

383

Analyzing the mid-low porosity sandstone dry frame in central Sichuan based on effective medium theory  

NASA Astrophysics Data System (ADS)

Tight gas sandstone reservoirs in Guang'an are characterized by wide distribution and low abundance. Sandstone samples from this area usually have low porosity and poor connectivity. We analyze the observed velocity data of tight sandstone samples with the Mori-Tanaka model, and give the sandstone framework physical model in this area based on theory and experiment analysis. The matrix modulus was obtained by an empirical relationship and then the experiment data were compared with the values predicted by the Mori-Tanaka model with different pore shapes. The results revealed that the experiment data were close to the model with low pore aspect ratio. Considering the matrix modulus and pore shape variation, we find that, under the condition of small mineral composition change, the effective pore aspect ratio of these samples increased with porosity evidently.

Yan, Xin-Fei; Yao, Feng-Chang; Cao, Hong; Ba, Jing; Hu, Lian-Lian; Yang, Zhi-Fang

2011-09-01

384

Tomography-based, high-resolution modelling of mantle flow under North America: Implications for surface stress in the central and eastern US  

NASA Astrophysics Data System (ADS)

Plate tectonics is fundamentally a 3-D process and the mantle convection stresses that drive the horizontal motions of plates also produce vertical bending stresses that generate large (km-scale) topographic undulations. The impact of these bending stresses in continental interiors is not generally recognised or well understood and yet they can provide a large (order 10 MPa) contribution to the ambient tectonic stress field. Depending on the geometrical relationship with pre-existing crustal weak zones or faults, the convection- induced surface stresses can be potentially important contributors to intraplate seismic activity, particularly in the central and eastern portions of North America. These stresses, and the associated surface undulations, evolve slowly on geological (Myr) time scales and it is therefore difficult to resolve them using space-based geodesy (e.g. GPS). We determine the impact of mantle convection on intraplate stresses in North America using a mantle flow calculation that is based on a new high-resolution tomography model that is constrained by simultaneously inverting global seismic and mantle-convection data sets (Simmons et al. 2009). The mantle flow model adopts a depth dependent mantle viscosity structure which reconciles both glacial isostatic adjustment (GIA) and convection data (Mitrovica and Forte 2004). The flow model successfully reproduces plate velocities and observations of surface gravity and topography. We find a large region of maximum compressive stress in the central portion of North America that is largely driven by viscous flow coupled to density anomalies associated with the descent of the ancient Kula-Farallon plate system. These flow calculations also show the long lived nature of the convection-driven compressive stresses under the Mississippi Valley region, extending from the southern Great Lakes to the Gulf of Mexico.

Forte, A. M.; Moucha, R.; Mitrovica, J. X.; Simmons, N. A.; Grand, S. P.

2009-05-01

385

Central hyperthyroidism.  

PubMed

Central hyperthyroidism is a rare condition in which thyrotoxicosis results from primary overproduction of TSH by the pituitary gland with subsequent thyroid enlargement and hyperfunction. The two known causes of central hyperthyroidism are TSH-producing pituitary tumors (TSHomas) and the syndrome of PRTH. Both of these entities are characterized by clinical thyrotoxicosis, diffuse goiters, elevated circulating levels of free T4 and T3, and a nonsuppressed serum TSH. It is critical to distinguish central hyperthyroidism from the much more common types of primary hyperthyroidism, all of which have undetectable TSH values. TSHomas and PRTH can usually be differentiated from one another by measuring the serum alpha-subunit and the TSH response to intravenous TRH or exogenous thyroid hormone, and by pituitary imaging studies. TSHomas are usually benign adenomas arising from the monoclonal expansion of neoplastic thyrotropes. Causative oncogenes have not yet been convincingly identified. PRTH is a nonneoplastic disorder caused by inherited mutations in the gene for the thyroid hormone receptor beta; it is a poorly understood variant of GRTH. For unclear reasons, in PRTH, the pituitary gland is resistant to the feedback inhibitory effects of circulating thyroid hormones while peripheral tissues respond normally, causing patients to experience the toxic peripheral effects of thyroid hormone excess. TSHomas are best treated by transphenoidal surgical removal. Radiotherapy is indicated for inoperable or incompletely resected tumors. Octreotide administration is a useful adjunct for preoperatively reducing tumor size and for the medical management of surgical treatment failures. PRTH is ideally treated by chronically suppressing TSH secretion with medications such as D-thyroxine, TRIAC, octreotide, or bromocriptine. If such therapy is ineffective or unavailable, thyroid ablation with radioiodine or surgery may be employed with subsequent close monitoring of both thyroid hormone status and pituitary gland size. PMID:9534036

McDermott, M T; Ridgway, E C

1998-03-01

386

Neuropsychology Central  

NSDL National Science Digital Library

Neuropsychology Central is devoted to the subject of - "Neuropsychology, a new branch of science with the specific and unique aim of investigating the role of individual brain systems in complex forms of mental activity." - A.R. Luria "The Working Brain" The page aims to describe the importance of neuropsychology as a science of brain and behavior, and to act as a resource for the professional and layperson alike. See links to current technology for brain imaging, and sections covering different aspects of this ever growing field such as cognitive, developmental, and geriatric Neuropsychology. In addition, a reader survey is included to facilitate the expansion of the site.

Browndyke, J. N.

2007-03-24

387

Sonnet Central  

NSDL National Science Digital Library

Created by a dedicated sonnet aficionado, Sonnet Central is not intended for the scholar, per se, but for the reader, the Internaut with a weakness for poetry. The site contains a collection of English-language sonnets, grouped by period and region or by author, and modernized for contemporary readers. Pictures, contemporaneous critical works, a bibliography, and audio files of readings of selected poems complement the sonnets, some of which are maintained off-site (many at the University of Toronto). From Shakespeare to Wilfred Owen, selections from many well-known sonneteers are here alongside those of their less famous contemporaries.

388

A quantitative high-resolution summer temperature reconstruction back to AD 850 based on sedimentary pigments from Laguna Aculeo, Central Chile  

NASA Astrophysics Data System (ADS)

A quantitative high-resolution (3-5 years) austral summer DJF (December to February) temperature reconstruction for the central region of Chile back to AD 850 is presented here. We used non-destructive multi-channel in situ reflection spectrometry data from a short sediment core from Laguna Aculeo, Central Chile (33°50'S/70°54'W, 355m a.s.l.). The age model is based on 137Cs and 14C dates, and a series of seismites related to major historical earthquakes. Calibration-in-time (period AD 1901-2000, cross-validated with split periods) revealed robust correlations between local DJF temperatures (CRU TS 2.1) and total sedimentary chlorin (a proxy for biological productivity measured using the relative absorption band depth (RABD) centred in 660-670 nm RABD660;670: r=0.79, P<0.01; five-years triangular filtered) and the degree of pigment diagenesis (R660nm/670nm: r=0.82, P<0.01; five-years triangular filtered). The DJF temperature reconstructions back to AD 850 were then calculated using scaling and linear regression techniques; Root Mean Squared Error values are small (between 0.24 and 0.34°C) suggesting that most of the reconstructed decadal-scale climate variability is significant. Our data provide quantitative evidence for the presence of a Medieval Climate Anomaly (in this case, warm summers between AD 1150 and 1350; ?T = +0.27 to +0.37°C with respect to (wrt) twentieth century) and a cool period synchronous to the ‘Little Ice Age’ starting with a sharp drop between AD 1350 and AD 1400 (-0.3°C/10 yr, decadal trend) followed by constantly cool (?T = -0.70 to -0.90°C wrt twentieth century) summers until AD 1750. This lake sediment-based summer temperature record for central Chile is particularly valuable as most other known natural climate archives in this area (mostly tree rings) are sensitive to winter precipitation. Instrumental DJF temperatures and the reconstruction back to AD 850 (3-year resolution)

von Gunten, L.; Grosjean, M.; Rein, B.; Urrutia, R.; Appleby, P.

2009-12-01

389

The Relationship between Weight and CVD Risk Factors in a Sample Population from Central Iran (Based on IHHP)  

PubMed Central

BACKGROUND Atherosclerosis is one of the leading causes of mortality all around the world. Obesity is an independent risk factor for atherosclerosis and cardiovascular diseases (CVD). In this respect, we decided to examine the effect of the subgroups of weight on cardiovascular risk factors. METHODS This cross-sectional study was done in 2006 using the data obtained by the Iranian Healthy Heart Program (IHHP) and based on classification of obesity by the World Health Organization (WHO). In this study, the samples were tested based on the Framingham risk score, Metabolic Measuring Score (MMS) and classification of obesity. Chi-square and ANOVA were used for statistical analysis. RESULTS 12514 people with a mean age of 38 participated in this study. 6.8% of women and 14% of men had university degrees (higher than diploma). Obesity was seen in women more than men: 56.4% of women and 40% of men had a Body Mass Index of (BMI) ? 25 Kg/m2. 13% of the subjects had FBS > 110 and13.9% of them were using hypertensive drugs. In this study, we found that all risk factors, except HDL cholesterol in men, increased with an increase in weight. This finding is also confirmed by the Framingham flowfigure for men and women. CONCLUSION One of every two Americans, of any age and sex, has a Body Mass Index of (BMI) ? 25 Kg/m2. Obesity associated CVD and other serious diseases. Many studies have been done in different countries to find the relationship between obesity and CVD risk factors. For example, in the U.S.A and Canada they found that emteropiotic parameters, blood presser and lipids increased by age(of both sexes). Moreover, another study done in China, which is a country in Asia like Iran, shows that BMI has an indirect effect on HDL cholesterol, LDL cholesterol and triglyceride. This data is consistent with the results of the current study. However, In China they found that this relationship in men is stronger than women, but our study reveals the opposite.

Khosravi, Alireza; Akhavan Tabib, Afshan; Golshadi, Imandokht; Dana Siadat, Zahra; Bahonar, Ahmad; Zarfeshani, Sonia; Alikhasi, Hassan; Rezaee, Shahrzad; Noori, Fatemeh; Hashemi Jazi, Mohammad; Khosravi, Zahra

2012-01-01

390

The seasonality of east central North American precipitation based on three coeval Holocene speleothems from southern West Virginia  

NASA Astrophysics Data System (ADS)

We present a replicated record of Holocene climate change from a cave in West Virginia, USA. Based on analysis of stable isotopes in precipitation (?18Ow) from the closest Global Network of Isotopes in Precipitation (GNIP) station in Coshocton, OH, we interpret enriched oxygen isotopes in calcite (?18Oc) as representing an increase in the relative contribution of summer precipitation to annual totals. Significant coherence between local summer (July and August) precipitation and the Summer North Atlantic Oscillation (SNAO) index on multi-decadal timescales suggests that summer precipitation in our study area is strongly influenced by changes in the Bermuda High. A strengthened Bermuda High circulation would increase summer precipitation amounts in the region and lead to enriched ?18Oc of speleothem calcite. Our ?18Oc record achieves maximum values during the mid-Holocene, consistent with previous studies indicating an intensified Bermuda High circulation at that time. At 4.2 ka, ?18Oc transitions to lower values at a time when numerous records around the globe document significant changes in the hydrologic budget. Over the last 2000 years, there are intervals of substantially decreased ?18Oc, coincident with aridity in the Yucatan, Alpine glacial advances, and a weakened Asian summer monsoon.

Hardt, Ben; Rowe, Harold D.; Springer, Gregory S.; Cheng, Hai; Edwards, R. Lawrence

2010-07-01

391

Sarcoma: concordance between initial diagnosis and centralized expert review in a population-based study within three European regions  

PubMed Central

Background Sarcomas represent a heterogeneous group of tumors. Accurate determination of histological diagnosis and prognostic factors is critical for the delineation of treatment strategies. The contribution of second opinion (SO) to improve diagnostic accuracy has been suggested for sarcoma but has never been established in population-based studies. Methods Histological data of patients diagnosed with sarcoma in Rhone-Alpes (France), Veneto (Italy) and Aquitaine (France) over a 2-year period were collected. Initial diagnoses were systematically compared with SO from regional and national experts. Results Of 2016 selected patients, 1463 (73%) matched the inclusion criteria and were analyzed. Full concordance between primary diagnosis and SO (the first pathologist and the expert reached identical conclusions) was observed in 824 (56%) cases, partial concordance (identical diagnosis of connective tumor but different grade or histological subtype) in 518 (35%) cases and complete discordance (benign versus malignant, different histological type or invalidation of the diagnosis of sarcoma) in 121 (8%) cases. The major discrepancies were related to histological grade (n = 274, 43%), histological type (n = 144, 24%), subtype (n = 18, 3%) and grade plus subtype or grade plus histological type (n = 178, 29%). Conclusion More than 40% of first histological diagnoses were modified at second reading, possibly resulting in different treatment decisions.

Ray-Coquard, I.; Montesco, M. C.; Coindre, J. M.; Dei Tos, A. P.; Lurkin, A.; Ranchere-Vince, D.; Vecchiato, A.; Decouvelaere, A. V.; Mathoulin-Pelissier, S.; Albert, S.; Cousin, P.; Cellier, D.; Toffolatti, L.; Rossi, C. R.; Blay, J. Y.

2012-01-01

392

Assessment of projected climate change signals over central Africa based on a multitude of global and regional climate projections  

NASA Astrophysics Data System (ADS)

It is well accepted within the scientific community that only a large ensemble of different projections will allow achieving robust climate change information for a specific region. In the framework of the project "Climate changes scenarios for the Congo basin" (funded by the German Ministry for Environment, Nature Conservation and Nuclear Safety) a regional climate change assessment is conducted by the Climate Service Center (CSC) over the greater Congo basin region. The analysis is based on a state-of-the-art multi-model multi-scenario ensemble of global and regional climate change projections. In this ensemble the results of several GCM projections from the CMIP3 and the CMIP5 projects are combined with some of the recently downscaled regional CORDEX-Africa projections. Altogether data from 77 different climate change projections are analysed; separated into 31 projections for a "high" and 46 for a "low" emission scenario. In the study several parameters and indices related to temperature and precipitation are considered for the assessment of projected climate change. The large size of the analyzed ensemble is expected to be useful for not only quantifying the magnitude of projected changes, but also to analyze their robustness as well. Moreover, potential differences between projected changes from GCMs and RCMs can also be analysed.

Hänsler, Andreas; Saeed, Fahad; Jacob, Daniela

2013-04-01

393

Assessment of the regional atmospheric impact of wildfire emissions based on CO observations at the ZOTTO tall tower station in central Siberia  

NASA Astrophysics Data System (ADS)

The impact of wildfires on surface air composition over central Siberia is investigated based on near-surface carbon monoxide (CO) measurements conducted at Zotino Tall Tower Observatory (ZOTTO), a remote station in the center of Siberia, during 2007 and 2008 warm seasons. Seasonal variations of intensity and spatial distribution of wildfires in south of western and eastern Siberia are found to be important factors contributing a substantial part of synoptic and year-to-year variability of background CO levels in the region. Based on the MODIS area burned product, the estimate of the total yearly CO emitted from wildfires in the regions potentially affecting the measurement site (those of European Russia and Siberia) is approximately 15 and 27 Tg CO in 2007 and 2008, versus 18.0 and 39.4 Tg CO from wildfires in all of Russia in 2007 and 2008, and 11 Tg CO from all anthropogenic sources in Russia according to EDGARv4.1 database for year 2005. The severe fire activity in northern Eurasia, particularly in western Siberia, during 2008 caused enhanced springtime surface CO levels observed at ZOTTO, with median CO mixing ratio in April-May 2008 by approximately 15 ppb higher compared to April-May 2007. Episodes of air transport from wildfires upwind of the measurements site are identified based on ensembles of backward trajectories and MODIS products. The impact of distinct wildfire smoke plumes on near-surface CO mixing ratios, along with the influence of wildfire and anthropogenic emissions on background CO levels in the region is estimated using backward Lagrangian trajectory statistics. The estimated relative CO enhancement in fire plumes with transport times up to 2 days is about 5-25 ppb in springs 2007 and 2008, and 50 ppb in summer 2008, based on the observed median values, with a maximal absolute value of 250 ppb observed in April 2008. Boreal forest fires over the vast areas of central Siberia along with regional anthropogenic sources are found to be the major factors driving short-term (synoptic) variability of near-surface CO during the warm season.

Vasileva, A. V.; Moiseenko, K. B.; Mayer, J.-C.; Jürgens, N.; Panov, A.; Heimann, M.; Andreae, M. O.

2011-04-01

394

Annotated genetic linkage maps of Pinus pinaster Ait. from a Central Spain population using microsatellite and gene based markers  

PubMed Central

Background Pinus pinaster Ait. is a major resin producing species in Spain. Genetic linkage mapping can facilitate marker-assisted selection (MAS) through the identification of Quantitative Trait Loci and selection of allelic variants of interest in breeding populations. In this study, we report annotated genetic linkage maps for two individuals (C14 and C15) belonging to a breeding program aiming to increase resin production. We use different types of DNA markers, including last-generation molecular markers. Results We obtained 13 and 14 linkage groups for C14 and C15 maps, respectively. A total of 211 and 215 markers were positioned on each map and estimated genome length was between 1,870 and 2,166 cM respectively, which represents near 65% of genome coverage. Comparative mapping with previously developed genetic linkage maps for P. pinaster based on about 60 common markers enabled aligning linkage groups to this reference map. The comparison of our annotated linkage maps and linkage maps reporting QTL information revealed 11 annotated SNPs in candidate genes that co-localized with previously reported QTLs for wood properties and water use efficiency. Conclusions This study provides genetic linkage maps from a Spanish population that shows high levels of genetic divergence with French populations from which segregating progenies have been previously mapped. These genetic maps will be of interest to construct a reliable consensus linkage map for the species. The importance of developing functional genetic linkage maps is highlighted, especially when working with breeding populations for its future application in MAS for traits of interest.

2012-01-01

395

Central pit craters on Ganymede  

NASA Astrophysics Data System (ADS)

Central pit craters are common on Mars, Ganymede and Callisto, and thus are generally believed to require target volatiles in their formation. The purpose of this study is to identify the environmental conditions under which central pit craters form on Ganymede. We have conducted a study of 471 central pit craters with diameters between 5 and 150 km on Ganymede and compared the results to 1604 central pit craters on Mars (diameter range 5-160 km). Both floor and summit pits occur on Mars whereas floor pits dominate on Ganymede. Central peak craters are found in similar locations and diameter ranges as central pit craters on Mars and overlap in location and at diameters <60 km on Ganymede. Central pit craters show no regional variations on either Ganymede or Mars and are not concentrated on specific geologic units. Central pit craters show a range of preservation states, indicating that conditions favoring central pit formation have existed since crater-retaining surfaces have existed on Ganymede and Mars. Central pit craters on Ganymede are generally about three times larger than those on Mars, probably due to gravity scaling although target characteristics and resolution also may play a role. Central pits tend to be larger relative to their parent crater on Ganymede than on Mars, probably because of Ganymede's purer ice crust. A transition to different characteristics occurs in Ganymede's icy crust at depths of 4-7 km based on the larger pit-to-crater-diameter relationship for craters in the 70-130-km-diameter range and lack of central peaks in craters larger than 60-km-diameter. We use our results to constrain the proposed formation models for central pits on these two bodies. Our results are most consistent with the melt-drainage model for central pit formation.

Alzate, Nathalia; Barlow, Nadine G.

2011-02-01

396

Central hypothyroidism  

PubMed Central

Central hypothyroidism is defined as hypothyroidism due to insufficient stimulation by thyroid stimulating hormone (TSH) of an otherwise normal thyroid gland. It has an estimated prevalence of approximately 1 in 80,000 to 1 in 120,000. It can be secondary hypothyroidism (pituitary) or tertiary hypothyroidism (hypothalamus) in origin. In children, it is usually caused by craniopharyngiomas or previous cranial irradiation for brain tumors or hematological malignancies. In adults, it is usually due to pituitary macroadenomas, pituitary surgeries or post-irradiation. Fatigue and peripheral edema are the most specific clinical features. Diagnosis is established by the presence of normal to low-normal TSH on the background of low-normal thyroid hormones, confirmed by the thyrotropin releasing hormone stimulation test. Therapy includes use of levothyroxine titrated to improvement in symptomology and keeping free T4 in the upper limit of normal reference range.

Gupta, Vishal; Lee, Marilyn

2011-01-01

397

PCR detection of North American and Central African isolates of epizootic hemorrhagic disease virus (EHDV) based on genome segment 10 of EHDV serotype 1.  

PubMed

PCR amplification technology for the detection of epizootic hemorrhagic disease virus (EHDV) ribonucleic acid in cell culture and clinical specimens was developed. With oligoribonucleotide primers selected from genome segment 10 of EHDV serotype 1 (EHDV-1), which codes for two nonstructural proteins (NS3 and NS3a), the PCR-based assay resulted in a 535-bp PCR product. RNAs from North American EHDV-1 prototype, EHDV-2 prototype, and a number of EHDV field isolates, including the Central African isolates of EHDV-5 and EHDV-318 propagated in cell cultures, were detected by this PCR-based assay. The specific 535-bp PCR products were visualized onto agarose gels, and the identity of the PCR products was confirmed by chemiluminescent hybridization with a 352-bp internal probe. The sensitivity of the EHDV PCR assay was increased by chemiluminescent hybridization; by this EHDV-NS3 PCR, 10 fg of EHDV RNA was detected (equivalent to 600 viral particles). Amplification product was not detected when the PCR-based assay was applied to RNAs from North American bluetongue virus prototype serotypes 2, 10, 11, 13, and 17; total nucleic acid extracts from uninfected BHK-21 cells; or unfractionated blood from calves and deer that were EHDV seronegative and virus isolation negative. The described EHDV PCR-based assay with primers derived from segment 10 of EHDV-1 resulted in detection of EHDV RNA from blood and tissues collected from calves and deer with natural and experimental EHDV infections and provides a valuable tool to study the epidemiology of EHDV infection in susceptible ruminants. PMID:9705400

Aradaib, I E; Wilson, W C; Schore, C E; Mohammed, M E; Yilma, T D; Cullor, J S; Osburn, B I

1998-09-01

398

Proton microprobe determination of fluorine profiles in the enamel and dentine of erupting incisors from sheep given low and high daily doses of fluoride.  

PubMed

Developmental defects in incisors were induced by daily oral ingestion of sodium fluoride solutions. Teeth extracted at eruption from sheep that had been subjected to four different fluoride regimens--0.2 or 0.5 mg F/kg body weight daily for 6 months, 2 or 6 mg F/kg body weight daily for 21 days--were analysed for fluorine by gamma emission using a proton microprobe. Calcium and zinc profiles were also measured using proton-induced X-ray emission. Diffuse opacities, similar in appearance to mild human fluorosis, were produced by the first two regimens, whereas the last two produced hypoplastic lesions. Different distributions of fluoride were found in the unerupted enamel and dentine, and these patterns reflected variations in both the duration and concentration of the fluoride dose used to induce the fluorotic lesions. PMID:2597035

Nelson, D G; Coote, G E; Vickridge, I C; Suckling, G

1989-01-01

399

Perihelium Shifts in Central Potentials.  

National Technical Information Service (NTIS)

Motivated by the rigorous results on level ordering for arbitrary central potentials recently derived in the literature a classical treatment of the perihelium shifts is presented, based on the consideration of those orbits which lie in the vicinity of a ...

A. E. A. Amorim P. L. Ferreira

1987-01-01

400

Central Cord Syndrome  

MedlinePLUS

NINDS Central Cord Syndrome Information Page Synonym(s): Central Cervical Cord Syndrome Table of Contents (click to jump to sections) ... is being done? Clinical Trials Organizations What is Central Cord Syndrome? Central cord syndrome is the most ...

401

Central Pain Syndrome  

MedlinePLUS

NINDS Central Pain Syndrome Information Page Table of Contents (click to jump to sections) What is Central Pain Syndrome? ... is being done? Clinical Trials Organizations What is Central Pain Syndrome? Central pain syndrome is a neurological ...

402

Centralized digital control of accelerators  

SciTech Connect

In contrasting the title of this paper with a second paper to be presented at this conference entitled Distributed Digital Control of Accelerators, a potential reader might be led to believe that this paper will focus on systems whose computing intelligence is centered in one or more computers in a centralized location. Instead, this paper will describe the architectural evolution of SLAC's computer based accelerator control systems with respect to the distribution of their intelligence. However, the use of the word centralized in the title is appropriate because these systems are based on the use of centralized large and computationally powerful processors that are typically supported by networks of smaller distributed processors.

Melen, R.E.

1983-09-01

403

Epidemic of Plasmodium falciparum malaria in Central India, an area where chloroquine has been replaced by artemisinin-based combination therapy  

Microsoft Academic Search

India contributes greatly to the global incidence of malaria. The factors influencing malaria in India are highly diverse and vary greatly from the epidemiological setting of any other country. Central India is the most vulnerable area to malaria in India. This study was carried out in three community health centres in Dindori District, Madhya Pradesh (Central India). Dindori District is

Neeru Singh; Man M. Shukla; Gyan Chand; Praveen K. Bharti; Mrigendra P. Singh; Mohan K. Shukla; Rajiv K. Mehra; Ravendra K. Sharma; Aditya P. Dash

2011-01-01

404

The use of sagebrush (Artemisia) as a biogeochemical indicator of base-metal deposits in Precambrian rocks of west-central Colorado  

USGS Publications Warehouse

The efficacy of sagebrush (Artemisia) as a biogeochemical indicator of base-metal mineralization in stratabound Precambrian ore deposits in west-central Colorado was investigated by collecting new (mostly flowering) growth from several sagebrush shrubs over and near five such deposits in three different areas. These are the Sedalia mine and two mines in the Turret district near Salida, and two mines in the Cochetopa district southeast of Gunnison. Two species were used, A. tridentata and A. frigida, depending on the area. Sagebrush clippings were separated into two subsamples consisting of (1) stems, and (2) leaves and blossoms stripped from the stems. These subsamples were ashed separately and the ash analyzed with an emission spectrograph for 30 elements. There appear to be no appreciable differences in the analyses of the two subsamples, indicating that composite samples would provide adequate information for further investigations. Eight of these elements, Ag, Bi, Cu, Pb, Sn, Y, Zn, and Zr, are present in notably higher concentrations in the ash of samples growing over mineralized ground than in that of control samples growing over barren ground. Although the distribution pattern, and the number of these anomalous elements, differs at each of the five localities, three of them, silver, copper, and lead, show good contrast and close association with subjacent mineralization in all five study areas. ?? 1983.

Lovering, T. G.; Hedal, J. A.

1983-01-01

405

PCR-based detection of Wolbachia, cytoplasmic incompatibility microorganisms, infected in natural populations of Laodelphax striatellus (Homoptera: Delphacidae) in central Japan: has the distribution of Wolbachia spread recently?  

PubMed

Cytoplasmic incompatibility is caused in various insects by intracellular infection with rickettsia-like microorganisms of the genus Wolbachia. In Japan Laodelphax striatellus shows unidirectional cytoplasmic incompatibility between northeastern and southwestern populations. In this study, nine natural populations of L. striatellus collected from central Japan, including the geographic boundary between the two cytotype populations, were analysed for Wolbachia infection by PCR using primers specific to Wolbachia 16S rDNA. The geographic pattern of the infection rates of the southwestern (high) and the northeastern (low or zero) populations broadly resembled that of a previous study of incompatibility. In populations which originated from the boundary regions between the southwestern and northeastern populations, the infected and uninfected cytotypes coexisted. It is suggested that in some populations of L. striatellus, which formerly had been uninfected with Wolbachia, the infection property has changed to the infected. Based on our results, we conclude that the distribution of Wolbachia-infected L. striatellus populations have spread northeasterly during the last 12 years. PMID:8825761

Hoshizaki, S; Shimada, T

1995-11-01

406

GIS-based multicriteria overlay analysis in soil-suitability evaluation for cotton (Gossypium spp.): A case study in the black soil region of Central India  

NASA Astrophysics Data System (ADS)

In this study an attempt was made to characterize the soils of the Ringanbodi watershed, Nagpur district, Maharashtra, Central India, for soil-suitability evaluation for cotton using geographic information system (GIS)-based multicriteria overlay analysis techniques. The study shows that 8 soil series and 16 soil series associations in the study area and soils were classified into three orders, i.e., Entisol, Inceptisol, and Vertisol. The analysis reveals that the soil associations E-F, F-G, G-H, and H-G are “moderately suitable” (S2), D-E are “marginally to moderately suitable,” and C-D are marginally (S3) suitable. However, soils B-C are “not suitable” to “marginally suitable” (N2-S3) and A-B are “unsuitable” (N2) for cultivation of cotton. The area analysis shows that for a cotton crop an area about 966.7 ha (49.1%) of TGA is moderately suitable and classified as S2. An area about 469.9 ha (23.8%) of TGA is marginal to moderately suitable (S3-S2). The marginally suitable soils for cotton are classified as S3 and cover an area about 35.2 ha (1.8%) of TGA. However, a 172.3 ha (8.7%) area is not suitable (N2) to marginally suitable (S3) and a 326.9 (16.6%) area is not suitable (N2) for cotton because of uncorrectable factors like soil depth, slope, etc. The study demonstrated that GIS-based multicriteria overlay analysis of soil thematic parameters will be of immense help in soil-suitability evaluation for cotton.

Walke, N.; Obi Reddy, G. P.; Maji, A. K.; Thayalan, S.

2012-04-01

407

Novel functional variants locus in PLCE1 and susceptibility to esophageal squamous cell carcinoma: Based on published genome-wide association studies in a central Chinese population.  

PubMed

A novel functional single nucleotide polymorphism (SNP) rs2274223 located in the phospholipase C epsilon 1 (PLCE1) gene was found to be associated with the risk of esophageal squamous cell carcinoma (ESCC) by three large-scale genome-wide association studies (GWAS) in Chinese populations. In the present study, we validated this finding and also explored the risk of ESCC associated with other two unreported potentially functional SNPs (rs17417407 G>T and rs2274224 C>G) of PLCE1 in a population-based case-control study to investigate the association between these three potentially functional SNPs in PLCE1 and susceptibility to ESCC. A total of 381 ESCC cases and 420 controls matched by age and sex were recruited and successfully genotyped for three SNPs (rs17417407, rs2274223 and rs2274224) of the PLCE1 in a central Chinese population. SNP rs2274223 was independently associated with increased risk of ESCC (adjusted odds ratio [OR], 2.80; 95% confidence interval [95% CI], 1.45-5.39 for GG vs. AA), and SNP rs2274224 was found to be associated with decreased risk of ESCC (adjusted OR, 0.65; 95% CI, 0.46-0.91 for CG vs. CC). The combined effects of risk alleles for three SNPs (rs17417407T, rs2274223G and rs2274224G) were found to be associated with elevated risk of ESCC in a dose-dependent effect manner (Ptrend=0.005). The Grs17417407Ars2274223Crs2274224 haplotype decreased the risk of ESCC (adjusted OR, 0.76; 95% CI, 0.62-0.93), meanwhile the Grs17417407Grs2274223Crs2274224 and Trs17417407Grs2274223Crs2274224 haplotypes could increase the risk of ESCC (adjusted OR, 1.75; 95% CI, 1.33-2.18 and OR, 2.51; 95% CI, 1.15-2.49). Gene-environment interaction analysis presented a best model consisted of four factors (rs2274223, rs2274224, family history, and smoking) with testing balance accuracy (TBA): 0.66 and cross validation consistency (CVC): 7/10, which could increase the esophageal cancer risk in the "high risk group" with 3.67-fold (OR: 3.67, 95% CI: 2.74-4.92), compared to the "low risk group". Our results further confirmed that genetic variations in PLCE1 may contribute to ESCC risk associated with tobacco exposure in a central Chinese population. Further functional studies are needed to validate our results. PMID:23688607

Duan, Fujiao; Xie, Wei; Cui, Lihong; Wang, Peng; Song, Chunhua; Qu, Honghong; Wang, Kaijuan; Zhang, Jianying; Dai, Liping

2013-05-17

408

Groundwater Central  

NSDL National Science Digital Library

This is a portal for internet-based groundwater information that may be publicly accessed for no fee. This site provides a one-stop shop to browse for a wide variety of information from on-line publications and bibliographies, to presentations, case studies, research descriptions, data repositories, and vendors. Each record includes an abstract, contact information, and one or more hyperlinks. Records can be searched by topic, keywords, author or publication date.

Center, Ground-Water R.

409

Think Globally, Act Locally, Plan (Also) Centrally  

Microsoft Academic Search

When an environmental studies curriculum was developed for senior high schools in Israel, special attention was paid to the methodological approach, to content selection, and to the integration of central and school-based curriculum strategies. While central curriculum teams usually have an advantage in their better access to budgets, to specialized sources of information, and to central examination bodies, local teachers

Abraham Blum

1988-01-01

410

Current and future centrally acting antitussives  

Microsoft Academic Search

The purpose of this review is to highlight some important issues regarding current centrally acting antitussive drugs as well as discuss the implications of these matters on the development of future cough suppressants. Drugs that act in the central nervous system to inhibit cough are termed centrally acting and this designation is based exclusively on evidence obtained from animal models.

Donald C. Bolser

2006-01-01

411

Geophysical modelling of the central Skellefte district, Northern Sweden; an integrated model based on the electrical, potential field and petrophysical data  

NASA Astrophysics Data System (ADS)

The central Skellefte district (CSD) is a part of a major ore-bearing district in northern Sweden. Studying the depth and patterns of the contact relationship between the two major stratigraphic units of the CSD, the Skellefte Group and the Vargfors Group, is a key issue to understand the geometry and structure of the area and to guide exploration of base metals. In this study, we interpret geoelectrical data collected along two profiles and magnetic and gravity data obtained from the database of the Swedish Geological Survey (SGU) and Boliden Mineral, to reveal contact relationship and depth extension of the major geological structures. Petrophysical analyses of the different lithologies were conducted on samples from the database of the SGU. Electric resistivity, induced polarisation (IP), magnetic susceptibility and density were determined on 154 core samples representing the different lithologies of the area. The resistivity/IP data were acquired to define structural relations down to a maximum depth of ~ 430 m. The major contact between sediments of the Vargfors basin and volcanic rocks of the Skellefte Group were outlined from the inversion of the resistivity/IP sections, suggesting a synform boundary between the Vargfors Group and Skellefte Group. The contact relationship between the felsic and mafic volcanic rocks of the Skellefte Group is also understood with the help of the resistivity/IP data. The resistivity models were tested using the magnetic data and magnetic susceptibility inferred on the resistivity bodies. The result suggests a good correlation between the initial resistivity model and the magnetic and gravity field calculated from that model. The integration and interpretation of geological and geophysical data improved the basic understanding of the geometry of CSD. Based on previous geological investigations, the potential ore deposits are believed to be found along the volcano-sedimentary contact. The result from this study can thus be used for the base metal exploration, finding the locations of potential sulphide deposits and give a better understanding about spatial relationship between different geology structures in the CSD.

Tavakoli, Saman; Elming, Sten-Åke; Thunehed, Hans

2012-07-01

412

The association between intima media thickness, central obesity and diastolic blood pressure in obese and owerweight children: A cross-sectional school-based study  

Microsoft Academic Search

ObjectiveTo examine relationship between carotid intima-media thickness (IMT) and central obesity, cardiovasculary risk factors, and chronic inflammation markers in overweight and obese schoolchildren in Eastern Turkey.

Ozlem Elkiran; Erdal Yilmaz; Mustafa Koc; Ayhan Kamanli; Bilal Ustundag; Necip Ilhan

413

Transcutaneously Tunneled Central Venous Lines in Cancer Patients: An Analysis of Device-Related Morbidity Factors Based on Prospective Data Collection  

Microsoft Academic Search

Abstaract  Background: Long-term transcutaneous tunneled central venous catheters are frequently placed in cancer patients, accounting for significant costs and morbidity. Factors influencing outcome, though, are poorly studied.Methods: Between June 1991 and June 1993, 923 central venous tunneled catheters were placed in 791 patients at Memorial Sloan-Kettering Cancer Center. Placement-, device-, and patient-related parameters were charted prospectively (median follow-up: 120 days) and

Roderich E. Schwarz; Daniel G. Coit; Jeffrey S. Groeger

2000-01-01

414

Centrality in affiliation networks  

Microsoft Academic Search

This paper discusses the conceptualization, measurement, and interpretation of centrality in affiliation networks. Although centrality is a well-studied topic in social network analysis, and is one of the most widely used properties for studying affiliation networks, virtually all discussions of centrality and centralization have concerned themselves with one-mode networks. Bonacich's work on simultaneous group and individual centralities is a notable

Katherine Faust

1997-01-01

415

Efficacy of two cannabis based medicinal extracts for relief of central neuropathic pain from brachial plexus avulsion: results of a randomised controlled trial.  

PubMed

The objective was to investigate the effectiveness of cannabis-based medicines for treatment of chronic pain associated with brachial plexus root avulsion. This condition is an excellent human model of central neuropathic pain as it represents an unusually homogenous group in terms of anatomical location of injury, pain descriptions and patient demographics. Forty-eight patients with at least one avulsed root and baseline pain score of four or more on an 11-point ordinate scale participated in a randomised, double-blind, placebo-controlled, three period crossover study. All patients had intractable symptoms regardless of current analgesic therapy. Patients entered a baseline period of 2 weeks, followed by three, 2-week treatment periods during each of which they received one of three oromucosal spray preparations. These were placebo and two whole plant extracts of Cannabis sativa L.: GW-1000-02 (Sativex), containing Delta(9)tetrahydrocannabinol (THC):cannabidiol (CBD) in an approximate 1:1 ratio and GW-2000-02, containing primarily THC. The primary outcome measure was the mean pain severity score during the last 7 days of treatment. Secondary outcome measures included pain related quality of life assessments. The primary outcome measure failed to fall by the two points defined in our hypothesis. However, both this measure and measures of sleep showed statistically significant improvements. The study medications were generally well tolerated with the majority of adverse events, including intoxication type reactions, being mild to moderate in severity and resolving spontaneously. Studies of longer duration in neuropathic pain are required to confirm a clinically relevant, improvement in the treatment of this condition. PMID:15561385

Berman, Jonathan S; Symonds, Catherine; Birch, Rolfe

2004-12-01

416

The CDF Central Outer Tracker  

SciTech Connect

We describe the CDF Central Outer Tracker (COT), an open-cell drift chamber currently being constructed for the CDF detector to run at the upgraded Fermilab Tevatron collider. This detector will provide central tracking with excellent momentum resolution in the high- density environment of a hadron collider. It will be able to resolve 132 ns beam crossings and provide tracking trigger information to the Level 1 trigger. The design is based upon the existing and successful CDF Central Tracking Chamber. The preliminary mechanical and electrical designs are presented. 5 refs., 5 figs., 1 tab.

Pitts, K.T.; CDF Collaboration

1997-01-01

417

Radiative forcing and climate impact resulting from SO2 injections based on a 200,000-year record of Plinian eruptions along the Central American Volcanic Arc  

NASA Astrophysics Data System (ADS)

We present for the first time a self-consistent methodology connecting volcanological field data to global climate model estimates for a regional time series of explosive volcanic events. Using the petrologic method, we estimated SO2 emissions from 36 detected Plinian volcanic eruptions occurring at the Central American Volcanic Arc (CAVA) during the past 200,000 years. Together with simple parametrized relationships collected from past studies, we derive estimates of global maximum volcanic aerosol optical depth (AOD) and radiative forcing (RF) describing the effect of each eruption on radiation reaching the Earth's surface. In parallel, AOD and RF time series for selected CAVA eruptions are simulated with the global aerosol model MAECHAM5-HAM, which shows a relationship between stratospheric SO2 injection and maximum global mean AOD that is linear for smaller volcanic eruptions (<5 Mt SO2) and nonlinear for larger ones (?5 Mt SO2) and is qualitatively and quantitatively consistent with the relationship used in the simple parametrized approximation. Potential climate impacts of the selected CAVA eruptions are estimated using an earth system model of intermediate complexity by RF time series derived by (1) directly from the global aerosol model and (2) from the simple parametrized approximation assuming a 12-month exponential decay of global AOD. We find that while the maximum AOD and RF values are consistent between the two methods, their temporal evolutions are significantly different. As a result, simulated global maximum temperature anomalies and the duration of the temperature response depend on which RF time series is used, varying between 2 and 3 K and 60 and 90 years for the largest eruption of the CAVA dataset. Comparing the recurrence time of eruptions, based on the CAVA dataset, with the duration of climate impacts, based on the model results, we conclude that cumulative impacts due to successive eruptions are unlikely. The methodology and results presented here can be used to calculate approximate volcanic forcings and potential climate impacts from sulfur emissions, sulfate aerosol or AOD data for any eruption that injects sulfur into the tropical stratosphere.

Metzner, D.; Kutterolf, S.; Toohey, M.; Timmreck, C.; Niemeier, U.; Freundt, A.; Krüger, K.

2012-09-01

418

Central Europe Today  

NSDL National Science Digital Library

If you are interested in reading news directly from Central Europe, then this is the publication for you. Central Europe Today is a daily English language radio news magazine syndicated throughout Central Europe.

419

Comparative evaluation of ceramic bracket base designs.  

PubMed

Since the initial introduction of ceramic brackets, base designs have been modified to reduce tooth damage during debonding. The purpose of this study was to compare shear and tensile bond strengths and fracture sites of four second-generation ceramic brackets: Allure IV (A) (GAC International, Inc., Central Islip, N.Y.), Ceramaflex (C) (TP Orthodontics, Inc., LaPorte, Ind.), Intrigue (I) (Lancer Orthodontics, Carlsbad, Calif.), Transcend 2000 (T) (Unitek Corp., Monrovia, Calif.), and a foil-mesh base stainless steel bracket, DynaBond II (D) (Unitek Corp., Monrovia, Calif.). Twenty brackets of each type were bonded to 100 mandibular bovine incisor teeth with Concise bonding adhesive. The samples were thermocycled for 24 hours and the brackets were debonded with an Instron universal testing machine (Instron Corp., Canton, Mass.). A modified Transcend debonding instrument was used for tensile debonding, whereas a chisel was used for shear debonding. An analysis of variance was performed with a 0.05 level of confidence. Mean shear strengths (kg/cm2) necessary to debond were 174.0 (A), 71.0 (C), 189.0 (I), 228.0 (T), and 160.0 (D). Mean tensile strengths (kg/cm2) were 27.0 (A), 26.7 (C), 51.3 (I), 56.5 (T), and 48.6 (D). Fracture sites examined with a light microscope showed no enamel damage with any of the ceramic brackets. Intrigue was the only bracket to fracture and had 30% bracket fracture in the tensile mode and 20% bracket fracture in the shear mode. The percentage of fractures at the adhesive-bracket base interface for shear and tensile modes, respectively, were 80, 100 (A); 100, 90 (C); 10, 60 (I); 60, 90 (T); and 90, 80 (D).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8198079

Bordeaux, J M; Moore, R N; Bagby, M D

1994-06-01

420

Central American electrical interconnection  

SciTech Connect

A technical cooperation grant of $2.25 million, designed to strengthen the capacity of Central American countries to operate their regional interconnected electrical system, was announced by the Inter-American Development Bank (IDB). The grant, extended from the banks Fund for Special Operations, will help improve the capacity of the regions electric power companies to achieve economical, safe operation of the interconnected electric power systems. The funds will also be used to finance regional studies of the accords, procedures, regulations, and supervisory mechanisms for the system, as well as program development and data bases.

Not Available

1988-12-01