Search results for "vertical"
showing 10 items of 417 documents
Vertical stratification patterns of methanotrophs and their genetic controllers in water columns of oxygen-stratified boreal lakes
2021
ABSTRACT The vertical structuring of methanotrophic communities and its genetic controllers remain understudied in the water columns of oxygen-stratified lakes. Therefore, we used 16S rRNA gene sequencing to study the vertical stratification patterns of methanotrophs in two boreal lakes, Lake Kuivajärvi and Lake Lovojärvi. Furthermore, metagenomic analyses were performed to assess the genomic characteristics of methanotrophs in Lovojärvi and the previously studied Lake Alinen Mustajärvi. The methanotroph communities were vertically structured along the oxygen gradient. Alphaproteobacterial methanotrophs preferred oxic water layers, while Methylococcales methanotrophs, consisting of putative…
Long-wavelength monolithic GaInNAs vertical-cavity optical amplifiers
2004
We report on the continuous-wave amplification characteristics of an optically pumped 1.3-μm multiple-quantum-well GaInNAs-GaAs vertical-cavity semiconductor optical amplifier (VCSOA). The VCSOA structure was monolithically grown by molecular beam epitaxy and operated in reflection mode in a fiber-coupled system. The maximum on-chip gain attained, limited by the onset of laser action, was 15.6 dB at 196 mW of 980-nm pump power. For a chip gain of 10.4 dB, the optical bandwidth was 10.8 GHz and the saturation output power was -9 dBm. By varying the pump laser power, a maximum extinction ratio of 22.3 dB was obtained. Temperature-controlled tuneable operation of the device is also presented a…
GaInNAs/GaAs Bragg-mirror-based structures for novel 1.3μm device applications
2004
We report the use of GaInNAs/GaAs material system for a range of 1.3 μm vertical-cavity devices namely VCSELs, VCSOAs, VECSELs and SESAMs. Using optical pumping, we demonstrate that up to 4 mW of 1290 nm output power can be fibre-coupled from a VCSEL. We also show that tayloring the VCSEL structure allows to produce a monolithic long-wavelength VCSOA with up to 16 dB of gain. We also report the first demonstration of a 1.3 μm VECSEL with more than 0.5 W of CW ouptut power. Finally, annealing effects on the properties of a GaInNAs SBR and modelocking of two Nd:doped solid state lasers using this element are described.
Differentiation in knowledge‐creating organizations
2007
PurposeThe purpose of this paper is to focus on the analysis of the influence of organizational design variables on the creation of knowledge within the organization. The impact that enablers have on knowledge creation has been widely demonstrated and established in the relevant literature. Using this assumption as a starting‐point, the main aim of this study is to consider and explore the role of differentiation – horizontal and vertical – in knowledge creation using enablers as mediator variables.Design/methodology/approachThe paper has created a model of relations of the design variables that correspond to differentiation – horizontal job specialization, vertical job specialization and n…
In vivo detection of vertical root fractures in endodontically treated teeth : accuracy of cone-beam computed tomography and assessment of potential …
2021
Background This study aimed: (a) to determine the diagnostic performance of cone-beam computed tomography (CBCT) for detection of vertical root fractures (VRFs); (b) to evaluate the predictive value of diagnostic criteria regarding the definition of VRFs; and (c) to examine the robustness of the association of patient-, tooth-, and treatment-related variables with VRFs. Material and methods 130 root-filled teeth with signs/symptoms of VRFs underwent clinical and CBCT assessments. Definite diagnosis of VRF was confirmed by endodontic microsurgical (EMS) exploration. Determination of diagnostic performance of CBCT was based on standard algorithms derived from two-way contingency table analysi…
Bone height measurement of maxillary and mandibular bones in panoramic radiographs of edentulous patients
2011
Objectives. The purpose of this in vitro study were to determine variation in maxillary and mandibular vertical measurements and to assess vertical bone loss made from panoramic radiographs in edentulous measurements. Study Design. In this descriptive study, a total of 600 panoramic radiograph’s of edentulous patient were examined. The mean ages of edentulous patients were 31 and 87 years respectively. Measurements were made from reference lines drawn from anatomic landmarks on standardized panoramic rediographs. All radiographs were made using a standardized manner by the same technician. Twelve sites were measured on every panoramic radiograph whenever possible, five sites in the maxilla …
A new technique to determine vertical dimension of occlusion from anthropometric measurement of interpupillary distance
2014
Background: A number of techniques are being practiced for the evaluation of VDO, but none of them is scientifically more accurate than other. Each method advocated has its own limitations. Objectives: The purpose of this study was to find correlation between vertical dimension of occlusion (VDO) and interpupillary distance (IPD). Material and Methods: A cross-sectional study was conducted on 400 dentate subjects comprising of 200 males and 200 females. Anthropometric measurement of VDO was recorded clinically using modified digital vernier caliper. Also, a standardized digital photograph of face was generated from the frontal aspect using a digital camera for the measurement of IPD in mill…
Influence of Vertical Dimension of Occlusion on Peak Force During Handgrip Tests in Athletes
2018
Background: In contact sports, such as martial arts, protection from oral injuries is generally recommended. Several authors have focused on the effects of wearing such oral protective gear on sports performances and, in particular, occlusal devices. Although many studies have shown improvements in athletic performance, especially in maximal isometric strength, to date there is still no consensus on the issue. Objectives: The aim of our study was to evaluate differences in isometric handgrip before and after the application of an occlusal splint (OS) in martial arts athletes. Methods: A repeated measures within-subjects design was adopted for the study. Twenty-five young martial arts athlet…
Orthodontics and veneers to restore the anterior guidance. A minimally invasive approach
2017
Tooth wear is defined as the progressive loss of a tooth's surface due to actions other than those which cause tooth decay or dental trauma. It is a pathological condition with an increasing prevalence among young people. The aim of this article is to describe an alternative treatment modality to rehabilitate the anterior guidance by a minimally invasive interdisciplinary ortho-restorative treatment. Two patients came to the dental clinic for restorative treatment in order to rehabilitate the worn anterior dentition. Clinical analysis showed tooth surface loss located at the incisal edges by attrition due to an inadequate anterior guidance. In both cases the occlusal vertical dimension was …
Full mouth functional and aesthetic rehabilitation of a patient affected with hypoplastic type of amelogenesis imperfecta
2020
The management of Amelogenesis imperfecta often poses a challenge for the dentists. It not only includes aesthetic and functional rehabilitation of the patient, but also requires a positive rapport building with the patient due to psychosocial issues. The treatment plan is driven by patient demands, age, cost-affordability, severity of the disease and the presenting condition. The present case report elucidates step by step management of a 20 year-old female who presented with generalized hypersensitivity, intermittent pain associated with multiple decayed posterior teeth, poor dental aesthetics and anterior deep bite. The management consisted of endodontic treatments in all teeth, crown le…