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We investigate the property of strict coherence in the setting of many-valued logics. Our main results read as follows: (i) a map from an MV-algebra to [0,1] is strictly coherent if and only if it satisfies Carnap’s regularity condition, and (ii) a [0,1]-valued book on a finite set of many-valued events is strictly coherent if and only if it extends to a faithful state of an MV-algebra that contains them. Remarkably this latter result allows us to relax the rather demanding conditions for the Shimony-Kemeny characterisation of strict coherence put forward in the mid 1950s in this Journal.
This study aimed to evaluate the presence of the N3 potential (acoustically evoked short latency negative response) in profound sensorineural hearing loss, its association with the cervical vestibular evoked myogenic potential and the relationship between both potentials and loss of auditory function.
Otological examinations of 66 ears from 50 patients aged from 4 to 36 years were performed, and the vestibular evoked myogenic potential and auditory brainstem response were measured.
The N3 potential was recorded in 36 out of 66 ears (55 per cent) and a vestibular evoked myogenic potential was recorded in 34 (52 per cent). The N3 potential was recorded in 23 out of 34 ears (68 per cent) with a vestibular evoked myogenic potential response and absent in 19 out of 32 ears (59 per cent) without a vestibular evoked myogenic potential response. The presence of an N3 potential was significantly associated with a vestibular evoked myogenic potential response (p = 0.028), but there was no significant difference in the latency or amplitude of the N3 potential in either the presence or absence of a vestibular evoked myogenic potential.
The presence of an N3 potential in profound sensorineural hearing loss with good or poor vestibular function can be explained by the contribution of the efferent cochlear pathway through olivocochlear fibres that join the inferior vestibular nerve. This theory is supported by its early latency and reversed polarity, which is masked in normal hearing by auditory brainstem response waves.
A systematic study has been carried out to compare the surface morphology, shell thickness, mechanical properties, and binding behavior of melamine–formaldehyde microcapsules of 5–30 μm diameter size with various amounts of core content by using scanning and transmission electron microscopy including electron tomography, in situ nanomechanical tensile testing, and electron energy-loss spectroscopy. It is found that porosities are present on the outside surface of the capsule shell, but not on the inner surface of the shell. Nanomechanical tensile tests on the capsule shells reveal that Young’s modulus of the shell material is higher than that of bulk melamine–formaldehyde and that the shells exhibit a larger fracture strain compared with the bulk. Core-loss elemental analysis of microcapsules embedded in epoxy indicates that during the curing process, the microcapsule-matrix interface remains uniform and the epoxy matrix penetrates into the surface micro-porosities of the capsule shells.
We provide a new explanation for the narrowing and reversal of the gender education gap. We assume that parents maximize the full income of their children and that males have an additional income, independently of education. This additional income biases preferences toward sons and implies that females have relative advantage in producing income through education. When the returns to human capital are low, the bias toward sons is high, so that parents whose first newborns are females have more children. Consequently, daughters are born to larger families and hence receive less education. As returns to human capital increase, gender differences in producing income diminish, bias toward sons declines, variation in family size falls and the positive correlation between family size and the number of daughters is weakened. Ultimately, the relative advantage of females in education dominates differences in family size, triggering the reversal in the gender education gap.
This paper presents a model of development that is driven by matching between talents and technologies. Differences in productivity across countries are amplified by three dimensions of talent utilization: the range of talents utilized, the density of a specific talent utilized, and the average match quality in the economy. In our model, higher productivity increases the number of technologies available, enhancing the opportunities for individuals to match their talents to specific technologies and increasing the returns to search. More intensive search further contributes to talent utilization.
Focused ion beam (FIB) induced damage in nanocrystalline Al thin films has been characterized using advanced transmission electron microscopy techniques. Electron tomography was used to analyze the three-dimensional distribution of point defect clusters induced by FIB milling, as well as their interaction with preexisting dislocations generated by internal stresses in the Al films. The atomic structure of interstitial Frank loops induced by irradiation, as well as the core structure of Frank dislocations, has been resolved with aberration-corrected high-resolution annular dark-field scanning TEM. The combination of both techniques constitutes a powerful tool for the study of the intrinsic structural properties of point defect clusters as well as the interaction of these defects with preexisting or deformation dislocations in irradiated bulk or nanostructured materials.
The suitability of performing laser inferior turbinectomy under local anaesthesia in an out-patient setting was assessed, regarding its effectiveness and patients' toleration of the procedure. Prospective data collection was undertaken from 129 patients undergoing laser inferior turbinectomy over four years. Patients were assessed, pre-operatively, operatively and at two weeks and three months post-operatively, for pain, complications and symptoms, using the sino-nasal assessment questionnaire.
All patients had hypertrophied inferior turbinates. Ninety-eight patients complained of nasal obstruction and 67 had the procedure as part of treatment for snoring. One hundred and twenty-one of the patients had treatment to both inferior turbinates. There were no cases of intra-operative haemorrhage. The average pre-operative sino-nasal assessment questionnaire score was 18.22, which improved to 10.68 at the three month post-operative assessment (p<0.001). Five patients had significant intra-operative pain.
This study shows that laser inferior turbinectomy under local anaesthesia is well tolerated and that good results can be achieved when performing the procedure in the out-patient department.
4H-SiC samples are bent in compression mode at 550°C and 620°C. The introduced-defects are identified by Weak Beam and HRTEM techniques. They consist of double stacking faults bounded by 30° Si(g) partial dislocations whose glide locally transforms the material in its cubic phase. The velocity of partial dislocations is measured after chemical etching of the sample surface. The formation and the expansion of the double stacking faults are discussed.
The clinical and radiological differential diagnosis of cystic lesions of the submandibular region can be difficult. We report an unusual case of a submandibular salivary duct cyst mimicking an external laryngocele on presentation by appearing to expand on Valsalva manoeuvre, and where computed tomography (CT) scanning was unhelpful in reaching a diagnosis. We present the case, discuss the theories of pathogenesis, and review the literature on the differential diagnosis of cystic lesions in the submandibular region.
An EcoRI 1428 bp A+T-rich, DNA element (MYCDIRE: MYCorrhizal fungus DIspersed Repetitive Element) has been identified in
the genome of Scutellospora castanea, an arbuscular mycorrhizal fungus. After sequencing, primers were designed and used in PCR
reactions to amplify portions of this element in five species of arbuscular mycorrhizal fungi belonging to four genera of Glomales.
Southern hybridizations and partial analysis of the main PCR products confirmed that this element was highly conserved in all the
species. Southern blot analysis of single and double digested DNA from two of the glomalean fungi gave smears suggesting that
MYCDIRE is scattered throughout the fungal genome. Sequence analyses revealed three copies of a previously reported
autonomously replicating sequence (ARS) from Saccharomyces cerevisiae and comparisons indicated similarities of MYCDIRE with the
autonomously replicating, A+T-rich element (ACARS) from Acremonium chrysogenum.
There is controversy whether idiopathic mid-line destructive disease remains a valid entity, some authors considering that such cases are unrecognized malignant lymphoma or Wegener's disease. A case is presented in which numerous nasal biopsies over several years failed to show evidence of either lymphoma or Wegener's disease. Molecular genetic analysis of archival tissue did not demonstrate a monoclonal lymphoid population. It is proposed that idiopathic mid-line destructive disease remains a valid description in a small number of cases.
An important part of the initial assessment of children presenting with congenital nasal masses is to exclude an intracranial extension using either magnetic resonance imaging (MRI) or computed tomography (CT) imaging.
We present three patients with such lesions in which unusual radiological findings were noted as part of the investigations.
The differential diagnosis of stridor in an infant depends on a careful history and examination, followed by radiological and endoscopic investigations. Currently a chest, lateral neck and antero-posterior, high kilovolt (Cincinnatti) view radiographs in association with a diagnostic barium swallow are performed prior to the definitive diagnostic procedure of microlaryngobronchoscopy.
Our impression was that some of the routinely ordered radiological investigations were of limited value in the differential diagnosis. We undertook a retrospective audit study to determine the value of radiological investigations in the pre-endoscopic assessment of infants with stridor. The radiological and endoscopic information of 100 infants presenting over the three-year period 1991–1993 at Great Ormond Street Hospital, London (a tertiary referral centre) was collected.
It was found that only five out of 65 barium swallow investigations performed had consistent positive findings at diagnostic microlaryngobronchoscopy. The lateral neck and Cincinnatti views identified many of the more gross pathologies of the larynx and trachea e.g. the space occupying lesions, which occur infrequently. The more common diseases e.g. laryngomalacia or subglottic stenosis are rarely identified radiologically.
Our results confirmed that radiology had a limited screening role and that in a child presenting with stridor the initial radiological assessment should be a chest radiograph with further imaging and a barium swallow only if an abnormality is found at microlaryngobronchoscopy.
Laryngotracheal injuries are relatively rare but their mortality rate is fairly high. Complete disruption of the trachea is extremely rare and a systematic approach is needed for early diagnosis and favourable outcome. The patient's symptoms and physical signs do not necessarily correlate with the severity of the injury as this case report highlights. X-rays, CT scans, barium swallows and endoscopies are recommended for evaluation of such injuries. However, direct laryngoscopy and fibre optic bronchoscopy are the most accurate.
Two cases of hereditary haemorrhagic telangiectasia are presented. Epistaxis was intractable in both patients. Young's procedure proved successful in controlling nose bleeds. One of the patients has been followed-up for 14 years. Methods of treatment are discussed with a review of the literature.
The synchronous or metachronous occurrence of two tumours of the salivary glands in one patient is rare. These are mainly benign and of the same histological type. Here we report a 56-year-old man who developed a mucoepidermoid tumour of the left parotid gland four years after diagnosis of adenoid cystic carcinoma of the right submandibular gland. This combination of neoplasms has not to our knowledge been reported before.
Metastatic carcinoma involving the temporal bone is extremely rare. A case is reported with an unusual presentation – recurrent episodes of acute mastoiditis. Mastoid exploration and biopsy established the diagnosis. We believe this to be the first reported case to present in this manner.