Tissue-conducted spatial sound fields

We describe experiments using multiple cranial transducers to achieve auditory spatial perceptual impressions via bone (BC) and tissue conduction (TC), bypassing the peripheral hearing apparatus. This could be useful in cases of peripheral hearing damage or where ear-occlusion is undesirable. Previous work (e.g. Stanley and Walker 2006, MacDonald and Letowski 2006)1,2 indicated robust lateralization is feasible via tissue conduction. We have utilized discrete signals, stereo and first order ambisonics to investigate control of externalization, range, direction in azimuth and elevation, movement and spaciousness. Early results indicate robust and coherent effects. Current technological implementations are presented and potential development paths discussed

Hearing Without Ears

We report on on-going work investigating the feasibility of using tissue conduction to evince auditory spatial perception. Early results indicate that it is possible to coherently control externalization, range, directionality (including elevation), movement and some sense of spaciousness without presenting acoustic signals to the outer ear. Signal control techniques so far have utilised discrete signal feeds, stereo and 1st order ambisonic hierarchies. Some deficiencies in frontal externalization have been observed. We conclude that, whilst the putative components of the head related transfer function are absent, empirical tests indicate that coherent equivalents are perceptually utilisable. Some implications for perceptual theory and technological implementations are discussed along with potential practical applications and future lines of enquiry

Inside-outside: 3-D music through tissue conduction

Eliciting an auditory perception by means of mechanical transduction bypassing the peripheral hearing apparatus has been recorded as early as the 16th century. Excluding its audiometric use to assess ear pathology, bone and soft tissue conduction has received very little interest until the last two decades. Previous work during this time (Stanley and Walker 2006, MacDonald and Letowski 2006) has indicated robust lateralization is feasible via mechanical transduction. We have extended this, adding the front-back and up-down axes

Arms Control: A Naval Perspective

The U.S. Navy recognizes that arms control, both as a process and a goal, is a prominent feature of today\u27s international security evironment. Arms control is often protrayed as an attractive method for reducing the threat to national security and thus permitting reduced levels of defense spending. Public enthusiasm and political support for arms control reductions and agreements have been focused by a series of events

A critical review of some textbooks used for the teaching of ecology in Standard 8 biology

Quantitative and qualitative analyses of prescribed standard eight biology textbooks are discussed in relation to the teaching of the ecology syllabus, an area which is very important in understanding the bio-physical aspect of environmental education. The analysis identifies some of the problems of relying solely on prescribed texts for instruction and considers some of the facets that need to be addressed in the compilation of texts for use by teachers and pupils

Advances in the pathophysiology and treatment of heparin-induced thrombocytopenia.

PURPOSE OF REVIEW: To review the recent developments in understanding the pathophysiology of heparin-induced thrombocytopenia (HIT) and in applying this knowledge to the treatment of patients with suspected and proven HIT. RECENT FINDINGS: HIT pathophysiology is dynamic and complex. HIT pathophysiology is initiated by four essential components--heparin (Hep), platelet factor 4 (PF4), IgG antibodies against the Hep-PF4 complex, and platelet FcγRIIa. HIT is propagated by activated platelets, monocytes, endothelial cells, and coagulation proteins. Insights into the unique HIT antibody response continue to emerge, but without consensus as to the relative roles of B cells, T cells, and antigen-presenting cells. Platelet activation via FcγRIIa, the sine qua non of HIT, has become much better appreciated. Therapy remains challenging for several reasons. Suspected HIT is more frequent than proven HIT, because of the widespread use of Hep and the inadequacies of current diagnostic tests and scoring systems. In proven HIT, approved treatments reduce but do not eliminate thrombosis, and have substantial bleeding risk. Rational novel therapeutic strategies, directed at the initiating steps in HIT pathophysiology and with potential combinations staged over time, are in various phases of development. SUMMARY: Progress continues in understanding the breadth of molecular and cellular players in HIT. Translation to improved diagnosis and treatment is needed

Water-use efficiency and the effect of water deficits on crop growth and yield of Kabuli chickpea (Cicer arietinum L.) in a cool-temperate subhumid climate

The present study was conducted from 1998 to 2000, to evaluate seasonal water use and soil-water extraction by Kabuli chickpea (Cicer arietinum L.). The response of three cultivars to eight irrigation treatments in 1998/99 and four irrigation treatments in 1999/2000 at different growth stages was studied on a Wakanui silt loam soil in Canterbury, New Zealand. Evapotranspiration was measured with a neutron moisture meter and water use efficiency (WUE) was examined at crop maturity. Water use was about 426 mm for the fully irrigated treatment and at least 175 mm for the non-irrigated plants. There was a significant correlation (P<0·001) between water use and biomass yield (R²=0·80) and water use and seed yield (R²=0·75). There were also highly significant (P<0·001) interacting effects of irrigation, sowing date and cultivar on WUE and the trend was similar to that for seed yield. The estimated WUE ranged from 22–29 kg DM/ha per mm and 10–13 kg seed yield/ha per mm water use. The three chickpea cultivars were capable of drawing water from depths greater than 60 cm. However, most of the water use (0·49–0·93 mm/10 cm soil layer per day) came from the top 0–30 cm, where most of the active roots were concentrated. The study has shown that using actual evapotranspiration and water-use efficiency, the biomass yield and seed yield of Kabuli chickpeas can be accurately predicted in Canterbury. Soil water shortage has been identified as a major constraint to increasing chickpea production. Drought was quantified using the concept of maximum potential soil moisture deficit (Dpmax) calculated from climate data. Drought responses of yield, phenology, radiation use efficiency and yield components were determined, and were highly correlated with Dpmax. The maximum potential soil moisture deficit increased from about 62 mm (irrigated throughout) to about 358 mm (dryland plots). Chickpea yield, intercepted radiation and the number of pods per plant decreased linearly as the Dpmax increased. Penman's irrigation model accurately described the response of yield to drought. The limiting deficit for this type of soil was c. 165 and 84 mm for the November and December sowings in 1998/99 and 170 mm in 1999/2000. Beyond these limiting deficits, yield declined linearly with maximum potential soil moisture deficits of up to 358 mm. There was little evidence to support the idea of a moisture sensitive period in these Kabuli chickpea cultivars. Yield was increased by irrigating at any stage of crop development, provided that the water was needed as determined by the potential soil moisture deficit and sowing early in the season

Low input weed management in field peas

Two trials were conducted on a Templeton silt loam soil at Lincoln University, New Zealand (43 ° 38' S, 172 ° 28' E.) in 2007/08. The aim was to compare the competitive ability of different pea canopy architectures as influenced by genotype, population, sowing date and their interaction as a means of low input weed control strategy. The first experiment had three sowing dates, two pea genotypes and two herbicide treatments. Experiment 2 treatments were a factorial combination of four pea populations and three sown artificial weed populations. A significant sowing date x pea genotype interaction showed that in the August sowing genotype had no effect on seed yield. However, in September sown plots Pro 7035 yielded 559 g m⁻², which was 40% more than Midichi, and in the October sowing, the difference was 87% more. Herbicide-sprayed peas produced 19% more seed (508 g m⁻²) than the unsprayed plants. When no weeds were sown, the highest pea total dry matter (TDM) of 1,129 g m⁻² occurred at 200 plants m⁻². This was more than twice (513 g m⁻²) the yield of the lowest population (50 plants m⁻²). There was distinct variation in the weed spectrum over time. Coronopus didymus, Stellaria media and Lolium spp were present in relatively large numbers throughout the season. Some weeds only occurred late in the season meaning they could be successfully controlled by early sowing. It could be concluded that it is possible to obtain high pea yields by using the right sowing date and appropriate seed rate as a means of low input weed management strategy.Lincoln University Research Committee funded this research. Plant Research New Zealand limited provided the pea seed and the fungicides that were used for all the trials

Axillary nodal metastasis at primary presentation of an oropharyngeal primary carcinoma: a case report and review of the literature

<p>Abstract</p> <p>Introduction</p> <p>Axillary nodal metastasis is very rare in head and neck squamous cell carcinoma. The few cases reported in the literature all involve patients who have previously undergone either neck dissection alone, or neck dissection and radiotherapy to the neck, and subsequently develop delayed recurrences of disease, with axillary nodal involvement.</p> <p>Case presentation</p> <p>We present the case of a 62-year-old man of Cape Malay ethnicity, who presented with an oropharyngeal squamous cell carcinoma, and cervical and axillary nodal metastasis at primary presentation.</p> <p>Conclusion</p> <p>Whilst previous reports in the literature suggest routine examination of the axilla is advisable in patients with previously treated neck cancer and recurrence of head and neck cancer, we propose that the axilla should be routinely examined in new cases, particularly when there is involvement of the level 5 nodes.</p