Development of Oral Communication in Infants with a Profound Hearing Loss: Pre- and Post-cochlear Implantation

An in-depth, longitudinal study of the speech and oral language development of eight infants with a profound hearing loss who receive early interventions focused on developing their auditory, speech and oral language capacity is presented in this thesis. Infants were tracked for two years, during the period when they are changed from a hearing aid to a cochlear implant. All infants in this study had their hearing loss identified early and were fitted with hearing aids between 1 and 7 months of age and received their cochlear implant between 8 and 16 months of age. They attended a number of different auditory-verbal early intervention programs (depending on where they lived) all of which focused on developing speech and language skills through listening. Attendance at their particular early intervention program at least once a week was in addition to weekly attendance the Sydney Cochlear Implant Centre for therapy and audiological services. A broad range of measures has been used to track the infants’ acquisition of oral language skills, including measures of communicative intention, pre-speech and speech development, and oral language development. Despite a wide range of individual differences across the group of infants, the results suggest some general trends. In the area of communicative intent most infants followed typical development patterns in terms of both the types (e.g. requesting, answering etc) and forms (gestural, vocal, verbal) used, but they showed delays in their frequency of usage of these types and forms. For speech development the infants demonstrated typical speech skills by 18-months post-cochlear implantation in the areas of consonant inventories, severity of phonological involvement (speech intelligibility) and phonological process development, but they showed delays in vowel and consonant acquisition. Finally, for language development the infants were delayed relative to typical development at 18 months post-implantation. The findings support and extend previous studies which have demonstrated the benefits of early intervention for communication development in infants with hearing loss (Calderon & Naidu, 2000; Mayne, Yoshinaga-Itano & Sedey, 2000; Moeller, 2000; Yoshinaga-Itano & Apuzzo, 1998). However, the delays in the oral communication skills of the infants in the current study suggest that more intensive long-term intervention is required if the infants are to attain typical oral speech and language development. The findings capture the complexity of early oral language development, which has been lacking in previous studies of infants with significant hearing loss, receiving a cochlear implant (Dettman, Briggs, & Dowell, 2005; Houston, Ying, Pisoni, & Iler Kirk, 2003; Schauwers, Gillis, Daemers, De Beukelaer, & Govaerts, 2004). The present data also provide some limited support for earlier implantation, that is, before 12 months of age, as the infants made little progress in oral language development while using hearing aids. The reduced amount of auditory signal available to them prior to implantation may be the determining factor in their inability to follow typical rates and patterns of development. However, rates of development with the implant were not straightforward and further research on this population is needed. Universal neonatal screening programs for hearing loss will potentially provide a larger population of early identified infant for future research. This will create the opportunity for large scale, prospective, longitudinal, studies examining the acquisition of speech and oral language development. Limitations of this study, tracking the early stages of speech and language development over a two year period are identified. Future studies are needed to follow the infants for a longer time to determine if their rate of development is sufficient for them to catch up in areas of delay and maintain their performance in areas where they match their typically developing peers

The effect of deformation on dispersion hardened alloys Final report

High temperature tensile properties of TD nickel after mechanical working and recrystallization treatment

Impact resistant boron/aluminum composites for large fan blades

Blade-like specimens were subjected to static ballistic impact testing to determine their relative FOD impact resistance levels. It was determined that a plus or minus 15 deg layup exhibited good impact resistance. The design of a large solid boron/aluminum fan blade was conducted based on the FOD test results. The CF6 fan blade was used as a baseline for these design studies. The solid boron/aluminum fan blade design was used to fabricate two blades. This effort enabled the assessment of the scale up of existing blade manufacturing details for the fabrication of a large B/Al fan blade. Existing CF6 fan blade tooling was modified for use in fabricating these blades

Artificial Metalloenzymes as Catalysts for Oxidative Lignin Degradation

We report novel artificial metalloenzymes (ArMs), containing tris­(pyridylmethyl)­amine (TPA), for the atom economic oxidation of lignin β-O-4 model compounds, using hydrogen peroxide. The protein scaffold alters the selectivity of the reaction from a low yielding cleavage reaction when using the parent Fe-tpa complex to a high yielding benzylic alcohol oxidation when using the complex incorporated into a protein scaffold, SCP-2L A100C. Engineering the protein scaffold to incorporate glutamic acid was found to improve the ArM activity, showing that rational design of the protein environment using metal binding amino acids can be a first step toward improving the overall activity of an artificial metalloenzyme

Engineering Thermostability in Artificial Metalloenzymes to Increase Catalytic Activity

Protein engineering has shown widespread use in improving the industrial application of enzymes and broadening the conditions they are able to operate under by increasing their thermostability and solvent tolerance. Here, we show that protein engineering can be used to increase the thermostability of an artificial metalloenzyme. Thermostable variants of the human steroid carrier protein 2L, modified to bind a metal catalyst, were created by rational design using structural data and a 3DM database. These variants were tested to identify mutations that enhanced the stability of the protein scaffold, and a significant increase in melting temperature was observed with a number of modified metalloenzymes. The ability to withstand higher reaction temperatures resulted in an increased activity in the hydroformylation of 1-octene, with more than fivefold improvement in turnover number, whereas the selectivity for linear aldehyde remained high up to 80%

First observation of the KS->pi0 gamma gamma decay

Using the NA48 detector at the CERN SPS, 31 KS->pi0 gamma gamma candidates with an estimated background of 13.7 +- 3.2 events have been observed. This first observation leads to a branching ratio of BR(KS->pi0 gamma gamma) = (4.9 +- 1.6(stat) +- 0.9(syst)) x 10^-8 in agreement with Chiral Perturbation theory predictions.Comment: 10 pages, 4 figures submitted to Phys. Lett.

A precision measurement of direct CP violation in the decay of neutral kaons into two pions

The direct CP violation parameter Re(epsilon'/epsilon) has been measured from the decay rates of neutral kaons into two pions using the NA48 detector at the CERN SPS. The 2001 running period was devoted to collecting additional data under varied conditions compared to earlier years (1997-99). The new data yield the result: Re(epsilon'/epsilon) = (13.7 +/- 3.1) times 10^{-4}. Combining this result with that published from the 1997, 98 and 99 data, an overall value of Re(epsilon'/epsilon) = (14.7 +/- 2.2) times 10^{-4} is obtained from the NA48 experiment.Comment: 19 pages, 5 figures, to be published in Physics Letters

Search for CP violation in K0 -> 3 pi0 decays

Using data taken during the year 2000 with the NA48 detector at the CERN SPS, a search for the CP violating decay K_S -> 3 pi0 has been performed. From a fit to the lifetime distribution of about 4.9 million reconstructed K0/K0bar -> 3 pi0 decays, the CP violating amplitude eta_000 = A(K_S -> 3 pi0)/A(K_L -> 3 pi0) has been found to be Re(eta_000) = -0.002 +- 0.011 +- 0.015 and Im(eta_000) = -0.003 +- 0.013 +- 0.017. This corresponds to an upper limit on the branching fraction of Br(K_S -> 3 pi0) < 7.4 x 10^-7 at 90% confidence level. The result is used to improve knowledge of Re(epsilon) and the CPT violating quantity Im(delta) via the Bell-Steinberger relation.Comment: 18 pages, 7 figures, submitted to Phys. Lett.

GSK3-mediated raptor phosphorylation supports amino acid-dependent Q2 mTORC1-directed signalling

The mammalian or mechanistic target of rapamycin (mTOR) complex 1 (mTORC1) is a ubiquitously expressed multimeric protein kinase complex that integrates nutrient and growth factor signals for the co-ordinated regulation of cellular metabolism and cell growth. Herein, we demonstrate that suppressing the cellular activity of glycogen synthase kinase-3 (GSK3), by use of pharmacological inhibitors or shRNA-mediated gene silencing, results in substantial reduction in amino acid (AA)-regulated mTORC1-directed signalling, as assessed by phosphorylation of multiple downstream mTORC1 targets. We show that GSK3 regulates mTORC1 activity through its ability to phosphorylate the mTOR-associated scaffold protein raptor (regulatory-associated protein of mTOR) on Ser(859). We further demonstrate that either GSK3 inhibition or expression of a S859A mutated raptor leads to reduced interaction between mTOR and raptor and under these circumstances, irrespective of AA availability, there is a consequential loss in phosphorylation of mTOR substrates, such as p70S6K1 (ribosomal S6 kinase 1) and uncoordinated-51-like kinase (ULK1), which results in increased autophagic flux and reduced cellular proliferation

A new measurement of direct CP violation in two pion decays of the neutral kaon

The NA48 experiment at CERN has performed a new measurement of direct CP violation, based on data taken in 1997 by simultaneously collecting K_L and K_S decays into pi0pi0 and pi+pi-. The result for the CP violating parameter Re(epsilon'/epsilon) is (18.5 +/- 4.5(stat)} +/- 5.8 (syst))x10^{-4}.Comment: 18 pages, 6 figure