Australian New Zealand Clinical Trials Registry (ANZCTR). ACTRN: ACTRN12611000243910. URL: http://www.ANZCTR.org.au/ACTRN12611000243910.aspx

Variability during spirometry can persist despite control of technical and personal factors. We postulate spirometry induces gastro-oesophageal reflux (GOR), which may cause variability and affect results of spirometry. Fifty-eight (58) subjects undergoing GOR investigation with oesophageal manometry and 24hr pH monitoring were recruited. Oesophageal dysmotility and GOR were assessed as part of clinical care. Subjects performed 2 sets of spirometry separated by a 10-minute rest period. The assessment of GOR during spirometry procedure (defined by a lower oesophageal pH<4) started from the first set of spirometry and concluded when the second set of spirometry was completed. We calculated variability (%) of FEV 1 , FVC and PEFR within each set as well as changes over 10-minutes. Twenty-six subjects (45%) recorded GOR during assessment. Of these, 23 subjects recorded GOR during the 10-minute rest period. Four subjects had GOR recorded only during spirometry tests. We did not find variability of spirometry parameters between the groups with and without GOR during spirometry procedure. However, in subjects with GOR, we found small but significant reductions of PEFR (0.5L/s, 8%, p<0.001) and FEV 1 (84 mL, 3%, p = 0.048) in the second set of spirometry compared to the first spirometry set. This pilot study demonstrates that GOR can occur during and following spirometry. Presence of GOR during spirometry in this patient population caused small decreases in PEFR and FEV 1 when it is repeated 10-minutes later however not increase variability in a single series of measurements.

No abstract

The IEEE 802.16 standard was proposed to provide Broadband Wireless Access for fixed and nomadic subscribers. However, Shon et al [9] identified three vulnerabilities in the existing 802.16 standards. The vulnerabilities are 1) important messages sent during the initial network entry process are not secured in the existing 802.16 standard, 2) there are some Access Network vulnerabilities (the IEEE 802. standard does not cover the security of intra-Access Service Network (intra-ASN) and ASN-to-Connectivity Service Network (ASN-to-CSN) communications) and 3) the HandOver (HO) optimization flags are able to allow malicious users to cause critical security vulnerabilities during the handover process. Shon et al [9] then proposed countermeasures for the above-mentioned vulnerabilities. In this paper, we review Shon et al's countermeasures to initial network entry andAccess Network vulnerabilities and show that their proposed countermeasures are ineffective in preventing attacks to initial network entry and access network communications. We then proposed improved countermeasures that are able to protect against initial network entry and access network communications vulnerabilities.