Tear film surface quality with rigid and soft contact lenses

Objectives: To measure tear film surface quality (TFSQ) using dynamic high-speed videokeratoscopy during short-term (8 hours) use of rigid and soft contact lenses. Methods: A group of fourteen subjects wore 3 different types of contact lenses on 3 different non-consecutive days (order randomized) in one eye only. Subjects were screened to exclude those with dry eye. The lenses included a PMMA hard, an RGP (Boston XO) and a soft silicone hydrogel lens. Three 30 second long high speed videokeratoscopy recordings were taken with contact lenses in-situ, in the morning and again after 8 hours of contact lens wear, both in normal and suppressed blinking conditions. Recordings were also made on a baseline day with no contact lens wear. Results: The presence of a contact lens in the eye had a significant effect on the mean TFSQ in both natural and suppressed blinking conditions (p=0.001 and p=0.01 respectively, repeated measures ANOVA). TFSQ was worse with all the lenses compared to no lens in the eye (in the afternoon during both normal and suppressed blinking conditions (all p<0.05). In natural blinking conditions, the mean TFSQ for the PMMA and RGP lenses was significantly worse than the baseline day (no lens) for both morning and afternoon measures (p<0.05). Conclusions: This study shows that both rigid and soft contact lenses adversely affect the TFSQ in both natural and suppressed blinking conditions. No significant differences were found between the lens types and materials. Keywords: Tear film surface quality, rigid contact lens, soft contact lens, dynamic high-speed videokeratoscopy

Identifying customer behaviour and dwell time using soft biometrics

In a commercial environment, it is advantageous to know how long it takes customers to move between different regions, how long they spend in each region, and where they are likely to go as they move from one location to another. Presently, these measures can only be determined manually, or through the use of hardware tags (i.e. RFID). Soft biometrics are characteristics that can be used to describe, but not uniquely identify an individual. They include traits such as height, weight, gender, hair, skin and clothing colour. Unlike traditional biometrics, soft biometrics can be acquired by surveillance cameras at range without any user cooperation. While these traits cannot provide robust authentication, they can be used to provide identification at long range, and aid in object tracking and detection in disjoint camera networks. In this chapter we propose using colour, height and luggage soft biometrics to determine operational statistics relating to how people move through a space. A novel average soft biometric is used to locate people who look distinct, and these people are then detected at various locations within a disjoint camera network to gradually obtain operational statistics

Inactivation and structural changes of E. Cloacae and B. Subtilis Endospores during IR laser water treatment

IR radiation has been studied for micro-organism inactivation of bacterial spores on metal substrates [1] and on metal and paper substrates [2]. A near-point near infrared laser water treatment apparatus for use in dental hand-pieces was also developed [3]. To date water sterilisation research using a mid-IR laser technique is very rare. According to the World Health Organisation [4], examinations for faecal indicator bacteria remain the most sensitive and specific way of assessing the hygienic quality of water. Bacteria that fall into this group are E. coli, other coliform bacteria (including E. cloacae) and to a lesser extent, faecal streptococci [5]. Protozoan cysts from organisms which cause giardiasis are the most frequently identified cause of waterborne diseases in developed countries [6,7]. The use of aerobic bacterial endospores to monitor the efficiency of various water treatments has been shown to provide a reliable and simple indicator of overall performance of water treatment[8,9].The efficacy of IR radiation for water disinfection compared to UV treatment has been further investigated in the present study. In addition FTIR spectroscopy in conjunction with Principle Component Analysis was used to characterise structural changes within the bacterial cells and endospores following IR laser treatment. Changes in carbohydrate content of E. cloacae following IR laser treatment were observed.

Towards determining soft tissue properties for modelling spine surgery : current progress and challenges

Current complication rates for adolescent scoliosis surgery necessitate the development of better surgical planning tools to improve outcomes. Here we present our approach to developing finite element models of the thoracolumbar spine for deformity surgery simulation, with patient-specific model anatomy based on low-dose pre-operative computed tomography scans. In a first step towards defining patient-specific tissue properties, an initial 'benchmark' set of properties were used to simulate a clinically performed pre-operative spinal flexibility assessment, the fulcrum bending radiograph. Clinical data for ten patients were compared with the simulated results for this assessment and in cases where these data differed by more than 10%, soft tissue properties for the costo-vertebral joint (CVJt) were altered to achieve better agreement. Results from these analyses showed that changing the CVJt stiffness resulted in acceptable agreement between clinical and simulated flexibility in two of the six cases. In light of these results and those of our previous studies in this area, it is suggested that spinal flexibility in the fulcrum bending test is not governed by any single soft tissue structure acting in isolation. More detailed biomechanical characterisation of the fulcrum bending test is required to provide better data for determination of patient-specific soft tissue properties.

Hydrogen-bonding in the structures of the 1:1 salts of isonipecotamide with a set of four polyfunctional monocyclic heteroaromatic carboxylic acids

The crystal structures of the 1:1 proton-transfer compounds of isonipecotamide (piperidine-4-carboxamide) with the monocyclic heteroaromatic carboxylic acids, isonicotinic acid, picolinic acid, dipicolinic acid and pyrazine-2,3-dicarboxylic acid have been determined at 200 K and their hydrogen-bonding patterns examined. The compounds are respectively anhydrous 4-carbamoylpiperidinium pyridine-4-carboxylate (1), the partial hydrate 4-carbamoylpiperidinium pyridine-2-carboxylate 0.25 water (2), the solvate 4-carbamoylpiperidinium 6-carboxypyridine-2-carboxylate methanol monosolvate (3), and anhydrous 4-carbamoylpiperidinium 3-carboxypyrazine-2-carboxylate (4). In compounds 1 and 3, hydrogen-bonding interactions give two-dimensional sheet structures which feature enlarged cyclic ring systems, while in compounds 2 and 4, three-dimensional structures are found. The previously described cyclic R2/2(8) hydrogen-bonded amide-amide dimer is present in 2 and 3. The hydrogen-bonding in 2 involves the partial-occupancy water molecule while the structure of 4 is based on inter-linked homomolecular hydrogen-bonded cation-cation and anion-anion associated chains comprising head-to-tail interactions. This work further demonstrates the utility of the isonipecotamide cation in the generation of chemically stable hydrogen-bonded systems, particularly with aromatic carboxylate anions, providing crystalline solids.

Using optical coherence tomography to assess corneoscleral morphology after soft contact lens wear

Purpose. To evaluate the use of optical coherence tomography (OCT) to assess the effect of different soft contact lenses on corneoscleral morphology. Methods. Ten subjects had anterior segment OCT B-scans taken in the morning and again after six hours of soft contact lens wear. For each subject, three different contact lenses were used in the right eye on non-consecutive days, including a hydrogel sphere, a silicone hydrogel sphere and a silicone hydrogel toric. After image registration and layer segmentation, analyses were performed of the first hyper-reflective layer (HRL), the epithelial basement membrane (EBL) and the epithelial thickness (HRL to EBL). A root mean square difference (RMSD) of the layer profiles and the thickness change between the morning and afternoon measurements, was used to assess the effect of the contact lens on the corneoscleral morphology. Results. The soft contact lenses had a statistically significant effect on the morphology of the anterior segment layers (p <0.001). The average amounts of change for the three lenses (average RMSD values) for the corneal region were lower (3.93±1.95 µm for the HRL and 4.02±2.14 µm for the EBL) than those measured in the limbal/scleral region (11.24±6.21 µm for the HRL and 12.61±6.42 µm for the EBL). Similarly, averaged across the three lenses, the RMSD in epithelial thickness was lower in the cornea (2.84±0.84 µm) than the limbal/scleral (5.47±1.71 µm) region. Post-hoc analysis showed that ocular surface changes were significantly smaller with the silicone hydrogel sphere lens than both the silicone hydrogel toric (p<0.005) and hydrogel sphere (p<0.02) for the combined HRL and EBL data. Conclusions. In this preliminary study, we have shown that soft contact lenses can produce small but significant changes in the morphology of the limbal/scleral region and that OCT technology is useful in assessing these changes. The clinical significance of these changes is yet to be determined.

Do thermal agents affect range of movement and mechanical properties in soft tissues? A systematic review

OBJECTIVES: To examine the effect of thermal agents on the range of movement (ROM) and mechanical properties in soft tissue and to discuss their clinical relevance. DATA SOURCES: Electronic databases (Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE) were searched from their earliest available record up to May 2011 using Medical Subjects Headings and key words. We also undertook related articles searches and read reference lists of all incoming articles. STUDY SELECTION: Studies involving human participants describing the effects of thermal interventions on ROM and/or mechanical properties in soft tissue. Two reviewers independently screened studies against eligibility criteria. DATA EXTRACTION: Data were extracted independently by 2 review authors using a customized form. Methodologic quality was also assessed by 2 authors independently, using the Cochrane risk of bias tool. DATA SYNTHESIS: Thirty-six studies, comprising a total of 1301 healthy participants, satisfied the inclusion criteria. There was a high risk of bias across all studies. Meta-analyses were not undertaken because of clinical heterogeneity; however, effect sizes were calculated. There were conflicting data on the effect of cold on joint ROM, accessory joint movement, and passive stiffness. There was limited evidence to determine whether acute cold applications enhance the effects of stretching, and further evidence is required. There was evidence that heat increases ROM, and a combination of heat and stretching is more effective than stretching alone. CONCLUSIONS: Heat is an effective adjunct to developmental and therapeutic stretching techniques and should be the treatment of choice for enhancing ROM in a clinical or sporting setting. The effects of heat or ice on other important mechanical properties (eg, passive stiffness) remain equivocal and should be the focus of future study.

Intercalation of kaolins by alkaline earth metal salts

A suite of new materials, based on chemical modification of kaolins, has been successfully prepared via manipulation of the kaolin structure and subsequent intercalation by CaCl2 and MgCl2. A standard kaolinite(KGa-1)and a commercially available halloysite (New Zealand china clay) were used for this study. The kaolins are given several cycles of intercalation and deintercalation using a common intercalant such as potassium acetate. The number of cycles given depends on the type of kaolin. After this treatment, both kaolinite and halloysite hydrate show considerable broadening of the (00l) reflections which indicate extensive exfoliation of the layers. In the case of kaolinite, exfoliated layers roll to form tubes similar to proper halloysite. Kaolins modified by the above treatment readily intercalate MgCl2 and CaCl2 from saturated solutions of these salts. On intercalation with CaCl2 and MgCl2, kaolinite layers expand to 10A and 9.8A, and those of halloysite to 12.8A and 15.5A, respectively. To our knowledge, this is the first report of successful intercalation of alkaline-earth halides by kaolins.

Modified kaolins

A process for the preparation of a modified kaolin from a kaolin group mineral which includes expansion and contraction of layers of the kaolin group mineral. The layers comprising one Si-tetrahedral sheet and one Al-octahedral sheet. The expansion and contraction may be initiated by initial intercalation of a reagent which can penetrate kaolin layers to reach an interlayer region there between to form an intercalate. Subsequently, the intercalation may be followed by de-intercalation which involves the removal of the reagent. By the above process, there is provided crystalline modified kaolins having the following properties: (i) an increased interlayer space compared to corresponding kaolin group minerals; (ii) an increased susceptibility to intercalation by cations, anions or salts compared to corresponding kaolin group minerals; and (iii) an increased exfoliated morphology compared to corresponding kaolin group minerals.

Soft power in China : public diplomacy through communication [Review]

Review of Soft Power in China: Public diplomacy through communication, edited by J IAN WANG, New York, Palgrave Macmillan, 2011, US$89 (hard), 220 pp

Who's afraid of China? The challenge of Chinese soft power [Review]

What role does China play in Western imagination and how does it affect Western selfconceptions? The rise of China as an alternative model to Western liberalism has created a fear that developing countries will stray from Western standards of democracy, transparency and human rights. However, such fears often say as much about those who hold them as they do about China itself. In this short and easily readable book Barr holds a mirror to Sino–Western relations in order to better understand how the West’s own past, hopes and fears shape the way it thinks about and engages with China. Focusing on three key areas—models of development, soft power and ethnocentrism—he argues that the rise of China ‘hits a nerve in the Western psyche . . . because its actions reflect the West’s own ambivalence to modernity and uncertainty over the proper role and limits of state power’ (p. 21). To make his point, Barr focuses on China’s soft power and the connections between China’s domestic politics and its attempts to shape its image internationally...

A new model to study healing of a complex femur fracture with concurrent soft tissue injury in sheep

High energy bone fractures resulting from impact trauma are often accompanied by subcutaneous soft tissue injuries, even if the skin remains intact. There is evidence that such closed soft tissue injuries affect the healing of bone fractures, and vice versa. Despite this knowledge, most impact trauma studies in animals have focussed on bone fractures or soft tissue trauma in isolation. However, given the simultaneous impact on both tissues a better understanding of the interaction between these two injuries is necessary to optimise clinical treatment. The aim of this study was therefore to develop a new experimental model and characterise, for the first time, the healing of a complex fracture with concurrent closed soft tissue trauma in sheep. A pendulum impact device was designed to deliver a defined and standardised impact to the distal thigh of sheep, causing a reproducible contusion injury to the subcutaneous soft tissues. In a subsequent procedure, a reproducible femoral butterfly fracture (AO C3-type) was created at the sheep’s femur, which was initially stabilised for 5 days by an external fixator construct to allow for soft tissue swelling to recede, and ultimately in a bridging construct using locking plates. The combined injuries were applied to twelve sheep and the healing observed for four or eight weeks (six animals per group) until sacrifice. The pendulum impact led to a moderate to severe circumferential soft tissue injury with significant bruising, haematomas and partial muscle disruptions. Posttraumatic measurements showed elevated intra-compartmental pressure and circulatory tissue breakdown markers, with recovery to normal, pre-injury values within four days. Clinically, no neurovascular deficiencies were observed. Bi-weekly radiological analysis of the healing fractures showed progressive callus healing over time, with the average number of callus bridges increasing from 0.4 at two weeks to 4.2 at eight weeks. Biomechanical testing after sacrifice showed increasing torsional stiffness between four and eight weeks healing time from 10% to 100%, and increasing ultimate torsional strength from 10% to 64% (relative to the contralateral control limb). Our results demonstrate the robust healing of a complex femur fracture in the presence of a severe soft tissue contusion injury in sheep and demonstrate the establishment of a clinically relevant experimental model, for research aimed at improving the treatment of bone fractures accompanied by closed soft tissue injuries.

A finite element model of seat cushion indentation with a soft tissue human occupant model

Effective digital human model (DHM) simulation of automotive driver packaging ergonomics, safety and comfort depends on accurate modelling of occupant posture, which is strongly related to the mechanical interaction between human body soft tissue and flexible seat components. This paper presents a finite-element study simulating the deflection of seat cushion foam and supportive seat structures, as well as human buttock and thigh soft tissue when seated. The three-dimensional data used for modelling thigh and buttock geometry were taken on one 95th percentile male subject, representing the bivariate percentiles of the combined hip breadth (seated) and buttock-to-knee length distributions of a selected Australian and US population. A thigh-buttock surface shell based on this data was generated for the analytic model. A 6mm neoprene layer was offset from the shell to account for the compression of body tissue expected through sitting in a seat. The thigh-buttock model is therefore made of two layers, covering thin to moderate thigh and buttock proportions, but not more fleshy sizes. To replicate the effects of skin and fat, the neoprene rubber layer was modelled as a hyperelastic material with viscoelastic behaviour in a Neo-Hookean material model. Finite element (FE) analysis was performed in ANSYS V13 WB (Canonsburg, USA). It is hypothesized that the presented FE simulation delivers a valid result, compared to a standard SAE physical test and the real phenomenon of human-seat indentation. The analytical model is based on the CAD assembly of a Ford Territory seat. The optimized seat frame, suspension and foam pad CAD data were transformed and meshed into FE models and indented by the two layer, soft surface human FE model. Converging results with the least computational effort were achieved for a bonded connection between cushion and seat base as well as cushion and suspension, no separation between neoprene and indenter shell and a frictional connection between cushion pad and neoprene. The result is compared to a previous simulation of an indentation with a hard shell human finite-element model of equal geometry, and to the physical indentation result, which is approached with very high fidelity. We conclude that (a) SAE composite buttock form indentation of a suspended seat cushion can be validly simulated in a FE model of merely similar geometry, but using a two-layer hard/soft structure. (b) Human-seat indentation of a suspended seat cushion can be validly simulated with a simplified human buttock-thigh model for a selected anthropomorphism.