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The enhanced understanding of nanomaterials properties and processing has led to increased use of nanotechnologies, which has also led to greater scrutiny on the commercialization and acquisition of emerging nanoenabled technologies. Caused by knowledge gaps on the unique behaviors, risks, and liabilities of novel engineered nanomaterials, this caution, when not evidence based, slows production and stifles innovation. Reducing the uncertainty surrounding the environmental risks and benefits of nanoenabled technologies, including their resilience in harsh environments, will speed the development and transition of advanced material technologies. In this work, a multifaceted research program generated data and processes to reduce that environmental uncertainty. Specifically, this case study examined printed, nanoenabled environmental sensors and their components to develop toxicological data and parameterize a life-cycle assessment. The study tested the sensors’ resilience in environmental weathering studies that considered both the potential release of the ingredient nanomaterials and the performance of the sensors after exposure to several harsh environmental climates and then created life-cycle inventories to determine environmental impact and reduce cost of research and development. Finally, this case study developed software tools to mitigate the cost of research and provide a framework for presenting toxicology data.

The evaluation of a pediatric patient with leg pain and/or limping can be challenging in many cases, including younger nonverbal or preverbal children who are unable to characterize or localize the pain, and those with referred pain from sites other than the actual area of pathology. This chapter discusses common causes of hip pathology in pediatric patients presenting with vague upper leg pain without any other systemic symptoms (e.g., fever). It describes the various presentations and differential diagnoses and highlights the importance of initial imaging choice and pertinent radiographic findings. Early diagnosis is critical as delay can lead to significant morbidity.

Researchers have developed numerous per- and polyfluoroalkyl substances (PFAS)-free aqueous film-forming foam (AFFF) formulations to replace PFAS-containing AFFF used for fire suppression. As part of the Department of Defense's Strategic Environmental Research and Development Program (SERDP), we examined the direct lethal effects of seven PFAS-free AFFF and a PFAS-containing AFFF on 14 aquatic species using a series of lethal concentration (LC50) tests. We assessed the LC10, LC50, and LC90 values using log-logistic and logit analyses. Across all aquatic species tested, we discovered that exposure to at least one PFAS-free AFFF was more or as toxic as exposure to the PFAS-containing AFFF. For most cases, National Foam Avio F3 Green KHC 3% and Buckeye Platinum Plus C6MILSPEC 3% were the most and least toxic formulations, respectively. Moreover, we found consistency among results from multiple experiments using the same minnow species (

Technology has changed the way we approach medical care: health data is constantly being generated, medical discoveries are progressing more rapidly, and individuals are more connected across the world than ever before. Backpack Health is a global personal health record platform that harnesses the power of technology to connect users to their primary health data sources, the medical community, and researchers. By syncing with existing patient portals, health data can be stored on the Backpack Health platform and easily accessed and controlled by users in one connected interface. Individuals manage and collate their current and past conditions, genetic test results, symptoms, medications, procedures, labs, and other health data. Users are empowered to disseminate their information to clinicians, researchers, foundations, and pharmaceutical and biotechnology companies they connect with through the Backpack Health application. Here, we describe how two rare disease advocacy groups, The Marfan Foundation and Project Alive, utilize Backpack Health to connect with their target populations. Through secure transfer of pseudonymized data, groups can query their members to improve understanding of clinical features and to facilitate meaningful research. Responses to the groups' surveys show strong member engagement with high completion rates and increases in new Backpack Health users when surveys are deployed. Data from these surveys have been published and used to better inform clinical outcomes for treatment trials. By connecting users directly to the foundations, clinicians, researchers, and industry partners working on their condition, Backpack Health is instrumental in fast-tracking medical discoveries and treatment for rare diseases.

To describe a novel, minimally invasive surgical technique to treat severe, intractable periorbital neuropathic pain.A retrospective analysis of patients with severe, treatment-refractory periorbital pain who underwent transection of affected sensory trigeminal branches with nerve repair was performed. Collected data included etiology and duration of neuropathic pain, comorbidities, prior treatment history, surgical technique including site of transected sensory nerves and type of nerve repair, preoperative and postoperative pain scores as well as follow-up duration. Differences between preoperative and postoperative values were analyzed by the Wilcoxon signed-rank test.A total of 5 patients with severe periorbital neuropathic pain underwent transection of affected supraorbital, supratrochlear, infratrochlear, infraorbital, zygomaticotemporal, and zygomaticofacial nerves with customized nerve reconstruction. All 5 had improvement of periorbital pain after surgery, with 3 (60%) noting complete resolution of pain and 2 (40%) experiencing partial pain relief over a median follow-up period of 9 months (interquartile range [IQR], 6-19 months). Of the 3 patients who had complete resolution of pain, all reported continued pain relief. Median McGill pain scores significantly decreased from 8.4 (IQR, 8.2-10.0) preoperatively to 0.0 (IQR, 0.0-4.8; p0.001) postoperatively. All patients reported satisfaction with the surgical procedure and stated that they would undergo the procedure again if given the option. One patient with history of postherpetic neuralgia (PHN) had reactivation of herpes zoster at postoperative month 3, which was self-limited, without worsening of her neuropathic pain. Another patient with PHN required a staged procedure to achieve complete pain relief.Peripheral neurectomy with customized reconstruction of involved sensory nerves can successfully reduce and even eradicate periorbital neuropathic pain that was previously recalcitrant to combination pharmacotherapy and prior neurolysis procedures.

The impacts of Harmful Algal Blooms (HAB), often caused by cyanobacteria (Figure 1), on water resources are increasing. Innovative solutions for treatment of HABs and their associated toxins are needed to mitigate these impacts and decrease risks without introducing persistent legacy contaminants that cause collateral ecosystem impacts. This technical note (TN) identifies novel opportunities enabled by Additive Manufacturing (AM), or 3D printing, to produce high surface area advanced material composites to rapidly prototype sustainable environmental solutions for aquatic nuisance species control. This innovative research explores deployment of 3D-printable polymer composite structures containing nano-scale photocatalysts for targeted open water treatment of HABs that are customizable to the site-of-concern and also retrievable, reusable, and sustainable. The approach developed to control cyanobacteria HAB events has the potential to augment or replace broadcast, non-specific chemical controls that otherwise put non-target species and ecological resources at long-term risk. It can also augment existing UV-treatment HAB treatment control measures. The expected research outcome is a novel, effective, and sustainable HAB management tool for the US Army Corps of Engineers (USACE) and resource managers to deploy in their HAB rapid response programs. The research will provide a framework for scale-up into other manufacturing methods (e.g., injection molding) to produce the devices in bulk (quickly and efficiently). Research for this project title “Mitigation of Harmful Algal Bloom Toxins using 3D Printed Photocatalytic Materials (FY21-23)” was sponsored by the US Army Engineer Research Development Center’s (ERDC) Aquatic Nuisance Species Research Program (ANSRP).

Degradation of insensitive munitions (IMs) by ultraviolet (UV) light has become a concern following observations that some UV-degradation products have increased toxicity relative to parent compounds in aquatic organisms. This investigation focused on the Army's IM formulation, IMX-101, composed of three IM constituents: 2,4-dinitroanisole (DNAN), 3-nitro-1,2,4-triazol-5-one (NTO), and nitroguanidine (NQ). The IM constituents and IMX-101 were irradiated in a UV photo-reactor and then administered to Daphnia pulex in acute (48 h) exposures comparing toxicities relative to the parent materials. UV-degradation of DNAN had little effect on mortality whereas mortality for UV-degraded NTO and NQ increased by factors of 40.3 and 1240, making UV-degraded NQ the principle driver of toxicity when IMX-101 is UV-degraded. Toxicity investigations for specific products formed during UV-degradation of NQ, confirmed greater toxicity than the parent NQ for degradation products. Summation of the individual toxic units for the complete set of individually measured UV-degradation products identified for NQ only accounted for 25% of the overall toxicity measured in the exposures to the UV-degraded NQ product mixture. Given the underestimation of toxicity using the sum toxic units for the individually measured UV-degradation products of NQ, we conclude that: (1) other unidentified NQ degradation products contributed principally to toxicity and/or (2) synergistic toxicological interactions occurred among the NQ degradation product mixture that exacerbated toxicity.

The US Environmental Protection Agency's short-term freshwater effluent test methods include a fish (Pimephales promelas), a cladoceran (Ceriodaphnia dubia), and a green alga (Raphidocelis subcapitata). There is a recognized need for additional taxa to accompany the three standard species for effluent testing. An appropriate additional taxon is unionid mussels because mussels are widely distributed, live burrowed in sediment and filter particles from the water column for food, and exhibit high sensitivity to a variety of contaminants. Multiple studies were conducted to develop a relevant and robust short-term test method for mussels. We first evaluated the comparative sensitivity of two mussel species (Villosa constricta and Lampsilis siliquoidea) and two standard species (P. promelas and C. dubia) using two mock effluents prepared by mixing ammonia and five metals (cadmium, copper, nickel, lead, and zinc) or a field-collected effluent in 7-day exposures. Both mussel species were equally or more sensitive (more than two-fold) to effluents compared with the standard species. Next, we refined the mussel test method by first determining the best feeding rate of a commercial algal mixture for three age groups (1, 2, and 3 weeks old) of L. siliquoidea in a 7-day feeding experiment, and then used the derived optimal feeding rates to assess the sensitivity of the three ages of juveniles in a 7-day reference toxicant (sodium chloride [NaCl]) test. Juvenile mussels grew substantially (30%-52% length increase) when the 1- or 2-week-old mussels were fed 2 ml twice daily and the 3-week-old mussels were fed 3 ml twice daily. The 25% inhibition concentrations (IC25s) for NaCl were similar (314-520 mg Cl/L) among the three age groups, indicating that an age range of 1- to 3-week-old mussels can be used for a 7-day test. Finally, using the refined test method, we conducted an interlaboratory study among 13 laboratories to evaluate the performance of a 7-day NaCl test with L. siliquoidea. Eleven laboratories successfully completed the test, with more than 80% control survival and reliable growth data. The IC25s ranged from 296 to 1076 mg Cl/L, with a low (34%) coefficient of variation, indicating that the proposed method for L. siliquoidea has acceptable precision. Environ Toxicol Chem 2021;40:3392-3409. © 2021 SETAC.

The TGF-β and Wnt/β-catenin pathways have important roles in modulating CKD, but how these growth factors affect the epithelial response to CKD is not well studied. TGF-β has strong profibrotic effects, but this pleiotropic factor has many different cellular effects depending on the target cell type. To investigate how TGF-β signaling in the proximal tubule, a key target and mediator of CKD, alters the response to CKD, we injured mice lacking the TGF-β type 2 receptor specifically in this epithelial segment. Compared with littermate controls, mice lacking the proximal tubular TGF-β receptor had significantly increased tubular injury and tubulointerstitial fibrosis in two different models of CKD. RNA sequencing indicated that deleting the TGF-β receptor in proximal tubule cells modulated many growth factor pathways, but Wnt/β-catenin signaling was the pathway most affected. We validated that deleting the proximal tubular TGF-β receptor impaired β-catenin activity in vitro and in vivo. Genetically restoring β-catenin activity in proximal tubules lacking the TGF-β receptor dramatically improved the tubular response to CKD in mice. Deleting the TGF-β receptor alters many growth factors, and therefore, this ameliorated response may be a direct effect of β-catenin activity or an indirect effect of β-catenin interacting with other growth factors. In conclusion, blocking TGF-β and β-catenin crosstalk in proximal tubules exacerbates tubular injury in two models of CKD.

Archaeology’s ability to generate long-term datasets of natural and human landscape change positions the discipline as an inter-disciplinary bridge between the social and natural sciences. Using a multi-proxy approach combining archaeological data with palaeoenvironmental indicators embedded in coastal sediments, we outline millennial timescales of lowland landscape evolution in the Society Islands. Geomorphic and cultural histories for four coastal zones on Mo‘orea are reconstructed based on stratigraphic records, sedimentology, pollen analysis, and radiocarbon determinations from mid- to late Holocene contexts. Prehuman records of the island’s flora and fauna are described utilizing landsnail, insect, and botanical data, providing a palaeo-backdrop for later anthropogenic change. Several environmental processes, including sea level change, island subsidence, and anthropogenic alterations, leading to changes in sedimentary budget have operated on Mo‘orea coastlines from c. 4600 to 200 BP. We document significant transformation of littoral and lowland zones which obscured earlier human activities and created significant changes in vegetation and other biota. Beginning as early as 440 BP (1416–1490 cal. ad), a major phase of sedimentary deposition commenced which can only be attributed to anthropogenic effects. At several sites, between 1.8 and 3.0 m of terrigenous sediments accumulated within a span of two to three centuries due to active slope erosion and deposition on the coastal flats. This phase correlates with the period of major inland expansion of Polynesian occupation and intensive agriculture on the island, indicated by the presence of charcoal throughout the sediments, including wood charcoal from several economically important tree species.

Phosphatidylinositol 3-kinases (PI3Ks) are a family of lipid kinases. The PI3K/Akt signalling cascade has crucial roles in many cellular processes associated with malignant behaviour including cell growth, proliferation, migration and survival. Aberrations to this pathway have been detected in many human cancers, including colorectal cancer (CRC). Mutations in the PIK3CA gene, which encodes the p110α catalytic subunit of PI3K, have been identified in up to 30% of sporadic CRCs. However, it is not known at which stage during CRC pathogenesis mutations in PIK3CA are arising. To investigate the effect of this mutation during CRC development in vivo, a novel mouse model was created with a conditional Cre recombinase (Cre) inducible Pik3caH1047R mutation. Initially, expression of the Pik3caH1047R mutation was achieved ubiquitously by crossing the Pik3caH1047R mouse with the Cre-deleter mouse strain. This revealed the Pik3caH1047R mutation to be embryonic lethal when expressed from the zygote stage. Analysis of the cause of this lethality revealed dysfunctional embryonic ‘turning’ and failed vascular system development. Endothelial cell-specific expression of the Pik3caH1047R mutation during embryogenesis confirmed that the failure of the vascular system to develop resulted in embryonic lethality. To combat the lethality, the Pik3caH1047R mutation was targeted specifically to the gastrointestinal tract by crossing it with the A33CrePR2 mouse which has an RU486 inducible Cre under the control of the gastrointestinal specific gpa33 locus. The result was the induction of Pik3caH1047R in A33-expressing cells of the gastrointestinal tract. This study demonstrated that alone, the Pik3caH1047R mutation was insufficient to initiate CRC in vivo. However, when combined with the loss of the tumour suppressor gene Adenomatous polyposis coli (Apc), known to induce intestinal adenomas, the Pik3caH1047R mutation successfully caused progression of these adenomas to invasive adenocarcinomas. This confirmed the hypothesis that mutations in Pik3ca require a ‘second hit’ to initiate tumourigenesis in order for it to exert is effect on CRC progression. This study also investigated the role of the Pik3caH1047R mutation on CRC metastasis. Intestinal carcinomas were induced by a chemical carcinogen in combination with expression of the Pik3caH1047R mutation. Although tumours were observed in the livers of some animals, results were inconclusive as to whether these were the result of intestinal metastasis, as the histology of these tumours was heterogeneous. However, small areas of intestinal cells were observed in some liver tumours suggesting a potential role for constitutively active PI3K/Akt signalling on the migratory ability of intestinal cancer cells. The effect of the Pik3caH1047R mutation on chemosensitivity was also assessed in vitro. While there was no significant differences in the sensitivity of wild type and Pik3caH1047R mutant fibroblasts to several common chemotherapies and PI3K inhibitors, there appeared to be a trend for mutant immortalised mouse mammary epithelial cells requiring higher concentrations of PI3K inhibitors to achieve 50% growth inhibition. This thesis provides evidence that the PI3K/Akt signalling cascade plays a significant role in the correct development of the vasculature of mice during embryogenesis. It has also presents compelling data confirming the role of the Pik3caH1047R mutation in the progression of CRC in vivo.

Introduction. Intussusception after bariatric surgery is an uncommon complication that is now being frequently reported. Most people consider dysmotility to be the causative mechanism in the absence of obvious etiology. Material and Methods. A worldwide search identified literature describing intussusception after bariatric surgery. We also included our own patients and analyzed information regarding demographic profile, risk factors, presentation, diagnosis, and post treatment course. Results. Seventy one patients were identified between 1991 and 2011. Majority of the affected patients were females ( 𝑛 = 7 0 , 98.6%); median time to presentation after gastric bypass surgery was 36 months. Most patients presented with abdominal pain, nausea and vomiting, but without obvious peritonitis. Sixty eight patients (96%) required surgery; 48 (70.6%) underwent revision of anastomosis, 16 (23.5%) had reduction without resection, while 4 patients (5.9%) had plication only. Amongst these, most patients ( 𝑛 = 5 1 , 75%) were found to have retrograde intussusception. Post-operatively, 9 patients presented with recurrence (range, 0.5–32 months). Five patients, who had earlier been treated without resection, eventually required revision of the anastomosis. There was no mortality noted. Conclusion. Intussusception after bariatric surgery is uncommon and its diagnosis is based on a combination of physicial, radiological and operative findings. An early surgical intervention reduces morbidity and prevents recurrence.

Background: Traditionally, the results of revision total knee arthroplasty have been determined with use of surgeon-based measures such as the Knee Society rating system. Recently, outcome and quality-of-life measures have shifted toward a greater emphasis on patient-based evaluation. The aim of our study was to determine the validity and respon- siveness of the Knee Society rating system compared with the Short Form-36 health survey (SF-36), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and a four-question 4-point Likert scale satisfaction questionnaire following revision total knee arthroplasty. Methods: A total of 152 patients underwent revision total knee arthroplasty at our institution, between August 2003 and January 2007, and had a two-year follow-up evaluation after revision surgery. The SF-36, WOMAC, Knee Society rating system, and satisfaction scores were completed preoperatively and postoperatively. Spearman correlation coefficients were calculated to determine the degree of correlation for each outcome scale. The SF-36, WOMAC, and patient satis- faction were correlated with the Knee Society rating system. Results: Both before and after surgery, the correlation among items of the Knee Society rating system displayed low to negligible levels of association. The Knee Society rating system pain score showed modest levels of convergent construct validity with the WOMAC and SF-36. However, the Knee Society functional score displayed negligible to low correlation with its WOMAC functional counterpart preoperatively. The Knee Society pain and functional scores, respectively, showed marked and moderate association with satisfaction. The change in the Knee Society pain and functional scores had moderate association with the SF-36 and WOMAC counterparts, except low correlation was displayed between the pain scores for the Knee Society rating system and the SF-36. The Knee Society rating system pain score was found to be the most responsive of the measures with a standardized response mean of 1.6, whereas the Knee Society rating system functional score was found to be the least responsive at 0.7. Conclusions: Currently, there is no so-called gold standard that optimally reflects the status of the knee, as well as the patient, prior to and following revision total knee arthroplasty. Ideally, numerous assessment scales should be administered to the patient in order to accurately reflect the patient characteristics for the purpose of academic study, but from a practical standpoint, this may not be feasible. We encourage further research and development of a simple and concise standardized questionnaire for use before and after revision total knee arthroplasty.

As universities seek to adopt increased e-business, e-commerce and e-learning initiates, the overall approach taken for security management within the organisation plays an increasingly relevant role. In many cases security in universities is approached through the addition of tactical solutions. Often systems security is added on as a final consideration instead of during early design stages. This approach can be incomprehensive and inefficient. Although this approach can provide limited security, there is no guarantee that business requirements for security are incorporated and integrated effectively. This situation is partly due to security management in Australian universities being challenged by the complexity of both university culture and diverse operating environments. In many circumstances the champion for security in universities tends to be relegated to an officer in the IT department, hidden away from the business itself. Often this person with operational responsibility for security will have a detailed understanding of what should occur in security, but faces difficulties in determining exactly how to go about achieving this on an enterprise level. In order to assist in securing university IT systems and thereby improving e-business security, this research proposes a security practitioner’s management model. This model is aimed at facilitating the transition of security knowledge into actual implementation across the enterprise, with an end goal of an improved culture of compliance towards security practices in the university sector. This work is of significant value as it results from a study into specific security management issues facing Australian universities. This study highlights that future research would be well-placed to focus on benchmarking information security management within the university sector.

From an early age, people develop an inner sense of being male or female. Transsexuals however, identify with a physical sex opposite to their biological sex. Such individuals might seek to alleviate their distress by altering their bodies through hormone therapy and sex reassignment surgery (1). The prevalence of transsexualism ranges from 1:2,900 to 1:100,000; and little is known about the etiology of this condition (2–4). Some theories have suggested that psychosocial factors— including dysfunctional family dynamics (5) and traumatic childhood experiences (6)—lead to the development of a transsexual identity. Increasingly, biomedical research is implicating biological factors. Co-occurrence among twin pairs, father-son pairs, and brother-sister pairs (7,8) raises the question of whether gender dysphoria is heritable. Anatomical studies show that certain brain structures in male-to-female transsexuals are more “female-like” in volume and neuronal density (9,10). Furthermore, the response to the odor of male and female steroids in male-to-female transsexuals was more similar to that of control women than control men (11). Other studies suggest that sex steroids influence gender identity. Female-to-male transsexuality has been associated with polycystic ovary syndrome and hyperandrogenemia (12). Moreover, female subjects with the disorder of sex development called congenital adrenal hyperplasia are exposed to high levels of androgens prenatally and seem to be at much higher risk of gender identity disorder than the general population (13). A significant association was identified between female-to-male transsexualism and the CYP17 gene (which encodes 17α-hydroxylase, the enzyme deficient in some virilized congenital adrenal hyperplasia patients) (14). Aromatase (CYP19), the enzyme that converts testosterone to estrogen, has also been implicated in female gender identity. A 46, XX woman with congenital adrenal hyperplasia carried a null CYP19 mutation, was born with phallic enlargement, a uterus, and ovaries, and exhibited a persistent male gender identity and male gender role behavior (15). There are few genetic association studies of male-to-female transsexualism. A study of 29 Swedish male-to-female transsexuals identified a significant association with a dinucleotide CA polymorphism in the estrogen receptor β (ERβ) gene (p = .03) (16). It has been suggested that ERβ has a defeminization role in male brain and behavior, on the basis of knockout mouse studies (17). Altogether, genetic studies on transsexuals suggest that both androgen and estrogen might play a role in gender identity. We sought to investigate whether sex steroidogenesis genes are associated with male-to-female transsexualism in the largest cohort collected to date. We analyzed the variable polymorphism lengths of three genes—androgen receptor (AR), ERβ, and CYP19—in Caucasian transsexuals and compared these with non-transsexual male control subjects.

This issues paper is concerned with ensuring the integrity of Australia’s e-court processes through the development of information protection standards and protocols. The integrity of the court process is important to the national interest because businesses and citizens depend on the certainty of court decisions, naturally assuming that their information and privacy is protected. This paper is a catalyst for future research leading to the creation of an information protection framework, including policies and standards enabling courts to define the use of courtroom technologies, thus ensuring that their design and application is grounded within established information protection principles. Without substantiation of the quality of technological structures and processes used by e-courts, the system of certainty upon which the courts and law are based has the potential to become inherently uncertain.

In this paper we present practical guidelines for designing secure block cipher key schedules. In particular we analyse the AES key schedule and discuss its security properties both from a theoretical viewpoint, and in relation to published attacks exploiting weaknesses in its key schedule. We then propose and analyse an efficient and more secure key schedule.

Purpose To assess the efficacy of a novel ultraviolet (UV) lens device on the killing of Acanthamoeba cysts and the impact of efficacious doses of UV upon soft contact lens parameter and material characteristics. Design Prospective, in vitro, experimental study of a device. Methods A UV lens device was constructed and used to expose Acanthamoeba cysts to various levels of UV irradiation. Once an efficacious dose, as defined by a greater than 3 log reduction, was determined (130 mJ/cm 2 ), 6 soft contact lens materials (etafilcon A, senofilcon A, galyfilcon A, lotrafilcon A, polymacon, and comfilcon A) were exposed to that dose for 30 cycles and tested for visual parameters, mechanical parameters, and cytotoxicity. Results The UV device produced an average log reduction of over 3.5 log of Acanthamoeba cysts when the lens and solution inside of the inset case was irradiated with 130 mJ per cm 2 of UV or greater. After 30 cycles of 130 mJ per cm 2 UV dose each, no gross changes were observed in mechanical properties or cytotoxicity tests in any soft contact lenses tested. In visual parameters, polymacon and lotrafilcon A exhibited a shift in sphere power and diameter, respectively. Conclusions The novel UV lens device was able to provide a marked log reduction to Acanthamoeba cysts, one of the most resistant ocular disease–causing organisms found in lens cases, without a detrimental effect on many lens materials.

In this paper we describe an implementation of the DES (and Triple-DES) algorithm using the bitslicing technique on an Intel Pentium MMX processor. Implementation specifics are discussed and comparisons made with an optimised C-coded DES implementation and an assembly language DES implementation. This paper sets the scene for future research of the inter-relation between design and implementation of the newer 128-bit symmetric block ciphers.

Purpose: Silver-infused contact lenses (CLs) may provide benefits to CL wearers by reducing adherence of potential pathogens to CL surfaces; however, they have the potential to modify the normal ocular biota during wear. This study investigated the effect of silverinfused silicone hydrogel CLs on conjunctival flora over six months of daily wear (DW). Method: A prospective, randomised, doublemasked, contralateral study was conducted. Sixty subjects were randomly assigned to wear silverinfused (galyfilcon A with incorporated silver ions, test) and standard (galyfilcon A, control) silicone hydrogel CLs on a contralateral basis for six months of DW. Prior to assignment of the test and control CLs, all subjects were fitted with etafilcon A daily disposable CLs for a one week wearin period. Conjunctival flora were cultured at screening/pre-baseline (with subjects’ habitual CLs), baseline (after daily disposable wear) and four weeks, three and six months following commencement of test and control CL wear, using sterile calcium alginate swabs moistened with sterile unpreserved 0.9% saline. Results: There were no statistically significant differences between the conjunctivae of test and control eyes in incidence of positive cultures (p>0.05), culture classification grades (p>0.05), microorganism levels (p>0.05) or numbers of different types of microorganisms isolated (p>0.05). Wear of the test CLs did not promote fungal or yeast colonisation of the conjunctivae. The most frequently isolated microorganisms were Gram-positive bacteria considered to be part of the normal ocular flora. Conclusions: Wear of the silver-infused CLs did not result in any statistically or clinically significant alterations to the ocular biota over six months of DW.