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Bicondylar tibial plateau fractures are serious injuries to a major weight-bearing joint. These injuries are often associated with severe soft tissue injuries that complicate surgical management. We reviewed 54 consecutive patients who sustained bicondylar tibial plateau fractures that were treated with limited open reduction and cannulated screw fixation combined with fine-wire circular external fixation. Forty-six patients met the inclusion criteria of this retrospective review. Eight patients were excluded because they did not complete a minimum of 1-year follow-up. Thirty-six patients had Schatzker type-VI, and ten patients had Schatzker type-V fractures. All fractures were united without loss of reduction; there were no incidences of wound complications, osteomyelitis or septic arthritis. The average Knee Society Clinical Rating Score was 81.6, translating to good clinical results. Minor pin track infection was the most common complication encountered. This review concludes that fine-wire circular external fixation, combined with limited open reduction and cannulated screw fixation, consistently produces good functional results without serious complications.

Parents are under pressure from their adolescent children if they, contrary to their own convictions, are compelled to bend rules or adapt decisions to submit to the demands of their children. The objective of this investigation was to determine which factors contribute to this phenomenon. Method: The sample comprised 177 adolescents and their parents in the Mpumalanga province. Variables taken into account were individual factors (gender, age and personality of parents and adolescents); factors related to the family (family structure, working circumstances of parents, family relationships and birth order position of adolescents); developmental factors (identity formation of adolescents); and wider contextual factors (peer pressure during adolescence). Results: From the parents’ side factors such as self-concept, personality and parent–adolescent relationship explained almost 62% of the variance in the pressure that parents experience. Only one prominent adolescent factor could be identified, namely adolescent–parent relationship (seen from the adolescents’ side). Conclusion: The results indicate that the pressure which parents encounter from their adolescent children is associated with parental variables rather than adolescent variables. Adolescents do not deliberately plan to place their parents under pressure, but factors on the parents’ side create such a situation. Journal of Child and Adolescent Mental Health 2014, 26(1): 15–33

Primary malignant giant cell tumour of bone is extremely rare and very few examples exist in the literature. We report a case of a 37-year-old man with a primary malignant giant cell tumour of the proximal tibia. He was HIV positive on anti-retroviral treatment and had no history of radiotherapy or prior surgery. Radiographic staging included an MRI scan that clearly defined two distinctly different, juxtaposed tumours. These two tumours were histologically confirmed as a giant cell tumour with no evidence of malignancy and a conventional osteosarcoma.

Background. HIV infection has reached epidemic proportions in South Africa, with an estimated prevalence of 21.5% in adults living in the province of KwaZulu-Natal. Several malignancies have been identified as part of the spectrum of immunosuppression-related manifestations of HIV infection. Very few reports, however, exist regarding the occurrence of non-AIDS-defining sarcomas in the extremities or limb girdles. Methods. A retrospective review was performed on all adult patients, between the ages of 30 and 60 years, with histologically confirmed osteosarcomas of the appendicular skeleton referred to a tertiary-level orthopaedic oncology unit. Results. Five out of the nine patients (62.5%) included in the study were found to be HIV positive. The average CD4 count of these patients was 278 (237–301) cells/mm3, indicating advanced immunological compromise. Three of the malignancies in HIV-positive patients occurred in preexisting benign or low-grade tumours. Conclusion. A heightened index of suspicion is required in HIV patients presenting with unexplained bone and joint pain or swelling. Judicious use of appropriate radiological investigation, including magnetic resonance imaging of suspicious lesions and timely referral to an appropriate specialized orthopaedic oncology unit, is recommended.

Objective(s): There is limited information on full-length genome sequences and the early evolution of transmitted HIV-1 subtype C viruses, which constitute the majority of viruses spread in Africa. The purpose of this study was to characterize the earliest changes across the genome of subtype C viruses following transmission, to better understand early control of viremia. Design: We derived the near full-length genome sequence responsible for clinical infection from five HIV subtype C-infected individuals with different disease progression profiles and tracked adaptation to immune responses in the first 6 months of infection. Methods: Near full-length genomes were generated by single genome amplification and direct sequencing. Sequences were analyzed for amino acid mutations associated with cytotoxic T lymphocyte (CTL) or antibody-mediated immune pressure, and for reversion. Results: Fifty-five sequence changes associated with adaptation to the new host were identified, with 38% attributed to CTL pressure, 35% to antibody pressure, 16% to reversions and the remainder were unclassified. Mutations in CTL epitopes were most frequent in thefirst 5 weeks of infection, with the frequency declining over time with the decline in viral load. CTL escape predominantly occurred in nef, followed by pol and env. Shuffling/toggling of mutations was identified in 81% of CTL epitopes, with only 7% reaching fixation within the 6-month period. Conclusion: There was rapid virus adaptation following transmission, predominantly driven by CTL pressure, with most changes occurring during high viremia. Rapid escape and complex escape pathways provide further challenges for vaccine protection. 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins AIDS 2013, 27:507‐518

INTRODUCTION: Limited data is available with regard to the epidemiology of primary malignant orthopaedic tumours in the South African clinical setting. As a result, orthopaedic surgeons have to rely on data from other countries when formulating differential diagnoses for malignant bone lesions. Existing data, however, demonstrates variance in the incidence between different geographic regions. By analysing the tumour epidemiology at our centre and comparing it to published data from other parts of the world, we aim to better define the local prevalence of primary malignant bone tumours. Materials and methods: A retrospective review of all patients with biopsy confirmed malignant primary bone tumours that presented between January 2008 and June 2015 were conducted. Patients with multiple myeloma and lymphoma were excluded. Epidemiological data pertaining to patient demographics, tumour location and histological diagnosis were recorded and analysed. RESULTS: Included for review were 117 patients with biopsy-confirmed primary malignant bone tumours. Tumours involving the proximal humerus, distal femur, proximal tibia and pelvis accounted for 80% of all tumours. Osteosarcoma was the most common histological diagnosis (72.6%) and higher than reported figures from any other country. It was followed by chondrosarcoma (11.4%), Ewing's sarcoma (9.4%), spindle cell sarcoma (4.2%) and malignant giant cell tumour (GCT) (1.7%). A single patient was diagnosed with adamantinoma. HIV infection had no significant association with primary bone tumour incidence. CONCLUSION: Epidemiological data from this review reflect small but significant differences compared to international literature. The incidence of osteosarcoma appeared to be higher than in previous reports from other regions. Future study in this area may identify a reason for this difference, socio-economic reasons may be responsible.

BACKGROUND: Human-inflicted bite wounds to the hand are serious injuries that may result in significant morbidity and permanent impairment. Irrespective of the mechanism, they are associated with a high complication rate and this has been attributed to the unique anatomy of the hand and the pathogens involved in human bites. HIV (human immunodeficiency virus) infection is known to compromise the immune system through immune exhaustion and senescence. This potentially increases the risk of complications following human bites to the hand in HIV-positive patients. The aim of this study was to determine if HIV infection is associated with an increased risk for the development of early complications following human bites to the hand. PATIENTS AND METHODS: We retrospectively reviewed the records of a cohort of consecutive patients treated between June 2013 and October 2014. Patient charts were reviewed and information extracted with regard to demographics, the location and mechanism of the bite, occurrence of complications, HIV status and CD4 counts, as well as whether they were taking ARV (antiretroviral) medication at the time. The time from injury to presentation was recorded, as well as the time from injury to surgical intervention. RESULTS: Thirty-nine patients were included in the study and there were no exclusions. The mean age of patients was 31.5 years (range 14-60 years), with an approximately equal distribution between males and females. Sixteen patients (41%) in our study cohort were found to be HIV-positive, 15 patients were HIV-negative (38%), and in eight cases (21%) the HIV status was unknown. Of the HIV-positive patients, 44% had CD4 counts below 350 cells/mm3 but only four (25%) were on ART (anti-retroviral therapy) at the time of injury. Complications occurred in 88% (14/16) of the HIV-positive patients compared to 80% (12/15) in the HIV-negative group (risk ratio [RR] = 1.09; 95% confidence interval [CI] = 0.8-1.5; p=0.65. CONCLUSIONS: HIV infection was not associated with an increased risk of developing complications following human bites to the hand in this series. An increase in the time from injury to presentation was however associated with an increased risk of amputation.

Background: Managing cancer in a multicultural environment poses several challenges, which include the communication between the patient and the healthcare provider. Culture is an important consideration in clinical care as it contributes to shaping patients’ health-related values, beliefs, and behaviours. This integrative literature review gathered evidence on how culturally competent patient–provider communication should be delivered to patients diagnosed with cancer.Design: Whittemore and Knafl’s approach to conducting an integrative literature review was used. A number of databases were systematically searched and a manual search was also conducted. Specific inclusion and exclusion criteria were set and documents were critically appraised independently by two reviewers. Thirty-five documents were included following these processes. Data extraction and synthesis followed and were also independently verified.Results: Various strategies and personal characteristics and attitudes for culturally competent communication were identified. The importance of culturally competent healthcare systems and models for culturally competent communication were also emphasised. The findings related to all themes should be treated with caution as the results are based mostly on low-level evidence (Level VII).Conclusions: More rigorous research yielding higher levels of evidence is needed in the field of culturally competent patient–provider communication in the management of cancer. Most of the available literature was classified as non-research evidence. The themes that emerged do, however, provide some insight into how culturally competent patient–provider communication may be delivered in order to improve treatment outcomes in patients diagnosed with cancer.Keywords: cultural competence; patient–provider communication; cancer; oncology; culture(Published: 30 November 2016)To access the supplementary material for this article, please see Supplementary files in the column to the right (under ‘Article Tools’).Citation: Glob Health Action 2016, 9: 33208 - http://dx.doi.org/10.3402/gha.v9.33208

The development of biomedical interventions to reduce acquisition of HIV-1 infection remains a global priority, however their potential effectiveness is challenged by very high HIV-1 envelope diversity. Two large prophylactic trials in high incidence, clade C epidemic regions in southern Africa are imminent; passive administration of the monoclonal antibody VRC01, and active immunization with a clade C modified RV144-like vaccines. We have created a large representative panel of C clade viruses to enable assessment of antibody responses to vaccines and natural infection in Southern Africa, and we investigated the genotypic and neutralization properties of recently transmitted clade C viruses to determine how viral diversity impacted antibody recognition. We further explore the implications of these findings for the potential effectiveness of these trials. A panel of 200 HIV-1 Envelope pseudoviruses was constructed from clade C viruses collected within the first 100 days following infection. Viruses collected pre-seroconversion were significantly more resistant to serum neutralization compared to post-seroconversion viruses (p = 0.001). Over 13 years of the study as the epidemic matured, HIV-1 diversified (p = 0.0009) and became more neutralization resistant to monoclonal antibodies VRC01, PG9 and 4E10. When tested at therapeutic levels (10ug/ml), VRC01 only neutralized 80% of viruses in the panel, although it did exhibit potent neutralization activity against sensitive viruses (IC50 titres of 0.42 μg/ml). The Gp120 amino acid similarity between the clade C panel and candidate C-clade vaccine protein boosts (Ce1086 and TV1) was 77%, which is 8% more distant than between CRF01_AE viruses and the RV144 CRF01_AE immunogen. Furthermore, two vaccine signature sites, K169 in V2 and I307 in V3, associated with reduced infection risk in RV144, occurred less frequently in clade C panel viruses than in CRF01_AE viruses from Thailand. Increased resistance of pre-seroconversion viruses and evidence of antigenic drift highlights the value of using panels of very recently transmitted viruses and suggests that interventions may need to be modified over time to track the changing epidemic. Furthermore, high divergence such as that observed in the older clade C epidemic in southern Africa may impact vaccine efficacy, although the correlates of infection risk are yet to be defined in the clade C setting. Findings from this study of acute/early clade C viruses will aid vaccine development, and enable identification of new broad and potent antibodies to combat the HIV-1 C-clade epidemic in southern Africa., Author Summary Vaccine and passive immunization prophylactic trials that rely on antibody-mediated protection are planned for HIV-1 clade C epidemic regions of southern Africa, which have amongst the highest HIV-1 incidences globally. This includes a phase 2b trial of passively administered monoclonal antibody, VRC01; as well as a phase 3 trial using the clade C modified version of the partially efficacious RV144 vaccine. The extraordinary diversity of HIV-1 poses a major obstacle to these interventions, and our study aimed to determine the implications of viral diversity on antibody recognition. Investigations using our panel of very early viruses augment current knowledge of vulnerable targets on transmitted viruses for vaccine design and passive immunization studies. Evidence of antigenic drift with viruses becoming more resistant over time suggests that these prevention modalities will need to be updated over time and that combinations of antibodies will be necessary to achieve coverage in passive immunization studies. We further show that it may be more difficult to obtain protection in the genetically diverse clade C epidemic compared to RV144 where the epidemic is less diverse, although it should be noted that the correlates of infection risk are yet to be defined in the clade C setting.

The Merck Adenovirus-5 Gag/Pol/Nef HIV-1 subtype-B vaccine evaluated in predominately subtype B epidemic regions (Step Study), while not preventing infection, exerted vaccine-induced immune pressure on HIV-1 breakthrough infections. Here we investigated if the same vaccine exerted immune pressure when tested in the Phambili Phase 2b study in a subtype C epidemic.A sieve analysis, which compares breakthrough viruses from placebo and vaccine arms, was performed on 277 near full-length genomes generated from 23 vaccine and 20 placebo recipients. Vaccine coverage was estimated by computing the percentage of 9-mers that were exact matches to the vaccine insert.There was significantly greater protein distances from the vaccine immunogen sequence in Gag (p=0.045) and Nef (p=0.021) in viruses infecting vaccine recipients compared to placebo recipients. Twenty-seven putative sites of vaccine-induced pressure were identified (p0.05) in Gag (n=10), Pol (n=7) and Nef (n=10), although they did not remain significant after adjustment for multiple comparisons. We found the epitope sieve effect in Step was driven by HLA A∗02:01; an allele which was found in low frequency in Phambili participants compared to Step participants. Furthermore, the coverage of the vaccine against subtype C Phambili viruses was 31%, 46% and 14% for Gag, Pol and Nef, respectively, compared to subtype B Step virus coverage of 56%, 61% and 26%, respectively.This study presents evidence of sieve effects in Gag and Nef; however could not confirm effects on specific amino acid sites. We propose that this weaker signal of vaccine immune pressure detected in the Phambili study compared to the Step study may have been influenced by differences in host genetics (HLA allele frequency) and reduced impact of vaccine-induced immune responses due to mismatch between the viral subtype in the vaccine and infecting subtypes.

INTRODUCTION: Giant cell tumour of bone is a rare entity in children and seldom involves the distal humerus, even in adult patients. We present a case of giant cell tumour in the distal humerus of a child CASE REPORT: A 12-year-old boy presented to our tertiary level tumour unit with progressive pain in his left elbow and was radiologically and histologically found to have a giant cell tumour of his left distal humerus. He was treated with extended curettage, cryotherapy and PMMA cement with the addition of a supportive postero-medial locking plate. There was no recurrence noted at one-year follow-up DISCUSSION: The literature is reviewed to determine the epidemiology of this tumour, the histological and radiological findings unique to the lesion and the current best practice of treatment CONCLUSION: A rare case of giant cell tumour in the distal humerus of a child is presented. Giant cell tumour of bone should be considered in the differential diagnosis of a lytic metaphyseal lesion if the growth plates are open

Bone healing is a unique and complex reparative process that results in fractures healing without scar tissue formation. Multiple factors have been implicated in altering this process. This paper reviews the factors that influence the process of bone healing and predispose to non-union development. Cognisance of these factors will assist orthopaedic surgeons in identifying fractures at risk of altered healing and guide the development of comprehensive management strategies for established non-unions.

Achieving quiescence in chronic osteomyelitis remains challenging. Wide resection of all infected and necrotic tissues improves the chances of achieving remission of the disease. Extensive debridement however decreases the already compromised bone stock that increases the complexity of reconstruction. We report on the outcome of eight patients with Cierny and Mader stage IV chronic osteomyelitis of the humerus who underwent debridement followed by bone graft and circular fixator application as a second stage procedure. Resolution of infection and humeral shaft union was achieved in all patients. Our study finds that two-stage reconstruction of stage IV chronic osteomyelitis with the use of circular external fixation is effective in achieving infection control and union in these complex cases.

INTRODUCTION: Giant cell tumour of bone (GCT) is a rare primary bone tumour. Little is known about the epidemiology of this tumour in South Africa as most demographic information is based on research from Asia, Europe and North America. This research aims to raise awareness and promote early recognition of these tumours. Materials and methods: A retrospective analysis was conducted of all patients with biopsy-confirmed GCTs that presented between January 2010 and December 2014. Information pertaining to patient demographics, tumour location, treatment and outcome was recorded and analysed. RESULTS: Twenty-two patients were included in the study. The mean age of patients was 32.4 years (range 12-63), and a slight male predominance (1.2:1) was observed. Tumours were mainly located at the end of long bones (91%) with the distal femur and proximal tibia being most commonly affected (55%). Two patients (9%) were diagnosed with primary malignant giant cell tumours. We observed a higher rate of lung metastases (18%) than previously reported. The median tumour volume was significantly higher in patients who developed lung metastases (467.4 cm3 vs 137.8 cm3; p=0.03). Three of the patients with lung metastases were HIV-positive (odds ratio [OR] = 10.5, 95% confidence interval [CI] = 0.84-130.66, p=0.076). All patients were treated surgically with extended curettage, local adjuvant therapy, polymethyl methacrylate (PMMA) and internal fixation or en-bloc resection with prosthetic or osteochondral allograft replacement. CONCLUSION: Giant cell tumours of bone are uncommon. Demographics from South Africa emulate international statistics. No recurrence of GCTs was observed in our cohort despite the relatively large tumours at time of presentation compared to international literature that report recurrence rates of approximately 2%. The incidence of metastases and primary malignant GCT was higher than in previous reports. The association of these findings with HIV infection warrants further investigation. Metastases appear to be associated with the size of the primary tumour.

The perceived ability of systematic reviews and meta-analyses to concisely and definitively summarise existing literature regarding a specific medical issue has made them the most highly read and cited form of academic literature. However, the evidence they provide is only as good as the data evaluated and the methodology followed when doing them. In order to conduct a rigorous systematic review, all the elements of the research question should be clearly stated, all relevant studies should be identified, the inclusion criteria should be appropriate and the included studies valid, heterogeneity should be identified, and finally the results of the meta-analyses should be appropriately presented. This paper aims to provide an overview of systematic reviews and meta-analyses. Furthermore, we examine the rationale for conducting such a study, overview the methodology, and highlight pitfalls and weaknesses inherent in the process.

Grade III open tibia fractures have previously been shown to have high infection and non-union rates, and the optimal treatment remains controversial. We present the short-term results of 94 consecutive Gustilo-Anderson grade III open tibia fractures, definitively treated with circular external fixators in this retrospective study. A total of 94 patients (80 males and 14 females), with a mean age of 36.5 years (range 8-73) were followed up for a mean period of 12 months (range 6-52). Deep infection occurred in four patients (4.3%) and non-union in three patients (3.2%). The mean time to union was 23 weeks (range 11-79). The prevalence of HIV infection was 32.9% and no statistically significant association between HIV infection and an increased risk of deep infection (p = 0.601) or nonunion (p = 0.577) could be demonstrated. Pin-site infection occurred in 16% with the majority being low-grade infections. The management of grade III open tibia fractures with definitive circular external fixation delivered promising short-term results with low complication rates in terms of infection and non-union.

Pin track-associated complications are almost universal findings with the use of external fixation. These complications are catastrophic if it leads to the failure of the bone–pin interface and could lead to pin loosening, fracture non-union and chronic osteomyelitis. Strategies proposed for the prevention and management of pin track complications are diverse and constantly changing. Prevention of external fixation pin track infection is a complex and ongoing task that requires attention to detail, meticulous surgical technique and constant vigilance.

Position du probleme La radiofrequence de l’œsophage (RFO) est un traitement endoscopique disponible dans la palette des methodes de traitement endoscopique de l’œsophage de Barrett (OB). Son efficacite et faible morbidite de gravite moderee ont ete demontrees dans des etudes prospectives et/ou randomisees.

The Mbeya region of Tanzania has a genetically complex HIV epidemic with multiple subtypes and recombinant forms circulating, together with a high frequency of dual infections with more than one subtype. This study aimed to determine whether this impacted the HIV-1 transmission bottleneck. A total of 210 env sequences from 22 participants were generated from recently infected women from Mbeya using the single genome amplification approach. Participants were infected with subtypes C ( n = 9), A ( n = 4), or D ( n = 1), and recombinants AC ( n = 4), CD ( n = 2), AD ( n = 1), or ACD ( n = 1). Sixteen participants (73%) were infected with a single variant; five (23%) with multiple variants; and one (4%) was dually infected. Thus the frequency of single variant infections was similar to cohorts located in genetically restricted subtype B or C epidemics, suggesting that multiple circulating subtypes and unique recombinant forms do not have a significant impact on the transmission bottleneck.

Features extracted online from froth images on flotation plants are potentially useful to the development of advanced control for flotation systems, provided that these features can be related to the key indicator variables of the plant, such as valuable metal loadings and recovery. Although such relationships have been established in a number of base metal plants in industry, this is not the case in the platinum industry. In this paper, estimation of flotation grades and recoveries from froth image data is therefore considered based on laboratory and industrial plant data. It is shown that grades and recoveries can be reliably estimated from a number of different features by use of linear and nonlinear models. This includes simple colour information that on the industrial plant showed a strong correlation with grade measurement.

Research and development into the application of machine vision in froth flotation systems has continued since its introduction in the late 1980s. Machine vision is able to accurately and rapidly extract froth characteristics, both physical (e.g. bubble size) and dynamic (froth velocity) in nature, from digital images and present these results to operators and/or use the results as inputs to process control systems. Currently, machine vision has been implemented on several industrial sites worldwide and the technology continues to benefit from advances in computer technology. Effort continues to be directed into linking concentrate grade with measurable attributes of the froth phase, although this is proving difficult. As a result other extracted variables, such as froth velocity, have to be used to infer process performance. However, despite more than 20 years of development, a long-term, fully automated control system using machine vision is yet to materialise. In this review, the various methods of data extraction from images are investigated and the associated challenges facing each method discussed. This is followed by a look at how machine vision has been implemented into process control structures and a review of some of the commercial froth imaging systems currently available. Lastly, the review assesses future trends and draws several conclusions on the current status of machine vision technology.

During their service life, fibre-reinforced polymers are subjected to the influences of numerous ageing factors such as temperature, pressure, oxygen or moisture, which generally result in a decrease of the composite properties. This study deals with the combined actions of two damaging parameters, temperature and oxygen. Thermo-oxidation is analysed in an original way by ageing in air plain and multi-hole laminates for 9000 h. Since perforated panels have a greater surface exposed to the oxidative environment, the degradation due to oxygen is increased, thus allowing a better understanding of thermo-oxidation mechanisms. Characterisation of the aged composite includes FTIR, microscopy, weight loss measurements, DMA, compression and SBS tests. Thermo-oxidative ageing leads to oxidation and cracking of the laminates surfaces, weight loss and decrease of both compression and SBS failure strengths. The glass transition temperature remains constant. Degradation is more important for the multi-hole panels and results in a greater decrease of the physical and mechanical properties for these laminates.

The concept of water neutrality, based on its carbon equivalent, was first coined during the World Summit on Sustainable Development in 2002. Since then the term has been loosely used, with little quantitative validation. Here we present a first quantitative framework for a water-neutral scheme that allows a private water user to balance its water account through both demand- and supply-side interventions. Such innovative voluntary mechanisms can provide benefits in a chronically water stressed and developing country, such as South Africa. This scheme seeks to harness private sector investment in water security, by allowing investors to balance quantitatively their water account based on sound scientific rationale. Investors are required to engage in a three-step process of: reviewing their water usage, implementing a reduction strategy, and replenishment of water to hydrological systems through the investment in watershed services, equivalent to their water usage. Initially, the scheme allows participants to replenish quantitatively their water usage through investment in the clearing of water-intensive invasive alien plants. The project, however, encourages the innovation and development of further quantitative mechanisms for investing in watershed services, and proposes an operational model for the promotion of a water-neutral market in South Africa.

Working for Water forms part of the Expanded Public Works Programme of the South African Government, aimed at the sustainable management of natural resources through the control and management of invasive alien plants while enhancing socio-economic empowerment in South Africa. The programme's name was taken from one of the original motivations: namely, reducing the impacts of invasive alien trees on water resources. A number of studies have looked at the potential impacts of the programme but only one or two have used actual management data to quantify its costs and benefits. This paper is the first, in hopefully a series of papers, on the costs and impacts of the programme over recent years. The paper focuses on the extent, costs and impacts of clearing invasive alien plants from riparian areas. Data were extracted from the Working for Water Information Management System (WIMS) and analysed to assess clearing costs and estimated impacts of clearance on water resources. Some of the most significant findings of the study again illustrate the need to treat invasions as early as possible. Very scattered (1–5%) invasions of selected species for example were between 3 and 25 times cheaper to clear than closed canopy stands (75– 100%). On the other hand, unit reference values, used to compare clearing operations in terms of cost efficiency in generating extra water yield, were much higher for low levels of invasion than denser invasions, to the extent that the former's viability could be questioned by the uninformed. However, this was only assessed in terms of extra water generated and not in terms of volumes of water secured, as invasive alien plants spread and become denser if not actively controlled. If left unchecked, water losses increase, which makes the clearing of light infestations much more viable. Overall, it is estimated that around 7% of riparian invasions have been cleared, resulting in significant yield increases. The increased estimated yield of 34.4 million m 3 is about 42% of the yield of the new Berg River Scheme in the Western Cape (81 million m 3 ). The investment in clearing species known for excessive water use from riparian areas, at a cost of R116 million, was found to be a very good investment. However, it is important to note that the clearing of invasive alien plants will seldom result in the total elimination of shortfalls in water supply and should be seen as part of a package of water resource options to optimize supply, aimed at minimizing wastage of water. © 2008 SAAB. Published by Elsevier B.V. All rights reserved.

English Findings of a research study are offered, which explored the interface between indigenous and industrial culture from the perception of indigenous people from South Africa and New Mexico, USA. Adaptability and resilience are confirmed, as are confusion and threats to indigenous ways of life. French Cette étude livre les résultats d’une recherche visant à explorer l’interface entre la culture autochtone et la culture industrielle à partir du point de vue des peuples autochtone de l’Afrique du Sud, du Nouveau-Mexique (É tas-Unis d’Amérique). Les notions d’adaptation et de résilience y sont confirmées, de même que sont soulevées la confusion et les menaces à l’endroit des modes de vie autochtone. Spanish Se presentan los hallazgos de una investigación que explora la junción entre la cultura indígena y la industrial, a partir de la percepción de indígenas de Sud Africa y Nuevo México, en los Estados Unidos de América. Se confirman la adaptabilidad y la resistencia, lo que supone confusión y amenaza para el estilo de vida indígena.

Recent research indicates that atrophic nonunions are biologically active and may heal in the optimal biomechanical environment.Thirty-three patients with mobile atrophic and oligotrophic tibial nonunions were treated with circular external fixation and functional rehabilitation. Seven patients required autogenous bone graft procedures.Bony union was achieved after the initial surgery in 31/33 (93.9%) tibias. Two persistent nonunions were successfully treated with repeat circular external fixation without bone graft. This resulted in final bony union in 33/33 (100%) patients.Mechanobiological stimulation of tibial nonunions can produce union even if the biological activity appears to be low.

Tibial nonunion represents a spectrum of conditions which are challenging to treat, and optimal management remains unclear despite its high rate of incidence. We present 44 consecutive patients with 46 stiff tibial nonunions, treated with hexapod external fixators and distraction to achieve union and gradual deformity correction. There were 31 men and 13 women with a mean age of 35 years (18 to 68) and a mean follow-up of 12 months (6 to 40). No tibial osteotomies or bone graft procedures were performed. Bony union was achieved after the initial surgery in 41 (89.1%) tibias. Four persistent nonunions united after repeat treatment with closed hexapod distraction, resulting in bony union in 45 (97.8%) patients. The mean time to union was 23 weeks (11 to 49). Leg-length was restored to within 1 cm of the contralateral side in all tibias. Mechanical alignment was restored to within 5° of normal in 42 (91.3%) tibias. Closed distraction of stiff tibial nonunions can predictably lead to union without further surgery or bone graft. In addition to generating the required distraction to achieve union, hexapod circular external fixators can accurately correct concurrent deformities and limb-length discrepancies.Cite this article: Bone Joint J 2015;97-B:1417–22.

Agro-Ecological Infrastructures (AEIs) include many semi-natural habitats (hedgerows, grass strips, grasslands, thickets ) and play a key role in biodiversity preservation, water quality and erosion control. Indirect biodiversity indicators based on AEISs are used in many national and European public policies to analyze ecological processes. The identification of these landscape features is difficult and expensive and limits their use. Remote sensing has a great potential to solve this problem. In this study, we propose an operational tool for the identification and characterization of AEISs. The method is based on segmentation, contextual classification and fusion of temporal classifications. Experiments were carried out on various temporal and spatial resolution satellite data (20-m, 10-m, 5-m, 2.5-m, 50-cm), on three French regions southwest landscape (hilly, plain, wooded, cultivated), north (open-field) and Brittany (farmland closed by hedges). The results give a good idea of the potential of remote sensing image processing methods to map fine agro-ecological objects. At 20-m spatial resolution, only larger hedgerows and riparian forests are apparent. Classification results show that 10-m resolution is well suited for agricultural and AEIs applications, most hedges, forest edges, thickets can be detected. Results highlight the multi-temporal data importance. The future Sentinel satellites with a very high temporal resolution and a 10-m spatial resolution should be an answer to AEIs detection. 2.50-m resolution is more precise with more details. But treatments are more complicated. At 50-cm resolution, accuracy level of details is even higher; this amplifies the difficulties previously reported. The results obtained allow calculation of statistics and metrics describing landscape structures. Keyword: remote sensing, agro-ecological infrastructure, classification, image processing, mapping, biodiversity

Tibial non-unions represent a spectrum of conditions that are challenging to treat. The optimal management remains unclear despite the frequency with which these diagnoses are encountered. The aim of this study was to determine the outcome of tibial non-unions managed according to a novel tibial non-union treatment algorithm. One hundred and eighteen consecutive patients with 122 uninfected tibial non-unions were treated according to our proposed tibial non-union treatment algorithm. All patients were followed-up clinically and radiologically for a minimum of six months after external fixator removal. Four patients were excluded because they did not complete the intended treatment process. The final study population consisted of 94 men and 24 women with a mean age of 34 years. Sixty-seven non-unions were stiff hypertrophic, 32 mobile atrophic, 16 mobile oligotrophic and one true pseudoarthrosis. Six non-unions were classified as type B1 defect non-unions. Bony union was achieved after the initial surgery in 113/122 (92.6%) tibias. Nine patients had failure of treatment. Seven persistent non-unions were successfully retreated according to the tibial non-union treatment algorithm. This resulted in final bony union in 120/122 (98.3%) tibias. The proposed tibial non-union treatment algorithm appears to produce high union rates across a diverse group of tibial non-unions. Tibial non-unions however, remain difficult to treat and should be referred to specialist units where advanced reconstructive techniques are practiced on a regular basis.

Aims To investigate the short-term outcome of treatment of chronic osteomyelitis where management was based on a refined host stratification system. Methods A retrospective review of 109 adult patients with chronic osteomyelitis. Results At a minimum follow-up of 12 months (range 12–36) we observed an overall success rate of 89.9% (95% CI: 82.7–94.9%). There was no statistically significant difference in success rates by host status (p-value = 0.201). Conclusion By integrating the redefined host status and treatment strategy, we were able to achieve comparable short-term outcomes in both low and high-risk cases while maintaining a low rate of amputation.

The thermal oxidative degradation of carbon fiber/bismaleimide (Hexel T800H/F655-2) and carbon fiber/amine-cross-linked epoxy (Cytec Fiberite IM7/977-2) unidirectional composites and their corresponding neat polymers has been studied in air at temperatures ranging from 150 to 240 C by optical microscopy, using an interferential contrast, and IR microspectrophotometry. A coarse analysis of the damaged zone allowed the determination of main kinetic characteristics in the whole degradation process (oxidation, crack propagation, and their interaction) for each principal direction of the composite materials. It has been found that cracks initiate at the sample free surfaces when a critical value of embrittlement is reached in the oxidized layer. Then, cracks propagate differently toward the core according to both the fiber orientation and the nature of the composite system. The difference in behavior between T800H/F655-2 and IM7/977-2 systems can be explained by a difference in polymer toughness and oxygen permeability of the fiber-matrix interface.

A kinetic analysis has been made on the gravimetric curves obtained for carbon fibre/bismaleimide (T800H/BMI) and carbon fibre/amine crosslinked epoxy (IM7/ACE) composites and the corresponding unreinforced matrices in various O2 partial pressures (between 0 and 1.2 × 105 Pa) at high temperature (between 180 and 240 °C). It has been found that the composite behaviour cannot be predicted using the previously established kinetic model for the unreinforced matrices with a simple correction factor for the matrix mass fraction. The results put in evidence a clear stabilizing effect of carbon fibres on matrix oxidation. This effect was tentatively attributed to the well known radical scavenging property of carbon (Carb) and the kinetic model was modified to take into account this property using the following additional elementary step: PO 2 + Carb → inactive products ( k 8 ) . The stabilizing efficiency can be described satisfyingly by the ratio ϕ8 equal to the number of PO 2 radicals scavenged by carbon per propagation events. ϕ8 ranges between 0.01 and 0.1 for ACE in the 180–200 °C interval and between 0.1 and 0.4 for BMI in the 210–240 °C one.

A simplification of a previously presented “closed-loop” kinetic scheme of radical chain oxidation consisting in taking into account the substrate consumption is applied to the thermal oxidation (in oxygen excess) of a polybismaleimide (BMI) and an amine crosslinked epoxy (ACE). The model fits gravimetric curves in the 0–12% mass loss range well, for both polymers and constitutes a noticeable progress compared to the previously established “steady-state” models. The qualitative difference between BMI (presence of an initial maximum) and ACE (continuous mass decrease), is explained by the fact that ACE hydroperoxides are considerably less stable than BMI ones, which can be mechanistically justified. A generalisation of these results leading to a classification of gravimetric oxidation curves according to their shape, is tentatively proposed.

[This corrects the article DOI: 10.1371/journal.ppat.1005742.].

Background: Tibial nonunions pose significant treatment challenges despite the regularity with which they are encountered. While several studies have reported the outcome of treating different nonunion subtypes with various strategies, few have investigated the factors that influence treatment and outcome. Aims: This study aims to identify factors that complicate the management of uninfected tibial nonunions and are associated with failure of treatment. Materials and Methods: We retrospectively reviewed all patients with uninfected tibial nonunions who were treated according to a standardized treatment algorithm over a 5-year period. Results: The final cohort consisted of 84 patients with a mean age of 36.5 years (range 5–68 years). Bony union was achieved in 79 out of 84 (94%) tibias. Malalignment (P < 0.001), smoking (P = 0.008), alcohol use (P = 0.039), and time from injury to nonunion management (P = 0.003) were found to be associated with treatment failure. The factors found to be associated with increased treatment complexity were smoking (P = 0.035), alcohol use (P = 0.011), and time from injury to nonunion management (P < 0.001). Conclusion: General orthopedic surgeons should, therefore, refer these patients to reconstructive surgeons as soon as the diagnosis of a tibial nonunion is made while reconstructive surgeons should note the importance of host optimization and mechanical alignment during the management of these conditions.

To investigate whether distinct populations have differing human immunodeficiency virus type 1 (HIV) neutralizing antibody responses, we compared 20 women from Tanzania's HIV Superinfection Study (HISIS) cohort, who were infected multiple HIV subtypes, and 22 women from the Centre for the AIDS Programme of Research in South Africa (CAPRISA) cohort, who were infected exclusively with HIV subtype C. By 2 years after infection, 35% of HISIS subjects developed neutralization breadth, compared with 9% of CAPRISA subjects (P = .0131). Cumulative viral loads between 3 and 12 months were higher in the HISIS group (P = .046) and strongly associated with breadth (P < .0001). While viral load was the strongest predictor, other factors may play a role, as the odds of developing breadth remained higher in HISIS even after correction for viral load.

Wide resection of infected bone improves the odds of achieving remission of infection in patients with chronic osteomyelitis. Aggressive debridement is followed by the creation of large bone defects. The use of antibiotic-impregnated PMMA spacers, as a customized dead space management tool, has grown in popularity. In addition to certain biological advantages, the spacer offers a therapeutic benefit by serving as a vehicle for delivery of local adjuvant antibiotics. In this study, we investigate the efficacy of physician-directed antibiotic-impregnated PMMA spacers in achieving remission of chronic tibial osteomyelitis. This retrospective case series involves eight patients with chronic osteomyelitis of the tibial diaphysis managed with bone transport through an induced membrane using circular external fixation. All patients were treated according to a standardized treatment protocol. A review of the anatomical nature of the disease, the physiological status of the host and the outcome of treatment in terms of remission of infection, time to union and the complications that occurred was carried out. Seven patients, with a mean bone defect of 7 cm (range 5–8 cm), were included in the study. At a mean follow-up of 28 months (range 18–45 months), clinical eradication of osteomyelitis was achieved in all patients without the need for further reoperation. The mean total external fixation time was 77 weeks (range 52–104 weeks), which equated to a mean external fixation index of 81 days/cm (range 45–107). Failure of the skeletal reconstruction occurred in one patient who was not prepared to continue with further reconstructive surgery and requested amputation. Four major and four minor complications occurred. The temporary insertion of antibiotic-impregnated PMMA appears to be a useful dead space management technique in the treatment of post-infective tibial bone defects. Although the technique does not appear to offer an advantage in terms of the external fixation index, it may serve as a useful adjunct in order to achieve resolution of infection.

The thermal oxidation of poly(bismaleimide) of the F655-2 type, supplied by Hexcel-Genin, was studied by isothermal gravimetry at 180, 210, and 240°C and various oxygen pressures ranging from 0 to 1.2 bar. Comparison of various sample thicknesses and visible microscopy observations on bulk aged samples shows that the whole oxidized layer has a depth of about 75 μm at 240°C, 138 μm at 210°C, and 229 μm at 180°C. An attempt was made to build a kinetic model to predict this depth. It is based on a differential equation in which O 2 diffusion and its consumption rate, r(C), are coupled, C being the O 2 concentration. Its resolution needs two sets of experiments: the first one to determine the O 2 diffusivity and solubility in the polymer, and the second one to determine r(C). The mathematical form of r(C) is derived from a mechanistic scheme of radical chain oxidation in which initiation is mainly due to POOH decomposition. This expression contains two kinetic parameters, α and β, the values of which are determined from the experimental curves of mass loss rate against O 2 pressure (in the stationary state). The theoretical predictions, at each temperature under consideration, are in excellent agreement with experimental results.

The thermal oxidation of an aromatic amine crosslinked epoxy network has been studied in air below its glass transition temperature by optical microscopy, IR spectroscopy and gravimetry. The superficial oxidised layer has a thickness of 147 μm at 150°C, 94 μm at 180°C and 62 μm at 200°C. A method is proposed to predict the oxidised thickness. It is based on a differential equation in which O 2 diffusion and its chemical consumption rate, r ( C ), are coupled, C being the O 2 concentration. The knowledge of equation parameters requires two sets of experiments: permeation tests to estimate both O 2 diffusivity and solubility into the polymer and also, gravimetric measurements on thin polymer films oxidised at various O 2 partial pressures to determine the kinetic parameters of r ( C ). Predictions are in good agreement with experimental results for all temperatures under consideration.

SYNOPSIS Monitoring plots were established in two mountain catchment areas in the Western Cape to assess the impacts of dense alien plant stands and alien plant clearance on indigenous Fynbos vegetation. In both areas Pinus pinaster was the dominant alien species with Hakea sericea also common. Indigenous vegetation persisted in the understorey of invaded stands, indicating that the high density of aliens was of recent development. Species richness of indigenous vegetation was lower in invaded, compared to uninvaded plots. After clearance by felling and burning, the aliens were effectively controlled, except for pines at Genadendal, where unfelled, older generation pines released seeds to recruit in the post-fire environment. The post-fire recovery of indigenous vegetation at both sites was rapid, with no significant differences measured in projected canopy cover, plant density and functional guild richness between invaded and uninvaded control plots. This improved condition of the indigenous vegetation w...

To establish the constitutive equations for carbon/PMR-15 composites and to determine the contribution of the matrix to the mechanical response, an analysis of the behavior of the PMR-15 polyimide alone has been performed under thermomechanical loading conditions corresponding to military aeroengine applications. In particular, the creep behavior of the material has been studied for several combinations of stress (0.3 to 0.7 σr), temperature (250 to 300°C), and time (5 and 1300 h). The creep compliance has been modeled in the field where the behavior is linear, using the Burgers model, together with a retardation time distribution for the viscoelastic region. The viscoelastic behavior is described satisfactorily by the Kohlrausch function, and combined with the Maxwell relation, enables the creep compliance of PMR-15 polyimide to be modeled in the temperature range considered for short loading times. For long times at 250°C and 0.3 σr, the polymer undergoes slow plastic deformation, but nevertheless, conserves its overall viscoelastic properties. There is no equivalence between time and temperature. The master curve, constructed graphically on the basis of linear viscoelastic strains, short times, and a reference temperature of 250°C, deviates quite significantly from the experimental curve at longer times. In the latter case, the creep compliance curve can be correctly fitted to a simple power law. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1983–1991, 1998

La difficulte de mise en oeuvre de la resine PMR-15 sous forme de plaques massives pour realiser des eprouvettes n'a pas permis jusqu'alors de determiner ses proprietes mecaniques. Cette difficulte est contournee ici par la mise au point d'un procede specifique de fabrication en deux etapes. La caracterisation mecanique des produits obtenus a ete effectuee en chaque point d'un plan d'experiences construit a partir de conditions de moulage possibles. A l'aide des courbes de niveau, notamment celles de la contrainte a la rupture en traction, on definit les conditions optimales de cuisson. Les proprietes mecaniques determinees aux conditions de cuisson optimisees situent la PMR-15 a un niveau remarquable parmi les resines organiques.

[Introduction][1] Closed distraction of stiff tibial nonunions with a hexapod external fixator can predictably lead to union without the need for additional surgery or bone graft. [Indications & Contraindications][2] [Step 1: Fibular Osteotomy][3] Resect 5 to 10 mm of the fibula, from its distal half or at the level of the fibular deformity if present. [Step 2: Application of Hexapod Proximal Ring Using “Rings First” Method][4] Apply the proximal ring orthogonal to the proximal bone segment. [Step 3: Application of Hexapod Distal Ring Using “Rings First” Method][5] Apply the distal ring orthogonal to the distal bone segment. [Step 4: Connection of Struts and Application of Sterile Dressing][6] Connect the proximal and distal rings with 6 oblique struts. [Step 5: Postoperative Planning, Deformity Correction, and Distraction][7] Perform gradual deformity correction and distraction at a rate of 1 mm per day. [Step 6: Postoperative Care Until Union][8] Perform pin-site care and functional rehabilitation. [Step 7: “Trial of Union” and Frame Removal][9] Ensure adequate union prior to removal of the circular fixator. [Results][10] Hexapod closed distraction has been successfully used for the management of stiff hypertrophic tibial nonunions in our practice over the last 6 years. [Pitfalls & Challenges][11] [Introduction][1] Closed distraction of stiff tibial nonunions with a hexapod external fixator can predictably lead to union without the need for additional surgery or bone graft. [Indications & Contraindications][2] [Step 1: Fibular Osteotomy][3] Resect 5 to 10 mm of the fibula, from its distal half or at the level of the fibular deformity if present. [Step 2: Application of Hexapod Proximal Ring Using “Rings First” Method][4] Apply the proximal ring orthogonal to the proximal bone segment. [Step 3: Application of Hexapod Distal Ring Using “Rings First” Method][5] Apply the distal ring orthogonal to the distal bone segment. [Step 4: Connection of Struts and Application of Sterile Dressing][6] Connect the proximal and distal rings with 6 oblique struts. [Step 5: Postoperative Planning, Deformity Correction, and Distraction][7] Perform gradual deformity correction and distraction at a rate of 1 mm per day. [Step 6: Postoperative Care Until Union][8] Perform pin-site care and functional rehabilitation. [Step 7: “Trial of Union” and Frame Removal][9] Ensure adequate union prior to removal of the circular fixator. [Results][10] Hexapod closed distraction has been successfully used for the management of stiff hypertrophic tibial nonunions in our practice over the last 6 years. [Pitfalls & Challenges][11] [1]: #sec-13 [2]: #sec-14 [3]: #sec-17 [4]: #sec-18 [5]: #sec-19 [6]: #sec-20 [7]: #sec-21 [8]: #sec-22 [9]: #sec-23 [10]: #sec-24 [11]: #sec-25

Background. Osteosarcoma is the most common malignant bone tumour found in children and adolescents. Changed treatment protocols have resulted in improved survival and the opportunity for limb salvage surgery. Despite these advances, the outcome is mainly determined by the stage of disease at presentation, making early referral to a tumour unit essential. Methods. Between July 2009 and October 2011, 25 consecutive patients were diagnosed with biopsy-confirmed osteosarcoma. Their records were reviewed and information extracted regarding clinical presentation, histological subtype and stage of disease. Results. Twenty-four patients met the inclusion and exclusion criteria. Conventional osteosarcoma was the most common histological diagnosis encountered; 16 out of 24 (66.7%) patients had metastases at presentation; 6 of the remaining had advanced local disease with very large tumours or pathological fractures that precluded limb salvage surgery. Conclusion. The great majority of patients referred to our tumour unit present with locally advanced or metastatic disease, which limits treatment options and adversely affects survival. Increased awareness, a high index of suspicion and appropriate early referral is crucial to enable limb salvage surgery and increase disease-free survival rates.

The aim of this work is to investigate the sensitivity of multi-incidence, multi-frequency and multi-polarized radar signatures over different crops (wheat, rapeseed, soybean, corn and sunflower). Time series of SAR images are acquired by TerraSAR-X (HH), RADARSAT-2 (full polarization) and ALOS (HH) over an agricultural site located in South West of France during the MCM'10 experiment synchronously with ground measurements. The angular normalization of radar signals is performed per crop type at X- and C-bands. The angular sensitivity of the backscatters decreases with the increase of the vegetation index (from 0.4 dB.°−1 over bare soils to 0.05 dB.°−1 for fully vegetated fields). Analyses of the radar time series show that X-, C- and L-bands behaviors are strongly contrasted, depending on the phenological stages of crops, highlighting the interest of using multi-frequency data. Crop height retrieval based on microwave data indicates promising results, with R2 ranging from 0.7 to 0.93.

The MCM'10 experiment (Multi-sensors Crop Monitoring, 2010) aims to evaluate the potentialities of optical, microwave and thermal satellite images for monitoring agricultural surfaces. The Experiment is conducted during ten month in 2010, from February to November over a super-site located in the South West of France. Remote sensing data (>150 images) are provided by nine low orbit satellites, from high to low spatial resolutions (several meters to 50km). Ground data are collected over winter and summer crops, quasi synchronously with satellite images. More than 30 000 measurements are collected over 387 agricultural fields. They concern soil and vegetation parameters (moisture, roughness, height, biomass…). Results show great complementarities of multi-sensors and multiwavelength data for monitoring agricultural landscape. The ground data collection highlights the importance of field-scale approaches, linked to the strong heterogeneity in space and time of surface parameters (soil properties, vegetation type, farmers' practices…).

The prediction of infrared (IR) emission spectra from the exhaust gases of rocket plumes finds numerous applications in the strategic identification of rockets. These rocket fingerprints could be classified, thus allowing for the distinction between friend and foe. Likewise, the plume radiation intensity could also be reduced for stealth purposes, where accurate prediction of the spectra could be used to determine whether rockets have the required stealth characteristics during their design phase already. This would reduce the high manufacturing and testing costs involved in later stages.

Background An understanding of the biological characteristics of transmitted viruses provides important insights into HIV pathogenesis and informs vaccine development. The aim of the study was to characterize env function of transmitted viruses and its role in disease progression.