Extra-articular knee resection for a secondary chondrosarcoma evolving from an isolated enchondroma of the distal femur: A case report.

Introduction: Enchondromas are among the most current benign bone tumours. Malignant degeneration is extremely rare (<1%) and generally presents as a low grade chondrosarcoma. For localized grade 1 lesions, the treatment of choice is curettage. Wide excision and reconstruction is generally not necessary, unless locally advanced or more aggressive behaviour is suspected at presentation. Case report: A healthy 72 yo male presented with pain and recurrent knee joint effusion. X-rays show a classical central distal metaphyseal enchondroma of the femur associated with subtle osteolysis of the lateral condyle. MRI confirms the presence of a locally aggressive chondromatous lesion based in a classical enchondroma. Core needle biopsy revealed a grade 1 chondrosarcoma, which was in contrast to the radiological aggressiveness of the lesion. Total body CT-scan did not reveal metastatic disease. A wide resection was planned, as a high-grade lesion and joint contamination was suspected. We performed an extra-articular knee resection and reconstruction with a hinged modular total knee megaprosthesis. The definitive histology was grade 1 chondrosarcoma, the surgical margins were wide. The evolution was favourable and the patient was able to perform all his activities of daily living independently without pain at 6 weeks postop. Knee flexion reached 90°. The oncologic screening at 18 months did not show local or distant recurrence. Conclusion: Joints near a benign tumour that suddenly become symptomatic or present an effusion might indicate a malignant transformation. Wide resection and prosthetic reconstruction remains an effective treatment option even in low grade cartilaginous lesions if (1) the adjacent joint is contaminated, or (2) joint-sparing surgery would result in a severe functional impairment of the limb.

Inferring the degree of incipient speciation in secondary contact zones of closely related lineages of Palearctic green toads (Bufo viridis subgroup).

Reproductive isolation between lineages is expected to accumulate with divergence time, but the time taken to speciate may strongly vary between different groups of organisms. In anuran amphibians, laboratory crosses can still produce viable hybrid offspring >20 My after separation, but the speed of speciation in closely related anuran lineages under natural conditions is poorly studied. Palearctic green toads (Bufo viridis subgroup) offer an excellent system to address this question, comprising several lineages that arose at different times and form secondary contact zones. Using mitochondrial and nuclear markers, we previously demonstrated that in Sicily, B. siculus and B. balearicus developed advanced reproductive isolation after Plio-Pleistocene divergence (2.6 My, 3.3-1.9), with limited historic mtDNA introgression, scarce nuclear admixture, but low, if any, current gene flow. Here, we study genetic interactions between younger lineages of early Pleistocene divergence (1.9 My, 2.5-1.3) in northeastern Italy (B. balearicus, B. viridis). We find significantly more, asymmetric nuclear and wider, differential mtDNA introgression. The population structure seems to be molded by geographic distance and barriers (rivers), much more than by intrinsic genomic incompatibilities. These differences of hybridization between zones may be partly explained by differences in the duration of previous isolation. Scattered research on other anurans suggests that wide hybrid zones with strong introgression may develop when secondary contacts occur <2 My after divergence, whereas narrower zones with restricted gene flow form when divergence exceeds 3 My. Our study strengthens support for this rule of thumb by comparing lineages with different divergence times within the same radiation.

Shifts in species and phylogenetic diversity between sapling and tree communities indicate negative density dependence in a lowland rain forest

1. As trees in a given cohort progress through ontogeny, many individuals die. This risk of mortality is unevenly distributed across species because of many processes such as habitat filtering, interspecific competition and negative density dependence. Here, we predict and test the patterns that such ecological processes should inscribe on both species and phylogenetic diversity as plants recruit from saplings to the canopy. 2. We compared species and phylogenetic diversity of sapling and tree communities at two sites in French Guiana. We surveyed 2084 adult trees in four 1-ha tree plots and 943 saplings in sixteen 16-m2 subplots nested within the tree plots. Species diversity was measured using Fisher's alpha (species richness) and Simpson's index (species evenness). Phylogenetic diversity was measured using Faith's phylogenetic diversity (phylogenetic richness) and Rao's quadratic entropy index (phylogenetic evenness). The phylogenetic diversity indices were inferred using four phylogenetic hypotheses: two based on rbcLa plastid DNA sequences obtained from the inventoried individuals with different branch lengths, a global phylogeny available from the Angiosperm Phylogeny Group, and a combination of both. 3. Taxonomic identification of the saplings was performed by combining morphological and DNA barcoding techniques using three plant DNA barcodes (psbA-trnH, rpoC1 and rbcLa). DNA barcoding enabled us to increase species assignment and to assign unidentified saplings to molecular operational taxonomic units. 4. Species richness was similar between saplings and trees, but in about half of our comparisons, species evenness was higher in trees than in saplings. This suggests that negative density dependence plays an important role during the sapling-to-tree transition. 5. Phylogenetic richness increased between saplings and trees in about half of the comparisons. Phylogenetic evenness increased significantly between saplings and trees in a few cases (4 out of 16) and only with the most resolved phylogeny. These results suggest that negative density dependence operates largely independently of the phylogenetic structure of communities. 6. Synthesis. By contrasting species richness and evenness across size classes, we suggest that negative density dependence drives shifts in composition during the sapling-to-tree transition. In addition, we found little evidence for a change in phylogenetic diversity across age classes, suggesting that the observed patterns are not phylogenetically constrained.

Secondary Aural Symptoms in Relation to Cranio-Cervical and General Disorders

The present thesis comprises two study populations. The first study sample (SS1) consisted of 411 adults examined and interviewed at three annual visits. The second study sample (SS2) consisted of 1720 adults who filled in a mailed questionnaire about secondary otalgia, tinnitus and fullness of ears. In the second phase of the SS2, 100 subjects with otalgia were examined and interviewed by specialist in stomatognathic physiology and otorhinolaryngology. In the third phase, 36 subjects participated in a randomized, controlled and blinded trial of effectiveness of occlusal appliance on secondary otalgia, facial pain, headache and treatment need of temporomandibular disorders (TMD). The standardized prevalence of recurrent secondary otalgia was 6%, tinnitus 15% and fullness of ears 8%. Aural symptoms were more frequent among young than old subjects. They were associated with other, simultaneous aural symptoms, TMD pain, head and neck region pain, and visits to a physician. The subjects with aural symptoms more often had tenderness on palpation of masticatory muscles and clinical signs of temporomandibular joint than the subjects without. 85% of the subjects reporting secondary otalgia had cervical spine or temporomandibular disorder or both. In SS1, the final model of secondary otalgia included active need treatment for TMD, elevated level of stress symptoms, and bruxism. In SS2, the final models of aural symptoms included associated aural symptoms, young age, TMD pain, headache and shoulder ache. Stabilization splint more effectively alleviated secondary otalgia and active treatment need for TMD than a palatal control splint. In patients with aural pain, tinnitus or fullness of ears, it is important to first rule out otologic and nasopharyngeal diseases that may cause the symptoms. If no explanation for aural symptoms is found, temporomandibular and cervical spine disorders should be rouled out to minimize unnecessary visits to a physician.

Thermal energetics of the New-Guinean moss-forest rat (Rattus niobe) in comparison with other tropical murid rodents.

The thermal energetics of rodents from cool, wet tropical highlands are poorly known. Metabolic rate, body temperature and thermal conductance were measured in the moss-forest rat, Rattus niobe (Rodentia), a small murid endemic to the highlands of New Guinea. These data were evaluated in the context of the variation observed in the genus Rattus and among tropical murids. In 7 adult R. niobe, basal metabolic rate (BMR) averaged 53.6±6.6mLO2h(-1), or 103% of the value predicted for a body mass of 42.3±5.8g. Compared to other species of Rattus, R. niobe combines a low body temperature (35.5±0.6°C) and a moderately low minimal wet thermal conductance cmin (5.88±0.7mLO2h(-1)°C(-1), 95% of predicted) with a small size, all of which lead to reduced energy expenditure in a constantly cool environment. The correlations of mean annual rainfall and temperature, altitude and body mass with BMR, body temperature and cmin were analyzed comparatively among tropical Muridae. Neither BMR, nor cmin or body temperature correlated with ambient temperature or altitude. Some of the factors which promote high BMR in higher latitude habitats, such as seasonal exposure to very low temperature and short reproductive season, are lacking in wet montane tropical forests. BMR increased with rainfall, confirming a pattern observed among other assemblages of mammals. This correlation was due to the low BMR of several desert adapted murids, while R. niobe and other species from wet habitats had a moderate BMR.

Ammonium alters creatine transport and synthesis in a 3D culture of developing brain cells, resulting in secondary cerebral creatine deficiency.

Hyperammonemic disorders in pediatric patients lead to poorly understood irreversible effects on the developing brain that may be life-threatening. We showed previously that some of these NH4+-induced irreversible effects might be due to impairment of axonal growth that can be protected under ammonium exposure by creatine co-treatment. The aim of the present work was thus to analyse how the genes of arginine:glycine amidinotransferase (AGAT) and guanidinoacetate methyltransferase (GAMT), allowing creatine synthesis, as well as of the creatine transporter SLC6A8, allowing creatine uptake into cells, are regulated in rat brain cells under NH4+ exposure. Reaggregated brain cell three-dimensional cultures exposed to NH4Cl were used as an experimental model of hyperammonemia in the developing central nervous system (CNS). We show here that NH4+ exposure differentially alters AGAT, GAMT and SLC6A8 regulation, in terms of both gene expression and protein activity, in a cell type-specific manner. In particular, we demonstrate that NH4+ exposure decreases both creatine and its synthesis intermediate, guanidinoacetate, in brain cells, probably through the inhibition of AGAT enzymatic activity. Our work also suggests that oligodendrocytes are major actors in the brain in terms of creatine synthesis, trafficking and uptake, which might be affected by hyperammonemia. Finally, we show that NH4+ exposure induces SLC6A8 in astrocytes. This suggests that hyperammonemia increases blood-brain barrier permeability for creatine. This is normally limited due to the absence of SLC6A8 from the astrocyte feet lining microcapillary endothelial cells, and thus creatine supplementation may protect the developing CNS of hyperammonemic patients.

Secondary Accident Data Fusion for Assessing Long-Term Performance of Transportation Systems, 2007

Secondary accident statistics can be useful for studying the impact of traffic incident management strategies. An easy-to-implement methodology is presented for classifying secondary accidents using data fusion of a police accident database with intranet incident reports. A current method for classifying secondary accidents uses a static threshold that represents the spatial and temporal region of influence of the primary accident, such as two miles and one hour. An accident is considered secondary if it occurs upstream from the primary accident and is within the duration and queue of the primary accident. However, using the static threshold may result in both false positives and negatives because accident queues are constantly varying. The methodology presented in this report seeks to improve upon this existing method by making the threshold dynamic. An incident progression curve is used to mark the end of the queue throughout the entire incident. Four steps in the development of incident progression curves are described. Step one is the processing of intranet incident reports. Step two is the filling in of incomplete incident reports. Step three is the nonlinear regression of incident progression curves. Step four is the merging of individual incident progression curves into one master curve. To illustrate this methodology, 5,514 accidents from Missouri freeways were analyzed. The results show that secondary accidents identified by dynamic versus static thresholds can differ by more than 30%.

Lack of Discipline in Cape Verdean Secondary Schools: The Need to Better Define the Problem and Develop Strategies to Prevent or Manage the Situation

This research paper has been written with the intention to discuss the problem of discipline in Cape Verdean secondary schools. While many of us discuss the effects that student misbehavior has on the student misbehavior has on the student, school and society as a whole, very few of us seek solutions which would impact on the prevention and management of this problem that each day becomes more complicated and harder to handle. This paper will discuss the need to better define discipline at the school level; identify the causes and factors that aggravate the problem, in addition, to provide what I hope to be useful strategies to better manage the problem as we make the effort to reclaim our schools and better educate our students. My research included surveys completed by teachers and student alike as they baffled over the question: what is discipline and how can we better manage discipline problems at our schools?

The use of textbooks in Capeverdean secondary schools: The Relationship between Use, Evaluation and Adaptation of Textbooks

This study examines the relationship between teacher’s use of English textbooks and the way teachers evaluate and adapt them, looking at a particular context, the Capeverdean secondary schools, specifically in Praia. The referred relationship was analyzed through teachers’ responses about how they use, evaluate and adapt their textbooks. The results of the study revealed that, on the one hand, the way teachers use their textbooks influences the way they evaluate the same textbooks; on the other hand, the use of textbooks doesn’t necessarily influence the way teachers adapt them. Moreover, the findings revealed that, in general, due to some particular constraints the Capeverdean English teachers are using their textbooks as resources, in which several textbooks are used in combination with one another. Additionally, although teachers assume that they are doing their best, they still need more confidence concerning the way they use, evaluate and adapt available textbooks. Teachers’ confidence in the way they are using their textbooks can be reinforced by establishing an intensive teacher training module on materials evaluation and adaptation, taking into account that a textbook is one of the most important tools in the process of teaching and learning. I hope that the elements presented may lead to further studies on this matter, specifically regarding textbook evaluation and adaptation.

A new spot-thoraxed species of Drosophila from the Atlantic Forest of southeastern Brazil (Diptera, Drosophilidae)

Drosophila boraceia sp. nov. is described from a single male specimen collected at the Estação Biológica de Boracéia, Salesópolis, state of São Paulo, Brazil. At first inspection it looks like a species of Drosophila belonging to the fasciola subgroup of the repleta group, mainly because of the fasciola-like pattern of fused spots on the thorax. However, mostly due to the quite distinct structures of the male terminalia, it seems to be more similar to one ungrouped and also spot-thoraxed South American species, Drosophila atalaia Vilela & Sene, 1982. Illustrations of the terminalia are also provided.

Analysis of secondary growth in the Arabidopsis shoot reveals a positive role of jasmonate signalling in cambium formation.

After primary growth, most dicotyledonous plants undergo secondary growth. Secondary growth involves an increase in the diameter of shoots and roots through formation of secondary vascular tissue. A hallmark of secondary growth initiation in shoots of dicotyledonous plants is the initiation of meristematic activity between primary vascular bundles, i.e. in the interfascicular regions. This results in establishment of a cylindrical meristem, namely the vascular cambium. Surprisingly, despite its major implications for plant growth and the accumulation of biomass, the molecular regulation of secondary growth is only poorly understood. Here, we combine histological, molecular and genetic approaches to characterize interfascicular cambium initiation in the Arabidopsis thaliana inflorescence shoot. Using genome-wide transcriptional profiling, we show that stress-related and touch-inducible genes are up-regulated in stem regions where secondary growth takes place. Furthermore, we show that the products of COI1, MYC2, JAZ7 and the touch-inducible gene JAZ10, which are components of the JA signalling pathway, are cambium regulators. The positive effect of JA application on cambium activity confirmed a stimulatory role of JA in secondary growth, and suggests that JA signalling triggers cell divisions in this particular context.

Activities of tabanids (Diptera, Tabanidae) attacking domestic duck-Cairina moschata (Linnaeus) (Aves, Anatidae), introduced in a forest area in the Central Amazon, Manaus, Brazil

Presented here are the feeding habits, attack behavior, daily and annual activity of adult of Phorcotabanus cinereus (Wiedeman, 1821), Chrysops laetus (Fabricius, 1805) and Phaeotabanus cajennensis (Fabricius, 1787), while biting a domestic duck, Cairina moschata (Linnaeus, 1758). The last two species were recorded for the first time attacking birds. This study comprehended monthly observations of two consecutive days from April/97 to March/98 between 5:30 a.m. and 6:30 p.m. at the Army Instructional Base ((BI-2/CIGS) near Manaus. Annual occurrence of P. cinereus was from July to September, with a daily occurrence between 9:00 a.m. and 5:00 p.m. and highest activity at 12:00 a.m. and 2:00 p.m. C. laetus ocurred from June to October; with a daily occurrence between 8:00 a.m. and 3 p.m. and highest activity at 11:00 and 12:00 a.m. Occurrence of P. cajennensis with one specimen only, was in July between 10:00 and 11:00 a.m.

Interference of Native Language in English Language Acquisition in Santa Cruz and Calheta Secondary schools

This study analyzes the interference of native language when students are learning a foreign language, in this case English. According to this study, interferences from the native language such as lexical-semantic and phonological are not infrequent. It is one of the main barriers that create difficulties when learning English. The outcome of this study is presented at the end of the Monografia: to provide English-language teachers and students the most significant linguistic interferences that occur during the learning process of English language. Furthermore, some teaching strategies are discussed to avoid the biases that appear due to the interferences of the native language. As a result of this study, I hope to contribute to the learning success among English-language students.

Leptin and smoking cessation: secondary analyses of a randomized controlled trial assessing physical activity as an aid for smoking cessation.

BACKGROUND: Smokers have a lower body weight compared to non-smokers. Smoking cessation is associated with weight gain in most cases. A hormonal mechanism of action might be implicated in weight variations related to smoking, and leptin might be implicated. We made secondary analyses of an RCT, with a hypothesis-free exploratory approach to study the dynamic of leptin following smoking cessation. METHODS: We measured serum leptin levels among 271 sedentary smokers willing to quit who participated in a randomized controlled trial assessing a 9-week moderate-intensity physical activity intervention as an aid for smoking cessation. We adjusted leptin for body fat levels. We performed linear regressions to test for an association between leptin levels and the study group over time. RESULTS: One year after smoking cessation, the mean serum leptin change was +3.23 mg/l (SD 4.89) in the control group and +1.25 mg/l (SD 4.86) in the intervention group (p of the difference < 0.05). When adjusted for body fat levels, leptin was higher in the control group than in the intervention group (p of the difference < 0.01). The mean weight gain was +2.91 (SD 6.66) Kg in the intervention and +3.33 (SD 4.47) Kg in the control groups, respectively (p not significant). CONCLUSIONS: Serum leptin levels significantly increased after smoking cessation, in spite of substantial weight gain. The leptin dynamic might be different in chronic tobacco users who quit smoking, and physical activity might impact the dynamic of leptin in such a situation. CLINICAL TRIAL REGISTRATION NUMBER: NCT00521391.