Back to Gondwanaland: can ancient vicariance explain (some) Indian Ocean disjunct plant distributions?

Oceans, or other wide expanses of inhospitable environment, interrupt present day distributions of many plant groups. Using molecular dating techniques, generally incorporating fossil evidence, we can estimate when such distributions originated. Numerous dating analyses have recently precipitated a paradigm shift in the general explanations for the phenomenon, away from older geological causes, such as continental drift, in favour of more recent, long-distance dispersal (LDD). For example, the 'Gondwanan vicariance' scenario has been dismissed in various studies of Indian Ocean disjunct distributions. We used the gentian tribe Exaceae to reassess this scenario using molecular dating with minimum (fossil), maximum (geological), secondary (from wider analyses) and hypothesis-driven age constraints. Our results indicate that ancient vicariance cannot be ruled out as an explanation for the early origins of Exaceae across Africa, Madagascar and the Indian subcontinent unless a strong assumption is made about the maximum age of Gentianales. However, both the Gondwanan scenario and the available evidence suggest that there were also several, more recent, intercontinental dispersals during the diversification of the group.

Siliceous deep-sea sponge Monorhaphis chuni: A potential paleoclimate archive in ancient animals

The deep-sea sponge Monorhaphis chuni forms giant basal spicules, which can reach lengths of 3 m; they represent the largest biogenic silica structures on Earth that is formed from an individual metazoan. The spicules offer a unique opportunity to record environmental change of past oceanic and climatic conditions. A giant spicule collected in the East China Sea in a depth of 1110 m was investigated. The oxygen isotopic composition and Mg/Ca ratios determined along center-to-surface segments are used as geochemical proxies for the assessment of seawater paleotemperatures. Calculations are based on the assumption that the calculated temperature near the surface of the spicule is identical with the average ambient temperature of 4 degrees C. A seawater temperature of 1.9 degrees C is inferred for the beginning of the lifespan of the Monorhaphis specimen. The temperature increases smoothly to 2.3 degrees C, to be followed by sharply increased and variable temperatures up to 6-10 degrees C. In the outer part of the spicule, the inferred seawater temperature is about 4 degrees C. The lifespan of the spicule can be estimated to 11,000 +/- 3000 years using the long-term trend of the inferred temperatures fitted to the seawater temperature age relationships since the Last Glacial Maximum. Specimens of Monorhaphis therefore represents one the oldest living animals on Earth. The remarkable temperature spikes of the ambient seawater occurring 9500-3100 years B.P. are explained by discharges of hydrothermal fluids in the neighborhood of the spicule. The irregular lamellar organization of the spicule and the elevated Mn concentrations during the high-temperature growth are consistent with a hydrothermal fluid input. (C) 2012 Elsevier B.V. All rights reserved.

Indications et techniques actuelles de reconstruction mammaire après mastectomie [Indications and techniques of reconstruction after mastectomy].

Reconstructive surgery takes an important place in breast cancer treatment. Immediate breast reconstruction is performed during the same operation as mastectomy. It is contraindicated following radiotherapy. Reconstruction performed after mastectomy is called differed breast reconstruction. It is completed 6 months after chemotherapy and 1 year after radiotherapy. Prosthetic breast reconstruction is indicated when tissues are of good qualities and breast are small. Autologous reconstruction is performed in case of radiotherapy or large breast. After breast reconstruction, imperfections can be corrected with autologous fat injection.

Techniques for analytical testing of unconventional samples.

Forensic scientists have long detected the presence of drugs and their metabolites in biological materials using body fluids such as urine, blood and/or other biological liquids or tissues. For doping analysis, only urine has so far been collected. In recent years, remarkable advances in sensitive analytical techniques have encouraged the analysis of drugs in unconventional biological samples such as hair, saliva and sweat. These samples are easily collected, although drug levels are often lower than the corresponding levels in urine or blood. This chapter reviews recent studies in the detection of doping agents in hair, saliva and sweat. Sampling, analytical procedures and interpretation of the results are discussed in comparison with those obtained from urine and blood samples.

Neuroimaging techniques in Alzheimer's disease

Neuroimaging techniques provide valuable tools for diagnosing Alzheimer's disease (AD), monitoring disease progression and evaluating responses to treatment. There is currently a wide array of techniques available including computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET), and, for recording electrical brain activity, electroencephalography (EEG). The choice of technique depends on the contrast between tissues of interest, spatial resolution, temporal resolution, requirements for functional data and the probable number of scans required. For example, while PET, CT and MRI can be used to differentiate between AD and other dementias, MRI is safer and provides better contrast of soft tissues. Neuroimaging is a technique spanning many disciplines and requires effective communication between doctors requesting a scan of a patient or group of patients and those with technical expertise. Consideration and discussion of the most suitable type of scan and the necessary settings to achieve the best results will help ensure appropriate techniques are chosen and used effectively. Neuroimaging techniques are currently expanding understanding of the structural and functional changes that occur in dementia. Further research may allow identification of early neurological signs ofAD, before clinical symptoms are evident, providing the opportunity to test preventative therapies. CombiningMRI and machine learning techniques may be a powerful approach to improve diagnosis ofAD and to predict clinical outcomes.

Evaluation of two minimally invasive techniques for electroencephalogram recording in wild or freely behaving animals.

Insight into the function of sleep may be gained by studying animals in the ecological context in which sleep evolved. Until recently, technological constraints prevented electroencephalogram (EEG) studies of animals sleeping in the wild. However, the recent development of a small recorder (Neurologger 2) that animals can carry on their head permitted the first recordings of sleep in nature. To facilitate sleep studies in the field and to improve the welfare of experimental animals, herein, we test the feasibility of using minimally invasive surface and subcutaneous electrodes to record the EEG in barn owls. The EEG and behaviour of four adult owls in captivity and of four chicks in a nest box in the field were recorded. We scored a 24-h period for each adult bird for wakefulness, slow-wave sleep (SWS), and rapid-eye movement (REM) sleep using 4 s epochs. Although the quality and stability of the EEG signals recorded via subcutaneous electrodes were higher when compared to surface electrodes, the owls' state was readily identifiable using either electrode type. On average, the four adult owls spent 13.28 h awake, 9.64 h in SWS, and 1.05 h in REM sleep. We demonstrate that minimally invasive methods can be used to measure EEG-defined wakefulness, SWS, and REM sleep in owls and probably other animals.

Systematized stenting of Baerveldt shunts: techniques to reduce early post-operative hypotony

Purpose: To investigate the effect of the systematized use of intraluminal stents in Baerveldt shunts (BS) on early postoperative IOP control and complication rates. Methods: One hundred and twenty eyes with medically uncontrolled glaucoma were prospectively recruited to undergo BS implantation at Jules Gonin Eye Hospital, Switzerland. Baerveldt shunts were stented (full-length of the intraluminal tube) using a Supramid® 3.0 suture. A minority of shunts (37%) were also ligated intraoperatively and laser suture lysis performed postoperatively. Stent removals, either partial (retraction of 5mm) or complete, were carried out according to a predetermined protocol. Surgery was considered a success when IOP was ≤ 21mmHg and a minimum of 20% reduction from baseline was achieved with/without glaucoma medication (GMs). Hypotony related complications were defined as: choroidal effusions, shallow AC, hypotonous maculopathy or IOP≤5mmHg for over 2 weeks. Results: Mean age was 61.8 years (± standard deviation; ±21.5). Mean follow-up was 17.1 (±7.9) months. Mean preoperative IOP was 26.9 mmHg; mean IOP on the last visit 13.2 mmHg (p<0.001). At year one, the success rate was 87%. In 90% of eyes, IOP was ≤18 mmHg at last visit. Mean number of preoperatively GMs was 3.1; postoperatively 1.4 (p<0.001). Stent removals were performed in 87% of eyes (24% partial; 61% complete). 13% of eyes required no stent removal to reach target IOP. Complications were minor and infrequent (16%) and only 7% were hypotony related. Conclusions: Systematized use of intraluminal stents with Baerveldt aqueous shunts resulted in gradual and controlled IOP lowering with minimal hypotony-related complications. This may have important implications on clinical practice, given the rising rates of aqueous shunt implantation.