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Madagascar’s biota is hyperdiverse and includes exceptional levels of endemicity. We review the current state of knowledge on Madagascar’s past and current terrestrial and freshwater biodiversity by compiling and presenting comprehensive data on species diversity, endemism, and rates of species description and human uses, in addition to presenting an updated and simplified map of vegetation types. We report a substantial increase of records and species new to science in recent years; however, the diversity and evolution of many groups remain practically unknown (e.g., fungi and most invertebrates). Digitization efforts are increasing the resolution of species richness patterns and we highlight the crucial role of field- and collections-based research for advancing biodiversity knowledge and identifying gaps in our understanding, particularly as species richness corresponds closely to collection effort. Phylogenetic diversity patterns mirror that of species richness and endemism in most of the analyzed groups. We highlight humid forests as centers of diversity and endemism because of their role as refugia and centers of recent and rapid radiations. However, the distinct endemism of other areas, such as the grassland-woodland mosaic of the Central Highlands and the spiny forest of the southwest, is also biologically important despite lower species richness. The documented uses of Malagasy biodiversity are manifold, with much potential for the uncovering of new useful traits for food, medicine, and climate mitigation. The data presented here showcase Madagascar as a unique “living laboratory” for our understanding of evolution and the complex interactions between people and nature. The gathering and analysis of biodiversity data must continue and accelerate if we are to fully understand and safeguard this unique subset of Earth’s biodiversity.

Madagascar’s unique biota is heavily affected by human activity and is under intense threat. Here, we review the current state of knowledge on the conservation status of Madagascar’s terrestrial and freshwater biodiversity by presenting data and analyses on documented and predicted species-level conservation statuses, the most prevalent and relevant threats, ex situ collections and programs, and the coverage and comprehensiveness of protected areas. The existing terrestrial protected area network in Madagascar covers 10.4% of its land area and includes at least part of the range of the majority of described native species of vertebrates with known distributions (97.1% of freshwater fishes, amphibians, reptiles, birds, and mammals combined) and plants (67.7%). The overall figures are higher for threatened species (97.7% of threatened vertebrates and 79.6% of threatened plants occurring within at least one protected area). International Union for Conservation of Nature (IUCN) Red List assessments and Bayesian neural network analyses for plants identify overexploitation of biological resources and unsustainable agriculture as the most prominent threats to biodiversity. We highlight five opportunities for action at multiple levels to ensure that conservation and ecological restoration objectives, programs, and activities take account of complex underlying and interacting factors and produce tangible benefits for the biodiversity and people of Madagascar.

Septic arthritis is a serious disease and its treatment remains a major challenge. Demonstration of the microorganism is the key to diagnosis according to all international guidelines. In developing countries such as Madagascar, where access to basic health services is still difficult, bacteriological analysis of the joint fluid is not yet available in most healthcare facilities. We propose effective solutions that are scientifically valid, adapted to the country's socioeconomic conditions and current health situation, while taking international recommendations into consideration. We propose that the few university hospitals with rheumatology departments and good reference laboratories should be supported to participate in a pilot program to compile data to establish the clinical and bacteriological profiles of septic arthritis here. In lower level health centers where bacteriological examinations of the joint fluid and other complementary tests are more or less impossible, a diagnosis of septic arthritis is mainly based on clinical findings. Accordingly, all diagnosis and management should be centralized in these reference centers, which will allow the adaptation and progressive update of guidelines for the management of septic arthritis.

Madagascar has a long history of using Orthoptera as food and feed. Our understanding of the biological diversity of this resource, its contemporary use, and its future potentials in Madagascar is extremely limited. The present study contributes basic knowledge of the biological diversity and local uses of edible Orthoptera in Malagasy food cultures. Data was collected with key informants in 47 localities covering most of the ecoregions of Madagascar and corresponding to 12 of the 19 ethnic groups. Orthoptera are consumed throughout Madagascar. We report 37 edible Orthoptera species, of which 28 are new species records of edible Orthoptera in Madagascar and 24 are new species records of edible Orthoptera in the world. Most species are endemic and occur in farming zones. Children are the primary collectors and consumers of edible Orthoptera. The insects are eaten both as snacks and main meals. Edible Orthoptera are primarily collected casually and marketing is rare, with the notable exceptions of the large cricket Brachytrupes membranaceus colosseus and during locust outbreaks (e.g., Locusta migratoria). The use of Orthoptera as feed seems rare. Further investigations of cultural and personal preferences are required to assess the future potential roles of Orthoptera in Malagasy food habits.

Bilharziasis is a parasitic disease that affects the urinary tract and intestines. Finding bilharzia in joints is exceptional. We report two cases of Malagasy patients living in a highly endemic bilharziasis area and having chronic arthritis due to bilharziasis. The first case was a 32-year-old man presenting with a clinical picture of spondylitis with chronic oligoarthritis and paroxysmal asymmetric in his lower limbs, accompanied with sacroiliac pain and episodic dysentery. We retained the diagnosis of bilharziasis arthritis because of positive schistosomiasis serology in the joint fluid and the blood, poor response to therapy with nonsteroidal anti-inflammatory drugs (NSAIDs), and high efficacy of treatment with specific antiparasitic drugs. The second case was a 42-year-old woman with pain in her knees, hips, and low back for 1 year. She was presented inflammatory pain which were persisting despite the use of non steroidal anti inflammatory drugs. She had a history of splenectomy resulting to a splenomegaly by liver-spleen schistosomiasis. Results of paraclinical examinations were similar with the first case as well as the high efficacy of anti-parasitic treatment. Schistosoma haematobium and S. mansoni are the endemic strains found in Madagascar. The lifestyle of the Malagasy population exposes them to recurrent infestations, even massive. If the affinity for joint of schistosoma is known, the diagnosis of bilharzial arthropathy is exceptional. The diagnosis is based on a set of clinical and biological arguments as well as evolution. Serological testing for bilharzia in joint fluid could be an efficient way of diagnosis. So, in a country where bilharzia is endemic, clinical presentation of spondylitis or nondestructive chronic polyarthritis should lead to bilharzia arthropathy.

Chronic hepatitis B virus (HBV) infection is linked to development of hepatocellular carcinoma (HCC). The HBV X protein (pX) is implicated in HCC pathogenesis acting as a weak oncogene or a cofactor in hepatocarcinogenesis. pX induces DNA re-replication, DNA damage, and partial polyploidy in a poorly differentiated, immortalized hepatocyte cell line. In this study we employed sorted, pX-induced polyploid cells to investigate their growth and oncogenic transformation potential over the course of 70 cell doublings. Immediately after live cell-sorting, nearly 40% of pX-induced polyploid cells undergo apoptosis, whereas the surviving cells exhibit proliferation sensitive to p53. After 40 cell generations the pX-expressing polyploid cultures exhibit loss of p53 function and become growth factor- and anchorage-independent, indicative of oncogenic transformation. The pX-induced polyploid cultures in the course of 70 cell generations undergo progressively increasing DNA damage, propagate damaged DNA to daughter cells, and display increased expression of a cluster of proliferation genes shown to be elevated in human HCC, including HBV-HCC. One of these genes is the mitotic kinase Polo-like kinase 1 (Plk1). Oncogenic transformation is suppressed in the absence of pX expression, and significantly, by inhibition of Plk1. These results identify Plk1 as crucial in pX-mediated oncogenic transformation. Conclusion: Partial polyploidy induced by pX is not immediately associated with oncogenic transformation. Continued DNA damage for 40 cell generations is reproducibly associated with loss of p53 function, enhanced expression of Plk1, and oncogenic transformation. Because Plk1 expression is also elevated in HBV-HCC tumors, this in vitro cellular model simulates liver cancer progression and pathogenesis in chronic HBV patients. Inhibition of Plk1 activity suppresses pX-mediated oncogenic transformation, identifying Plk1 as a promising therapeutic target for HBV-mediated HCC. (HEPATOLOGY 2009.)

We address the issue of the convective or absolute nature of the instability of core-annular pipe flows, in experiments using two miscible fluids of equal density but different viscosities, the core fluid being much less viscous than the wall one. We use a concentric co-current injection of the two fluids. An axisymmetric parallel base state is obtained downstream the injector. The core radiusRIand the Reynolds numberReof the so-obtained base state are varied independently due to the control of the flow rate of each fluid. However, a downstream destabilization of this base state was observed within the explored range of the two control parametersRIandRe. Moreover, the fixed location of this destabilization, observed for some particular parameters, suggests an absolute nature of the instability. We present a tentative delineation of the nature (convective or absolute) of the instability and discuss the accessible measurements to experimentally address this issue.

We study the displacement of miscible fluids of different viscosities (viscosity ratio AI) between two parallel plates, using the BGK lattice gas method. At high Peclet numbers, a symmetric interface develops in the gap between the plates. Above M +J 10, the interface becomes a well-defined finger, the reduced width of which tends to A~n = 0.56 at large AI. Assuming that a miscible displacement at high Peclet numbers is equivalent to an immiscible displacement at high capillary numbers, we extend the calculations of Reinelt & Saffman for immiscible fluids, and find the analytical shape of the finger. The result is compared to the celebrated Saffman-Taylor finger.

We study miscible fluid displacement in heterogeneous porous media, in the presence of gravity, where the heterogeneity consists of multiple layers. Miscible fluids of different density and viscosity contrasts are used, such that the displacement is hydrodynamically stable. Depending on the values of the control parameters, the overall fluid displacement exhibits either an enhancement of the effect of heterogeneity or a damping. For a sufficiently large viscosity and/or density contrast, the effect of heterogeneity is overcome and the multi-layer system behaves as a single homogeneous layer. We determine experimentally an associated phase diagram and compare our data to a theoretical model valid for systems of large aspect ratio.

We study the effect of fluid contact area on viscous coupling in the parallel flow of immiscible fluids in a porous media geometry. We consider flow on opposite sides of a planar interface, consisting of alternating solid and open (slit) segments. We use the analytical solution of Tio and Sadhal [15] to derive explicit expressions for viscous coupling in terms of the fractional area of contact between the fluids and the viscosity ratio,M. ForM=1, the coefficient matrix obtained is symmetric showing that Onsager's relations are satisfied. In this case, the resulting viscous coupling is typically very small, in agreement with recent experimental results. Lattice gas simulations forM=1 using theBGK model support the theoretical results and show that viscous coupling further diminishes as the wall thickness increases. Assuming the same configuration, analytical results are next derived forM≠1. The results confirm an existing reciprocity relation between the off-diagonal terms. Viscous coupling remains small.

Following Einsteins's argument for the diffusion coefficient of colloidal dispersions, we postulate that the steady state concentration profile in a suspension of noncolloidal monodisperse particles reflects the dynamic equilibrium resulting from a balance between gravity-driven convection and hydrodynamic dispersion. Using an acoustic technique, the steady state concentration profile of a counterflow-stabilized suspension (a fluidized bed) as well as stationary propagating sedimentation fronts inside the bed were determined. From these profiles we can derive the concentration dependence of the hydrodynamic dispersion coefficient.

and the signal looks like noise. Measured and simulated signals are analyzed in terms of Hurst's rescaled range (the R/S analysis, where R is the range and S the standard deviation) and the power spectrum T.he signal is sampled and we find a clear crossover from persistent behavior (Hurst exponent H 1) for short times corresponding to the fact that particles reside a finite time in the pore to an independent process (H 0.5) corresponding to the uncorrelated entry of particles into the pore Th.e calculated effective Hurst exponent depends on the time resolution (sampling interval) used, but R/S curves for difFerent sampling intervals scale when reduced time (sampling interval divided by pulse width) is included in the analysis and yields a nice data collapse for experiments on different types of particles, Bow rates, and pore sizes.

We investigate effects of capillary heterogeneity induced by variations in permeability in the direction of displacement in heterogeneous porous media under drainage conditions. The investigation is three-pronged and uses macroscopic simulation, based on the standard continuum equations, experiments with the use of an acoustic technique and pore network numerical models. It is found that heterogeneity affects significantly the saturation profiles, the effect being stronger at lower rates. A good agreement is found between the continuum model predictions and the experimental results based on which it can be concluded that capillary heterogeneity effects in the direction of displacement act much like a body force (e.g. gravity). A qualitative agreement is also found between the continuum approach and the pore network numerical models, which is expected to improve when finite size effects in the pore network simulations diminish. The results are interpreted with the use of invasion percolation concepts.

In a viscous lock-exchange gravity current, which describes the reciprocal exchange of two fluids of different densities in a horizontal channel, the front between two Newtonian fluids spreads as the square root of time. The resulting diffusion coefficient reflects the competition between the buoyancy driving effect and the viscous damping, and depends on the geometry of the channel. This lock-exchange diffusion coefficient has already been computed for a porous medium, a 2D Stokes flow between two parallel horizontal boundaries separated by a vertical height, H, and, recently, for a cylindrical tube. In the present paper, we calculate it, analytically, for a rectangular channel (horizontal thickness b, vertical height, H) of any aspect ratio (H/b) and compare our results with experiments in horizontal rectangular channels for a wide range of aspect ratios (1/10-10). We also discuss the 2D Stokes-Darcy model for flows in Hele-Shaw cells and show that it leads to a rather good approximation, when an appropriate Brinkman correction is used., Comment: 16 pages,7 figures

Capillary effects can be important in immiscible flow in heterogeneous media, particularly at low capillary numbers. Experiments are performed to study steady-state saturation profiles during drainage in 3D porous media with sharp changes in permeability. It is found that the saturation response is closely linked to the permeability variation. The results are in good agreement with numerical simulations based on a macroscopic description.

Autocatalytic reactions may propagate as solitary waves, namely, at a constant front velocity and with a stationary concentration profile, resulting from a balance between molecular diffusion and chemical reaction. When the reaction is exothermic, a thermal wave is linked to the chemical front. As the thermal diffusivity is nearly two orders of magnitude larger than the molecular one, the temperature profile spreads over length scales (mm) two orders of magnitude larger than the concentration one. Using an infrared camera, we measure the temperature profiles for a chlorite-tetrathionate autocatalytic reaction. The profiles are compared quantitatively to lattice Bhatnagar-Gross-Krook (BGK) numerical simulations. Our analysis also accounts for the lack of observation of the thermal wave for the iodate arsenous acid reaction.

Hepatitis B virus X protein (pX) is implicated in hepatocellular carcinoma pathogenesis by an unknown mechanism. Employing the tetracycline-regulated pX-expressing 4pX-1 cell line, derived from the murine AML12 hepatocyte cell line, we demonstrate that pX induces partial polyploidy (>4N DNA). Depletion of p53 in 4pX-1 cells increases by 5-fold the polyploid cells in response to pX expression, indicating that p53 antagonizes pX-induced polyploidy. Dual-parameter flow cytometric analyses show pX-dependent bromodeoxyuridine (BrdUrd) incorporation in 4pX-1 cells containing 4N and >4N DNA, suggesting pX induces DNA re-replication. Interestingly, pX increases expression of endogenous replication initiation factors Cdc6 and Cdtl while suppressing geminin expression, a negative regulator of rereplication. In comparison to a geminin knockdown 4pX-1 cell line used as DNA re-replication control, the Cdt1/geminin ratio is greater in 4pX-1 cells expressing pX, indicating that pX promotes DNA re-replication. In support of this conclusion, pX-expressing 4pX-1 cells, similar to the geminin knockdown 4pX-1 cells, continue to incorporate BrdUrd in the G2 phase and exhibit nuclear Cdc6 and MCM5 co-localization and the absence of geminin. In addition, pX expression activates the ATR kinase, the sensor of DNA re-replication, which in turn phosphorylates RAD17 and H2AX. Interestingly, phospho-H2AX-positive and BrdUrd -positive cells progress through mitosis, demonstrating a link between pX-induced DNA re-replication and polyploidy. Our studies high-light a novel function of pX that likely contributes to hepatocellular carcinoma pathogenesis.

Capillary effects can be important in immiscible flows in heterogeneous media, particularly at low capillary numbers (Ca). We present experiments and simulations of slow drainage in 3-D porous media, either homogeneous and in the presence of buoyancy or heterogeneous and in its absence. An acoustic technique allows for an accurate study of the 3-D fronts and the cross-over region. Our results suggest that both cases can be described by invasion percolation in a gradient. Both front tails scale with the corresponding Bond numbers as σft≈B−47 in agreement with the theory. An analogous scaling for viscous effects is also given. The noise of these fronts are found correlated in the form of a fractional Brownian motion (fBm) of a Hurst exponent H≈.5. At higher Ca, experiments performed in 3-D porous media with sharp changes in permeability, exhibit a saturation profile response closely linked to the permeability variations. This viscous response to heterogeneity provides an opportunity to investigate and determine correlated (even at all scales, i.e. fBm), permeability fields.

Leprosy is endemic in Madagascar. The authors report the results of an epidemiologic study performed between 1996 and 1998 in Farafanguna, localized in the South-Eastern of the country. During this period, 217 new cases have been diagnosed. Of the 130 cases included in the study, 69.23% were children aged lower than 15 years and 76.91% suffered from a multibacillary form. More than 50% of the cases belonged to a large family (6 persons or more) and at least one family case was found in more than 60% of cases. These results enhance the severity of the disease in the country and show the presence of multiple risk factors (promiscuity, family cases and multibacillary forms).

We present experiments and simulations of slow drainage in three-dimensional (3D) porous media, either homogeneous and in the presence of gravity or heterogeneous and in its absence. An acoustic technique allows for an accurate study of the 3D fronts and the crossover region. Our results suggest that both cases can be described by invasion percolation in a gradient. For the case of gravity, the front tail width scales with the Bond number as ${\mathrm{\ensuremath{\sigma}}}_{\mathrm{FT}}$\ensuremath{\sim}${\mathit{B}}^{\mathrm{\ensuremath{-}}0.47}$, in agreement with the theory. For the case of permeability gradient a different scaling is found, in agreement with a modified theory of gradient percolation developed here.

An acoustical technique is used to determine fluid concentrations in 3D‐porous media with a 0.1 inch resolution. Stable and unstable miscible fluid flows in consolidated and unconsolidated porous media are investigated. Using a third immiscible fluid it was possible to change the morphology of the network on which dispersion occurs in order to compare with prediction of percolation theory. (AIP)