Evaluation of the effect of Miller cycle on the main parameters of a diesel engine using mathematical modeling

The influence of the angles of closure of the intake valves on the technical, economic and ecological parameters of a diesel engine was studied by numerical simulation. The study was carried out in the program complex Diesel-RK developed by the MGTU named after N. E. Bauman. Diesel 12DM-185 was chosen as the base engine for the study. It is shown that application of the Miller cycle (early valve closing) has a significant impact on the performance of diesel. It is established that the optimum closing angles of the intake valves for the diesel when using the Miller cycle is 25 degrees before BDC.В данной статье на основе численного моделирования было исследовано влияние углов закрытия впускных клапанов на технико-экономические и экологические показатели дизельного двигателя. Исследование выполнено в программном комплексе Дизель-РК, разработанном в МГТУ имени Н. Э. Баумана. В качестве базового двигателя для исследования был выбран дизель 12ДМ-185. Показано, что применение цикла Миллера (раннее закрытие клапана) оказывает существенное влияние на показатели дизеля. Установлено, что оптимальные углы закрытия впускных клапанов для исследуемого дизеля при использовании цикла Миллера составляют 25 градусов до НМТ

Unexpected Rift Valley Fever Outbreak, Northern Mauritania

During September–October 2010, an unprecedented outbreak of Rift Valley fever was reported in the northern Sahelian region of Mauritania after exceptionally heavy rainfall. Camels probably played a central role in the local amplification of the virus. We describe the main clinical signs (hemorrhagic fever, icterus, and nervous symptoms) observed during the outbreak

PERCHING syndrome: Clinical presentation in the first African patient confirmed by clinical whole genome sequencing.

peer reviewedPERCHING syndrome is a rare multisystem developmental disorder caused by autosomal recessive (AR) variants (truncating and missense) in the Kelch-like family member 7 gene (KLHL7). We report the first phenotypic and molecular description of PERCHING syndrome in a patient from Central Africa. The patient presented multiple dysmorphic features in addition to neurological, respiratory, gastroenteric, and dysautonomic disorders. Clinical Whole Genome Sequencing in the proband and his mother identified two novel heterozygous variants in the KLHL7 gene, including a maternally inherited intronic variant (NM_001031710.2:c.793 + 5G > C) classified as Variant of Uncertain Significance and a frameshift stop gain variant (NM_001031710.2:c.944delG; p.Ser315ThrfsTer23) of unknown inheritance classified as likely pathogenic. Although the diagnosis was only evoked after genomic testing, the review of published patients suggests that this disease could be clinically recognizable and maybe considered as an encephalopathy. Our report will allow expanding the phenotypic and molecular spectrum of Perching syndrome

Madagascar’s extraordinary biodiversity: Evolution, distribution, and use

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 extraordinary biodiversity: Threats and opportunities

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 themost 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

Impacts of GeV heavy ions in amorphous metallic alloys investigated by near-field scanning microscopy

The modifications of the surface topography of amorphous metallic alloys irradiated with swift heavy ions are for the first time studied by near-field microscopy techniques. Irradiations with Pb or U ions (high (${\rm d}E/{\rm d}x)_{\rm e}$ values) lead to the formation of hillocks surrounded by hollows, whereas no visible modifications of the specimen surface is observed after irradiation with Kr ions (low (${\rm d}E/{\rm d}x)_{\rm e}$ value). The formation of hillocks can be ascribed to the damage created in individual ion tracks, while hollows would be linked to the occurrence of the anisotropic-growth phenomenon. Both processes are induced by severe electronic excitation in the wake of incident ions