76 research outputs found
Vibrating Wire for Beam Profile Scanning
The method for measurement of transverse profile (emittance) of the bunch by
detecting of radiation arising scattering at of the bunch on the scanning wire
is wide-spread. In this work the information about scattering bunch is proposed
to measure using the oscillation frequency of the tightened scanning wire. In
such way the system of radiation (or secondary particles) extraction and
measurement can be removed. Dependence of oscillations frequency on beam
scattering is determined by several factors, including changes of wire tension
caused by transverse force of the beam, influence of beam self field.
Preliminary calculations show that influence caused by wire heating will
dominate. We have studied strain gauges on the basis of vibrating wire from
various materials (tungsten, beryl bronze, niobium zirconium alloys). A scheme
of self oscillations generation by alternating current in autogeneration
circuit with automatic frequency adjustment was selected. Special method of
wire fixation and elimination of transverse degrees of freedom allow to achieve
relative stability better than 1E-5 during several days. For a tungsten wire
with a fixed end dependence of frequency on temperature was 1E-5/K.
Experimental results and estimates of wire heating of existing scanners show,
that the wire heats up to a few hundred grades, which is enough for
measurements
Interpretation of y-scaling of the nuclear response
The behavior of the nuclear matter response in the region of large momentum
transfer, in which plane wave impulse approximation predicts the onset of
y-scaling, is discussed. The theoretical analysis shows that scaling violations
produced by final state interactions are driven by the momentum dependence of
the nucleon-nucleon scattering cross section.
Their study may provide valuable information on possible modifications of
nucleon-nucleon scattering in the nuclear medium.Comment: 4 pages with 3 figures. To appear in Physical Review Letter
Primates in peril: the significance of Brazil, Madagascar, Indonesia and the Democratic Republic of the Congo for global primate conservation
Primates occur in 90 countries, but fourâBrazil, Madagascar, Indonesia, and the Democratic Republic of the Congo (DRC)âharbor 65% of the worldâs primate species (439) and 60% of these primates are Vulnerable, Endangered, or Critically Endangered (IUCN Red List of Threatened Species 2017-3). Considering their importance for global primate conservation, we examine the anthropogenic pressures each country is facing that place their primate populations at risk. Habitat loss and fragmentation are main threats to primates in Brazil, Madagascar and Indonesia. However, in DRC hunting for the commercial bushmeat trade is the primary threat. Encroachment on primate habitats driven by local and global market demands for food and non-food commodities hunting, illegal trade, the proliferation of invasive species, and human and domestic-animal borne infectious diseases cause habitat loss, population declines, and extirpation. Modeling agricultural expansion in the 21st century for the four countries under a worst-case-scenario, showed a primate range contraction of 78% for Brazil, 72% for Indonesia 62% for Madagascar and 32% for DRC. These pressures unfold in the context of expanding human populations with low levels of development. Weak governance across these four countries may limit effective primate conservation planning. We examine landscape and local approaches to effective primate conservation policies and assess the distribution of protected areas and primates in each country. P rimates in Brazil and Madagascar have 38% of their range inside protected areas, 17% in Indonesia and 14% in DRC, suggesting that the great majority of primate populations remain vulnerable. We list the key challenges faced by the four countries to avert primate extinctions now and in the future. In the short term, effective law enforcement to stop illegal hunting and illegal forest destruction is absolutely key. Long-term success can only be achieved by focusing local and global public awareness, actively engaging with international organizations, multinational businesses and consumer nations to reduce unsustainable demands on the environment. Finally, the four primate range states need to ensure that integrated, sustainable land-use planning for economic development includes the maintenance of biodiversity and intact, functional natural ecosystems
Global importance of Indigenous Peoples, their lands, and knowledge systems for saving the worldâs primates from extinction
Primates, represented by 521 species, are distributed across 91 countries primarily in the Neotropic, Afrotropic, and Indo-Malayan realms. Primates inhabit a wide range of habitats and play critical roles in sustaining healthy ecosystems that benefit human and nonhuman communities. Approximately 68% of primate species are threatened with extinction because of global pressures to convert their habitats for agricultural production and the extraction of natural resources. Here, we review the scientific literature and conduct a spatial analysis to assess the significance of Indigenous Peoplesâ lands in safeguarding primate biodiversity. We found that Indigenous Peoplesâ lands account for 30% of the primate range, and 71% of primate species inhabit these lands. As their range on these lands increases, primate species are less likely to be classified as threatened or have declining populations. Safeguarding Indigenous Peoplesâ lands, languages, and cultures represents our greatest chance to prevent the extinction of the worldâs primates.info:eu-repo/semantics/publishedVersio
Global importance of Indigenous Peoples, their lands, and knowledge systems for saving the world's primates from extinction
Publisher Copyright: Copyright © 2022 The Authors, some rights reserved.Primates, represented by 521 species, are distributed across 91 countries primarily in the Neotropic, Afrotropic, and Indo-Malayan realms. Primates inhabit a wide range of habitats and play critical roles in sustaining healthy ecosystems that benefit human and nonhuman communities. Approximately 68% of primate species are threatened with extinction because of global pressures to convert their habitats for agricultural production and the extraction of natural resources. Here, we review the scientific literature and conduct a spatial analysis to assess the significance of Indigenous Peoples' lands in safeguarding primate biodiversity. We found that Indigenous Peoples' lands account for 30% of the primate range, and 71% of primate species inhabit these lands. As their range on these lands increases, primate species are less likely to be classified as threatened or have declining populations. Safeguarding Indigenous Peoples' lands, languages, and cultures represents our greatest chance to prevent the extinction of the world's primates.Peer reviewe
Synopsis of the Strophariaceae (Basidiomycota, Agaricales) from Floresta Nacional de SĂŁo Francisco de Paula, Rio Grande do Sul State, Brazil
Recommended from our members
Putting susceptibility on the map to improve conservation planning, an example with terrestrial mammals
Aim
To propose a general approach to spatially synthesize known predictors of vulnerability at the species level in order to identify areas directly associated with specific conservation problems. Under this problem-detection framework, the coincidence or divergence of main strengths and weaknesses can be used to propose tailor-made conservation strategies. This approach is illustrated for terrestrial mammal species evaluating two of their main components of vulnerability: life-history traits and land use pressure.
Location
Global.
Methods
We determine, at the species level, the relationships between extinction risk and two well-known predictors of vulnerability: life-history traits (intrinsic) and land use (extrinsic). Transferring these findings into the spatial domain, we identify the areas of the world where one of these two facets is predominant and those areas where both coincide.
Results
The proposed approach allows us to recognize four types of areas: 1) double-susceptibility areas: where both the characteristics of the species and the existing human activities pose a threat, therefore the simultaneous management of both species/habitats and human activities are needed; 2) intrinsic-susceptibility areas: where species are naturally fragile and human presence is scarce, thus species-specific management plans would be particularly efficient; 3) extrinsic-susceptibility areas: where human pressure is high but species are not intrinsically vulnerable; which requires special attention to human activities; and 4) low-susceptibility areas: where there are not remarkable threats for existing terrestrial mammals, which additionally are not particularly fragile.
Main conclusions
Our approach can spatially synthesize known predictors of vulnerability identifying areas where different factors predispose species to become extinct. This method builds on conservation planning approaches by targeting actions based on known strengths and weaknesses of a given area, and offering a new implementation of comparative studies of extinction risk. This approach may be applied to different species and to particular regions, focusing on different drivers, and complemented by incorporating social and economic trade-offs
Connectivity and vagility determine beta diversity and nestedness in North American and European freshwater fish
Performance and Consistency of Indicator Groups in Two Biodiversity Hotspots
In a world limited by data availability and limited funds for conservation, scientists and practitioners must use indicator groups to define spatial conservation priorities. Several studies have evaluated the effectiveness of indicator groups, but still little is known about the consistency in performance of these groups in different regions, which would allow their a priori selection.We systematically examined the effectiveness and the consistency of nine indicator groups in representing mammal species in two top-ranked Biodiversity Hotspots (BH): the Brazilian Cerrado and the Atlantic Forest. To test for group effectiveness we first found the best sets of sites able to maximize the representation of each indicator group in the BH and then calculated the average representation of different target species by the indicator groups in the BH. We considered consistent indicator groups whose representation of target species was not statistically different between BH. We called effective those groups that outperformed the target-species representation achieved by random sets of species. Effective indicator groups required the selection of less than 2% of the BH area for representing target species. Restricted-range species were the most effective indicators for the representation of all mammal diversity as well as target species. It was also the only group with high consistency.We show that several indicator groups could be applied as shortcuts for representing mammal species in the Cerrado and the Atlantic Forest to develop conservation plans, however, only restricted-range species consistently held as the most effective indicator group for such a task. This group is of particular importance in conservation planning as it captures high diversity of endemic and endangered species
- âŠ