138 research outputs found

    Hierarchical social modularity in gorillas

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    Modern human societies show hierarchical social modularity (HSM) in which lower-order social units like nuclear families are nested inside increasingly larger units. It has been argued that this HSM evolved independently and after the chimpanzee–human split due to greater recognition of, and bonding between, dispersed kin. We used network modularity analysis and hierarchical clustering to quantify community structure within two western lowland gorilla populations. In both communities, we detected two hierarchically nested tiers of social structure which have not been previously quantified. Both tiers map closely to human social tiers. Genetic data from one population suggested that, as in humans, social unit membership was kin structured. The sizes of gorilla social units also showed the kind of consistent scaling ratio between social tiers observed in humans, baboons, toothed whales, and elephants. These results indicate that the hierarchical social organization observed in humans may have evolved far earlier than previously asserted and may not be a product of the social brain evolution unique to the hominin lineage

    National land use specific reference values: a basis for maximum values in Dutch soil policy

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    The National Institute for Public Health and the Environment has derived Reference Values for maximum permissible soil pollution. The Netherlands Ministry of Housing, Spatial Planning and the Environment (VROM) used these values as a basis for the maximum values for soil pollution. The ministry set these values down according to a proposal for an update of soil policy and the Soil Protection Act in 2003. Reference values refer to allowed concentrations of pollutants in soil, depending on the land use. The soil concentrations of pollutants with values below these concentrations meet all the requirements. The risks for humans, the ecosystem and agriculture were analyzed as critical factors, with risk thresholds derived for different types of land use, such as playgrounds, gardens, and agricultural and nature areas. Furthermore, an accelerated procedure was used to compile a complete list of reference values in 2006. The RIVM used state-of-the-art knowledge to complete the 'old' knowledge for information on toxicity of substances; figures were used where knowledge gaps occurred. A recommendation for the coming years is to address resulting inconsistencies in the list of reference values.Het RIVM heeft de referentiewaarden afgeleid waarmee het ministerie van VROM de maximaal toelaatbare bodemverontreinigingen onderbouwt (maximale waarden). Het ministerie heeft deze normen ingesteld in lijn met zijn voorstel uit 2003 om het bodembeleid en de Wet bodembescherming te actualiseren. Referentiewaarden zijn concentraties van verontreinigende stoffen in de bodem die, afhankelijk van het bodemgebruik, zijn toegestaan. Onder deze concentraties voldoet de bodem aan alle eisen. Voor verschillende vormen van bodemgebruik, zoals landbouw, kinderspeelplaatsen of industrie, zijn grensgehalten voor risico's bepaald. Dat zijn bijvoorbeeld, afhankelijk van het gebruik, risico's voor de mens, voor het ecosysteem en voor de landbouw. Het RIVM heeft gebruikgemaakt van een versnelde procedure om in 2006 een compleet voorstel van referentiewaarden gereed te hebben. Die snelheid was ingegeven door de werkgroep NOBO (normstelling en bodemkwaliteitsbeoordeling). Deze werkgroep heeft tevens uitgangspunten en beslissingen geformuleerd op basis waarvan het RIVM de referentiewaarden heeft afgeleid. Het RIVM heeft voor zijn onderzoek zo veel mogelijk gebruikgemaakt van de nieuwste kennis en inzichten, voor zover die beschikbaar zijn. Deze informatie is aangevuld met 'oude' kennis over stoffen. Deze combinatie heeft evenwel tot inconsistenties geleid in de afleiding van referentiewaarden. Het RIVM beveelt daarom aan de komende jaren aandacht te besteden aan de inconsistenties en zwakke plekken van de referentiewaarden

    Population dynamics of the last leopard population of eastern Indochina in the context of improved law enforcement

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    Poaching, a major threat to wildlife worldwide, is pushing species toward extinction. To reduce poaching pressure and combat biodiversity loss, improved law-enforcement efforts reportedly are required; the effectiveness of which can be determined through rigorous monitoring of wildlife populations, particularly of endangered large carnivores. In the Eastern Plains Landscape of Cambodia, law-enforcement efforts increased to counter the severe threats from illegal activities; however, it is unknown if these strategies are benefiting the population of the Critically Endangered Indochinese leopard (Panthera pardus delacouri), the last large felid population of eastern Indochina. We used open population spatial capture-recapture models to estimate density, survival, per-capita recruitment, and population growth rates of leopard using data from 7 camera-trap surveys conducted over 11 years (2009–2019). We found that the population (a) declined by over 82 % (from 1.5 to 0.3 leopard/100 km2), (b) had low survival probability (0.58) and low recruitment rates (males: 0.04, females: 0.24), and (c) is expected to continue declining. An additional survey in 2021 failed to detect leopard, suggesting the species now is functionally extinct, if not fully extirpated, from the landscape. Over the study period, there was a drastic increase in human activity, with a 20-fold increase in detection frequencies of humans and a 1000-fold increase in lethal-trap encounter rate. The rise in anthropogenic pressures, particularly snaring, appeared to be the primary reason for the leopard decline, indicating the last decade of management interventions was insufficient to conserve the species, which now appears to be extirpated in all of Cambodia, Laos and Vietnam. This has implications for leopard conservation in the wider region, notably that efforts should now focus on populations within the two remaining strongholds. Our results suggest that increases in law-enforcement efforts alone are unlikely to protect wildlife in eastern Indochina; thus, additional strategies are needed to address the region's snaring crisis, including legislative reforms, community engagement, and programs that reduce demand for wildlife meat and products. Long-term studies of remaining Indochinese leopard populations coupled with timely and effective conservation actions are needed to avoid the complete demise of this subspecies

    Towards Automated Visual Monitoring of Individual Gorillas in the Wild

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    Periconception maternal folate status and human embryonic cerebellum growth trajectories: The Rotterdam predict study

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    We aimed to investigate whether periconceptional maternal folate status affects human embryonic cerebellar size and growth trajectories. In a prospective periconceptional cohort participants filled out questionnaires and received weekly transvaginal 3D-ultrasounds between 7+0 and 12+6 weeks gestational age (GA). Viable non-malformed singleton pregnancies were selected for cerebellar measurements; transcerebellar diameter, (TCD), left and right cerebellar diameters (LCD, RCD). Linear mixed models were performed to estimate associations between questionnaire data on the timing of maternal folic acid supplement initiation and longitudinal cerebellar measurements as a function of crown-rump length (CRL) and GA. Maternal red blood cell folate concentrations were analysed before 8 weeks GA to validate the associations. A total of 263 serial high quality three-dimensional ultrasound scans of 135 pregnancies were studied. Preconceptional compared to postconceptional initiation of folic acid use was associated with slightly larger cerebellar diameters per millimetre increase of CRL (TCD: β = 0.260mm, 95%CI = 0.023-0.491, p<0.05; LCD: β = 0.171mm, 95%CI = 0.038-0.305, p<0.05; RCD: β = 0.156mm, 95%CI = 0.032-0.280, p<0.05) and with proportional cerebellar growth (TCD/CRL:β = 0.015mm/mm, 95%CI = 0.005-0.024, p<0.01; LCD/CRL:β = 0.012mm/mm, 95%CI = 0.005-0.018, p<0.01; RCD/ CRL:β = 0.011mm/mm, 95%CI = 0.005-0.017, p

    Calculation of critical loads for cadmium, lead and mercury; background document to a mapping manual on critical loads of cadmium, lead and mercury

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    This report on heavy metals provides up-to-date methodologies to derive critical loads for the heavy metals cadmium (Cd), lead (Pb) and mercury (Hg) for both terrestrial and aquatic ecosystems. It presents background information to a Manual on Critical Loads for those metals. Focus is given to the methodologies and critical limits that have to be used to derive critical loads can be derived for Cd, Pb and Hg in view of : (i) ecotoxicological effects for either terrestrial or aquatic ecosystems.and (ii) human health effects for either terrestrial or aquatic ecosystems. For Hg, a separate approach is described to estimate critical levels in precipitation in view of human health effects due to the consumption of fish. The limitations and uncertainties of the approach are discussed including: (i) the uncertainties and particularities of the steady-state models used and (ii) the reliability of the approaches that are applied to derive critical limits for critical total dissolved metal concentrations in soil solution and surface wate

    Impact of soil properties on critical concentrations of cadmium, lead, copper, zinc and mercury in soil and soil solution in view of ecotoxicological effects

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    Concern about the input of metals to terrestrial ecosystems is related to (i) the ecotoxicological impact on soil organisms and plants (Bringmark et al. 1998; Palmborg et al. 1998) and also on aquatic organisms resulting from runoff to surface water and (ii) the uptake via food chains into animal tissues and products, which may result in health effects on animals and humans (Clark 1989). Effects on soil organisms, including microorganisms/macrofungi and soil fauna, such as nematodes and earthworms, are reduced species diversity, abundance, and biomass and changes in microbe-mediated processes (Bengtsson and Tranvik 1989; Giller et al. 1998; Vig et al. 2003). Effects on vascular plants include reduced development and growth of roots and shoots, elevated concentrations of starch and total sugar, decreased nutrient contents in foliar tissues, and decreased enzymatic activity (Prasad 1995; Das et al. 1997). A review of these phytotoxic effects is given by Balsberg-PĂĄhlsson (1989). Effects on aquatic organisms, including algae, Crustacea, and fish, include effects on gill function (Sola et al. 1995), nervous systems (Baatrup 1991), and growth and reproduction rates (Mance 1987). Environmental quality standards or critical limits, often also denoted as Predicted No Effect Concentrations, or PNECs, for metals in soils and surface waters related to those effects serve as a guide in the environmental risk assessment process for those substances

    ZZ-boson polarization as a model-discrimination analyzer

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    Determining the spin of any new particle is critical in identifying the true theory among various extensions of the Standard Model (SM). The degree of ZZ-boson polarization in any two-body decay process A→BZA\to B Z is sensitive to the spin assignments of two new particles AA and BB. Considering all possible spin-0, 1/2 and 1 combinations in a renormalizable field theory, we demonstrate that ZZ-boson polarization can indeed play a role of a decisive and universal analyzer in distinguishing the different spin assignments.Comment: 10 pages, 3 figures, 1 tabl
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