101 research outputs found
Seasonal patterns of pollen sedimentation in Lake Montcortès (Central Pyrenees) and potential applications to high-resolution paleoecology: a 2-year pilot study
14 páginas, 2 tablas, 10 figuras.Lakes with varved sediments are especially
well suited for paleoecological study, from annual to
even seasonal resolution. The interpretative power of
such high-resolution paleoenvironmental reconstructions
relies on the availability of modern analogs with
the same temporal resolution. We studied seasonal
pollen sedimentation in varved Lake Montcorte`s, Central
Pyrenees (Spain), as a modern analog for highresolution
reconstruction of Late Holocene vegetation
and landscape dynamics. Seasonal samples were
obtained from sediment traps that were submerged near
the maximum water depth for a 2-year period (fall 2013
to fall 2015). Seasonal pollen sedimentation was compared
with meteorological variables from a nearby
weather station. Bulk pollen sedimentation, dominated
by Pinus (pine) and Quercus (oak), followed a clear
seasonal pattern that peaked during the spring/summer,
coinciding with maximum temperature and precipitation,
minimum relative humidity and moderate winds
from the SSE. Pollen sedimentation lags (PSL) were
observed formost pollen types, as substantial amounts of
pollen were found in the traps outside of their respective
flowering seasons. Two pollen assemblages were clearly
differentiated by their taxonomic composition, corresponding
to spring/summer and fall/winter. This pattern
is consistent with existing interpretation of the sediment
varves, specifically, that varves are formed by two-layer
couplets that represent the same seasonality as pollen.
We concluded that pollen sedimentation in Lake
Montcorte`s exhibits a strong seasonal signal in the
quantity of pollen, the taxonomic composition of the
pollen assembalges, and relationships between the pollen
and meteorological variables. Thus, varved sediments
provide a potentially powerful tool for paleoecological
reconstruction at seasonal resolution. This method could
be used not only to identify paleoenvironmental trends,
but also to identify annual layers and therefore date
sediments, even in the absence of evident sediment
laminations. A satisfactory explanation of PSL will
require further studies that examine internal lake
dynamics and pollen production/dispersal patterns.This work was funded by the Ministry of
Economy and Competitivity (project MONT-500; reference
CGL2012-33665; PI: Teresa Vegas-Vilarru´bia).Peer reviewe
Seasonal patterns of pollen sedimentation in Lake Montcortès (Central Pyrenees) and potential applications to high-resolution paleoecology: a two-year pilot study.
Lakes with varved sediments are especially well suited for paleoecological study, from annual to even seasonal resolution. The interpretative power of such high-resolution paleoenvironmental reconstructions relies on the availability of modern analogs with the same temporal resolution. We studied seasonal pollen sedimentation in varved Lake Montcorte`s, Central Pyrenees (Spain), as a modern analog for highresolution reconstruction of Late Holocene vegetation and landscape dynamics. Seasonal samples were obtained from sediment traps that were submerged near the maximum water depth for a 2-year period (fall 2013 to fall 2015). Seasonal pollen sedimentation was compared with meteorological variables from a nearby weather station. Bulk pollen sedimentation, dominated by Pinus (pine) and Quercus (oak), followed a clear seasonal pattern that peaked during the spring/summer, coinciding with maximum temperature and precipitation, minimum relative humidity and moderate winds from the SSE. Pollen sedimentation lags (PSL) were observed for most pollen types, as substantial amounts of pollen were found in the traps outside of their respective flowering seasons. Two pollen assemblages were clearly differentiated by their taxonomic composition, corresponding to spring/summer and fall/winter. This pattern is consistent with existing interpretation of the sediment varves, specifically, that varves are formed by two-layer couplets that represent the same seasonality as pollen. We concluded that pollen sedimentation in Lake Montcorte`s exhibits a strong seasonal signal in the quantity of pollen, the taxonomic composition of the pollen assembalges, and relationships between the pollen and meteorological variables. Thus, varved sediments provide a potentially powerful tool for paleoecological reconstruction at seasonal resolution. This method could be used not only to identify paleoenvironmental trends, but also to identify annual layers and therefore date sediments, even in the absence of evident sediment laminations. A satisfactory explanation of PSL will require further studies that examine internal lake dynamics and pollen production/dispersal patterns
Ecology of the collapse of Rapa Nui society
Collapses of food producer societies are recurrent events in prehistory and have triggered a growing concern for identifying the underlying causes of convergences/divergences across cultures around the world. One of the most studied and used as a paradigmatic case is the population collapse of the Rapa Nui society. Here, we test different hypotheses about it by developing explicit population dynamic models that integrate feedbacks between climatic, demographic and ecological factors that underpinned the sociocultural trajectory of these people. We evaluate our model outputs against a reconstruction of past population size based on archaeological radiocarbon dates from the island. The resulting estimated demographic declines of the Rapa Nui people are linked to the long-term effects of climate change on the island's carrying capacity and, in turn, on the 'per-capita food supply'
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Environmental factors of food insecurity in adolescents: A scoping review protocol
Data Availability: No datasets were generated or analysed during the current study. All relevant data from this study will be made available upon study completion.Copyright: © 2023 Capitán-Moyano et al. Food insecurity in recent years has increased worldwide due to many planetary events such as the COVID-19 pandemic, geopolitical conflicts, the climate crisis, and globalization of markets. Adolescents are a particularly vulnerable group to food insecurity, as they enter adulthood with less parental supervision and greater personal autonomy, but less legislative or institutional protection. The experience of food insecurity in adolescents is influenced by several environmental factors at different levels (interpersonal, organizational, community, and societal), although they are not usually addressed in the design of interventions, prioritizing the individual behavioural factors. We present a scoping review protocol for assessing and identifying the environmental factors that could influence adolescents’ food insecurity. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA-P) and the PRISMA guidelines for Scoping Reviews (PRISMA-ScR) to prepare the protocol. The search strategy will be performed in the following databases: Pubmed/Medline, EMBASE, Biblioteca Virtual de Salud, EBSCOHost, Scopus, Web of Science, and Cochrane Library Plus. The reference list of the included studies will also be hand-searched. Grey literature will be search through the electronic database Grey Literature Report, and local, provincial, national, and international organisations’ websites. Assessment of eligibility after screening of titles, abstract and full text, and the resolution of discrepancies will be performed by three independent reviewers. This scoping review will contribute to refine the “logic model of the problem” which constitutes the first step in the intervention mapping protocol. The “logic model of the problem” from the intervention mapping protocol will serve to classify and analyse the environmental factors. The findings from this review will be presented to relevant stakeholders that have a role in shaping the environmental factors.The authors received no specific funding for this work
Characterization of the Earwig, Doru lineare, as a Predator of Larvae of the Fall Armyworm, Spodoptera frugiperda: A Functional Response Study
Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) is considered as the most important pest of maize in almost all tropical America. In Argentina, the earwig Doru lineare Eschscholtz (Dermaptera: Forficulidae) has been observed preying on S. frugiperda egg masses in corn crops, but no data about its potential role as a biocontrol agent of this pest have been provided. The predation efficiency of D. lineare on newly emerged S. frugiperda larva was evaluated through a laboratory functional response study. D. lineare showed type II functional response to S. frugiperda larval density, and disc equation estimations of searching efficiency and handling time were (a) = 0.374 and (t) = 182.9 s, respectively. Earwig satiation occurred at 39.4 S. frugiperda larvae
Effects of thinning intensity on radial growth patterns and temperature sensitivity in Pinus canariensis afforestations on Tenerife Island, Spain
Psychometric characteristics of the Spanish version of instruments to measure neck pain disability
Background: The NDI, COM and NPQ are evaluation instruments for disability due to NP. There was no Spanish version of NDI or COM for which psychometric characteristics were known. The objectives of this study were to translate and culturally adapt the Spanish version of the Neck Disability Index Questionnaire (NDI), and the Core Outcome Measure (COM), to validate its use in Spanish speaking patients with non-specific neck pain (NP), and to compare their psychometric characteristics with those of the Spanish version of the Northwick Pain Questionnaire (NPQ).
Methods: Translation/re-translation of the English versions of the NDI and the COM was done blindly and independently by a multidisciplinary team. The study was done in 9 primary care Centers and 12 specialty services from 9 regions in Spain, with 221 acute, subacute and chronic patients who visited their physician for NP: 54 in the pilot phase and 167 in the validation phase. Neck pain (VAS), referred pain (VAS), disability (NDI, COM and NPQ), catastrophizing (CSQ) and quality of life (SF-12) were measured on their first visit and 14 days later. Patients' self-assessment was used as the external criterion for pain and disability. In the pilot phase, patients' understanding of each item in the NDI and COM was assessed, and on day 1 test-retest reliability was estimated by giving a second NDI and COM in which the name of the questionnaires and the order of the items had been changed.
Results: Comprehensibility of NDI and COM were good. Minutes needed to fill out the questionnaires [median, (P25, P75)]: NDI. 4 (2.2, 10.0), COM: 2.1 (1.0, 4.9). Reliability: [ICC, (95%CI)]: NDI: 0.88 (0.80, 0.93). COM: 0.85 (0.75,0.91). Sensitivity to change: Effect size for patients having worsened, not changed and improved between days 1 and 15, according to the external criterion for disability: NDI: -0.24, 0.15, 0.66; NPQ: -0.14, 0.06, 0.67; COM: 0.05, 0.19, 0.92. Validity: Results of NDI, NPQ and COM were consistent with the external criterion for disability, whereas only those from NDI were consistent with the one for pain. Correlations with VAS, CSQ and SF-12 were similar for NDI and NPQ (absolute values between 0.36 and 0.50 on day 1, between 0.38 and 0.70 on day 15), and slightly lower for COM (between 0.36 and 0.48 on day 1, and between 0.33 and 0.61 on day 15). Correlation between NDI and NPQ: r = 0.84 on day 1, r = 0.91 on day 15. Correlation between COM and NPQ: r = 0.63 on day 1, r = 0.71 on day 15.
Conclusion: Although most psychometric characteristics of NDI, NPQ and COM are similar, those from the latter one are worse and its use may lead to patients' evolution seeming more positive than it actually is. NDI seems to be the best instrument for measuring NP-related disability, since its results are the most consistent with patient's assessment of their own clinical status and evolution. It takes two more minutes to answer the NDI than to answer the COM, but it can be reliably filled out by the patient without assistance
A search for Very High Energy gamma-ray emission from Scorpius X-1 with the MAGIC telescopes
The acceleration of particles up to GeV or higher energies in microquasars
has been the subject of considerable theoretical and observational efforts in
the past few years. Sco X-1 is a microquasar from which evidence of highly
energetic particles in the jet has been found when it is in the so-called
Horizontal Branch (HB), a state when the radio and hard X-ray fluxes are higher
and a powerful relativistic jet is present. Here we present the first very high
energy gamma-ray observations of Sco X-1 obtained with the MAGIC telescopes. An
analysis of the whole dataset does not yield a significant signal, with 95% CL
flux upper limits above 300 GeV at the level of 2.4x10^{-12} ph/cm^2/s.
Simultaneous RXTE observations were conducted to search for TeV emission during
particular X-ray states of the source. A selection of the gamma-ray data
obtained during the HB based on the X-ray colors did not yield a signal either,
with an upper limit of 3.4x10^{-12} ph/cm^2/s. These upper limits place a
constraint on the maximum TeV luminosity to non-thermal X-ray luminosity of
L_{VHE}/L_{ntX}<0.02, that can be related to a maximum TeV luminosity to jet
power ratio of L_{VHE}/L_{j}<10^{-3}. Our upper limits indicate that the
underlying high-energy emission physics in Sco X-1 must be inherently different
from that of the hitherto detected gamma-ray binaries.Comment: 5 pages, 2 figures, 2 tables. Version as published in ApJ
PG 1553+113: five years of observations with MAGIC
We present the results of five years (2005-2009) of MAGIC observations of the
BL Lac object PG 1553+113 at very high energies (VHEs, E > 100 GeV). Power law
fits of the individual years are compatible with a steady mean photon index
\Gamma = 4.27 0.14. In the last three years of data, the flux level above
150 GeV shows a clear variability (probability of constant flux < 0.001%). The
flux variations are modest, lying in the range from 4% to 11% of the Crab
Nebula flux. Simultaneous optical data also show only modest variability that
seems to be correlated with VHE gamma ray variability. We also performed a
temporal analysis of (all available) simultaneous Fermi/LAT data of PG 1553+113
above 1 GeV, which reveals hints of variability in the 2008-2009 sample.
Finally, we present a combination of the mean spectrum measured at very high
energies with archival data available for other wavelengths. The mean spectral
energy distribution can be modeled with a one-zone Synchrotron Self Compton
(SSC) model, which gives the main physical parameters governing the VHE
emission in the blazar jet.Comment: 11 pages, 6 figures, accepted for publication in Ap
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