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1.
Nature ; 613(7944): 526-533, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36631607

RESUMEN

Financial incentives to encourage healthy and prosocial behaviours often trigger initial behavioural change1-11, but a large academic literature warns against using them12-16. Critics warn that financial incentives can crowd out prosocial motivations and reduce perceived safety and trust, thereby reducing healthy behaviours when no payments are offered and eroding morals more generally17-24. Here we report findings from a large-scale, pre-registered study in Sweden that causally measures the unintended consequences of offering financial incentives for taking the first dose of a COVID-19 vaccine. We use a unique combination of random exposure to financial incentives, population-wide administrative vaccination records and rich survey data. We find no negative consequences of financial incentives; we can reject even small negative impacts of offering financial incentives on future vaccination uptake, morals, trust and perceived safety. In a complementary study, we find that informing US residents about the existence of state incentive programmes also has no negative consequences. Our findings inform not only the academic debate on financial incentives for behaviour change but also policy-makers who consider using financial incentives to change behaviour.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Conductas Relacionadas con la Salud , Motivación , Vacunación , Humanos , COVID-19/prevención & control , COVID-19/psicología , Vacunas contra la COVID-19/economía , Conductas Relacionadas con la Salud/ética , Seguridad del Paciente , Suecia , Confianza , Estados Unidos , Vacunación/economía , Vacunación/ética , Vacunación/psicología , Recolección de Datos
2.
Glob Chang Biol ; 30(8): e17444, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39082602

RESUMEN

Converting natural vegetation for agriculture has resulted in the loss of approximately 5% of the current global terrestrial soil organic carbon (SOC) stock to the atmosphere. Increasing the agricultural area under grassland may reverse some of these losses, but the effectiveness of such a strategy is limited by how quickly SOC recovers after conversion from cropland. Using soil data and extensive land-use histories gathered during the national German agricultural soil inventory, this study aims to answer three questions regarding agricultural land-use change (LUC): (i) how do SOC stocks change with depth following LUC; (ii) how long does it take to reach SOC equilibrium after LUC; and (iii) what is the legacy effect of historic LUC on present day SOC dynamics? By using a novel approach that substitutes space for time and accounts for differences in site properties using propensity score balancing, we determined that sites that were converted from cropland to grassland reached a SOC equilibrium level 47.3% (95% confidence interval (CI): 43.4% to 49.5%) above permanent cropland levels 83 years (95% CI: 79 to 90 years) after conversion. Meanwhile, sites converted from grassland to cropland reached a SOC equilibrium level -33.6% (95% CI: -34.1% to -33.5%) below permanent grassland levels after 180 years (95% CI: 151 to 223 years). We estimate that, over the past century, today's German agricultural soils (16.6 million ha) have gained about 40 million Mg C. Furthermore, croplands with historic LUC from grassland are losing SOC by -0.26 Mg ha-1 year-1 (10% of agricultural land) while grasslands historically converted from cropland are gaining SOC by 0.27 Mg ha-1 year-1 (18% of agricultural land). This study shows that even long-standing temperate agricultural sites likely have ongoing SOC change as a result of historical LUC.


Asunto(s)
Agricultura , Carbono , Suelo , Suelo/química , Agricultura/historia , Alemania , Carbono/análisis , Pradera
3.
Phys Chem Chem Phys ; 26(16): 12282-12288, 2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38426875

RESUMEN

Desorption of molecules from surfaces is widespread both in nature and technology. Despite its omnipresence and conceptual simplicity, fundamental details can be surprisingly complex and are often poorly understood. In many cases, first-order kinetics is assumed, which implies that the adsorbates do not interact with each other and desorption is the rate-limiting process. While this might be a good approximation in some cases, it is far from reality in the case of adsorbates that form ordered structures. Here, we study the desorption of a submonolayer film of 3-nitrophenol from the natural cleavage plane of calcite kept in ultrahigh vacuum. Interestingly, two distinctly different desorption regimes are observed during isothermal desorption monitored by dynamic atomic force microscopy. Initially, at high coverages, the coverage decreases almost linearly in time, indicating a constant desorption rate. Beyond this linear regime, at low coverages, a drastic increase in desorption rate is observed until the surface is completely empty. The transition between these two regimes is associated with a critical island width. We propose an existence of a long-range attractive interaction between the molecules as a possible explanation for the sudden increase in the desorption rate when a critical island width is reached. The herein observed phenomenon of two different desorption regimes is expected to be of general nature when interactions beyond next-neighbour attraction are present.

4.
Glob Chang Biol ; 27(21): 5670-5679, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34351036

RESUMEN

Treatment effects are traditionally quantified in controlled experiments. However, experimental control is often achieved at the expense of representativeness. Here, we present a data-driven reciprocal modelling framework to quantify the individual effects of environmental treatments under field conditions. The framework requires a representative survey data set describing the treatment (A or B), its responding target variable and other environmental properties that cause variability of the target within the region or population studied. A machine learning model is trained to predict the target only based on observations in group A. This model is then applied to group B, with predictions restricted to the model's space of applicability. The resulting residuals represent case-specific effect size estimates and thus provide a quantification of treatment effects. This paper illustrates the new concept of such data-driven reciprocal modelling to estimate spatially explicit effects of land-use change on organic carbon stocks in European agricultural soils. For many environmental treatments, the proposed concept can provide accurate effect size estimates that are more representative than could feasibly ever be achieved with controlled experiments.


Asunto(s)
Ecosistema , Suelo , Agricultura , Carbono , Secuestro de Carbono
5.
Glob Chang Biol ; 27(19): 4921-4934, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34228862

RESUMEN

The ratio of soil organic carbon stock (SOC) to annual carbon input gives an estimate of the mean residence time of organic carbon that enters the soil (MRTOC ). It indicates how efficiently biomass can be transformed into SOC, which is of particular relevance for mitigating climate change by means of SOC storage. There have been few comprehensive studies of MRTOC and their drivers, and these have mainly been restricted to the global scale, on which climatic drivers dominate. This study used the unique combination of regional-scale cropland and grassland topsoil (0-30 cm) SOC stock data and average site-specific OC input data derived from the German Agricultural Soil Inventory to elucidate the main drivers of MRTOC . Explanatory variables related to OC input composition and other soil-forming factors were used to explain the variability in MRTOC by means of a machine-learning approach. On average, OC entering German agricultural topsoils had an MRT of 21.5 ± 11.6 years, with grasslands (29.0 ± 11.2 years, n = 465) having significantly higher MRTOC than croplands (19.4 ± 10.7, n = 1635). This was explained by the higher proportion of root-derived OC inputs in grassland soils, which was the most important variable for explaining MRTOC variability at a regional scale. Soil properties such as clay content, soil group, C:N ratio and groundwater level were also important, indicating that MRTOC is driven by a combination of site properties and OC input composition. However, the great importance of root-derived OC inputs indicated that MRTOC can be actively managed, with maximization of root biomass input to the soil being a straightforward means to extend the time that assimilated C remains in the soil and consequently also increase SOC stocks.


Asunto(s)
Carbono , Suelo , Agricultura , Secuestro de Carbono
6.
J Sex Med ; 18(10): 1807-1817, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34600646

RESUMEN

BACKGROUND: Little information is available on steroid hormone profiles in transwomen on the day of gender affirming surgery (GAS) after gender affirming hormone therapy (GAHT). AIM: We compared extended serum steroid hormone profiles of 77 transwomen with 3 different treatment regimens in order to get more insight on how GAHT changes the hormone system. METHODS: Samples were obtained from 3 independent clinics. Individuals in clinic A (n = 13) and B (n = 51) discontinued GAHT 4-6 weeks and 2 weeks before GAS, individuals in clinic C (n = 13) continued treatment. Testicular tissue, blood samples and questionnaires on age, weight, height, and medication use were received from each patient. Steroid hormones were measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS), 6 sex hormones were determined by immunofluorometric assays, and ELISA. Spermatogenesis was scored using the Bergman/Kliesch score. OUTCOMES: Participants were not different with regard to age, BMI, treatment duration, and dosage. Feminized blood serum levels with low LH, low FSH and low testosterone, however, were achieved in persons taking GAHT until GAS. Significantly reduced cortisone levels were seen after stopping GAHT before GAS. RESULTS: GAHT had marked effects on the sex-steroid profile in each person. Factor analysis provided a model explaining 78% of the variance and interdependency of sex steroid levels. Stopping treatment was inversely associated with intactness of the corticosteroid-axis with adrenal steroidogenesis as well as it was inversely associated with pituitary-gonadal hormone production. CLINICAL IMPLICATIONS: Transwomen generally did not have elevated cortisone levels but differed significantly depending on and when GAHT was stopped. STRENGTHS & LIMITATIONS: This is the first study examining the steroid hormone profiles of transgender persons on the day of GAS in a multi-center setting. Additional studies (including follow ups before and after GAS and stress questionnaires) will be necessary to assess these conflicting results about the possible psychological impact on persons undergoing GAS to improve care. CONCLUSION: Concerning feminized blood serum levels, continued GAHT seems the better alternative, however stopping treatment 4-6 weeks prior to surgery was associated with reduced cortisone levels. Schneider F, Wistuba J, Holterhus P-M, et al. New Insights Into Extended Steroid Hormone Profiles in Transwomen in a Multi-Center Setting in Germany. J Sex Med 2021;18:1807-1817.


Asunto(s)
Espectrometría de Masas en Tándem , Personas Transgénero , Cromatografía Liquida , Alemania , Hormonas , Humanos , Masculino , Esteroides
7.
J Public Econ ; 195: 104367, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33531719

RESUMEN

Socially responsible behavior is crucial for slowing the spread of infectious diseases. However, economic and epidemiological models of disease transmission abstract from prosocial motivations as a driver of behaviors that impact the health of others. In an incentivized study, we show that a large majority of people are very reluctant to put others at risk for their personal benefit. Moreover, this experimental measure of prosociality predicts health behaviors during the COVID-19 pandemic, measured in a separate and ostensibly unrelated study with the same people. Prosocial individuals are more likely to follow physical distancing guidelines, stay home when sick, and buy face masks. We also find that prosociality measured two years before the pandemic predicts health behaviors during the pandemic. Our findings indicate that prosociality is a stable, long-term predictor of policy-relevant behaviors, suggesting that the impact of policies on a population may depend on the degree of prosociality.

8.
Environ Monit Assess ; 193(4): 200, 2021 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-33738573

RESUMEN

The monitoring of the spatial and temporal dynamics of vegetation productivity is important in the context of carbon sequestration by terrestrial ecosystems from the atmosphere. The accessibility of the full archive of medium-resolution earth observation data for multiple decades dramatically improved the potential of remote sensing to support global climate change and terrestrial carbon cycle studies. We investigated a dense time series of multi-sensor Landsat Normalized Difference Vegetation Index (NDVI) data at the southern fringe of the boreal forests in the Mongolian forest-steppe with regard to the ability to capture the annual variability in radial stemwood increment and thus forest productivity. Forest productivity was assessed from dendrochronological series of Siberian larch (Larix sibirica) from 15 plots in forest patches of different ages and stand sizes. The results revealed a strong correlation between the maximum growing season NDVI of forest sites and tree ring width over an observation period of 20 years. This relationship was independent of the forest stand size and of the landscape's forest-to-grassland ratio. We conclude from the consistent findings of our case study that the maximum growing season NDVI can be used for retrospective modelling of forest productivity over larger areas. The usefulness of grassland NDVI as a proxy for forest NDVI to monitor forest productivity in semi-arid areas could only partially be confirmed. Spatial and temporal inconsistencies between forest and grassland NDVI are a consequence of different physiological and ecological vegetation properties. Due to coarse spatial resolution of available satellite data, previous studies were not able to account for small-scaled land-cover patches like fragmented forest in the forest-steppe. Landsat satellite-time series were able to separate those effects and thus may contribute to a better understanding of the impact of global climate change on natural ecosystems.


Asunto(s)
Larix , Ecosistema , Monitoreo del Ambiente , Bosques , Estudios Retrospectivos
9.
Acta Oncol ; 59(11): 1357-1364, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32686979

RESUMEN

PURPOSE: To assess the relationship between F-18-fluoro-ethyl-tyrosine positron emission tomography (FET-PET) parameters of relapsing oligodendroglioma and progression-free survival. MATERIAL AND METHODS: The relationship of clinical parameters, FET-PET parameters (SUVmax, TBRmax, BTV, time-activity curves) and progression-free survival was analyzed using univariate and multivariate analysis in 42 adult patients with relapsing oligodendroglioma. Kaplan-Meier analysis was used to assess survival. RESULTS: Patients who did not undergo surgical resection of their relapsing tumor had significantly lower PFS if the tumor exhibited an SUVmax above 3.40 than those with an SUVmax below 3.40 (13.1 ± 2.3 months vs. 47.3 ± 6.0 months, respectively, p < .001). Patients who underwent surgery had similar PFS as the aforementioned non-operated patients with low SUVmax (53.6 ± 6.7 months, p = .948). The same was true for TBRmax using a threshold of 3.03 (PFS 12.5 ± 2.4 months vs. 44.0 ± 6.3 months / 53.6 ± 6.7 months, respectively; p < .001 / p = .825). Also, subjects with BTV below 10 cm3 that did not undergo surgery had a similar PFS as subjects who underwent surgery (40.2 ± 6.0 months vs. 52.4 ± 8.9 months, respectively, p = .587). Subjects with BTV above 10 cm3 and without surgery had a significantly worse PFS (13.8 ± 3.3 months, p < .001). Multivariate analysis showed that the prognostication by clinical parameters is improved by adding TBRmax to the model (AUC 0.945 (95% CI: 0.881-1.000), true classification rate 88.1%). CONCLUSION: FET-PET may provide added value for the prognostication of relapsing oligodendroglioma in addition to clinical parameters.


Asunto(s)
Neoplasias Encefálicas , Glioma , Oligodendroglioma , Adulto , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/cirugía , Humanos , Recurrencia Local de Neoplasia/diagnóstico por imagen , Oligodendroglioma/diagnóstico por imagen , Oligodendroglioma/cirugía , Tomografía de Emisión de Positrones , Pronóstico , Tirosina
10.
Soft Matter ; 13(15): 2738-2748, 2017 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-28217774

RESUMEN

In this work we investigated the behaviour of stimuli-responsive poly(N-vinylcaprolactam) (PVCL) microgels in poly(ethylene glycol) (PEGs) with a linear architecture. We performed small-angle neutron scattering (SANS) experiments at two different microgel concentrations and various temperatures. The results were compared with those on PVCL microgels in water. PVCL in PEG (molecular weight MW = 2 kg mol-1) exhibits a volume phase transition temperature (VPTT) at a temperature between 160 and 180 °C. The diameter of the swollen microgel is only slightly smaller than in water. Furthermore, with increasing molecular weight of the surrounding polymer matrices fewer chains penetrate the microgel particles. In agreement with that, we identify a decreasing diameter with increasing molecular weight. In the short chain polymers up to MW = 3 kg mol-1, PVCL is well dispersed in the matrices with only minor signatures of agglomeration. For the well dispersed systems, we find unperturbed chain conformation of the PEG. Our results clearly show that the miscibility of PVCL and PEG disappears in a molecular weight range of 3 to 10 kg mol-1.

11.
Glob Chang Biol ; 21(11): 3971-81, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26147063

RESUMEN

It is widely accepted that global warming will adversely affect ecological communities. As ecosystems are simultaneously exposed to other anthropogenic influences, it is important to address the effects of climate change in the context of many stressors. Nutrient enrichment might offset some of the energy demands that warming can exert on organisms by stimulating growth at the base of the food web. It is important to know whether indirect effects of warming will be as ecologically significant as direct physiological effects. Declining body size is increasingly viewed as a universal response to warming, with the potential to alter trophic interactions. To address these issues, we used an outdoor array of marine mesocosms to examine the impacts of warming, nutrient enrichment and altered top-predator body size on a community comprised of the predator (shore crab Carcinus maenas), various grazing detritivores (amphipods) and algal resources. Warming increased mortality rates of crabs, but had no effect on their moulting rates. Nutrient enrichment and warming had near diametrically opposed effects on the assemblage, confirming that the ecological effects of these two stressors can cancel each other out. This suggests that nutrient-enriched systems might act as an energy refuge to populations of species under metabolic constraints due to warming. While there was a strong difference in assemblages between mesocosms containing crabs compared to mesocosms without crabs, decreasing crab size had no detectable effect on the amphipod or algal assemblages. This suggests that in allometrically balanced communities, the expected long-term effect of warming (declining body size) is not of similar ecological consequence to the direct physiological effects of warming, at least not over the six week duration of the experiment described here. More research is needed to determine the long-term effects of declining body size on the bioenergetic balance of natural communities.


Asunto(s)
Biota , Eutrofización , Cadena Alimentaria , Temperatura , Anfípodos/fisiología , Animales , Tamaño Corporal , Braquiuros/crecimiento & desarrollo , Braquiuros/fisiología , Irlanda del Norte , Conducta Predatoria , Algas Marinas/fisiología
12.
J Sex Med ; 12(11): 2190-200, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26559385

RESUMEN

INTRODUCTION: Cross-sex hormone treatment of gender dysphoria (GD) patients changing from male to female a prerequisite for sex reassignment. For initial physical adaptation, a combined treatment of anti-androgens and estrogens is used. Provided that patients fulfill specific criteria, sex reassignment surgery (SRS) presents the final step toward physical adaptation. However, systematic studies analyzing effects of hormone treatment regimens are lacking. AIM: The aim of this study was to compare the effects of three different hormonal treatment strategies regarding endocrinological parameters and testicular histology. METHODS: Testicular tissues were obtained in a multicenter study from 108 patients on the day of SRS from three clinics following different treatment strategies. Patients either discontinued treatment 6 weeks (clinic A) or 2 weeks (clinic B) prior to SRS or not at all (clinic C). Testicular tissues, ethylenediaminetetraacetic acid blood and questionnaires were obtained on the day of SRS. MAIN OUTCOME MEASURES: Blood hormone and intratesticular testosterone (ITT) levels were measured. Testicular weight and histology were evaluated and the percentage of luteinizing hormone/choriogonadotropin receptor (LHCGR) positive cells was determined. RESULTS: According to the questionnaires, patients showed desired phenotypical changes including breast growth (75%) and smooth skin (32%). While patients from clinics A and B presented with rather virilized hormonal levels, patients from clinic C showed generally feminized blood serum levels. Histological evaluation revealed highly heterogeneous results with about 24% of patients presenting with qualitatively normal spermatogenesis. In accordance with serum endocrine profile, ITT levels were lowest in clinic C and correlated with testosterone and free testosterone, but not with the spermatogenic state. The percentage of LHCGR-positive cells and ITT levels did not correlate. CONCLUSION: Only patients that did not discontinue hormonal treatment showed feminized blood levels on the day of SRS. The ones who stopped re-virilized quickly. Interestingly, testicular histology was highly heterogeneous irrespective of the treatment strategy, a phenomenon that requires further investigation.


Asunto(s)
Disforia de Género/psicología , Cirugía de Reasignación de Sexo/métodos , Espermatogénesis/efectos de los fármacos , Testículo/fisiopatología , Personas Transgénero/psicología , Adulto , Antagonistas de Andrógenos/uso terapéutico , Estrógenos/uso terapéutico , Femenino , Disforia de Género/cirugía , Alemania/epidemiología , Hormonas Esteroides Gonadales/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios , Testículo/cirugía , Testosterona/sangre
13.
Langmuir ; 30(50): 15317-26, 2014 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-25493607

RESUMEN

The combination of a set of complementary techniques allows us to construct an unprecedented and comprehensive picture of the internal structure, temperature dependent swelling behavior, and the dependence of these properties on the cross-linker concentration of microgel particles based on N-vinylcaprolactam (VCL). The microgels were synthesized by precipitation polymerization using different amounts of cross-linking agent. Characterization was performed by small-angle neutron scattering (SANS) using two complementary neutron instruments to cover a uniquely broad Q-range with one probe. Additionally we used dynamic light scattering (DLS), atomic force microscopy (AFM), and differential scanning calorimetry (DSC). Previously obtained nuclear magnetic resonance spectroscopy (NMR) results on the same PVCL particles are utilized to round the picture off. Our study shows that both the particle radius and the cross-link density and therefore also the stiffness of the microgels rises with increasing cross-linker content. Hence, more cross-linker reduces the swelling capability distinctly. These findings are supported by SANS and AFM measurements. Independent DLS experiments also found the increase in particle size but suggest an unchanged cross-link density. The reason for the apparent contradiction is the indirect extraction of the parameters via a model in the evaluation of DLS measurements. The more direct approach in AFM by evaluating the cross section profiles of observed microgel particles gives evidence of significantly softer and more deformable particles at lower cross-linker concentrations and therefore verifies the change in cross-link density. DSC data indicate a minor but unexpected shift of the volume phase transition temperature (VPTT) to higher temperatures and exposes a more heterogeneous internal structure of the microgels with increasing cross-link density. Moreover, a change in the total energy transfer during the VPT gives evidence that the strength of hydrogen bonds is significantly affected by the cross-link density. A strong and reproducible deviation of the material density of the cross-linked microgel polymer chains toward a higher value compared to the respective linear chains has yet to be explained.

14.
Sci Rep ; 14(1): 4382, 2024 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-38388679

RESUMEN

The Bronze Age of Central Europe was a period of major social, economic, political and ideological change. The arrival of millet is often seen as part of wider Bronze Age connectivity, yet understanding of the subsistence regimes underpinning this dynamic period remains poor for this region, in large part due to a dominance of cremation funerary rites, which hinder biomolecular studies. Here, we apply stable isotope analysis, radiocarbon dating and archaeobotanical analysis to two Late Bronze Age (LBA) sites, Esperstedt and Kuckenburg, in central Germany, where human remains were inhumed rather than cremated. We find that people buried at these sites did not consume millet before the Middle Bronze Age (MBA) (ca. 1600 BCE). However, by the early LBA (ca. 1300-1050 BCE) people consumed millet, often in substantial quantities. This consumption appears to have subsequently diminished or ceased around 1050-800 BCE, despite charred millet grains still being found in the archaeological deposits from this period. The arrival of millet in this region, followed by a surge in consumption spanning two centuries, indicates a complex interplay of cultural and economic factors, as well as a potential use of millet to buffer changes in aridity in a region increasingly prone to crop failure in the face of climate change today.


Asunto(s)
Arqueología , Mijos , Humanos , Europa (Continente) , Alemania , Isótopos de Carbono/análisis
15.
Nat Commun ; 15(1): 1251, 2024 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-38341437

RESUMEN

Organismal functional strategies form a continuum from slow- to fast-growing organisms, in response to common drivers such as resource availability and disturbance. However, whether there is synchronisation of these strategies at the entire community level is unclear. Here, we combine trait data for >2800 above- and belowground taxa from 14 trophic guilds spanning a disturbance and resource availability gradient in German grasslands. The results indicate that most guilds consistently respond to these drivers through both direct and trophically mediated effects, resulting in a 'slow-fast' axis at the level of the entire community. Using 15 indicators of carbon and nutrient fluxes, biomass production and decomposition, we also show that fast trait communities are associated with faster rates of ecosystem functioning. These findings demonstrate that 'slow' and 'fast' strategies can be manifested at the level of whole communities, opening new avenues of ecosystem-level functional classification.


Asunto(s)
Biodiversidad , Ecosistema , Biomasa , Agricultura , Suelo
16.
Ecol Lett ; 16(9): 1126-34, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23819684

RESUMEN

The stability of ecological communities depends strongly on quantitative characteristics of population interactions (type-II vs. type-III functional responses) and the distribution of body masses across species. Until now, these two aspects have almost exclusively been treated separately leaving a substantial gap in our general understanding of food webs. We analysed a large data set of arthropod feeding rates and found that all functional-response parameters depend on the body masses of predator and prey. Thus, we propose generalised functional responses which predict gradual shifts from type-II predation of small predators on equally sized prey to type-III functional-responses of large predators on small prey. Models including these generalised functional responses predict population dynamics and persistence only depending on predator and prey body masses, and we show that these predictions are strongly supported by empirical data on forest soil food webs. These results help unravelling systematic relationships between quantitative population interactions and large-scale community patterns.


Asunto(s)
Artrópodos/anatomía & histología , Artrópodos/fisiología , Peso Corporal , Cadena Alimentaria , Conducta Predatoria/fisiología , Animales , Modelos Biológicos
17.
J Anim Ecol ; 82(1): 64-71, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23173560

RESUMEN

The global decline in biodiversity is especially evident in higher trophic levels as predators display higher sensitivity to environmental change than organisms from lower trophic levels. This is even more alarming given the paucity of knowledge about the role of individual predator species in sustaining ecosystem functioning. The effect of predator diversity on lower trophic level prey is often driven by the increasing chance of including the most influential species. Furthermore, intraguild predation can cause trophic cascades with net positive effects on basal prey. As a consequence, the effects of losing a predator species appear to be idiosyncratic and it becomes unpredictable how the community's net effect on lower trophic levels changes when species number is declining. We performed a full factorial microcosm experiment with litter layer arthropods to measure the effects of predator diversity and context-dependent identity effects on a detritivore population and microbial biomass. We show that major parts of the observed diversity effect can be assigned to the increasing likelihood of including the most influential predator. Further, the presence of a second predator feeding on the first predator dampens this dominant effect. Including this intraguild predator on top of the first predator is more likely with increasing predator diversity as well. Thus, the overall pattern can be explained by a second identity effect, which is nested into the first. When losing a predator from the community, the response of the lower trophic level is highly dependent on the remaining predator species. We mechanistically explain the net effects of the predator community on lower trophic levels by nested effects of predator identities. These identity effects become predictable when taking the species' body masses into account. This provides a new mechanistic perspective describing ecosystem functioning as a consequence of species composition and yields an understanding beyond simple effects of biodiversity.


Asunto(s)
Artrópodos/fisiología , Biodiversidad , Cadena Alimentaria , Conducta Predatoria , Animales , Bacterias , Biomasa , Tamaño Corporal
18.
J Shoulder Elbow Surg ; 22(9): 1173-9, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23523073

RESUMEN

BACKGROUND: This pilot study evaluates the outcome after occupational therapy, compared to home-based exercises in the conservative treatment of patients with full thickness rotator cuff tears. METHODS: Forty-three adult subjects (range, 18-75 years), who had a full thickness rupture of the rotator cuff which was verified by magnetic imaging tomography, with clinical signs of a chronic rotator cuff impingement, and who were available for follow-up, were randomized to occupational therapy or to independent home-based exercises using a booklet. After drop-out, 38 patients were available for full examination at follow-up. Before therapy and after 2 months of conservative treatment, pain intensity, the Constant-Murley score, isokinetic strength testing in abduction and external rotation, functional limitation, clinical shoulder tests and health-related quality of life (EQ-5D) were evaluated. RESULTS: Two-thirds of the patients improved in clinical shoulder tests, regardless of the therapy group. There were no significant differences between the groups with reference to pain, range of motion, maximum peak force (abduction, external rotation), the Constant-Murley score, and the EQ-5D index. The only significant difference observed was the improvement in the self-assessed health- related quality of life (EQ-5D VAS) favoring home-based exercises. CONCLUSION: Home-based exercise, on the basis of an illustrated booklet with exercises twice a day, supplies comparable results to formal occupational therapy in the conservative treatment of rotator cuff tears. The results of this pilot study suggest some potential advantages related to psychological benefits using home-based treatment.


Asunto(s)
Terapia por Ejercicio , Terapia Ocupacional , Lesiones del Manguito de los Rotadores , Autocuidado , Traumatismos de los Tendones/rehabilitación , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Estudios Prospectivos , Autoevaluación (Psicología) , Resultado del Tratamiento
19.
J Equine Vet Sci ; 131: 104926, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37717677

RESUMEN

An adequate supply of colostrum is important for the prevention of hypogammaglobulinaemia in foals. In addition to the quantity of colostrum consumed and the time of consumption, the quality of the colostrum, the immunoglobulin (Ig) G concentration, is crucial. The aim of this study was to determine whether the viscosity of equine colostrum was a suitable estimate of IgG concentration. IgG content of colostrum was measured by ELISA and viscosity directly measured with a cone plate viscometer and indirectly assessed with a funnel. Analysis of 56 colostrum samples obtained from 40 mares at different postpartum time points was conducted to assess colostrum samples with varying levels of quality. The range of IgG concentrations determined by ELISA was 0.83 to 245.5 mg/mL (30.69 ± 41.92 mg/mL). The range of viscosity values determined by the cone plate method was 1.84 to 110.00 cP (7.86 ± 17.48 cP) at a shear rate of 3 rpm. Colostrum drainage from the funnel (drainage time), varied between 7.9 and 30.0 s, with an average of 9.96 ± 4.48 s. As the data were not normally distributed, Spearman's rank correlation analyses were calculated and significant correlation found between viscosity and IgG content (ρ = 0.71, P < .001), as well as between drainage time and IgG content (ρ = 0.75, P < .001). These correlations indicate that determining the viscosity of equine colostrum by cone plate or drainage time, may be an effective proxy measurement of IgG content.


Asunto(s)
Calostro , Inmunoglobulina G , Embarazo , Animales , Caballos , Femenino , Viscosidad , Inmunoglobulina G/análisis , Periodo Posparto
20.
Trends Cogn Sci ; 27(12): 1099-1101, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37716894

RESUMEN

Governments and organizations often offer cash payments for vaccination. How effective are such payments? A literature review shows that incentives usually increase vaccination, especially for nonhesitant populations and when using guaranteed payments. Concerns about negative unintended consequences are unsupported. We also discuss open questions and avenues for future research.


Asunto(s)
Motivación , Vacunación , Humanos
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