Clearcutting is a common timber harvesting technique that represents a significant and abrupt change in habitat conditions for wildlife living in industrial forests. Most research on this type of ...impact has focused on comparing populations or communities in mature forests/plantations and the resulting clearcut stands. However, this approach does not separate the effect of changes in habitat attributes from direct mortality produced by the intensive use of heavy machinery required for cutting down trees and dragging them to a road. Because knowing the fate of individuals after a disturbance is important for modelling landscape-scale population dynamics in industrial forests, we conducted a study in South-Central Chile to understand the short-term response to clearcutting operations of the long-haired Akodont (Abrothrix longipillis), a forest specialist mouse. Between 2009 and 2013 we radiotracked a total of 51 adult male Akodonts, before, during and after the clearcutting of the pine plantations in which they lived. A minimum of 52.4% of the individuals died as a direct cause of the timbering operations, being crushed by vehicles or logs during logging operations. Our observations suggest that, instead of fleeing the area, the response of long-haired Akodonts to the approaching machinery is to hide under the forest litter or in burrows, which exposes them to a serious risk of death. The real mortality rate associated to clearcutting may be higher than that estimated by us because of some methodological biases (i.e. individuals with crushed radiotransmitters not recorded) and the fact that additional mortality sources may affect the population in the weeks following logging operations (e.g., higher exposure to predation, effects of site preparation for the new plantation, etc).
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The Stingray Nebula, a.k.a. Hen3-1357, appeared for the first time in 1990 when bright nebular lines and radio emission that had not been observed before were unexpectedly discovered. In the ensuing ...years, the nebula faded precipitously. We report changes in shape and large decreases in its nebular emission-line fluxes based on well-calibrated images obtained by the Hubble Space Telescope in 1996 and 2016. Hen3-1357 is now a "recombination nebula."
In this study, we explore photoinduced electron transport through a molecule weakly coupled to two electrodes by combining first-principles quantum chemistry calculations with a Pauli master equation ...approach that accounts for many-electron states. In the incoherent limit, we demonstrate that energy-level alignment of triplet and charged states plays a crucial role, even when the rate of intersystem crossing is much smaller than the rate of fluorescence. Furthermore, the field intensity dependence and an upper bound to the photoinduced electric current can be analytically derived in our model. Under an optical field, the conductance spectra (charge stability diagrams) exhibit unusual Coulomb diamonds, which are associated with molecular excited states, and their widths can be expressed in terms of energies of the molecular electronic states. This study offers new directions for exploring optoelectronic response in nanoelectronics.
The use of reclaimed wastewater for irrigation is foreseen as a possible strategy to mitigate the pressure on water resources in dry regions. However, there is the risk of potential accumulation of ...contaminants of emerging concern (CECs) in the edaphic environment, their percolation and consequently contamination of aquifers. In the present study, we measured the levels of a wide range of commonly used pharmaceutically active compounds (PhACs) in sewage from a local wastewater treatment plant (WWTP) and in soils irrigated with treated wastewater. Analysis of target compounds showed total concentrations between 73 and 372 μg L−1 in WWTP influents, and from 3 to 41 μg L−1 in effluents. The total concentrations of PhACs detected in surface soil samples were in the range of 2 and 15 ng g−1, with predominance of analgesics and anti-inflammatories (maximum concentration = 10.05 ng g−1), followed by antibiotics and psychiatric drugs (maximum concentration = 5.45 ng g−1 and 3.78 ng g−1, respectively). Both effluent samples and irrigated soils shared similar compositional patterns, with compounds such as hydrochlorothiazide and diclofenac being predominant. Additionally, PhACs were also detected in soil samples at a depth of 150 cm, indicating that these chemical undergo leaching associated with heavy-rain episodes. Their occurrence in soils was affected by temperature too, as maximum concentrations were measured in colder months (up to 14 ng g−1), indicating higher persistence at lower temperatures. Finally, the ecotoxicological risk of PhACs in soil was evaluated by calculating their risk quotients (RQs). The risk was very low as RQ values ranged between <0.01 and 0.07. However, this initial assessment could be improved by future works on toxicity using specific terrestrial organisms.
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•More than half of the compounds detected had poor removal efficiencies (<50%).•Most abundant PhACs in effluent were also predominant in irrigated soils (e.g., diclofenac and hydrochlorothiazide).•Total concentrations of up to 15 ng g−1 were detected down to 150 cm in the vertical soil profile.•A preliminary risk assessment showed that PhACs pose a potential low risk towards terrestrial species.
ABSTRACT
Non‐native tree (NNT) species have been transported worldwide to create or enhance services that are fundamental for human well‐being, such as timber provision, erosion control or ornamental ...value; yet NNTs can also produce undesired effects, such as fire proneness or pollen allergenicity. Despite the variety of effects that NNTs have on multiple ecosystem services, a global quantitative assessment of their costs and benefits is still lacking. Such information is critical for decision‐making, management and sustainable exploitation of NNTs. We present here a global assessment of NNT effects on the three main categories of ecosystem services, including regulating (RES), provisioning (PES) and cultural services (CES), and on an ecosystem disservice (EDS), i.e. pollen allergenicity. By searching the scientific literature, country forestry reports, and social media, we compiled a global data set of 1683 case studies from over 125 NNT species, covering 44 countries, all continents but Antarctica, and seven biomes. Using different meta‐analysis techniques, we found that, while NNTs increase most RES (e.g. climate regulation, soil erosion control, fertility and formation), they decrease PES (e.g. NNTs contribute less than native trees to global timber provision). Also, they have different effects on CES (e.g. increase aesthetic values but decrease scientific interest), and no effect on the EDS considered. NNT effects on each ecosystem (dis)service showed a strong context dependency, varying across NNT types, biomes and socio‐economic conditions. For instance, some RES are increased more by NNTs able to fix atmospheric nitrogen, and when the ecosystem is located in low‐latitude biomes; some CES are increased more by NNTs in less‐wealthy countries or in countries with higher gross domestic products. The effects of NNTs on several ecosystem (dis)services exhibited some synergies (e.g. among soil fertility, soil formation and climate regulation or between aesthetic values and pollen allergenicity), but also trade‐offs (e.g. between fire regulation and soil erosion control). Our analyses provide a quantitative understanding of the complex synergies, trade‐offs and context dependencies involved for the effects of NNTs that is essential for attaining a sustained provision of ecosystem services.
Molecularly imprinted polymers (MIPs) are synthetic polymers having a predetermined selectivity for a given analyte, or group of structurally related compounds, that make them ideal materials to be ...used in separation processes. In this sense, during past years a huge amount of papers have been published dealing with the use of MIPs as sorbents in solid-phase extraction, namely molecularly imprinted solid-phase extraction (MISPE). Although the majority of these papers were restricted to describe the use of different templates for different applications, several attempts proposing new alternatives to minimize the inherent drawbacks of the preparation and use of MIPs (i.e. template bleeding, tedious synthesis procedure, etc.) have been reported. Thus, this paper does not pretend to be a collection of MISPE-related papers but to give an overview on the significant attempts carried out during recent years to improve the performance of MIPs in solid-phase extraction. In addition, the use of MIPs packed in high performance liquid chromatography (HPLC) columns for the direct injection of crude sample extracts and the preparation of imprinted fibres for solid-phase microextraction will be also discussed.
The earliest Baltic amber in Western Europe Murillo-Barroso, M.; Cólliga, A. Martín; Martinón-Torres, M.
Scientific reports,
08/2023, Letnik:
13, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Abstract
The occurrence of Baltic amber through Europe has traditionally been associated to the spread of the Bell Beaker culture during the 3rd millennium BC. In Iberia, this phenomenon is ...particularly noticeable in the southern half. Here we present an amber bead recovered in a Late Neolithic funerary cave (3634–3363 cal BC) from northeastern Iberia where more than 12 individuals had been buried. Fourier transform infrared spectroscopy results of four samples revealed their complete resemblance with Baltic succinite reference spectra. Despite being a single bead, this finding provides the earliest evidence for the arrival of Baltic amber to the Mediterranean and Western Europe, before the Bell Beaker phenomenon and more than a millennium earlier than traditionally thought. This finding has implications for our understanding of early exchange networks of exotic materials, and their associated social structures.
Fast highly collimated outflows, including bipolar knots, jetlike features, and point-symmetric filaments or strings of knots, are common in planetary nebulae (PNe). These features, generally known ...as jets, are thought to play an active role in the nebular shaping immediately before or while fast stellar winds and D-type ionization fronts shock and sweep up the nebular envelope. The space velocity, radial distance from the central star, and kinematic age of the jets in PNe cannot be determined because the inclination angle with the line of sight is usually unknown. Here we have used the large number of jets already detected in PNe to derive orientation-independent properties from a statistical point of view. We find that jets in PNe can be assigned to two different populations: most (about 70%) have space velocities below 100 km s−1, and only 30% have larger velocities. Since a significant fraction of jets move at velocities similar to that of their parent PNe and are found close to the nebular edge, we propose that these jets have been slowed down in their interaction with the nebular envelope, contributing to the expansion of their PNe. The time spans before the jets dissolve are found to be generally shorter than 2500 yr. Since most jets are found in young PNe of similar (1000-3000 yr) age, it can be concluded that jets are mostly coeval with their PNe.
With just three CDRs in their variable domains, the antigen-binding site of camelid heavy-chain-only antibodies (HcAbs) has a more limited structural diversity than that of conventional antibodies. ...Even so, this does not seem to limit their specificity and high affinity as HcAbs against a broad range of structurally diverse antigens have been reported. The recombinant form of their variable domain nanobody (Nb) has outstanding properties that make Nbs, not just an alternative option to conventional antibodies, but in many cases, these properties allow them to reach analytical or diagnostic performances that cannot be accomplished with conventional antibodies. These attributes include comprehensive representation of the immune specificity in display libraries, easy adaptation to high-throughput screening, exceptional stability, minimal size, and versatility as affinity building block. Here, we critically reviewed each of these properties and highlight their relevance with regard to recent developments in different fields of immunosensing applications.
•Simultaneous extraction of 98 priority and emerging contaminants in sediments.•In-cell clean-up PLE using alumina as sorbent was the best option of all tested.•Recoveries >80% were achieved using ...dichloromethane at 100°C and 3 PLE cycles.•Analysis of coastal sediments reveals the predominance of fragrances and nonylphenol.
The main goal of this work was to develop, optimize and validate a multi-residue method for the simultaneous determination of 97 contaminants, including fragrances, UV filters, repellents, endocrine disruptors, biocides, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organophosphorus flame retardants, and several types of pesticides in marine sediment samples. Extraction and cleanup were integrated into the same step using pressurized liquid extraction (PLE) with in-cell clean-up (1g of alumina). The extraction was performed using dichloromethane at 100°C, 1500psi and 3 extraction cycles (5min per cycle). Extracts were derivatized with N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide (MTBSTFA) to improve the signal and sensitivity of some target compounds (i.e., triclosan, 2-hydroxybenzophenone). Separation, identification and quantification of analytes were carried out by gas chromatography (GC) coupled to tandem mass spectrometry. Under optimal conditions, the optimized protocol showed good recovery percentages (70–100%), linearity (>0.99) and limits of detection below 1ngg−1 for all compounds. Finally, the method was applied to the analysis of sediment samples from different coastal areas from Andalusia (Spain), where occurrence and distribution of emerging contaminants in sediments is very scarce. Twenty five compounds out of 98 were detected in all samples, with the endocrine disruptor nonylphenol and the fragrance galaxolide showing the highest concentrations, up to 377.6ngg−1 and 237.4ngg−1, respectively.
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