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Robert Ali,1 Junaid Arshad,1 Sofia Palacio,1 Raja Mudad2 1Department of Medicine, Division of Oncology, Jackson Memorial Hospital, University of Miami, Miller School of Medicine, Sylvester Comprehensive Cancer Centre, Miami, FL 33131, USA; 2Department of Medicine, Division of Oncology, University of Miami, Miller School of Medicine, Sylvester Comprehensive Cancer Centre, Miami, FL 33136, USA Abstract: Despite the benefits of first and second generation anaplastic lymphoma kinase (ALK) inhibitors in the management of ALK-rearranged advanced non-small-cell lung cancer (NSCLC), the development of acquired resistance poses an ongoing dilemma. Brigatinib has demonstrated a wider spectrum of preclinical activity against crizotinib-resistant ALK mutant advanced NSCLC. The current review narrates a brief history of tyrosine kinases, the development and clinical background of brigatinib (including its pharmacology and molecular structure) and its use in ALK-positive NSCLC. Keywords: non-small cell lung cancer, ALK positive, ALK inhibitors, brigatinib, TKI

The origin of a compact millimeter (mm, 100–250 GHz) emission in radio-quiet active galactic nuclei (RQ AGN) remains debated. Recent studies propose a connection with self-absorbed synchrotron emission from the accretion disk X-ray corona. We present the first joint ALMA (∼100 GHz) and X-ray (NICER/XMM-Newton/Swift; 2–10 keV) observations of the unobscured RQ AGN, IC 4329A (z = 0.016). The time-averaged mm-to-X-ray flux ratio aligns with recently established trends for larger samples, but with a tighter scatter (∼0.1 dex) compared to previous studies. However, there is no significant correlation on timescales of less than 20 days. The compact mm emission exhibits a spectral index of −0.23 ± 0.18, remains unresolved with a 13 pc upper limit, and shows no jet signatures. Notably, the mm flux density varies significantly (by factor of 3) within four days, exceeding the contemporaneous X-ray variability and showing the largest mm variations ever detected in RQ AGN over daily timescales. The high amplitude variability rules out scenarios of heated dust and thermal free–free emission, pointing toward a synchrotron origin for the mm radiation in a source of ∼1 light day (∼120 gravitational radii) size. While the exact source is not yet certain, an X-ray corona scenario emerges as the most plausible compared to a scaled-down jet or outflow-driven shocks. [ABSTRACT FROM AUTHOR]

Context. Quantifying the number density and physical characteristics of extragalactic polarized sources is important for the successful planning of future studies based on Faraday rotation measure (RM) grids of polarized sources to probe foreground Galactic and intergalactic magnetic fields. However, it is proving very hard to detect polarized signal from the population of very faint (sub-mJy) polarized sources at low radio frequencies, and their properties are mostly unknown. LOFAR can play an important role in such studies thanks to its sensitivity and angular resolution, combined with the precision on the inferred RM values that can be achieved through low-frequency broad-band polarimetry. Aims. The aim of this study is to probe the sub-mJy polarized source population with LOFAR. In this first paper, we present the method used to stack LOFAR polarization datasets, the resulting catalog of polarized sources, and the derived polarized source counts. Methods. The European Large Area ISO Survey-North 1 (ELAIS-N1) field, one of the deepest of the LOFAR Two-Metre Sky Survey (LoTSS) Deep Fields so far, was selected for a polarimetric study at 114.9–177.4 MHz. A total area of 25 deg2 was imaged at 6″-resolution in the Stokes Q and U parameters. Alignment of polarization angles was done both in frequency and in Faraday space before stacking datasets from 19 eight-hour-long epochs taken in two different LOFAR observing cycles. A search for polarized sources was carried out in the final, stacked dataset, and the properties of the detected sources were examined. The depolarization level of sources known to be polarized at 1.4 GHz was quantified. Results. A one-sigma noise level, σQU, of 19 µJy beam−1 was reached in the central part of the field after stacking. Twenty-five polarized sources were detected above 8σQU, five of which had not been detected in polarization at any other radio frequencies before. Seven additional polarized components were found by lowering the threshold to 6σQU at positions corresponding to sources known to be polarized at 1.4 GHz. In two radio galaxies, polarization was detected from both radio lobes, so the final number of associated radio continuum sources is 31. The detected sources are weakly polarized, with a median degree of polarization of 1.75% for the sample of sources detected in polarized emission. For the 10 polarized sources previously identified in a pilot LOFAR study of the ELAIS-N1 field at 20″-resolution, the RM values are consistent but the degrees of polarization are higher in the 6″-resolution data. The sources previously detected in polarization at 1.4 GHz are significantly depolarized at 150 MHz. The catalog is used to derive the polarized source counts at 150 MHz. Conclusions. This is the deepest and highest-resolution polarization study at 150 MHz to date. A full characterization of the sources and an analysis of the catalog will be presented in Paper II. [ABSTRACT FROM AUTHOR]

Dust emission fluxes during wind soil erosion are usually estimated using a dust concentration vertical gradient, by assuming a constant dust flux layer between the surface and the dust measurement levels. Here, we investigate the existence of this layer during erosion events recorded in Iceland and Jordan. Size‐resolved dust fluxes were estimated at three levels between 2 and 4 m using the eddy‐covariance method. Dust fluxes were found mainly constant only between the two upper levels in Iceland, the lower dust flux being often stronger and richer in coarse particles, while dust fluxes in Jordan were nearly constant across all levels. The wind dynamics could not explain the absence of a constant dust flux layer in Iceland. We show that the presence of stationary dust source patches in Iceland, related to surface humidity, created a non‐uniform dust layer near the surface, named dust roughness sublayer (DRSL), where individual plumes behind each patch interact but do not fully mix. The lowest dust measurement level was probably located within this sublayer while the upper ones were located above, such that there the emitted dust became spatially well‐mixed. This explains near the surface in Iceland, the more intermittent dust concentration, its low correlation with the dust concentrations above, and the richer dust flux in coarse particles due to their lower deposition contribution. Our findings highlight the importance of estimating dust fluxes above a dust blending height whose characteristics depend on the dust source patchiness caused by surface humidity or the presence of sparse non‐erosive elements. Plain Language Summary: During soil erosion by wind, dust flux from the surface is estimated at a few meters height, by assuming the existence of a constant dust flux layer between the surface and the dust measurement levels. Here, we investigated for the first time the existence of this layer during erosion events in Iceland and Jordan, by estimating the dust fluxes at three levels between 2 and 4 m height. In Iceland, the dust fluxes were constant only between the two upper levels. In Jordan, the dust fluxes remained constant across all levels. We demonstrates that the absence of a constant dust flux layer in Iceland is due to patches of stationary dust sources, which are related to surface humidity. These patches created a non‐uniform dust layer near the surface, known as the dust roughness sublayer. In this layer, individual plumes behind each patch interact but do not fully mix. The lowest dust measurement level was likely within this sublayer, while the upper measurements were located above it. Our findings highlight the importance of estimating dust fluxes above a dust blending height, which depends on the patchiness of the dust source caused by surface humidity or the presence of sparse non‐erosive elements. Key Points: Size‐resolved dust emission fluxes have been estimated for the first time at different heights during erosion events in Iceland and JordanUnlike in Jordan, the absence of a constant dust flux layer in Iceland is due to the dust source patchiness related to surface humidityOur results highlight the importance of estimating dust fluxes above a dust blending height that depends on the dust source patchiness [ABSTRACT FROM AUTHOR]

In a previous study (Assessment 1), an on-farm assessment tool was used to establish a standard across 60 Quebec dairy farms using animal-, stall-, and management-based measures of cow comfort. The objective of the present follow-up study (Assessment 2) was to perform a reassessment using an identical cow comfort assessment tool on a subset of the original farms expected to benefit most from applying the recommended changes, and to determine the effects of the modifications on cow comfort. From the subsample of farms, 24 reported applying stall modifications based on recommendations from Assessment 1 with the aim of promoting cow comfort (Adopters), while the remaining 10 farms did not (Non-adopters). The assessment tool included 19 target areas, grouped into 9 critical areas based on measures of cow comfort that considered housing, feed-water, health, and welfare. The on-farm report of Assessment 1 was found to increase producer awareness of issues in cow comfort measures on farms, as shown by an improvement in stall design according to recommendations based on cow body dimensions and reduced injury prevalence. Routine reassessment of cow comfort measures may be important to use in supporting target achievement improvements as part of welfare improvement strategies. [ABSTRACT FROM AUTHOR]

Los estudiantes se enfrentan cada vez más a retos y exigencias del medio que demandan una gran cantidad de recursos físicos y psicológicos de diversa índole. Muchos de ellos dejan sus estudios o disminuyen de manera considerable su rendimiento académico sin encontrar una explicación. Dos variables que han sido poco estudiadas en nuestro contexto y que pueden dar claridad a buena parte de esta situación son el burnout y la satisfacción. En esta investigación se estableció la relación del burnout, el rendimiento académico, con la satisfacción frente a los estudios en una muestra de 202 universitarios de la jornada nocturna de una universidad privada de Barranquilla, quienes respondieron el MBI-SS (Schaufeli, Martínez, Marques Pinto, Salanova, & Bakker, 2002). Los resultados indican correlaciones negativas entre agotamiento, cinismo, autoeficacia y rendimiento académico con la satisfacción frente al estudio, mientras que el vigor, dedicación y absorción se correlacionaron positivamente con esta. Por otro lado, el buen funcionamiento académico se correlaciona positivamente con las dimensiones del engagement y negativamente con el cinismo; de manera particular, ninguna de las variables se correlaciona con el agotamiento, a pesar de evidenciar cinismo y baja autoeficacia.

La investigación pretendía indagar el tipo de lazos predominantes (lazos fuertes/débiles) en las redes sociales personales de los desplazados y su relación con indicadores de calidad de vida en salud. Se esperaba encontrar modificaciones en el tipo de lazos según el tiempo de llegada al asentamiento (menos de tres meses y más de un año). La muestra se tomó en Pinar del Río (periferia de Barranquilla, Colombia), con 19 personas seleccionadas por muestreo en bola de nieve (8 hombres, 11 mujeres con edades entre 27 y 61 años). Respondieron un cuestionario sobre Calidad de Vida en Salud (SF-36) (McHorney et al., 1994), y el Arizona Social Support Interview Schedule (assis) de Barrera (1980, citado por Araya & Maya, 2005). Los resultados mostraron que no existen correlaciones significativas entre los que Llegan y los Asentados en las variables de estudio, pero se encontró evidencia que la calidad de vida en su dimensión de salud física, es menor en los desplazados que llevan más de un año en el asentamiento, con respecto a los que tienen menos de tres meses.

Los estudiantes se enfrentan cada vez más a retos y exigencias del medio que demandan una gran cantidad de recursos físicos y psicológicos de diversa índole. Muchos de ellos dejan sus estudios o disminuyen de manera considerable su rendimiento académico sin encontrar una explicación. Dos variables que han sido poco estudiadas en nuestro contexto y que pueden dar claridad a buena parte de esta situación son el burnout y la satisfacción. En esta investigación se estableció la relación del burnout, el rendimiento académico, con la satisfacción frente a los estudios en una muestra de 202 universitarios de la jornada nocturna de una universidad privada de Barranquilla, quienes respondieron el MBI-SS (Schaufeli, Martínez, Marques Pinto, Salanova, & Bakker, 2002). Los resultados indican correlaciones negativas entre agotamiento, cinismo, autoeficacia y rendimiento académico con la satisfacción frente al estudio, mientras que el vigor, dedicación y absorción se correlacionaron positivamente con esta. Por otro lado, el buen funcionamiento académico se correlaciona positivamente con las dimensiones del engagement y negativamente con el cinismo; de manera particular, ninguna de las variables se correlaciona con el agotamiento, a pesar de evidenciar cinismo y baja autoeficacia.

V341 Ara was recently recognized as one of the closest (d  ≃ 150 pc) and brightest (V ≃ 10) nova-like cataclysmic variables. This unique system is surrounded by a bright emission nebula, likely to be the remnant of a recent nova eruption. Embedded within this nebula is a prominent bow shock, where the system's accretion disc wind runs into its own nova shell. In order to establish its fundamental properties, we present the first comprehensive multiwavelength study of the system. Long-term photometry reveals quasi-periodic, super-orbital variations with a characteristic time-scale of 10–16 d and typical amplitude of ≃1 mag. High-cadence photometry from the Transiting Exoplanet Survey Satellite (TESS) reveals for the first time both the orbital period and a 'negative superhump' period. The latter is usually interpreted as the signature of a tilted accretion disc. We propose a recently developed disc instability model as a plausible explanation for the photometric behaviour. In our spectroscopic data, we clearly detect antiphased absorption and emission-line components. Their radial velocities suggest a high mass ratio, which in turn implies an unusually low white-dwarf mass. We also constrain the wind mass-loss rate of the system from the spatially resolved [O  iii ] emission produced in the bow shock; this can be used to test and calibrate accretion disc wind models. We suggest a possible association between V341 Ara and a 'guest star' mentioned in Chinese historical records in AD 1240. If this marks the date of the system's nova eruption, V341 Ara would be the oldest recovered nova of its class and an excellent laboratory for testing nova theory. [ABSTRACT FROM AUTHOR]

Context. High-mass microquasars (HMMQs) are systems from which relativistic jets are launched. At the scales of several times the binary system size, the jets are expected to follow a helical path caused by the interaction with a strong stellar wind and orbital motion. Such a trajectory has its influence on the non-thermal emission of the jets, which also depends strongly on the observing angle due to Doppler boosting effects. Aims. We explore how the expected non-thermal emission of HMMQ jets at small scales is affected by the impact of the stellar wind and the orbital motion on the jet propagation. Methods. We studied the broadband non-thermal emission, from radio to gamma rays, produced in HMMQ jets up to a distance of several orbital separations, taking into account a realistic jet trajectory, different model parameters, and orbital modulation. The jet trajectory is computed by considering momentum transfer with the stellar wind. Electrons are injected at the position where a recollimation shock in the jets is expected due to the wind impact. Their distribution along the jet path is obtained assuming local acceleration at the recollimation shock, and cooling via adiabatic, synchrotron, and inverse Compton processes. The synchrotron and inverse Compton emission is calculated taking into account synchrotron self-absorption within the jet, free-free absorption with the stellar wind, and absorption by stellar photons via pair production. Results. The spectrum is totally dominated by the jet over the counter-jet due to Doppler boosting. Broadband emission from microwaves to gamma rays is predicted, with radio emission being totally absorbed. This emission is rather concentrated in the regions close to the binary system and features strong orbital modulation at high energies. Asymmetric light curves are obtained owing to the helical trajectory of the jets. Conclusions. The presence of helical shaped jets could be inferred from asymmetries in the light curves, which become noticeable only for large jet Lorentz factors and low magnetic fields. Model parameters could be constrained if accurate phase-resolved light curves from GeV to TeV energies were available. The predictions for the synchrotron and the inverse Compton radiation are quite sensitive of the parameters determining the wind-jet interaction structure. [ABSTRACT FROM AUTHOR]

We present observations of the Cygnus OB2 region obtained with the Giant Metrewave Radio Telescope (GMRT) at frequencies of 325 and 610 MHz. In this contribution we focus on the study of proplyd-like objects (also known as free-floating evaporating gas globules or frEGGs) that typically show an extended cometary morphology. We identify eight objects previously studied at other wavelengths and derive their physical properties by obtaining their optical depth at radio-wavelengths. Using their geometry and the photoionization rate needed to produce their radio-continuum emission, we find that these sources are possibly ionized by a contribution of the stars Cyg OB2 #9 and Cyg OB2 #22. Spectral index maps of the eight frEGGs were constructed, showing a flat spectrum in radio frequencies in general. We interpret these as produced by optically thin ionized gas, although it is possible that a combination of thermal emission, not necessarily optically thin, produced by a diffuse gas component and the instrument response (which detects more diffuse emission at low frequencies) can artificially generate negative spectral indices. In particular, for the case of the Tadpole we suggest that the observed emission is not of non-thermal origin despite the presence of regions with negative spectral indices in our maps. [ABSTRACT FROM AUTHOR]

The massive binary system WR 11 (γ2-Velorum) has recently been proposed as the counterpart of a Fermi source. If this association is correct, this system would be the second colliding wind binary detected in GeV γ-rays. However, the reported flux measurements from 1.4 to 8.64 GHz fail to establish the presence of nonthermal (synchrotron) emission from this source. Moreover, WR 11 is not the only radio source within the Fermi detection box. Other possible counterparts have been identified in archival data, some of which present strong nonthermal radio emission. We conducted arcsec-resolution observations toward WR 11 at very low frequencies (150–1400 MHz) where the nonthermal emission – if existent and not absorbed – is expected to dominate. We present a catalog of more than 400 radio emitters, among which a significant portion are detected at more than one frequency, including limited spectral index information. Twenty-one of these radio emitters are located within the Fermi significant emission. A search for counterparts for this last group pointed at MOST 0808–471; this source is 2′ away from WR 11 and is a promising candidate for high-energy emission, having a resolved structure along 325–1390 MHz. For this source, we reprocessed archive interferometric data up to 22.3 GHz and obtained a nonthermal radio spectral index of − 0.97 ± 0.09. However, multiwavelength observations of this source are required to establish its nature and to assess whether it can produce (part of) the observed γ-rays. WR 11 spectrum follows a spectral index of 0.74 ± 0.03 from 150 to 230 GHz, consistent with thermal emission. We interpret that any putative synchrotron radiation from the colliding-wind region of this relatively short-period system is absorbed in the photospheres of the individual components. Notwithstanding, the new radio data allowed us to derive a mass-loss rate of 2.5 × 10−5 M⊙ yr−1, which, according to the latest models for γ-ray emission in WR 11, would suffice to provide the required kinetic power to feed nonthermal radiation processes. [ABSTRACT FROM AUTHOR]

Context. The innermost parts of powerful jets in active galactic nuclei are surrounded by dense, high-velocity clouds from the broad-line region, which may penetrate into the jet and lead to the formation of a strong shock. Such jet-cloud interactions are expected to have measurable effects on the γ-ray emission from blazars. Aims. We characterise the dynamics of a typical cloud-jet interaction scenario, and the evolution of its radiative output in the 0.1–30 GeV energy range, to assess to what extent these interactions can contribute to the γ-ray emission in blazars. Methods. We use semi-analytical descriptions of the jet-cloud dynamics, taking into account the expansion of the cloud inside the jet and its acceleration. Assuming that electrons are accelerated in the interaction and making use of the hydrodynamical information, we then compute the high-energy radiation from the cloud, including the absorption of γ-rays in the ambient photon field through pair creation. Results. Jet-cloud interactions can lead to significant γ-ray fluxes in blazars with a broad-line region (BLR), in particular when the cloud expansion and acceleration inside the jet are taken into account. This is caused by 1) the increased shocked area in the jet, which leads to an increase in the energy budget for the non-thermal emission; 2) a more efficient inverse Compton cooling with the boosted photon field of the BLR; and 3) an increased observer luminosity due to Doppler boosting effects. Conclusions. For typical broad-line region parameters, either (i) jet-cloud interactions contribute significantly to the persistent γ-ray emission from blazars or (ii) the BLR is far from spherical or the fraction of energy deposited in non-thermal electrons is small. [ABSTRACT FROM AUTHOR]

Context. Runaway stars produce bowshocks that are usually observed at infrared (IR) wavelengths. Non-thermal radio emission has been detected so far only from the bowshock of BD+43°3654, whereas the detection of non-thermal radiation from these bowshocks at high energies remains elusive. Aims. We aim at characterising in detail the radio, X-ray, and γ-ray emission from stellar bowshocks accounting for the structure of the region of interaction between the stellar wind and its environment. Methods. We develop a broadband-radiative, multi-zone model for stellar bowshocks that takes into account the spatial structure of the emitting region and the observational constraints. The model predicts the evolution and the emission of the relativistic particles accelerated and streaming together with the shocked flow. Results. We present broadband non-thermal spectral energy distributions for different scenarios, synthetic radio-cm synchrotron maps that reproduce the morphology of BD+43°3654, and updated predictions in X-ray and γ-ray energy ranges. We also compare the results of the multi-zone model applied in this work with those of a refined one-zone model. Conclusions. A multi-zone model provides better constraints than a one-zone model on the relevant parameters, namely the magnetic field intensity and the amount of energy deposited in non-thermal particles. However, one-zone models can be improved by carefully characterising the intensity of the IR dust photon field and the escape rate of the plasma from the shocked region. Finally, comparing observed radio maps with those obtained from a multi-zone model enables constraints to be obtained on the direction of stellar motion with respect to the observer. [ABSTRACT FROM AUTHOR]

Depending on their specificity to gypsum, plants can be classified as gypsophiles (gypsum exclusive) and gypsovags (non-exclusive). The former may further be segregated into wide and narrow gypsophiles, depending on the breadth of their distribution area. Narrow gypsum endemics have a putative similar chemical composition to plants non-exclusive to gypsum ( i.e. gypsovags), which may indicate their similar ecological strategy as stress-tolerant plant refugees on gypsum. However, this hypothesis awaits testing in different regions of the world. We compared the chemical composition of four narrow gypsum endemics, one widely distributed gypsophile and six gypsovags from Turkey. Further, we explored the plasticity in chemical composition of Turkish gypsovags growing on high- and low-gypsum content soils. Differences were explored with multivariate analyses ( RDA) and mixed models ( REML). Narrow gypsum endemics segregated from gypsovags in their chemical composition according to RDAs (mainly due to higher K and ash content in the former). Nevertheless, differences were small and disappeared when different nutrients were analysed individually. All the gypsovags studied accumulated more S and ash when growing on high-gypsum than on low-gypsum soils. Similar to narrow gypsum endemics from other regions of the world, most local gypsum endemics from Turkey show a similar chemical composition to gypsovags. This may indicate a shared ecological strategy as stress-tolerant plants not specifically adapted to gypsum. Nevertheless, the narrow gypsum endemic Gypsophila parva showed a chemical composition typical of gypsum specialists, indicating that various strategies are feasible within narrowly distributed gypsophiles. [ABSTRACT FROM AUTHOR]

Despite the importance of spring freezing events for alpine species distribution, few studies have analysed the response of alpine shrub species to early spring freezes. It is also not known how snow cover gradients influence the process of de-hardening between individuals of the same species and their vulnerability to early spring frosts. We analysed early spring freezing resistance for the buds of eight alpine Ericaceae shrubs growing at 1 m snow depth at treeline in the Swiss Alps. Moreover, buds of Rhododendron ferrugineum and Loiseleuria procumbens were analysed for freezing resistance and sugar content along a snow depth gradient. The LT 50 (lethal temperature for 50% of samples) of the eight species ranged from −25.1 ± 1.6 °C ( Vaccinium vitis-idaea ) to −11.1 ± 1.2 °C ( Vaccinium uliginosum ), with differences being related to the phenological stage in addition to shrub preferences for contrasting snow cover microsites. Although the effect of snow depth on the freezing resistance of plants was not significant, samples collected from 1 m to 1.5 m snow depth tended to be more vulnerable to freezing, particularly L. procumbens . Buds collected at shallower snow depths had higher sugar concentrations, indicative of their stronger physiological hardening. Consequently, we conclude that differences in snow cover may significantly affect the physiological hardening of plants during the onset of spring. Individuals growing at less than 0.5 m snow cover are hardier, i.e., show moderately higher freezing resistance than individuals from snow banks. Snow cover is a highly important aspect of climate change, and freezing resistance in alpine plants with respect to snow conditions can be a relevant driver of plant responses to climate change. [ABSTRACT FROM AUTHOR]

Whole-plant approaches allow quantification of the temporal overlap between primary and secondary growth. If the amount of time available to grow is short, there may be a high temporal overlap between shoot growth and wood formation. We hypothesise that such overlap depends on the duration of the growing season and relates to wood anatomy. We evaluated wood anatomy, shoot longitudinal and radial growth rates, fine root production and the concentrations of non-structural carbohydrates ( NSC) in the wood of six sub-shrub species growing in sites with contrasting climatic conditions ( Lepidium subulatum, Linum suffruticosum, Salvia lavandulifolia, Satureja montana, Ononis fruticosa, Echinospartum horridum). Sub-shrub species living in sites with a short growing season displayed a high overlap between aboveground primary and secondary growth and formed wide vessels, whereas species from the warmest and driest sites presented the reverse characteristics. The highest overlap was linked to a rapid shoot extension and thickening through the enhanced hydraulic conductivity provided by wide vessels. The reductions in NSC concentrations when growth peaked were low or moderate, indicating that sub-shrubs accumulate NSC in excess, as do trees. The temporal overlap among primary and secondary growth in woody plants may be connected to the duration and rates of shoot and wood growth, which in turn depend on the vessel lumen area. [ABSTRACT FROM AUTHOR]

Abstract: Gypsum soils are among the most restrictive substrates for plant life, yet the mechanisms of plant adaptation to gypsum are still poorly understood. Arbuscular mycorrhizal fungi (AMF) can improve host plant nutrition and survival in stressful environments but little is known about the ubiquity and function of AMF in plants that grow in gypsum soils, both specialists and generalists. Previous studies indicate that most gypsophiles (specialists) show much higher concentration of nutrients than gypsovags (generalists), hence our hypothesis was that this would be related to increased mycorrhizal colonisation in gypsum specialists. We therefore quantified colonisation of the roots by mycorrhizal arbuscules (AC), vesicles (VC) and hyphae (HC) in six species of gypsophiles and six species of gypsovags growing in gypsum outcrops. Both groups of plants showed significant differences in AC, VC and HC but in contrast to our hypothesis, colonisation was greater in gypsovags than in gypsophiles. The extent of AMF colonisation does not seem to explain the distinctively high nutrient concentrations reported for gypsophiles. Our results indicate that increased AM colonisation could be a mechanism allowing non-specialist plants to cope with the restrictive conditions of gypsum. [Copyright &y& Elsevier]

The terrestrial carbon (C) cycle has received increasing interest over the past few decades, however, there is still a lack of understanding of the fate of newly assimilated C allocated within plants and to the soil, stored within ecosystems and lost to the atmosphere. Stable carbon isotope studies can give novel insights into these issues. In this review we provide an overview of an emerging picture of plant-soil-atmosphere C fluxes, as based on C isotope studies, and identify processes determining related C isotope signatures. The first part of the review focuses on isotopic fractionation processes within plants during and after photosynthesis. The second major part elaborates on plant-internal and plant-rhizosphere C allocation patterns at different time scales (diel, seasonal, interannual), including the speed of C transfer and time lags in the coupling of assimilation and respiration, as well as the magnitude and controls of plant-soil C allocation and respiratory fluxes. Plant responses to changing environmental conditions, the functional relationship between the physiological and phenological status of plants and C transfer, and interactions between C, water and nutrient dynamics are discussed. The role of the C counterflow from the rhizosphere to the aboveground parts of the plants, e.g. via CO2 dissolved in the xylem water or as xylem-transported sugars, is highlighted. The third part is centered around belowground C turnover, focusing especially on above- and belowground litter inputs, soil organic matter formation and turnover, production and loss of dissolved organic C, soil respiration and CO2 fixation by soil microbes. Furthermore, plant controls on microbial communities and activity via exudates and litter production as well as microbial community effects on C mineralization are reviewed. A further part of the paper is dedicated to physical interactions between soil CO2 and the soil matrix, such as CO2 diffusion and dissolution processes within the soil profile. Finally, we highlight state-of-the-art stable isotope methodologies and their latest developments. From the presented evidence we conclude that there exists a tight coupling of physical, chemical and biological processes involved in C cycling and C isotope fluxes in the plant-soil-atmosphere system. Generally, research using information from C isotopes allows an integrated view of the different processes involved. However, complex interactions among the range of processes complicate or currently impede the interpretation of isotopic signals in CO2 or organic compounds at the plant and ecosystem level. This review tries to identify present knowledge gaps in correctly interpreting carbon stable isotope signals in the plant-soil-atmosphere system and how future research approaches could contribute to closing these gaps. [ABSTRACT FROM AUTHOR]

Leaf exchange is an abrupt phenological event that drastically modifies the morphology and physiology of the aerial portion of the plant. We examined if water and osmolyte differences between old leaves and new organs trigger leaf exchange, and whether the differences are closely linked to the resource resorption process in senescing leaves. We monitored concentrations of osmolyte, water, non-structural carbohydrate, nitrogen and potassium in senescing leaves and in emerging new leaves and inflorescences of a Mediterranean leaf exchanger (Cistus laurifolius L.) growing in NE Spain. Old leaves rehydrated markedly during most of the senescence process, which co-occurred with the extension of new shoots, suggesting the lack of a clear-cut switch in water supply from old to new organs. The accumulation of osmolytes in the early stage of leaf senescence might account for this rehydration. Osmolyte dynamics in old leaves depended largely on the progression of resource resorption from senescing organs but were mostly unrelated to water content during late senescence. We conclude that dehydration of old leaves is not a prerequisite for the triggering of leaf exchange. The finding that most nutrients and carbohydrates accumulated in new organs before senescing leaves massively exported resources, and the absence of relevant differences between the dynamics of old leaves at the base of inflorescences and those at the base of vegetative shoots, indicate that the nutrient and carbohydrate demands of new organs do not trigger leaf exchange. [ABSTRACT FROM PUBLISHER]

Abstract: The seasonal dynamics of non-structural carbohydrates in the woody organs of two co-existing mediterranean sub-shrubs were analyzed. The two species show different leaf phenology during summer: Linum suffruticosum, maintains many of its green leaves, while Lepidium subulatum sheds most of its leaves. These different leaf phenologies are related to different strategies with regard to summer stress. The maintenance of leaves in Linum is related to its stress tolerance while Lepidium avoids stress by shedding its leaves. The main objectives were to: (1) determine the differences in the seasonal dynamics of non-structural carbohydrates among the main woody organs of both species; (2) verify if differences in the leaf phenology, and hence in the strategy with regard to summer drought, lead to different seasonal patterns of carbohydrate storage and use between the two species; (3) compare the seasonal dynamics of carbohydrates of the two studied sub-shrubs with those of mediterranean trees and shrubs previously reported in the literature. The concentration of soluble sugars (SS), starch and total non-structural carbohydrates (TNC) were assessed monthly, over 17 months, in the main roots, stems and the transition zone between root and shoot systems of both species. Starch storage capacity and SS, starch and TNC pools were calculated. The seasonal pattern of carbohydrate accumulation was similar among the woody organs analyzed, but it differed with those reported for mediterranean trees and shrubs. The two species showed different pools and seasonal patterns of non-structural carbohydrate concentrations in its woody organ, which corresponded to their different extent of leaf shedding. The stress-avoider Lepidium accumulated starch during spring shoot growth as a carbon store for summer respiration and had low pools of SS, whereas the stress-tolerant Linum increased SS during summer drought to maintain photosynthetic activity during summer and had low starch pools and storage capacity. However, irrespective of their different leaf shedding patterns, both species had a similar relative variation of their TNC concentration, which contrasts with previous results on deciduous and evergreen woody species. [Copyright &y& Elsevier]

New zircon and apatite fission-track analyses and aluminium in hornblende thermobarometric data are presented from Cretaceous and Triassic plutons situated along an east-west transect across the Central Cordillera, the Cauca Romeral Fault System and the eastern slopes of the Western Cordillera in the Colombian Andes. The results are combined with published apatite (U–Th)/He ages revealing three episodes of increased cooling during the Late Cretaceous (~110 - 90 Ma), the Eocene (~55-40 Ma) and the Miocene (23-20 Ma). The latter two phases correlate well with the Pre-Andean and Proto-Andean periods previously identified on the basis of stratigraphic unconformities and thermochronology studies in the region. A fourth event, at ~10 Ma, is tentatively recognized in modelled data sets, but not by absolute age values. The thermochronology data imply a total of uplift-driven exhumation (i.e., crustal unroofing) in the study area of up to 10 kms since ~50 Ma at rates of ~0.1 km/Myr and 4 kms since ~23 Ma initially at 0.2 km/Myr. From 10 Ma the rates changed to 0.3–0.33 km/Myr with estimated geothermal gradients of 25–30 °C/km. Thermobarometry data suggest that the crystallization of the Cretaceous intrusions, now at the surface, took place at depths of 8–13 km confirming the amount of exhumation revealed by low-temperature thermochronology. • New thermochronology ages for Northern Andes combining apatite and zircon FT. • Thermochronology/thermobarometry dataset in the Northern Andes of Colombia. • Vertical profile shows pulses of uplift exhumation at ~110–90, 45–50 and 23 Ma. • Orogenic events involving erosional cooling and crustal unroofing from ~8 to 13 km. • Orogenic events are coeval with pulses in the Caribbean, Southern-Central Andes. [ABSTRACT FROM AUTHOR]

This article is based on a research that explored the relations between the Personal Social Network of people who have been displaced because of political violence and their Quality of Life in Health. These relations can be modified by the time of being in the new place of refuge - less than three months and more of one year. The hypothesis looked for if to greater density of the Personal Social Network of displaced people the Quality of Life in Health was low, which together with other social factors would reduce their Sense of community and capacity of adaptation. The data were collected in Pinar del Río (periphery of Barranquilla - Colombia), with 19 people selected in snow ball sample (8 men, 11 women, between 27 and 61 years). They responded to a questionnaire on Quality of Life in Health (Sf-36) (McHorney et al., 1994), and the Arizona Social Support Interview Schedule (ASSIS) of Barrera (1980, cited by Araya and Maya, 2005). The results do not show significant correlation between the time of refuge with the study variables, but it was observed that the Quality of Life, in its dimension of physic health, is smaller in displaced people with more of one year in the new place of refuge, with respect to displaced people who have less than three months in the new place of refuge.