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A general population model with variable carrying capacity consisting of a coupled system of nonlinear ordinary differential equations is proposed, and a procedure for obtaining analytical solutions for three broad classes of models is provided. A particular case is when the population and carrying capacity per capita growth rates are proportional. As an example, a generalised Thornley–France model is given. Further examples are given when the growth rates are not proportional. A criterion when inflexion may occur is also provided, and results of numerical simulations are presented.

An extension of the tourism area life cycle (TALC) model is proposed by considering two interacting tourism destinations. Three types of interaction dynamics are investigated: competition, mutualism (or cooperation) and predator–prey. Using dynamical systems theory, aqualitative analysis of the proposed model is performed and all possible tourist equilibria are identified. These three interaction dynamics are then discussed from the perspective of nation-branding and competitive identity in the context of the race for soft power, and further illustrated empirically with examples from Malaysia and the Middle East.

With more looming uncertainties in our present financial climate and environment, models with jump–diffusion more than ever are necessary. They are suited to reproduce the large and sudden fluctuations in the level of the underlying variable, and mimic various statistical properties in observed time series. The jump–diffusion modelling setup, however, brings complexity to the valuation and hedging of derivative securities. This paper delves into the subject of hedging along with the illustration of hedging’s intimate interplay with pricing. We harness the power of the Mellin transform and its convolution property to establish hedging sensitivities that capture the many dimensions of risk in option positions. Our methodology allows for a wide class of generalised payoffs (i.e. all piecewise linear functions). Each hedging parameter is shown to contain the impact of jumps and an explicit metric to quantify the jump risk is defined. The systematic and efficient calculations of higher-order sensitivities are demonstrated and their implications, from a practical perspective, are also considered. Inclusion of some numerical examples illustrates the ease of implementation of our results.

A new global high-resolution coupled climate model, EC-Earth3P-HR has been developed by the EC-Earth consortium, with a resolution of approximately 40 km for the atmosphere and 0.25∘ for the ocean, alongside with a standard-resolution version of the model, EC-Earth3P (80 km atmosphere, 1.0∘ ocean). The model forcing and simulations follow the High Resolution Model Intercomparison Project (HighResMIP) protocol. According to this protocol, all simulations are made with both high and standard resolutions. The model has been optimized with respect to scalability, performance, data storage and post-processing. In accordance with the HighResMIP protocol, no specific tuning for the high-resolution version has been applied. Increasing horizontal resolution does not result in a general reduction of biases and overall improvement of the variability, and deteriorating impacts can be detected for specific regions and phenomena such as some Euro-Atlantic weather regimes, whereas others such as the El Niño–Southern Oscillation show a clear improvement in their spatial structure. The omission of specific tuning might be responsible for this. The shortness of the spin-up, as prescribed by the HighResMIP protocol, prevented the model from reaching equilibrium. The trend in the control and historical simulations, however, appeared to be similar, resulting in a warming trend, obtained by subtracting the control from the historical simulation, close to the observational one.

Alpine ecosystems of the southern Iberian Peninsula are among the most vulnerable and the first to respond to modern climate change in southwestern Europe. While major environmental shifts have occurred over the last ∼1500 years in these alpine ecosystems, only changes in the recent centuries have led to abrupt environmental responses, but factors imposing the strongest stress have been unclear until now. To understand these environmental responses, this study, for the first time, has calibrated an algal lipid-derived temperature proxy (based on long-chain alkyl diols) to instrumental historical data extending alpine temperature reconstructions to 1500 years before present. These novel results highlight the enhanced effect of greenhouse gases on alpine temperatures during the last ∼200 years and the long-term modulating role of solar forcing. This study also shows that the warming rate during the 20th century (∼0.18 ∘C per decade) was double that of the last stages of the Little Ice Age (∼0.09 ∘C per decade), even exceeding temperature trends of the high-altitude Alps during the 20th century. As a consequence, temperature exceeded the preindustrial record in the 1950s, and it has been one of the major forcing processes of the recent enhanced change in these alpine ecosystems from southern Iberia since then. Nevertheless, other factors reducing the snow and ice albedo (e.g., atmospheric deposition) may have influenced local glacier loss, since almost steady climate conditions predominated from the middle 19th century to the first decades of the 20th century.

Many humans live in large, complex political centers, composed of multi-scalar communities including neighborhoods and districts. Both today and in the past, neighborhoods form a fundamental part of cities and are defined by their spatial, architectural, and material elements. Neighborhoods existed in ancient centers of various scales, and multiple methods have been employed to identify ancient neighborhoods in archaeological contexts. However, the use of different methods for neighborhood identification within the same spatiotemporal setting results in challenges for comparisons within and between ancient societies. Here, we focus on using a single method—combining Average Nearest Neighbor (ANN) and Kernel Density (KD) analyses of household groups—to identify potential neighborhoods based on clusters of households at 23 ancient centers across the Maya Lowlands. While a one-size-fits all model does not work for neighborhood identification everywhere, the ANN/KD method provides quantifiable data on the clustering of ancient households, which can be linked to environmental zones and urban scale. We found that centers in river valleys exhibited greater household clustering compared to centers in upland and escarpment environments. Settlement patterns on flat plains were more dispersed, with little discrete spatial clustering of households. Furthermore, we categorized the ancient Maya centers into discrete urban scales, finding that larger centers had greater variation in household spacing compared to medium-sized and smaller centers. Many larger political centers possess heterogeneity in household clustering between their civic-ceremonial cores, immediate hinterlands, and far peripheries. Smaller centers exhibit greater household clustering compared to larger ones. This paper quantitatively assesses household clustering among nearly two dozen centers across the Maya Lowlands, linking environment and urban scale to settlement patterns. The findings are applicable to ancient societies and modern cities alike; understanding how humans form multi-scalar social groupings, such as neighborhoods, is fundamental to human experience and social organization.

High-altitude peat bogs and lacustrine records are very sensitive to climate changes and atmospheric dust input. Recent studies have shown a close relationship between regional climate aridity and enhanced eolian input to lake sediments. However, changes in regional-scale dust fluxes due to climate variability at short scales and how alpine environments were impacted by climatic- and human-induced environmental changes are not completely understood.Here we present a multi-proxy (palynological, geochemical and magnetic susceptibility) lake sediment record of climate variability in the Sierra Nevada (southeastern Iberian Peninsula) over the Holocene. Magnetic susceptibility and geochemical proxies obtained from the high mountain lake record of Laguna Hondera evidence humid conditions during the early Holocene, while a trend towards more arid conditions is recognized since ∼ 7000 cal yr BP, with enhanced Saharan eolian dust deposition until the present. This trend towards enhanced arid conditions was modulated by millennial-scale climate variability. Relative humid conditions occurred during the Iberian Roman Humid Period (2600–1450 cal yr BP) and predominantly arid conditions occurred during the Dark Ages and the Medieval Climate Anomaly (1450–650 cal yr BP). The Little Ice Age (650–150 cal yr BP) is characterized in the Laguna Hondera record by an increase in runoff and a minimum in eolian input. In addition, we further suggest that human impact in the area is noticed through the record of Olea cultivation, Pinus reforestation and Pb pollution during the Industrial Period (150 cal yr BP–present). Furthermore, we estimated that the correlation between Zr and Ca concentrations stands for Saharan dust input to the Sierra Nevada lake records. These assumptions support that present-day biochemical observations, pointing to eolian input as the main inorganic nutrient source for oligotrophic mountain lakes, are comparable to the past record of eolian supply to these high-altitude lakes.

Introduction Patients with schizophrenia have a four-fold increased all-cause and a doubled cardiovascular mortality rate as compared to the general population. Objectives The study overall investigates the point-prevalence and prospective changes in cardiovascular risk factors in patients with schizophrenia, with baseline demographics of participants presented here. Methods A prospective study of patients diagnosed with schizophrenia divided into two subpopulations consisting of newly diagnosed (≤2 years from baseline in study (group A)) or chronic (diagnosed ≥10 years from baseline in study (group B)). Results A total of 199 patients (57 diagnosed ≤2 years preceding baseline and 142 diagnosed ≥10 years ago) were included. Group A had been diagnosed for an average of 1.13±0.58 years and 21.19±7.62 years in group B. The majority (n=135 (67.8%)) were diagnosed with paranoid schizophrenia. At baseline PANSS total (median[Q1;Q3]) for group A was 61.0[51.0;76.0] and 60.0[48.0;76.0] for group B, with PANNS Positive being 17.0[13.0;20.0] and 15.0[12;19], PANSS Negative being 16.0[11.0;20.0] and 14.5[10.0;20.0], and PANSS General being 28.0[22.0;35.0] and30.0 [25.0;37.0], respectively. No difference in Clinical Global Impression was observed between groups ((median[Q1;Q3): 4.0[3.0;4.0] in both groups). Lastly, global assessment of function was similar between groups ((median[Q1;Q3): group A symptom: 38.5[37.0;46.0] and group B 41.0[37.0;52.0], and with function being 48.0[44.5;53.5] in group A and 45.5[41.0;53.0] in group B). Conclusions Prospective studies investigating prevalence of and prospective changes in cardiovascular risk in patients with schizophrenia are essential to understand the increased all-cause and cardiovascular specific mortality. Demographic descriptions of participants are essential to estimate generalizability in different treatment settings. Disclosure No significant relationships.

Subpolar regions are key areas for studying natural climate variability due to their high sensitivity to rapid environmental changes, particularly through sea surface temperature (SST) variations. Here, we have tested three independent organic temperature proxies (UK'37; TEX86; and the long-chain diol index, LDI) regarding their potential applicability for SST reconstruction in the subpolar region around Iceland. UK'37, TEX86 and TEXL86 temperature estimates from suspended particulate matter showed a substantial discrepancy with instrumental data, while long-chain alkyl diols were below the detection limit at most of the stations. In the northern Iceland Basin, sedimenting particles revealed a seasonality in lipid fluxes, i.e., high fluxes of alkenones and glycerol dialkyl glycerol tetraethers (GDGTs) were measured during late spring and during summer and high fluxes of long-chain alkyl diols during late summer. The flux-weighted average temperature estimates had a significant negative (ca. 2.3 °C for UK'37) and positive (up to 5 °C for TEX86) offset with satellite-derived SSTs and temperature estimates derived from the underlying surface sediment. UK'37 temperature estimates from surface sediments around Iceland correlate well with summer mean sea surface temperatures, while TEX86-derived temperatures correspond with both annual and winter mean 0–200 m temperatures, suggesting a subsurface temperature signal. Anomalous LDI-SST values in surface sediments and low mass flux of 1,13- and 1,15-diols compared to 1,14-diols suggest that Proboscia diatoms are the major sources of long-chain alkyl diols in this area rather than eustigmatophyte algae, and therefore the LDI cannot be applied in this region.

Climate variability in the western Mediterranean is reconstructed for the last 4000 yr using marine sediments recovered in the west Algerian-Balearic Basin, near the Alboran Basin. Fluctuations in chemical and mineralogical sediment composition as well as grain size distribution are linked to fluvial-eolian oscillations, changes in redox conditions and paleocurrent intensity. Multivariate analyses allowed us to characterize three main groups of geochemical and mineralogical proxies determining the sedimentary record of this region. These three statistical groups were applied to reconstruct paleoclimate conditions at high resolution during the Late Holocene. An increase in riverine input (fluvial-derived elements – Rb/Al, Ba/Al, REE/Al, Si/Al, Ti/Al, Mg/Al and K/Al ratios), and a decrease in Saharan eolian input (Zr/Al ratio) depict the Roman Humid Period and the Little Ice Age, while drier environmental conditions are recognized during the Late Bronze Age-Iron Age, the Dark Ages and the Medieval Climate Anomaly. Additionally, faster bottom currents and more energetic hydrodynamic conditions for the former periods are evidenced by enhanced sortable silt (10-63 μm) and quartz content, and by better oxygenated bottom waters – as reflected by decreasing redox-sensitive elements (V/Al, Cr/Al, Ni/Al and Zn/Al ratios). In contrast, opposite paleoceanographic conditions are distinguished during the latter periods, i.e. the Late Bronze Age-Iron Age, the Dark Ages and the Medieval Climate Anomaly. Although no Ba excess was registered, other paleoproductivity indicators (total organic carbon content, Br/Al ratio, and organometallic ligands such as U and Cu) display the highest values during the Roman Humid Period, and together with increasing preservation of organic matter, this period exhibits by far the most intense productivity of the last 4000 yr. Fluctuations in detrital input into the basin as the main process managing deposition, reflected by the first eigenvector defined by the Principal Component Analyses, point to solar irradiance and the North Atlantic Oscillation variability as the main driving mechanisms behind natural climate variability over decadal to centennial time-scales for the last 4000 yr.

A combination of marine (Alboran Sea cores, ODP 976 and TTR 300 G) and terrestrial (Zoñar Lake, Andalucia, Spain) geochemical proxies provides a high-resolution reconstruction of climate variability and human influence in the southwestern Mediterranean region for the last 4000 years at inter-centennial resolution. Proxies respond to changes in precipitation rather than temperature alone. Our combined terrestrial and marine archive documents a succession of dry and wet periods coherent with the North Atlantic climate signal. A dry period occurred prior to 2.7 cal ka BP – synchronously to the global aridity crisis of the third-millennium BC – and during the Medieval Climate Anomaly (1.4–0.7 cal ka BP). Wetter conditions prevailed from 2.7 to 1.4 cal ka BP. Hydrological signatures during the Little Ice Age are highly variable but consistent with more humidity than the Medieval Climate Anomaly. Additionally, Pb anomalies in sediments at the end of the Bronze Age suggest anthropogenic pollution earlier than the Roman Empire development in the Iberian Peninsula. The Late Holocene climate evolution of the in the study area confirms the see-saw pattern between the eastern and western Mediterranean regions and the higher influence of the North Atlantic dynamics in the western Mediterranean.

The results of an experimental study devoted to the synthesis and characterisation of hybrid materials based on nanotubes (NT) of TiO2 modified by polyaniline (PANI) are presented in this work. The results demonstrated the final material performs well when applied as photoanode for water-splitting or for energy storage devices. TiO2 NTs have been synthesized by anodization of Ti foils from organic solution containing fluorides. The process of electro-polymerization of aniline has been carried out by cyclic voltammetry, starting from acid aqueous solution of the monomer. The performance of the polymeric structure has been investigated under the different conditions of electropolymerisation. The electrochemical capacitance of the samples has been investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge–discharge tests (CDT). Moreover, photocurrent tests were performed in order to evaluate their ability in exploit the light irradiation.

Current distribution is a very interesting technique for the characterization of fuel cells because it gives very valuable information about the performance of the cell and it could help to optimize its efficiency. In this work, this technique is used in combination with CFD modelling and a post-mortem physicochemical analysis to assess the performance of a high-temperature PBI-based fuel cell (HTPEMFC) with anelectrode area of 50 cm2. Experimental measurements were analysed with a CFD model, which enabledthe estimation of the characteristic local parameters of the fuel cell. The post-mortem analysis demonstrated that the combination of current distribution measurements and modelling can be an effective tool to evaluate PEM fuel cell performance.

This work presents a promising process to carry out the reclamation of urban treated wastewaters that consists of the application of UV irradiation to an electrocoagulation process with aluminium electrodes (photo-electrocoagulation). Results show that it is possible to perform the simultaneous removal of the microbiological content and turbidity in wastewater by applying low current densities. During the photo- electrocoagulation process, coagulant species are formed by the electrodissolution of the anode material (aluminium), causing the removal of turbidity in wastewater. The nature of these coagulant species will mainly depend on the pH and the metal concentration. In this context, the pH during the process remained constant around 8, a value that favours the formation of insoluble aluminium hydroxides and therefore, a sweep flocculation as main coagulation mechanism. On the other hand, it has been observed the presence of disinfectant species in wastewater during the process, specifically, free and combined chlorine disinfectants. Urban wastewater present significant concentration of chlorides in their composition and these species are susceptible of being oxidized on the anode surface favouring the generation of hypochlorite. In addition, the electrogenerated hypochlorite can react with the ammonium typically present in wastewater to form chloramines. Both species have noticeable disinfectant capacity and they are the main responsible of the elimination of E. coli. Finally, the application of UV radiation during the process favours the elimination of microorganisms due to the interaction of the light on the cell membrane of E. coli. Likewise, the application of UV light during the electrocoagulation promotes the formation of free radicals from the oxidizing species previously formed. These radicals not only increase the process performance in terms of E. coli removal but also favour the chemical dissolution of the sacrificial electrode and therefore, there is an increase in the turbidity removal performance.

In a photosynthetic MFC with algae at cathodic compartment, algae use inorganic carbon source, carbon dioxide, and sunlight and produce oxygen by photosynthesis. The oxygen produced is used at cathode as electron acceptor. In this way, the use of algae at the cathode of a MFC has interesting advantages: carbon dioxide fixation and oxygen supply. In order to study if algae form a biofilm on cathodic electrode of a photosynthetic microbial fuel cell and how this biofilm affects on performance of this photosynthetic MFC and on electricity production, cathodic electrode of a photosynthetic MFC at steady state was changed by another identical electrode. When cathode was changed, the cell voltage fell down from 14 mV to 0 mV (light phase). After 10 days, the cell voltage increased and steady state was reached after 22 days, with values of 9 mV (light phase). When electricity starts to increase after changing cathode, algae concentration in suspension decreased from 600 until 250 mg/L. The decrement of algae concentration and the increment of cell voltage indicated that algae in suspension could form a biofilm on cathodic electrode positively influencing on electricity production. The cathode polarization resistance increased after changing cathode due to the elimination of algae biofilm from electrode. Once biofilm was formed, this resistance decreased from 80800 until 23060 ?.

The goal of this work is to couple US and UV irradiations to CDEO in order to improve the degradation of these persistent pollutants from waters. The efficiency of different technologies (CDEO, sonolysis, photolysis, CDSEO, CDPEO and Conductive Diamond Sono-Photo Electrochemical Oxidation, CDSPEO) is also compared, observing the influence of the technology applied in the degradation rate and the mechanism of oxidation.

The work aims at studying the feasibility of the electrokinetic enhanced bioremediation. This is an emerging group of technologies that tries to combine the advantages of the electrokinetic soil flushing technology (EKSF) and biological soil remediation processes. Results demonstrate that combination of both technologies is not easy due to their very different characteristics. Results of direct combination are not completely positive because EKSF produces great changes in the pH and temperature, which affects negatively to the microbial viability. To overcome these drawbacks, different alternatives have been tested in this work in order to improve the efficiency of the combined biological and electrokinetic treatment. This work summarizes the main results obtained in each of them. The best results were obtained using a combination of EKSF with permeable reactive biobarriers in which the microorganisms were supported on gravel (EKSF-PRB). The position of the biobarrier was away from the extreme pH sections, and in this zone the supply of inorganic nutrients was ensured. Experimental results corroborated that the pollutant degradation efficiency is much higher using the combined EKSF-PBR technology (26.8% removal in a 14-day long treatment with an electric energy consumption below 100 kWh m-3) than using the simple biological treatment or the EKSF (11.8% removal in the same 14-day long treatment period).

Objective: To present 2 cases of massive hiatal hernia and review the literature on the subject. Materials and Methods: Information is obtained from electronic records of both cases and a review of the literature on classification and management is carried out. Results: 2 clinical cases of massive hiatal hernia with different forms of presentation are presented, both with surgical management and good postoperative evolution. Discussion: Type IV paraesophageal hiatal hernias usually contain the entire stomach, transverse colon, omentum, sometimes the small intestine and, more rarely, the spleen. In massive hiatal hernia (MHH), the duodenum, bile duct and pancreas are added to the indicated organs. MHH is a rare occurrence and constitutes a surgical challenge. The literature reports just over thirty cases in the last 50 years, not all of which have been operated on. Management must be surgical and early, in order to promptly restore the anatomy and performed by a team with experience in the management of complex hiatal hernias. [ABSTRACT FROM AUTHOR]

En este libro es una guía práctica sobre las serpientes de Colombia en cuanto a su clasificación y tratamiento del envenenamiento causado por sus mordeduras. Contiene los siguientes capítulos: 1. Características generales, 2. Serpiente Colombianas, 3. Aparato venenoso, 4. Clasificación fisiopatología de los efectos del veneno, 5. Mordedura por serpientes venenosas en Antioquía, listas de nombres populares y científicos, la bibliografía. Esta es una introducción a esta práctica guía sobre las serpientes Colombianas: Desde el origen del hombre, a través de la evolución de las distintas culturas y aún en la época actual en un amplio sector sociocultural, la serpiente ha sido considerada como un animal dotado de ciertos poderes sobrenaturales, bien sea como fuente de mal, de beneficio, de poder, de sabiduría o de salud. Considerada por su aspecto tóxico, la influencia en la patología humana es evidente y de gran importancia como causa de morbilidad sobre todo en aquellos países donde se le considera animal sagrado. En el aspecto simbólico, el folklor es abundante en creencias y tradiciones, que generalmente coinciden en la mayoría de los pueblos. En un país tropical como Colombia, con diversidad de climas y bosques, las serpientes venenosas de gran poder tóxico son también abundantes y significan un peligro real para nuestra población campesina en lucha abierta con la naturaleza. Los envenenamientos causados por sus mordeduras, graves de por sí, empeoran frecuentemente debido a diversos factores tales como la escasez y alto costo del suero antiofídico y la demora en la atención médica, condicionada esta última no sólo por la deficiencias de nuestras vías de comunicación, sino por la influencia nefasta del curandero. Sobre tema tan importante de nuestra patología, es entonces necesario que nuestras instituciones educativas y las encargadas de velar por la salud, se preocupen no sólo por su adecuada enseñanza y divulgación, sino también por la fabricación de antídotos específicos contra nuestras especies venenosas. A este propósito, y también como una ayuda elemental al médico rural en beneficio de nuestra población, va dirigido el esfuerzo de este manual.

Background: Rectal prolapse is a rare clinical entity, usually accompanied by other pelvic floor disorders, with a negative impact on quality of life. There are few models of quality of life adapted to our reality. One of them is the EQ-D5, adapted by Olivares-Tirado. Objectives: To evaluate the quality of life and functional outcomes of rectal prolapse surgery between 2015 and 2021 and correlate them with the different abdominal techniques. Material and Methods: This is a retrospective, observational, cross-sectional and cohort study. A total of 84 patients were screened, 59 were included. The EQ-D5 Survey was used for the analysis of quality of life. To complement the study, the Cleveland Clinic Incontinence Score and the Constipation Scoring System were measured. Results: There were significant changes in all surveys applied to pre- and postoperative improvement, with no differences between surgical techniques, but with a lower rate of postoperative stay in the laparoscopic group. Discussion: There is an improvement in the postoperative quality of life that is reflected in the indices obtained, independent of the surgical technique, however, this is attenuated in recidivated patients, which is related to the literature, also without finding differences between the techniques. There is less postoperative constipation in the ventral rectopexy technique. Conclusions: There is improvement in the quality of life independent of the surgical technique, without changes in relapsed patients. Perhaps the fastest and easiest technique for handling should be chosen, ideally laparoscopic [ABSTRACT FROM AUTHOR]