Neuro-Sliding Control for Underwater ROV's Subject to Unknown Disturbances.

Proposed in this paper is a model-free and chattering-free second order sliding mode control (2nd-SMC) in combination with a backpropagation neural network (BP-NN) control scheme for underwater vehicles to deal with external disturbances (i.e., ocean currents) and parameter variations caused, for instance, by the continuous interchange of tools. The compound controller, here called the neuro-sliding control (NSC), takes advantage of the 2nd-SMC robustness and fast response to drive the position tracking error to zero. Simultaneously, the BP-NN contributes with its capability to estimate and to compensate online the hydrodynamic variations of the vehicle. When a change in the vehicle's hydrodynamics occurs, the 2nd-SMC may no longer be able to compensate for the variations since its feedback gains are tuned for a different condition; thus, in order to preserve the desired performance, it is necessary to re-tune the feedback gains, which a cumbersome and time consuming task. To solve this, a viable choice is to implement a BP-NN control scheme along with the 2nd-SMC that adds or removes energy from the system according to the current condition it is in, in order to keep, or even improve, its performance. The effectiveness of the proposed compound controller was supported by experiments carried out on a mini-ROV.

Long-Term Climatic and Anthropogenic Impacts on Streamwater Salinity in New York State: INCA Simulations Offer Cautious Optimism.

The long-term application of road salts has led to a rise in surface water chloride (Cl-) concentrations. While models have been used to assess the potential future impacts of continued deicing practices, prior approaches have not incorporated changes in climate that are projected to impact hydrogeology in the 21st century. We use an INtegrated CAtchment (INCA) model to simulate Cl- concentrations in the Tioughnioga River watershed. The model was run over a baseline period (1961-1990) and climate simulations from a range of GCMs run over three 30-year intervals (2010-2039; 2040-2069; 2070-2099). Model projections suggest that Cl- concentrations in the two river branches will continue to rise for several decades, before beginning to decline around 2040-2069, with all GCM scenarios indicating reductions in snowfall and associated salt applications over the 21st century. The delay in stream response is most likely attributed to climate change and continued contribution of Cl- from aquifers. By 2100, surface water Cl- concentrations will decrease to below 1960s values. Catchments dominated by urban lands will experience a decrease in average surface water Cl-, although moderate compared to more rural catchments.

Marginalization and health service coverage among indigenous, rural, and urban populations: a public health problem in Mexico.

INTRODUCTION:   Marginalization is a significant issue in Mexico, involving a lack of access to health services with differential impacts on Indigenous, rural and urban populations. The objective of this study was to understand Mexico’s public health problem across three population areas, Indigenous, rural and urban, in relation to degree of marginalization and health service coverage. METHODS:   The sampling universe of the study consisted of 107 458 geographic locations in the country. The study was retrospective, comparative and confirmatory. The study applied analysis of variance, parametric and non-parametric, correlation and correspondence analyses. RESULTS:   Significant differences were identified between the Indigenous, rural and urban populations with respect to their level of marginalization and access to health services. The most affected area was Indigenous, followed by rural areas. The sector that was least affected was urban. CONCLUSIONS:   Although health coverage is highly concentrated in urban areas in Mexico, shortages are mostly concentrated in rural areas where Indigenous groups represent the extreme end of marginalization and access to medical coverage. Inadequate access to health services in the Indigenous and rural populations throws the gravity of the public health problem into relief.

Potential for long-term transfer of dissolved organic carbon from riparian zones to streams in boreal catchments.

Boreal regions store most of the global terrestrial carbon, which can be transferred as dissolved organic carbon (DOC) to inland waters with implications for both aquatic ecology and carbon budgets. Headwater riparian zones (RZ) are important sources of DOC, and often just a narrow 'dominant source layer' (DSL) within the riparian profile is responsible for most of the DOC export. Two important questions arise: how long boreal RZ could sustain lateral DOC fluxes as the sole source of exported carbon and how its hydromorphological variability influences this role. We estimate theoretical turnover times by comparing carbon pools and lateral exports in the DSL of 13 riparian profiles distributed over a 69 km(2) catchment in northern Sweden. The thickness of the DSL was 36 ± 18 (average ± SD) cm. Thus, only about one-third of the 1-m-deep riparian profile contributed 90% of the lateral DOC flux. The 13 RZ exported 8.7 ± 6.5 g C m(-2) year(-1) , covering the whole range of boreal stream DOC exports. The variation could be explained by local hydromorphological characteristics including RZ width (R(2) = 0.90). The estimated theoretical turnover times were hundreds to a few thousands of years, that is there is a potential long-lasting supply of DOC. Estimates of net ecosystem production in the RZ suggest that lateral fluxes, including both organic and inorganic C, could be maintained without drawing down the riparian pools. This was supported by measurements of stream DO(14) C that indicated modern carbon as the predominant fraction exported, including streams disturbed by ditching. The transfer of DOC into boreal inland waters from new and old carbon sources has a major influence on surface water quality and global carbon balances. This study highlights the importance of local variations in RZ hydromorphology and DSL extent for future DOC fluxes under a changing climate.

Effects of increasing omega-3 fatty acids on growth performance, immune response, and mortality in nursery pigs.

Three experiments evaluated omega-3 fatty acids, provided by O3 trial feed, on nursery pig growth performance, mortality, and response to an LPS immune challenge or natural Porcine reproductive and respiratory virus (PRRSV) outbreak. In experiment 1, 350 pigs (241 × 600, DNA; initially 5.8 kg) were used. Pens of pigs were randomly assigned to one of the five dietary treatments containing increasing omega-3 fatty acids (0%, 1%, 2%, 3%, and 4% O3 trial feed) with 14 replications per treatment. On day 25, two pigs per pen were injected intramuscularly with 20 µg Escherichia coli LPS per kg BW and one pig per pen was injected with saline as a control. Body temperature was taken from all three pigs prior to and 2, 4, 6, and 12 h post-LPS challenge. Serum IL-1ß and TNF-α concentrations were determined in LPS-challenged pigs 24 h prior and 4 h post-LPS challenge. There was no interaction between treatment and time for change in body temperature (P > 0.10). Overall, increasing the O3 trial feed did not affect (P > 0.10) ADG, ADFI, G:F, IL-1ß, or TNF-α. In experiment 2, 1,056 pigs (PIC TR4 × [Fast LW × PIC L02] initially 7.3 kg) were used. Pens of pigs were randomly assigned to one of the four dietary treatments containing increasing omega-3 fatty acids (0%, 0.75%, 1.5%, and 3% O3 trial feed) with 12 replications per treatment. Oral fluids tested negative on days 7 and 14, but then positive for North American PRRSV virus via PCR on days 21, 28, 35, and 42. Overall, increasing O3 trial feed increased (linear, P < 0.001) ADG, ADFI, and G:F and decreased (linear, P = 0.027) total removals and mortality. In experiment 3, 91,140 pigs (DNA 600 × PIC 1050; initially 5.1 kg), originating from PRRSV-positive sow farms, were used across eight nursery sites. Each site contained five barns with two rooms per barn and ~1,100 pigs per room. Rooms of pigs were blocked by nursery site and allocated within sow source to one of the two dietary treatments (control or 3% O3 trial feed) with 40 replications per treatment. Oral fluids from 61 of the 80 rooms tested positive for North American PRRSV virus 1 wk postweaning and 78 of the 80 rooms tested positive 3 wk after weaning. Overall, O3 trial feed did not affect ADG, ADFI, or G:F but increased (P < 0.001) total removals and mortalities. In summary, increasing omega-3 fatty acids, sourced by O3 trial feed, did not improve growth performance or immune response in healthy pigs given an LPS challenge. However, it appears that if omega-3 fatty acids are fed prior to a natural PRRSV break (as in experiment 2), growth performance may be improved, and mortality reduced.

[Transnasal endoscopic skull base surgery: analysis of complications in the first 120 procedures]. / Cirugía endoscópica transnasal de base de cráneo: Análisis de las complicaciones en los primeros 120 procedimientos.

Background: The endonasal endoscopic approach (EEA) has potential advantages over traditional open approaches. However, complications such as cerebrospinal fluid (CFS) leak, visual disturbances, and postoperative meningitis have been described. The aim was to present the experience accumulated in 120 cases of skull base EEA performed by the same surgical team and describe and analyze the main postoperative complications according to the complexity of the cases. Methods: Retrospective study on our database of patients undergoing skull base EEA for various pathologies between July 2011 and March 2022. Results: 120 skull base EEA surgeries were analyzed. 57.14% were performed on women. The median age was 44 years. 26.66% were reinterventions. The most frequent pathology was pituitary adenoma (49.17%) followed by CSF leak (8.33%). The most used EEA was the transelar 65.83%. 26 complications were recorded, with no differences according to complexity. There were 13 cases of diabetes insipidus (DI) and 8 of CSF leak. This was more frequent in patients with intraoperative CSF leak. The median hospital stay was 5.5 days. Conclusion: Skull base EEA has become increasingly common for the surgical management of skull base pathology, with a low frequency of immediate postoperative complications and low mortality. The improvement of the technique and the improvement in postoperative care are associated with a shorter hospital stay.

[Etiology and sensitivity of uropathogens identified in uncomplicated lower urinary tract infections in women (ARESC Study): implications on empiric therapy]. / Etiología y sensibilidad de los uropatógenos identificados en infecciones urinarias bajas no complicadas de la mujer (Estudio ARESC): implicaciones en la terapia empírica.

BACKGROUND AND OBJECTIVE: To determine the etiology and susceptibility of uropathogens identified in women with uncomplicated lower urinary tract infections (UTI). PATIENTS AND METHODS: In a multicenter study (ARESC) in 9 Spanish hospitals, 803 female patients with uncomplicated cystitis were consecutively enrolled and evaluated to identify the uropathogens and their susceptibility to 9 antimicrobials. RESULTS: Of 803 patients with uncomplicated cystitis, 784 patients were included. A positive urine culture was found in 87.7% of the samples. Of the 650 pathogens isolated, Escherichia coli (E. coli) was the most frequent (79.2%) followed by Staphylococcus saprophyticus (4.4%), Proteus mirabilis (4.3%), Enterococcus faecalis (3.2%) and Klebsiella pneumoniae (2.3%). E. coli showed a high rate of susceptibility to phosphomycin (97.2%), nitrofurantoin (94.1%) and somewhat lower to ciprofloxacin (88.1%). Fluorquinolone resistance rates were higher among postmenopausal women (17 versus 10%). E. coli was highly resistant to ampicillin (65%) and cotrimoxazole (34%) and 25% of the strains were resistant to amoxicillin/clavulanalic acid and cefuroxime. CONCLUSIONS: In Spain, E. coli shows high resistance rates to widely used antimicrobial antibiotics. Phosphomycin and nitrofurantoin have a high in vitro activity. Taking into account practical aspects such as convenience (only one dose), and the influence of the amount of fluorquinolone use on enterobacteriaceae and other microorganisms resistance levels, phosphomycin trometamol represents the option of first choice for the empirical treatment of uncomplicated cystitis in women.

An evaluation of high frequency turbidity as a proxy for riverine total phosphorus concentrations.

Surface water eutrophication resulting from excessive phosphorus (P) inputs is one of today's most challenging environmental issues. Riverine total phosphorus (TP) concentrations have high temporal variability, which complicates flux estimation. We evaluated the usefulness of high frequency in-situ turbidity measurements as a proxy for TP in Sävjaån, a river draining a mixed land use catchment (722 km2) in central Sweden. Turbidity was monitored every 10th-15th minute during 6 consecutive years (2012-2017). Linear regression showed a good relationship between high frequency turbidity and TP (r2 = 0.64) and could hence be used for comparison of flux estimation methods. Predictive power of the turbidity-TP relationship was not improved by adding seasons, hydrograph rising/falling limb or high/low stream discharge to the model which argues for a single transfer function relating turbidity and TP. Both TP and turbidity were log-normally distributed. However, flux estimates were sensitive to data transformation; predicted TP concentrations and fluxes based on log-transformed data were biased towards lower concentrations and fluxes compared to non-transformed data. In five of six years grab sample and high frequency estimated TP fluxes were similar (grab sample estimates -10% to +13% P transport compared to high frequency flux estimates). The exception was in 2013, when a 50-year spring flood occurred, and the grab sample estimated flux was 56% larger than that estimated from high frequency data. Thus, the flux comparisons were mostly affected by stream discharge, which underlines the importance of capturing high discharge episodes with, e.g. in situ sensors. While uncertainties regarding the use of turbidity as a proxy for TP remain, it is clear that credible water chemistry data can be obtained with current high frequency sensors. We conclude that high frequency data can be used to better understand catchment response to external pressures and gain insights into water quality that will be missed with grab sampling.

Ecohydrological consequences of tree removal in an urban park evaluated using open data, free software and a minimalist measuring campaign.

With ongoing global climate change and an increasingly urbanized population, the importance of city parks and other forms of urban vegetation increases. Trees in urban parks can play an important role in mitigating runoff and delivering other ecosystem services. Park managers, E-NGOs, citizen scientists and others are increasingly called upon to evaluate the possible consequences of changes in park management such as, e.g., tree removal. Here, we present an unorthodox approach to hydrological modelling and its potential use in local policy making regarding urban greenery. The approach consists of a minimalist field campaign to characterize vegetation and soil moisture status combined with a novel model calibration using freely available data and software. During modelling, we were able to obtain coefficients of determination (R2) of 0.66 and 0.73 for probe-measured and simulated soil moisture under tree stand and park lawn land covers respectively. The results demonstrated that tree cover had a significant positive effect on the hydrological regime of the locality through interception, transpiration and effects on soil moisture. Simulations suggested that tree cover was twice as effective at mitigating runoff than park lawn and almost seven times better than impervious surfaces. In the case of a potential replacement of tree vegetation in favour of park lawn or impervious surfaces an increase in runoff of 14% and 81% respectively could be expected. The main conclusion drawn from our study was that such an approach can be a very useful tool for supporting local decision-making processes as it offers a freely available, cheap and relatively easy-to-use way to describe the hydrological consequences of landcover change (e.g., tree removal) with sufficient accuracy.

Future hydrological constraints of the Montseny brook newt (Calotriton arnoldi) under changing climate and vegetation cover.

The Montseny brook newt (Calotriton arnoldi) is a critically endangered amphibian species which inhabits a small 20 km2 holm oak and beech forest area in NE Spain. Calotriton arnoldi strictly lives in running waters and might be highly vulnerable to hydrological perturbations expected to occur under climate and vegetation cover changes. Knowledge about the potential response of the species habitat to environmental changes can help assessing the actions needed for its conservation. Based on knowledge of the species and supported by observations, we proposed daily low and high streamflow event thresholds for the viability of C. arnoldi. We used the rainfall-runoff model PERSiST to simulate changes in the frequency and duration of these events, which were predicted under two climate and four vegetation cover scenarios for near-future (2031-2050) and far-future (2081-2100) periods in a reference catchment. All future scenarios projected a significant decrease in annual streamflow (from 21% to as much as 67%) with respect to the reference period. The frequency and length of low streamflow events will dramatically increase. In contrast, the risk of catastrophic drift linked to high streamflow events was predicted to decrease. The potential change in vegetation toward an expansion of holm oak forests will be more important than climate changes in determining threshold low flow conditions. We thus demonstrated that consideration of potential changes in vegetation and not only changes in climate variables is essential in simulating future streamflows. This study shows that future low streamflow conditions will pose a severe threat for the survival of C. arnoldi and may help taking management actions, including limiting the expansion of holm oak forest, for ameliorating the species habitat and help its conservation.

Modelling the effects of climate and land-use change on the hydrochemistry and ecology of the River Wye (Wales).

Interactions between climate change and land use change might have substantial effects on aquatic ecosystems, but are still poorly understood. Using the Welsh River Wye as a case study, we linked models of water quality (Integrated Catchment - INCA) and climate (GFDL - Geophysical Fluid Dynamics Laboratory and IPSL - Institut Pierre Simon Laplace) under greenhouse gas scenarios (RCP4.5 and RCP8.5) to drive a bespoke ecosystem model that simulated the responses of aquatic organisms. The potential effects of economic and social development were also investigated using scenarios from the EU MARS project (Managing Aquatic Ecosystems and Water Resources under Multiple Stress). Longitudinal position along the river mediated response to increasing anthropogenic pressures. Upland locations appeared particularly sensitive to nutrient enrichment or potential re-acidification compared to lowland environments which are already eutrophic. These results can guide attempts to mitigate future impacts and reiterate the need for sensitive land management in upland, temperate environments which are likely to become increasingly important to water supply and biodiversity conservation as the effects of climate change intensify.

[Adult Grisel Syndrome and Cervical Skull instability. Transnasal endoscopic odontoidectomy and occipito-cervical fusion. Case report and literature review]. / Síndrome de Grisel en el adulto e inestabilidad cráneo cervical. Odontoidectomía endoscópica transnasal y fijación occípito-cervical. Reporte de caso y revisión de literatura.

BACKGROUND: Craniocervical junction pathology is infrequent in daily neurosurgical practice. In general, most of these lesions are of traumatic or rheumatic origin. Atlantoaxial instability of inflammatory origin (Grisel syndrome) is a rare entity of which only 16 adult cases have been reported in the literature. This pathology is characterized by the development of an osteolytic lesion at the level of the atlantoaxial joint after an infectious event, usually of the upper airways. CASE DESCRIPTION: We present the case of a 76-year-old patient who attended our office for clinical symptoms of spinal instability secondary to an osteolytic lesion, with involvement of C1 and C2. The symptomatology began after an infectious respiratory process. A posterior cervical occiput fixation and an endoscopic transnasal odontoidectomy with anterior decompression were performed. The patient evolved with complete resolution of symptoms. The cultures were negative, and the pathological anatomy study concluded nonspecific inflammatory changes. CONCLUSION: Until a few years ago, the only option to address this pathology was the transoral pathway with microsurgical technique. Nowadays, endoscopy offers many technical advantages. This is an option to be considered when planning approaches to craniocervical junction.

Minimal climate change impacts on natural organic matter forecasted for a potable water supply in Ireland.

Natural organic matter poses an increasing challenge to water managers because of its potential adverse impacts on water treatment and distribution, and subsequently human health. Projections were made of impacts of climate change on dissolved organic carbon (DOC) in the primarily agricultural Boyne catchment which is used as a potable water supply in Ireland. The results indicated that excluding a potential rise in extreme precipitation, future projected loads are not dissimilar to those observed under current conditions. This is because projected increases in DOC concentrations are offset by corresponding decreases in precipitation and hence river flow. However, the results presented assume no changes in land use and highlight the predicted increase in DOC loads from abstracted waters at water treatment plants.

The interplay between total mercury, methylmercury and dissolved organic matter in fluvial systems: A latitudinal study across Europe.

Large-scale studies are needed to identify the drivers of total mercury (THg) and monomethyl-mercury (MeHg) concentrations in aquatic ecosystems. Studies attempting to link dissolved organic matter (DOM) to levels of THg or MeHg are few and geographically constrained. Additionally, stream and river systems have been understudied as compared to lakes. Hence, the aim of this study was to examine the influence of DOM concentration and composition, morphological descriptors, land uses and water chemistry on THg and MeHg concentrations and the percentage of THg as MeHg (%MeHg) in 29 streams across Europe spanning from 41°N to 64 °N. THg concentrations (0.06-2.78 ng L-1) were highest in streams characterized by DOM with a high terrestrial soil signature and low nutrient content. MeHg concentrations (7.8-159 pg L-1) varied non-systematically across systems. Relationships between DOM bulk characteristics and THg and MeHg suggest that while soil derived DOM inputs control THg concentrations, autochthonous DOM (aquatically produced) and the availability of electron acceptors for Hg methylating microorganisms (e.g. sulfate) drive %MeHg and potentially MeHg concentration. Overall, these results highlight the large spatial variability in THg and MeHg concentrations at the European scale, and underscore the importance of DOM composition on mercury cycling in fluvial systems.

Anestesia raquídea con bupivacaína isobárica en cesáreas / Spinal anesthesia with isobaric bupivacaine in cesarean sections

En la anestesia para las cesáreas, la anestesia raquídea con bupivacaína hiperbárica constituye la elección habitual en nuestro medio. Existen dos formas de bupivacaína disponibles, la isobárica (BI) y la hiperbárica (BH). La utilización de la BI es poco frecuente por lo que es relevante conocer la experiencia en su utilización para las anestesias de las cirugías obstétricas. El objetivo del estudio fue caracterizar la utilización de BI en las anestesias raquídeas para cesáreas. Se realizó un estudio observacional, descriptivo, de corte transversal en 23 pacientes que recibieron anestesia espinal con BI. La edad promedio fue de 28  5 años, la dosis promedio de BI utilizada de 9,4 mg. La latencia promedio fue 90 segundos y el tiempo para la instauración una anestesia adecuada fue en promedio 4,9 minutos. En el 82,6% el nivel anestésico alcanzó el dermatoma T4. En el 21,7% fue necesario administrar efedrina para aumentar la presión arterial. En el 52,1% se presentaron efectos adversos menores. A las 24 horas, el dolor fue nulo en 56,5% y leve en 43,5% de los casos. En conclusión, se encontró que las pacientes alcanzaron un nivel sensitivo adecuado en poco tiempo, con una dosis promedio de BI de 9 mg. Pocos pacientes requirieron la administración de un vasopresor para aumentar la presión arterial. Los efectos adversos fueron menores en casi la mitad de los pacientes. En el post operatorio la mayoría de las pacientes no presentaron dolor

In anesthesia for caesarean sections, spinal anesthesia with hyperbaric bupivacaine is the usual choice in our setting. There are two forms of bupivacaine available, isobaric (BI) and hyperbaric (BH). The use of BI is infrequent, so it is relevant to know the experience in its use for anesthesia in obstetric surgeries. The objective of the study was to characterize the use of BI in spinal anesthesia for cesarean sections. An observational, descriptive, cross-sectional study was carried out in 23 patients who received spinal anesthesia with BI. The average age was 28  5 years, the average dose of BI used was 9.4 mg. The average latency was 90 seconds and the time for establishment of adequate anesthesia was on average 4.9 minutes. In 82.6% of the cases, the anesthetic level reached dermatome T4. In 21.7% it was necessary to administer ephedrine to increase blood pressure. Minor adverse effects occurred in 52.1%. At 24 hours, the pain was null in 56.5% and mild in 43.5% of cases. In conclusion, it was found that the patients reached an adequate sensory level in a short time, with an average dose of BI of 9 mg. Few patients required administration of a vasopressor to increase blood pressure. Adverse effects were minor in almost half of the patients. In the postoperative period, most of the patients did not present pain

Boreal forest riparian zones regulate stream sulfate and dissolved organic carbon.

In boreal forest catchments, solute transfer to streams is controlled by hydrological and biogeochemical processes occurring in the riparian zone (RZ). However, RZs are spatially heterogeneous and information about solute chemistry is typically limited. This is problematic when making inferences about stream chemistry. Hypothetically, the strength of links between riparian and stream chemistry is time-scale dependent. Using a ten-year (2003-2012) dataset from a northern Swedish catchment, we evaluated the suitability of RZ data to infer stream dynamics at different time scales. We focus on the role of the RZ versus upslope soils in controlling sulfate (SO4(2)(-)) and dissolved organic carbon (DOC). A priori, declines in acid deposition and redox-mediated SO4(2)(-) pulses control sulfur (S) fluxes and pool dynamics, which in turn affect dissolved organic carbon (DOC). We found that the catchment is currently a net source of S, presumably due to release of the S pool accumulated during the acidification period. In both, RZ and stream, SO4(2-) concentrations are declining over time, whereas DOC is increasing. No temporal trends in SO4(2-) and DOC were observed in upslope mineral soils. SO4(2-) explained the variation of DOC in stream and RZ, but not in upslope mineral soil. Moreover, as SO4(2-) decreased with time, temporal variability of DOC increased. These observations indicate that: (1) SO4(2-) is still an important driver of DOC trends in boreal catchments and (2) RZ processes control stream SO4(2-) and subsequently DOC independently of upslope soils. These phenomena are likely occurring in many regions recovering from acidification. Because water flows through a heterogeneous mosaic of RZs before entering the stream, upscaling information from limited RZ data to the catchment level is problematic at short-time scales. However, for long-term trends and annual dynamics, the same data can provide reasonable representations of riparian processes and support meaningful inferences about stream chemistry.

Working in direct contact with the public as a predictor of burnout in the banking sector.

BACKGROUND: This study investigated the presence of the burnout syndrome amongst employees of the banking sector. This topic is of particular interest owing to recent changes in working conditions and the controversial commercial strategies employed in this sector in recent years. METHOD: A total of 1,341 professionals, 883 men and 458 women took part in the study. A Spanish version of the Maslach Burnout Inventory-General Survey was used, via electronic mail. RESULTS: The results revealed that at least 55.78% of the sample showed a high risk of burnout in at least two of the dimensions. The workers in commercial branch offices dealing with the general public showed a greater risk of burnout than those working in central services. CONCLUSIONS: The risk of burnout was higher than in other professions considered to be at risk and appears to be more closely associated with work-related stress and the controversial commercial strategies employed in the sector in recent years than with the possibility of cuts in salary. Psychological intervention programs aimed at stress management would be a recommendable way of helping employees address problems of this kind.

Resección microquirúrgica de schwannoma vestibular grado IVa con preservación de la función facial / Microsurgical resection of vestibular schwannoma grade IVa with preservation of facial function

Introducción: La cirugía de los schwannoma vestibulares constituye un desafío para los neurocirujanos. Debido a que se trata de un tumor benigno la resección completa de la lesión implica la curación del paciente. Sin embargo, este objetivo no siempre es fácil de lograr preservando la función de los nervios facial y acústico, especialmente en tumores de gran tamaño. Objetivos: Presentar detalles técnicos de la cirugía de resección de un schwannoma vestibular de gran tamaño (IVa) en el que se pudo preservar la función facial. Materiales y métodos: Se presenta el caso de una paciente femenina de 36 años que consultó por hipoacusia izquierda. En la RM preoperatoria se evidenciaba una lesión ocupante de espacio del ángulo pontocerebeloso izquierdo compatible con schwannoma vestibular con compresión del tronco encefálico y sin efecto de masa sobre el IV ventrículo (grado IVa). Mediante un abordaje suboccipital retromastoideo en posición de decúbito lateral se realizó la resección de la lesión en forma completa asistida por monitoreo del nervio facial. En todo momento se pudo preservar el plano aracnoideo que separaba el tumor de los nervios adyacentes. Resultados: Se logró una resección macroscópicamente completa con preservación de la función del nervio facial. La paciente permaneció internada por 96 hs en el postoperatorio sin complicaciones derivadas del procedimiento. Conclusión: La preservación del plano aracnoideo es un detalle técnico de mucha importancia para disminuir las posibilidades de lesión de los nervios facial y auditivo en la cirugía de resección de los schwannoma vestibulares.

Introduction: The surgery of vestibular schwannomas is a challenge for neurosurgeons.Because it is a benign tumor, complete resection of the lesion involves healing the patient. However, this objective is not always easy to achieve, preserving the function of both the facial and acoustic nerves, especially when dealing with large tumors. Objective: The objective of the video is to present some technical details of a large vestibular schwannoma (IVa) surgery in which the facial function could be preserved. Materials and methods: We present the case of a 36-year-old female patient who consulted for left hearing loss. The preoperative MRI showed a space- occupying lesion of the left pontocerebellar angle, which was compatible with vestibular schwannoma, with compression of the brainstem but with no mass effect on the IV ventricle (grade IVa). By means of a retromastoid suboccipital approach in the lateral prone position, the lesion was completely resected assisted by neurophysiological monitoring of the facial nerve. At all times, the arachnoid plane separating the tumor from the adjacent nerves was preserved. Results: A macroscopically complete resection was achieved preserving the facial nerve function. The patient stayed hospitalized for 96 hours during the postoperative period without any complication from the procedure. Conclusion: Preserving the arachnoid plane is a very important technical detail to reduce the possibilities of injury of the facial and auditory nerves in the vestibular schwannoma resection surgery.

Long-term dynamics of dissolved organic carbon: implications for drinking water supply.

Surface waters are the main source of drinking water in many regions. Increasing organic carbon concentrations are a cause for concern in Nordic countries since both dissolved and particulate organic carbon can transport contaminants and adversely affect drinking water treatment processes. We present a long-term study of dynamics of total (particulate and dissolved) organic carbon (TOC) concentrations in the River Fyris. This river supplies drinking water to approximately 200000 people in Uppsala, Sweden. The River Fyris is a main tributary to Lake Mälaren, which supplies drinking water to approximately 2 million people in the greater Stockholm area. Utilities responsible for drinking water supply in both Uppsala and Stockholm have expressed concerns about possible increases in TOC. We evaluate organic carbon dynamics within the Fyris catchment by calculating areal mass exports using observed TOC concentrations and modeled flows and by modeling dissolved organic carbon (as a proxy for TOC) using the dynamic, process based INCA-C model. Exports of TOC from the catchment ranged from 0.8 to 5.8 g m(-2) year(-1) in the period 1995-2010. The variation in annual exports was related to climatic variability which influenced seasonality and amount of runoff. Exports and discharge uncoupled at the end of 2008. A dramatic increase in TOC concentrations was observed in 2009, which gradually declined in 2010-2011. INCA-C successfully reproduced the intra- and inter-annual variation in concentrations during 1996-2008 and 2010-2011 but failed to capture the anomalous increase in 2009. We evaluated a number of hypotheses to explain the anomaly in 2009 TOC values, ultimately none proved satisfactory. We draw two main conclusions: there is at least one unknown or unmeasured process controlling or influencing surface water TOC and INCA-C can be used as part of the decision-making process for current and future use of rivers for drinking water supply.

Spontaneous ovarian hyperstimulation syndrome caused by a follicle-stimulating hormone-secreting pituitary macroadenoma in an early pubertal girl.

UNLABELLED: Gonadotroph adenomas are difficult to diagnose since they usually show as nonsecreting tumors or produce biologically inactive hormones with no clinical effects and classically grow silent until neurological symptoms appear. Presentation with bilateral ovarian masses and ovarian hyperstimulation has been described in fertile years. Gonadotroph adenomas are extremely infrequent in children. We report a 13-year-old postmenarcheal girl referred to our hospital with 6 months of amenorrhea, abdominal palpable mass presumptive of bilateral ovarian tumors. The patient had Tanner IV breast development and a large abdominal mass occupying the whole low hemiabdomen. Laboratory evaluation revealed high estradiol levels with suppressed luteinizing hormone and inappropriately high follicle-stimulating hormone (FSH) levels. Pelvic ultrasound showed enlarged ovaries containing multiple giant cysts. An MRI revealed a pituitary macroadenoma. Transsphenoidal resection of the adenoma was performed with an uneventful postoperative course. Immunohistologic examination only showed staining for FSH, thus confirming pituitary secreting FSH adenoma. Hormonal laboratory levels normalized and ovarian masses showed marked involution 1 month after surgery. Three months later the MRI showed tumor disappearance. CONCLUSION: The presence of bilateral ovarian tumors requires a careful endocrine and neurological evaluation to exclude the presence of an FSH-producing tumor in order to avoid unnecessary ovarian surgery.