Intra-annual density fluctuations in tree rings are proxies of air temperature across Europe.

Intra-Annual Density Fluctuations (IADFs) are an important wood functional trait that determine trees' ability to adapt to climatic changes. Here, we use a large tree-ring database of 11 species from 89 sites across eight European countries, covering a climatic gradient from the Mediterranean to northern Europe, to analyze how climate variations drive IADF formation. We found that IADF occurrence increases nonlinearly with ring width in both gymnosperms and angiosperms and decreases with altitude and age. Recently recorded higher mean annual temperatures facilitate the formation of IADFs in almost all the studied species. Precipitation plays a significant role in inducing IADFs in species that exhibit drought tolerance capability, and a growth pattern known as bimodal growth. Our findings suggest that species with bimodal growth patterns growing in western and southern Europe will form IADFs more frequently, as an adaptation to increasing temperatures and droughts.

Variation in xylem vulnerability to embolism in European beech from geographically marginal populations.

Climate change is expected to increase the frequency and intensity of droughts and heatwaves in Europe, leading to effects on forest growth and major forest dieback events due to hydraulic failure caused by xylem embolism. Inter-specific variability in embolism resistance has been studied in detail, but little is known about intra-specific variability, particularly in marginal populations. We evaluated 15 European beech populations, mostly from geographically marginal sites of the species distribution range, focusing particularly on populations from the dry southern margin. We found small, but significant differences in resistance to embolism between populations, with xylem pressures causing 50% loss of hydraulic conductivity ranging from -2.84 to -3.55 MPa. Significant phenotypic clines of increasing embolism resistance with increasing temperature and aridity were observed: the southernmost beech populations growing in a warmer drier climate and with lower habitat suitability have higher resistance to embolism than those from Northern Europe growing more favourable conditions. Previous studies have shown that there is little or no difference in embolism resistance between core populations, but our findings show that marginal populations have developed ways of protecting their xylem based on either evolution or plasticity.

When, how and how much: Gender-specific resource-use strategies in the dioecious tree Juniperus thurifera.

BACKGROUND AND AIMS: In dioecious species male and female plants experience different selective pressures and often incur different reproductive costs. An increase in reproductive investment habitually results in a reduction of the resources available to other demands, such as vegetative growth. Tree-ring growth is an integrative measure that tracks vegetative investment through the plant's entire life span. This allows the study of gender-specific vegetative allocation strategies in dioecious tree species thoughout their life stages. METHODS: Standard dendrochronological procedures were used to measure tree-ring width. Analyses of time-series were made by means of General Mixed Models with correction of autocorrelated values by the use of an autoregressive covariance structure of order one. Bootstrapped correlation functions were used to study the relationship between climate and tree-ring width. KEY RESULTS: Male and female trees invest a similar amount of resources to ring growth during the early life stages of Juniperus thurifera. However, after reaching sexual maturity, tree-ring growth is reduced for both sexes. Furthermore, females experience a significantly stronger reduction in growth than males, which indicates a lower vegetative allocation in females. In addition, growth was positively correlated with precipitation from the current winter and spring in male trees but only to current spring precipitation in females. CONCLUSIONS: Once sexual maturity is achieved, tree rings grow proportionally more in males than in females. Differences in tree-ring growth between the genders could be a strategy to respond to different reproductive demands. Therefore, and responding to the questions of when, how and how much asked in the title, it is shown that male trees invest more resources to growth than female trees only after reaching sexual maturity, and they use these resources in a different temporal way.

Factors controlling seedling germination after fire in Mediterranean gorse shrublands. Implications for fire prescription.

In Western Mediterranean areas, fires are frequent in forests established on old croplands where woody resprouting species are scarce and post-fire regeneration is limited to obligate-seeder species, such as Mediterranean gorse (Ulex parviflorus), that accumulate a great deal of fine dry fuel, increasing the risk of other severe fires. Under these conditions, fuel control techniques are required in order to prevent fires of high intensity and severity and the subsequent economic and ecological damage. Prescribed fires present an alternative to fuel control, and recent studies demonstrate that, under optimum climatic conditions, fire-line intensity values fall within the limits of those recommended for fire prescription. However, a better understanding of the consequences of fire on the regeneration of vegetation is needed in order to evaluate the suitability of prescribed fires as a technique for fuel reduction in Mediterranean gorse ecosystems. This paper analyses the factors controlling seedling germination after fire to make an evaluation from an ecological perspective of whether fire prescription is a suitable technique for fuel control in mature Mediterranean gorse shrublands. The results show that small differences in the composition of vegetation play a decisive role in fire behaviour, and have a decisive influence on the system's capacity for regeneration. Fire severity is low in mixed Mediterranean gorse communities with a low continuity of dead fine fuel (including Cistus sp., Rosmarinus sp., etc.) and fire creates a wide range of microhabitats where seedling emergence is high. In contrast, where U. parviflorus is more dominant, fire severity is higher and the regeneration of vegetation could be hindered. Our conclusions suggest that detailed studies of the composition of plant communities are required in order to decide whether prescribed burning should be applied.

Factors influencing fire behaviour in shrublands of different stand ages and the implications for using prescribed burning to reduce wildfire risk.

Fire behaviour under experimental conditions is described in nine Mediterranean gorse shrublands ranging from 3-12 years of age with different fuel loads. Significant differences in the fire-line intensity, fuel load and rate of fire spread have been found to be related to the stage of development of the communities. Fire spread is correlated with fuel moisture using multiple regression techniques. Differences in fuel moisture between mature and young communities under moderate weather conditions have been found. The lower moisture content identified in the mature shrubland is due both to the decreasing moisture content of senescent shrubland in some species, mainly in live fractions of Ulex parviflorus Pour. fuel, and to a substantial increase in dead fuel fractions with low percentages of moisture content. The result is that the older the shrubland is, the greater will be the decrease in the total moisture content of the vegetation. In these moderate weather conditions, the fire intensity of the mature community was as high as the maximum intensity recommended for prescribed fires. This fact seems to indicate that, even under moderate conditions, prescribed burning as an alternative management tool in the mature shrubland must always take into account fuel control; on the other hand, this technique could be applied more easily when the shrubland is at an intermediate growth stage (4-5 years of age). Therefore, more frequent low-intensity prescribed fires are indicated to abate the risk of catastrophic fire.

Tumor estromal CD34+ de localización en yeyuno. Presentación de un caso que se inicia con hemorragia digestiva / Jejunal CD34+ stromal tumor: report of case presenting as gastrointestinal hemorrhage

Se presenta el caso de un varón que tras estudio de una hemorragia digestiva no filiada con técnicas endoscópicas fue diagnosticado por angiografía selectiva y TAC de lesión sangrante en primeras asas yeyunales, que resultó ser un tumor estromal CD34+ sin diferenciación neural o miógena. Se analizan las características ultraestructurales e inmunohistoquímicas de los diferentes grupos de tumores estromales del tracto gastrointestinal, así como la dificultad diagnóstica cuando éstos se localizan en intestino delgado y requieren actitud terapéutica agresiva por presentar hemorragia (AU)

Fracture of the neck of a femoral component in a total hip arthroplasty: a case report.

Fracture of components of a total hip arthroplasty occur is a recognised complication. We report an unusual case in which the fracture occurred through the neck of a femoral component on a Lord type of total hip arthroplasty.

[The recurrence of colorectal cancer and blood transfusion]. / Recidiva del cáncer colorrectal y trasfusión sanguínea.

Report of a retrospective study on 303 patients operated from colorectal carcinoma to whom colonic resection was done in B and C stages of Astler-Coller's classification. The aim was to try to find a relation between blood transfusion and colorectal carcinoma recurrence. The statistical study is made with the program LOGIT, studying the surgical incision, evolutive stage and blood transfusion variables. The significant contribution of each variable in the occurrence of recurrence is studied with the Wald Test. As a result it can be deduced that the prognosis of colorectal cancer is influenced by three factors: the evolutive stage, the surgical incision (1.87 times more frequent for the abdomino-perineal) and the transfusion of more of three units of blood in the perioperative period which multiplies by 2.85 the risk of recurrence of colorectal carcinoma. In our hospital almost exclusively red cell concentrates (including red cells, white cells and minimal fraction of plasma), are transfused; possibly the white cells are responsible for the recurrence.

[Spontaneous biliodigestive fistula]. / Fístulas biliodigestivas espontáneas.

A retrospective study was made of 23 cases of spontaneous biliodigestive fistulae collected from bile tract surgery performed in our center from 1979 to 1987, representing 1.05% of the total number of cases. The etiology was cholelithiasis in almost all cases and the most frequent connection was to the duodenum. Forty-eight percent of the cases presented as biliary ileus. In each case surgery depended on the etiology, clinical manifestations and status of the patient. The mortality was 8.7% and the morbidity 52%. Results are analyzed and a bibliographic review of the topic is offered.

[Prognostic factors in colorectal cancer]. / Factores pronósticos en el cáncer colorrectal.

We present a retrospective study of 208 colorectal cancers, 131 of them followed during more than 5 years. Overall survival was 38%. We have tried to correlate clinical findings with prognosis and survival. The analyzed parameters have been the following: age, sex, site and size of the tumor, time and cause of surgical treatment, stage of the lesion, cytologic grade of differentiation of the tumor, delay between the presenting symptom and surgery, surgical procedure, local invasion and number of positive lymph nodes. The results show that the main factors related to prognosis are local extension through the intestinal wall and the presence of positive lymph nodes (particularly if more than 4) and, of course, distant metastases.

[Colonic surgery in the elderly. Comparative study with other age groups]. / Cirugía colónica en el anciano. Estudio comparativo con otros grupos de edad.

From 1980 to 1986, 569 patients with colonic disease underwent surgery in the General Surgery Service of "Nuestra Sra. de Aránzazu" Hospital, 131 of them over 75 and representing 23% of the total. In this group, neoplasms were the most common lesion, for a total of 108 cases (83.2%). Among nontumoral diseases, half corresponded to diverticula. Colonic surgery was practiced as an emergency in 35.87% of the cases and in 72.7% of the non-neoplastic lesions, with an overall operative mortality of 28 patients (21.37%). We analyze the distribution of the different lesions of the colon, the urgency of the operation and operative mortality as related to age, evaluating the limitations in elderly patients and their increased surgical risk.