Some meteorological conditions associated with forest fires in Galicia (Spain)

The present paper offers data on the effect of certain meteorological parameters on the outbreak of forest fires in Galicia (Spain). In a day-to-day analysis, the values of the stability of the air column and the saturation deficit at the lower levels are related to the number of fires occurring in the following 24 h.     

The effect of somatostatins (SRIF-14, 25 and 28), galanin and anti-SRIF on plasma growth hormone levels in Coho salmon (Oncorhynchus kisutch, Walbaum)

Porcine galanin, somatostatins (SRIF-25 and SRIF-28) and invariant SRIF-14, known to have inhibitory-stimulatory actions on growth hormone (GH) secretion in higher vertebrates, were tested for their ability to affect plasma GH levels in coho salmon. Peptides were administered by intraperitoneal injection of 10 or 100 ng g⁻¹ body weight. All three SRIFs decreased plasma GH concentrations, their activity following the order SRIF-14 > SRIF-28 > SRIF-25. Galanin and an anti-SRIF produced pronounced, although transient increases in plasma GH.     

Ethanol induces release of arachidonic acid but not synthesis of eicosanoids in mouse peritoneal macrophages

Exposure of mouse peritoneal macrophages to ethanol induces a rapid release of arachidonic acid to the extracellular medium. All major classes of phospholipids, phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol contribute to this release. Ethanol-induced mobilization of arachidonic acid occurs by deacylation, but it is not accompanied by eicosanoid synthesis. These data suggest that at least two signals are necessary for the release and metabolism of arachidonic acid. Ethanol also activates a phospholipase C which hydrolyzes only phosphatidylinositol, and not its phosphorylated derivatives.     

Testing a model of excitatory interactions between oscillators

The experimentally observed influence of regularly arriving tugs upon the AP discharge of the slowly-adapting stretch receptor organ (SAO) of crayfish was compared to a model of pacemaker excitatory synaptic interactions (Segundo and Kohn 1981). Criteria for compliance referred to facets as A) the excitation, B) the postulates, and C) the behavior. A) Excitation was implied primarily by the tug initially increasing the AP rate (it subsequently decreased it). B) The pacemaker AP discharges, and with more reason the electronically driven tugs, were considered acceptably regular sequence (postulate i). Tugs advanced the next AP (postulate ii); the "delay function" plots of delays vs. phases, i.e. interval shortenings vs. the time from the last AP to the tug, were close to the V of postulate iii, even though the shortest phases tended to postpone the next AP and the longest ones did not trigger immediately but with an around 5 ms latency. These effects were displayed also as "old phase vs. new phase" plots. The interval following that with the tug tended to be lengthened, but the pre-tug timing was not recovered. C) Behavior during a train of excitatory events, both in model and experiments, went through very similar initial settlings and eventual steady-states. The latter were characterized in the model by 1. an average excitatory vs. excited rate display formed by an endless number of segments with all positive rational slopes separated by negative-going discontinuities, 2. locking in the sense of preferential phases, and 3. periodic repetition of the same phases and inter-AP intervals. Experimental results were compatible with this. Such behavior was absent when the tug sequence was highly irregular. The initial settling, in the SAO as in the model, depended jointly on the first phase phi 1 and the intertug interval E. If the former was under lambda, it went through one or two monotonic phase-decreasing stages (one smaller, the other larger, than lambda), or through a single increasing one, depending on E being smaller or greater than, respectively, an estimated but never actually observed E leading to unstable lockings. If the initial phase was greater than lambda, settling with E's under rN + lambda involved jumps between larger than and smaller than lambda phases; with E's over rn + lambda, it involved an intermediate stable locking with phi = E-rN.(ABSTRACT TRUNCATED AT 400 WORDS)     

Characterization of the state of differentiation of six newly established human non-small-cell lung cancer cell lines

Six new non-small-cell lung cancer (NSCLC) cell lines were established directly from human tissue or indirectly via nude mouse xenografts in serum-supplemented media with success rates of 8% and 13%, respectively. They comprised one adenocarcinoma (ADLC-5M2), two squamous cell carcinomas (EPLC-32M1, EPLC-65H), two large cell carcinomas (LCLC-97TM1, LCLC-103H), and one malignant biphasic mesothelioma (MSTO-211H). All cell lines grew adherent to culture vessels with population doubling times (PDT) of 16-40 h, formed colonies in soft agarose with efficiencies of 0.1%-5.1%, and all grew in athymic nude mice. Xenograft histologies appeared as follows: (a) undifferentiated carcinomas with feeble resemblance to the original tumors in the case of adenocarcinomas and squamous cell carcinomas; (b) large cell carcinoma with high resemblance to the original tumor; (c) an undifferentiated tumor with predominance of large epithelial cells and few fibrous cells in the case of mesothelioma. Human chorionic gonadotropin (HCG) was found by radioimmunoassay and high-affinity binding sites for epidermal growth factor (EGF) by radio-receptor assay in 4/4 cell lines. A very low activity of L-DOPA decarboxylase (DDC) was detectable only in the adenocarcinoma cell line. All cell lines overexpressed the c-myc protooncogene, and no gene rearrangement or amplification was observed. Chromosome analysis revealed modal chromosome numbers of 70-73 in ADLC-5M2, EPLC-32M1, EPLC-65H, and MSTO-211H. Cell lines derived from large cell carcinoma had modal values of 65 and 170 and a wider chromosome distribution than all other cell lines. A NSCLC specific chromosomal aberration has been undetectable until now. These cell lines may aid in elucidating the biology of NSCLC and its interrelationship to other lung tumors.     

Models of the geometry of the human ankle bone pulley: two series of geometric models for demonstrating the biomechanics of the ankle joint

2 series of models demonstrate the geometrical shape of the human trochlea tali. We have changed step by step the shape of the 2 flanking articular facets of the trochlea, the course of the edges of the trochlea, and the length of their radii, and so we have found a model responding to the biomechanic conditions of the trochlea tali. The convex surface of this model (corresponding to the superior articular surface, i.e. the facies superior trochleae tali) is a torse, the medial flanking facet (corresponding to the medial articular facet of the trochlea, i.e. the facies malleolaris medialis) is a flat cone, the lateral flanking facet (corresponding to the lateral articular facet of the trochlea, i.e. the facies malleolaris lateralis) is a screwed (helicoidal) face. The resulting model shows the 2 completely different phases of motion in the ankle joint: During dorsiflexion (motion setting out from the neutral position towards the final position of dorsiflexion), the internal malleolus leads the talus, whereas the external malleolus is pushed outwards by the screwed lateral articular facet of the trocheal. The trochlea is moved like a hinge. In the final position of dorsiflexion, the malleoli tightly embrace the 2 flanking facets of the trochlea, whilst an obvious cleft appears dorsally and medially between the superior articular surface of the trochlea and the tibial roof (i.e. the facies articularis inferior tibiae). During plantarflexion (motion setting out from the neutral position towards the final position of plantarflexion), the external malleolus leads the talus, whereas the medial articular facet of the trochlea withdraws from the internal malleolus. The trochlea is moved like a screw. In the final position of plantarflexion, the superior articular surface of the trochlea closely contacts the tibial roof, whilst an obvious cleft appears between the medial articular facet of the trochlea and the internal malleolus.     

The interaction of ethanol and exogenous arachidonic acid in the generation of extracellular messengers by mouse peritoneal macrophages

It is increasingly recognized that macrophages play a crucial role in the development of chronic inflammatory states such as alcoholic liver disease. These cells can metabolize free arachidonic acid in the absence of a discernible trigger. The present study was undertaken to examine the short-term effects of ethanol on the generation of these exogenous arachidonate-derived extracellular mediators. Ethanol caused a dose-dependent decrease in the production of both cyclooxygenase and lipoxygenase metabolites. Similar effects were observed on the esterification of exogenous arachidonate into cellular lipids. To characterize further the effects of ethanol on exogenous arachidonic acid metabolism, we studied the short-term responses displayed by macrophages challenged with another soluble stimulus; the tumor-promoting agent phorbol myristate acetate. We observed an inhibition by ethanol of the superoxide anion response triggered by phorbol myristate acetate similar to that observed for exogenous arachidonate oxygenation. Our results show that ethanol can inhibit these soluble stimuli-elicited responses, possibly through its disorganizing effect on plasma membrane.     

Preferred Temperature of Meloidogyne incognita

In laboratory thermal gradients, newly hatched infective juveniles of the plant-parasitic root-knot nematode Meloidogyne incognita migrated toward a preferred temperature that was several degrees above the temperature to which they were acclimated. After shifting egg masses to a new temperature, the preferred temperature was reset in less than a day. Possible functions of this type of thermotaxis are discussed, including the use of thermal gradients around plant roots to locate hosts and to maintain a relatively straight path while ranging in the absence of other cues (a collimating stimulus).     

Statistical analysis for the spatial validity of a model to forecast the daily number of forest fires

In earlier papers a qualitative and quantitative model was developed for predicting the number of forest fires occurring per day. This model permits the forecast at 00.00 hours Universal Time Convention (UTC) of any day (d), the number of forest fires per day for a range of several days (d tod+5) over a particular region. Input data are the number of forest fires in the region during two preceding days (d–2 andd–1) and the type of day (real and evaluated from radiosonde ford–2,d–1,d and predicted from meteorological medium-range forecasts, i.e. of European Centre, ford+1,d+2,d+3,d+4 andd+5. As this model requires data obtained by radiosonde, particularly temperatures and geopotentials at 850 and 700 hPa and dew points (or specific humidity) at 850 hPa, this study investigates the spatial validity of the model in relation to the distance from the radiosonde station (RS). The highest quality forecast is obtained for the region immediately surrounding the RS, and diminishes with increasing distance from it, this being due to the data obtained from the RS not being representative of the atmospheric column over the region. Hence, the derivation of the critical distance for a particular quality level of measurement. Conversely, fixed quality level implies a specific separation between RS and the region for the prediction, with a higher predictive quality implying a shorter distance.