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ABSTRACTThe Polylepis tarapacana forests found in Bolivia are unique with respect to their altitudinal distribution (4200–5200 m). Given the extreme environmental conditions that characterize these altitudes, this species has to rely on distinct mechanisms to survive stressful temperatures. The purpose of this study was to determine low-temperature resistance mechanisms in P. tarapacana. Tissue was sampled for carbohydrate and proline contents and micro-climatic measurements were made at two altitudes, 4300 and 4850 m, during both the dry cold and wet warm seasons. Supercooling capacity (-3 to -6 °C for the cold dry and -7 to -9 °C for the wet warm season) and injury temperatures (-18 to -23 °C for both seasons), determined in the laboratory, indicate that P. tarapacana is a frost-tolerant species. On the other hand, an increase in supercooling capacity, as the result of significant increase in total soluble sugar and proline contents, occurs during the wet warm season as a consequence of higher metabolic activity. Hence, P. tarapacana, a frost-tolerant species during the colder unfavourable season, is able to avoid freezing during the more favourable season when minimum night-time temperatures are not as extreme. [ABSTRACT FROM AUTHOR]

Giant rosettes are ones of the most striking features of the vegetation in the high tropical Andes, with Coespeletia moritziana reaching the highest altitudes up to 4,600 m a.s.l. Different from other giant rosettes, this species grows on rock outcrops with poorly developed soils and where water availability may be limited. Two questions are addressed in this study: How does this species respond in terms of water relations to maintain favorable gas-exchange conditions? Considering that adult plants rely on a water-reserving central pith, how do early stages respond to this environment's extreme conditions? Water relations and gas-exchange studies were carried out on juveniles, intermediate and adult C. moritziana plants during wet and dry seasons in Páramo de Piedras Blancas at 4,200 m a.s.l. Adult plants maintained higher leaf water potentials (Ψ) during the wet season, however, no differences between stages were found for the dry season. Minimum dry season Ψ were never near the turgor loss point in any of the stages. Juveniles show a more strict stomatal control during the dry season to maintain a favorable water status. Net photosynthesis significantly decreased in intermediate and juvenile stages from wet to dry seasons. Our results suggest that C. moritziana resists more extreme conditions compared to other Andean giant rosettes [ABSTRACT FROM AUTHOR]

In order to study the ecophysiological relations that affect the growth of B. decumbens in monocrop (MO) and associated with L. leucocephala (AS), evaluations of photosynthetic active radiation (PAR), assimilation (A) stomatic conductance (Gs), transpiration (E), relative humidity (RH), water potential (Øh), differential of steam pressure (DSP) and leaf area index (LAI) were made in a tropical humid forest zone. The evaluations were made 5, 10 and 22 days after grazing under both conditions (MO and AS). The most positive values of Øh (P<0,05) were found in AS, as well as the lowest values of PAR (P<0,05) in all the evaluated dates. RH and DSP did not show differences (P 0,05). The gas exchange parameters (E, Gs and A) showed significantly higher values in MO (P<0,05) in all dates. LAI was higher in MO after 10 and 22 days of evaluation. Due to the limitation of the photosynthetic capacity exerted by the light decrease on the grass, that PAR is concluded to be the most important factor that determine growth and development of B. decumbens in AS. [ABSTRACT FROM AUTHOR]

In order to study the ecophysiological relations that affect the growth of B. decumbens in monocrop (MO) and associated withZ. leucocephala (AS), evaluations of photosynthetic active radiation (PAR), assimilation (A) stomatic conductance (Gs), transpiration (E), relative humidity (RH), water potential (0h), differential of steam pressure (DSP) and leaf area index (LAI) were made in a tropical humid forest zone. The evaluations were made 5,10 and 22 days after grazing under both conditions (MO and AS). The most positive values of 0h (P<0,05) were found in AS, as well as the lowest values of PAR (P<0,05) in all the evaluated dates. RH and DSP did not show differences (P 0,05). The gas exchange parameters (E, Gs and A) showed significantly higher values in MO (P<0,05) in all dates. LAI was higher in MO after 10 and 22 days of evaluation. Due to the limitation of the photosynthetic capacity exerted by the light decrease on the grass, that PAR is concluded to be the most important factor that determine growth and development of B. decumbens in AS. [ABSTRACT FROM AUTHOR]

Introduction. Choking phobia (or swallowing phobia) is characterized by a fear of swallowing foods, liquids or pills, sometimes after an episode of choking on food. Methods. Forty-one case reports on swallowing phobia from 1978 to 2005 were studied. Clinical and therapeutic variables of the disorder were studied. Results. It appears to occur more often in females (two-thirds of the cases) and has a high comorbidity with anxiety disorders (panic disorder, 41 %; obsessive conditions, 22 %, and separation anxiety, 15 %). Life-events and eating traumatic antecedents are frequently present (44% and 56% cases, respectively). Cognitive-behavioral treatments have been of proven efficacy, as well as antipanic drugs (alprazolam, lorazepam, bromazepan, imipramine, clomipramine, fluoxetine, paroxetine) with a remission rate of 58.5 %. Gender and treatment differences are also analyzed. [ABSTRACT FROM AUTHOR]

Evolutionary psychopathology incorporates psychiatry into biology via theory of evolution, generating new etiological hypothesis for mental disorders. For evolutionary psychopathology emotions are a response system or a genetically programmed, specialized state of functioning, formed by natural selection, that allows us to adapt to the environment, increasing the ability to cope with threats and opportunities. Emotions exert their function by coordinated physiological, psychological and behavioral changes. Many functions have been suggested for low mood or depression, including communicating a need for help, signaling yielding in a hierarchy conflict, fostering disengagement for commitments to unreachable goals, regulating patterns of investment, parallelism with despair phase of separation from mother situation in monkeys, hibernation, etc. Despite other evolutionary models, our model not only tries to explain depression but mania, hypomania and other affective disorders as well. For us, most affective disorders are pathological states (and not adaptive ones), due to dysfunction of an innate precipitating mechanism (IPM). IPM function is to regulate energy and activity levels according to intensity and duration of light (namely IPM-A). This IPM-A is responsible for vegetative, endocrine and behavioral responses that are present in humans and more ancient phylogenetic animals. More recently in the phylogeny, other mechanisms (IPM-AA) have coupled to this IPM-A. In the human being, the precipitating factors of IPM-AA are predominately social. IPM-AA add new responses (such as mood) to the older responses of IPM-A. [ABSTRACT FROM AUTHOR]

Open studies suggest that mirtazapine has efficacy in panic disorder treatment. We designed an open study that evaluates changes induced by mirtazapine compared with paroxetine in panic disorder. Patients 18–65 years old consecutively referred to a psychiatry liaison service with panic disorder (DSM-IV criteria) were offered either mirtazapine or paroxetine treatment. There were statistically significant reductions from baseline to week 3 and from week 3 to 8 for mirtazapine and paroxetine groups for: number of panic attacks, Beck Anxiety or Depression Inventory (BAI, BDI) Clinical Global Impresion (CGI) of panic disorder severity and CGI of panic disorder response (these variables were evaluated by the patient, the clinician or a blind evaluator). Responders at week 3 (BAI decrease of 50%) were 83% for the mirtazapine group and 84% for the paroxetine group. Responders at week 8 (number of panic attacks equal to 0) were 77% for the mirtazapine group and 73% for the paroxetine group Statistically significant differences between mirtazapine and paroxetine were found for number of panic attacks at weeks 3 and 8 and BAI at week 3, suggesting a faster response for mirtazapine. Responders at week 8 maintained a no recurrence figure of 95% at follow-up 6 months later. Panic disorder either with or without comorbid depression improved in both groups of treatment. Our study supports the hypothesis that mirtazapine has efficacy in the treatment of panic disorder either with or without comorbid depression. [ABSTRACT FROM AUTHOR]

Abstract: The seasonal effect of soil water availability on leaf gas exchange of plantain plants cv. Hartón growing on two different texture soils (loamy and clayey) were evaluated. Soil water deficits corresponded to 48, 24 and 4 days without precipitation. Daily measurements of leaf gas exchange and microclimatic conditions were carried out at 2h intervals in a humid tropical environment south of Maracaibo Lake, Venezuela. The results show that cv. Hartón is sensitive to conditions of low water deficit on loamy and to a much greater degree on clayey soils. A marked reduction in leaf conductance (gs) was observed under severe as well as moderate deficit (below 50mmolm-2s-1) on clayey soils. Under low deficit gs increases to values between 60 and 100mmolm-2s-1. The same trend was observed in plants on loamy soils but higher gs for all conditions were obtained compared with plants on clayey soil. Stomatal closure produced a reduction of 85 and 55% of total assimilation (Atot) for severe and moderate deficit in plants on clayey soils, respectively. While plants on loamy soil exhibited a 65 and 35% reduction, respectively. Water use efficiency (WUE) consistently decreased as available soil water decreased on both soil types. Independently of soil water conditions, higher WUE were always obtained for loamy soils. This suggests that cv. Hartón does not have the ability to adjust the CO2 assimilation to transpiration ratio in order to optimize gas exchange. This evidences the importance of maintaining high conditions of available soil water in order to avoid lower assimilation rates that probably influence negatively on yield and fruit quality. [Copyright &y& Elsevier]

This paper proposes a novel model that incorporates word semantics into information retrieval, enabling a whole new range of semantic based retrieval applications. Concepts can be sought instead of simple words, and the retrieval of words that are semantically related to the input keywords is also possible. A novel encoding scheme applied to words creates the groundwork for this model and enables the application of complex semantic operators. One of the most powerful operators introduced by the model is the semantic wildcard, able to fulfill information requests expressed along general-specific lines. For instance, a search for animal# will match any concept that is of type animal, going beyond the explicit knowledge stated in texts. Additionally, a new lexical locality operator is introduced, making possible the retrieval of paragraphs rather than entire documents. Both semantic indexing and paragraph indexing paradigms proposed in the model have been implemented in a system that was tested on questions run against an index of 130,000 documents. A significant improvement was observed over classic keyword based retrieval systems, in terms of precision, recall and success rate. [ABSTRACT FROM AUTHOR]

In this paper, we present a bootstrapping algorithm for Word Sense Disambiguation which succeeds in disambiguating a subset of the words in the input text with very high precision. It uses WordNet and a semantic tagged corpus, for the purpose of identifying the correct sense of the words in a given text. The bootstrapping process initializes a set of ambiguous words with all the nouns and verbs in the text. It then applies various disambiguation procedures and builds a set of disambiguated words: new words are sense tagged based on their relation to the already disambiguated words, and then added to the set. This process allows us to identify, in the original text, a set of words which can be disambiguated with high precision; 55% of the verbs and nouns are disambiguated with an accuracy of 92%. [ABSTRACT FROM AUTHOR]

The effect of a mistletoe, Phthirusa maritima, on the water, nitrogen and carbon balance of two mangrove host species, Conocarpus erectus and Coccoloba uvifera, was studied. Several daily cycles of water potential and its components (pressure-volume curves); leaf nitrogen content (Kjeldahl method); leaf conductance, transpiration rates and carbon assimilation (portable gas exchange system) were measured on mistletoe, infested and uninfested plants in the Caribbean coast of Venezuela. The mistletoe on both host species showed higher transpiration rates and lower CO2 assimilation rates, and therefore lower water use efficiencies. With respect to infested and uninfested plants, C. erectus did not show large differences in the parameters measured with the exception of assimilation rates which were significantly lower in the infested plants. On the other hand, C. uvifera did show differences in all parameters and, therefore, was affected to a greater degree by the mistletoe. The behaviour of mistletoe- infested and uninfested plants, with respect to habitats with different degrees of water stress and with respect to the salinity gradient in which these mangroves grow, is discussed. [ABSTRACT FROM AUTHOR]

Frost avoidance mechanisms were studied in Espeletia spicata and Espelelia timotensis, two Andean giant rosette species. The daily courses of soil, air and tissue temperatures were measured at a site at circa 4000 m. Only the leaves were exposed to subzero temperatures; the apical bud and stem pith tissues were insulated by surrounding tissues. The leaf tissues avoided freezing by supercooling rather than by undergoing active osmotic changes. The temperatures at which ice formed m the tissues (the supercooling points) coincided with injury temperatures indicating that Espeletia tissue does not tolerate any kind of ice formation. For insulated tissue (apical bud, stem pith, roots) the supercooling point was around -5°C coinciding with the injury temperature. Supercooling points of about -13 to -16°C were observed for leaves. These results contrast with those reported for Afroalpine giant rosettes which tolerate extracellular freezing. The significance of different adaptive responses of giant rosettes to similar cold tropical environments is discussed. [ABSTRACT FROM AUTHOR]

AbstractThe degree of crop sensitivity to water deficit, during the different developmental stages of a plant, is an important aspect to consider in tropical semiarid regions. The effect of water deficit on flowering dynamics and fruit production of sweet pepper (Capsicum chinense) was evaluated under several water regimes, during three consecutive years. A complete randomized block design with three replicates was employed. Flowering dynamics and fruit production were measured weekly, and water potentials were obtained twice during the experiments. For all years, flowering began at approximately 70 days after transplanting. In the most favourable year (trial 1996), there were no differences in total flower and fruit production in terms of irrigation frequency. For the other less favourable years, flowering and fruit production were significantly different between irrigation frequencies. Our results show that low water availability, prior to flowering, reduces the number of flowers produced and retards the occurrence of maximum flowering. On the other hand, a water deficit during the period between flowering and fruit development reduces final fruit production. This suggests that a water deficit during this last stage affects final yield to a greater extent. [ABSTRACT FROM AUTHOR]

Background: The purpose of this multicenter Spanish study was to evaluate the response to immediate-release methylphenidate by children and adults diagnosed with attention-deficit/hyperactivity disorder (ADHD), as well as to obtain information on current therapy patterns and safety characteristics. Methods: This multicenter, observational, retrospective, noninterventional study included 730 patients aged 4-65 years with a diagnosis of ADHD. Information was obtained based on a review of medical records for the years 2002-2006 in sequential order. Results: The ADHD predominantly inattentive subtype affected 29.7% of patients, ADHD predominantly hyperactive-impulsive was found in 5.2%, and the combined subtype in 65.1%. Overall, a significant lower Clinical Global Impression (CGI) score and mean number of DSM-IV TR (Diagnostic and Statistical Manual of Mental Disorders Fourth Edition, Text Revision) symptoms by subtype were found after one year of treatment with immediate-release methylphenidate; CGI decreased from 4.51 to 1.69, symptoms of inattention from 7.90 to 4.34, symptoms of hyperactivity from 6.73 to 3.39, and combined subtype symptoms from 14.62 to 7.7. Satisfaction with immediate-release methylphenidate after one year was evaluated as "very satisfied" or "satisfied" by 86.90% of the sample; 25.75% of all patients reported at least one adverse effect. At the end of the study, 41.47% of all the patients treated with immediate-release methylphenidate were still receiving it, with a mean time of 3.80 years on therapy. Conclusion: Good efficacy and safety results were found for immediate-release methylphenidate in patients with ADHD. [ABSTRACT FROM AUTHOR]

Introduction Treatment strategies in bipolar disorder (BPD) has changed in the last decades and polypharmacy including antipsychotics has become extremely common compared to monotherapy with mood stabilisers. Clinicians tend to use 2 or more atypical antipsychotics despite the lack of evidence to support safety, tolerability and efficacy of this practice. Objective To determine most frequently used treatment strategies in a sample of bipolar disorder patients and review of the literature. Methodology Analysis of a sample of 35 patients with BPD from Madrid and review of recent literature for evidence arising from international guidelines recommendations and meta-analyses. Results Most frequently used treatment approach in our sample was polytherapy, including at least 1 atypical antipsychotic (31%) and polytherapy, including at least 2 antipsychotics (47%) together with mood stabilisers. Only 11% were in monotherapy with mood stabilisers and another 11%were in monotherapy with one atypical antipsychotic but without mood stabilisers. Aripiprazol and olanzapine were among the most preferred atypical antipsychotics. Efficacy and safety of such combinations have not been systematically compared with monotherapy in the literature. Previous data indicate that polytherapy in BPD may incur in important disadvantages [1]. Conclusions Treatment of BPD remains challenging. Polytherapy seem to have replaced monotherapy due to less relapses and better results in treatment of affective symptoms. However, compliance and secondary long-term effects should be taken into account. Superiority in terms of efficacy in polytherapy needs to be balanced with tolerability issues. More studies on combination therapy, long-term efficacy and safety are needed. [ABSTRACT FROM AUTHOR]