Does Environmental Instability Favor the Production and Horizontal Transmission of Knowledge regarding Medicinal Plants? A Study in Southeast Brazil

Greater socio-environmental instability favors the individual production of knowledge because innovations are adapted to new circumstances. Furthermore, instability stimulates the horizontal transmission of knowledge because this mechanism disseminates adapted information. This study investigates the following hypothesis: Greater socio-environmental instability favors the production of knowledge (innovation) to adapt to new situations, and socio-environmental instability stimulates the horizontal transmission of knowledge, which is a mechanism that diffuses adapted information. In addition, the present study describes “how”, “when”, “from whom” and the “stimulus/context”, in which knowledge regarding medicinal plants is gained or transferred. Data were collected through semi-structured interviews from three groups that represented different levels of socio-environmental instability. Socio-environmental instability did not favor individual knowledge production or any cultural transmission modes, including vertical to horizontal, despite increasing the frequency of horizontal pathways. Vertical transmission was the most important knowledge transmission strategy in all of the groups in which mothers were the most common models (knowledge sources). Significantly, childhood was the most important learning stage, although learning also occurred throughout life. Direct teaching using language was notable as a knowledge transmission strategy. Illness was the main stimulus that triggered local learning. Learning modes about medicinal plants were influenced by the knowledge itself, particularly the dynamic uses of therapeutic resources.     

Effect of vitamin D3 on behavioural and biochemical parameters in diabetes type 1‐induced rats

Diabetes is associated with long‐term complications in the brain and reduced cognitive ability. Vitamin D₃ (VD₃) appears to be involved in the amelioration of hyperglycaemia in streptozotocin (STZ)‐induced diabetic rats. Our aim was to analyse the potential of VD₃ in avoiding brain damage through evaluation of acetylcholinesterase (AChE), Na⁺K⁺‐adenosine triphosphatase (ATPase) and delta aminolevulinate dehydratase (δ‐ALA‐D) activities and thiobarbituric acid reactive substance (TBARS) levels from cerebral cortex, as well as memory in STZ‐induced diabetic rats. Animals were divided into eight groups (n = 5): control/saline, control/metformin (Metf), control/VD₃, control/Metf + VD₃, diabetic/saline, diabetic/Metf, diabetic/VD₃ and diabetic/Metf + VD₃. Thirty days after treatment, animals were submitted to contextual fear‐conditioning and open‐field behavioural tests, after which they were sacrificed and the cerebral cortex was dissected. Our results demonstrate a significant memory deficit, an increase in AChE activity and TBARS levels and a decrease in δ‐ALA‐D and Na⁺K⁺‐ATPase activities in diabetic rats when compared with the controls. Treatment of diabetic rats with Metf and VD₃ prevented the increase in AChE activity when compared with the diabetic/saline group. In treated diabetic rats, the decrease in Na⁺K⁺‐ATPase was reverted when compared with non‐treated rats, but the increase in δ‐ALA‐D activity was not. VD₃ prevented diabetes‐induced TBARS level and improved memory. Our results show that VD₃ can avoid cognitive deficit through prevention of changes in important enzymes such as Na⁺K⁺‐ATPase and AChE in cerebral cortex in type 1 diabetic rats. Copyright © 2014 John Wiley & Sons, Ltd.     

The actin gene in Paracoccidioides brasiliensis: organization, expression and phylogenetic analyses

PbrACT1, the gene responsible for the synthesis of actin in Paracoccidioides brasiliensis, was found as a single copy, organized into six exons and five introns. Its open reading frame (ORF) codes for a putative protein of 375 amino acids, with a molecular mass of 41.5 kDa and an isoelectric point of 5.6. Analysis of the nucleotide sequence revealed a high homology to other fungal actins, the presence of characteristic fungal actin sequences, and heat shock elements at the 5′ untranslated region (UTR). Phylogenetic analyses with deduced amino acid sequences of fungal actins grouped P. brasiliensis within the phylum Ascomycota, order Onygenales, in concordance with a few previous reports. Patterns of expression through the temperature-induced morphological transitions from mycelial to yeast-like shapes and reverse, suggests that PbrACT1 is regulated in this process. The PbrACT1 gene sequence is available at the GenBank database under accession number AY383732.     

Sleep and rest activity measured by wrist actigraphy in an HIV-infected patient with Steven–Johnson syndrome

The Steven–Johnson syndrome (SJS) is characterized by a sudden onset of mucous membrane erosion (predominantly oral mucosa, lips, and conjunctivae) with widespread blistering of the skin involving up to 10% of the body surface area. It is almost always a drug-related reaction, although it can be caused by infections and immunizations. A 33-year-old man with recent diagnosis of HIV infection developed antiretroviral treatment (ART)-associated SJS. Physical activity and sleep parameters were recorded by wrist actigraphy in four different consecutive scenarios: baseline assessment, first ART regimen, hospitalization, and second ART regimen. Significant differences were observed in physical activity patterns between the four phases. No differences in sleep parameters were found. To our knowledge, this is the first study recording physical activity changes and sleep during a SJS reaction.     

Variation in the diet of the viperine snake Natvix mama in relation to prey availability

The diet of the viperine snake was compared with food availability in the Ebro Delta, a wetland largely occupied by rice fields, in 1990 and 1991. Snake selection of prey type and size was studied seasonally and by snake group: males, females and immature snakes. Overall, feeding activity (percentage of individuals with prey and number of prey per stomach) increased with food availability. Diet analysis showed that viperine snakes mainly foraged on the green frog Rana perezi (adults and tadpoles) and the carp Cyprinus earpio. Conversely, viperine snakes rejected the mosquito fish Gambusia holbroki which is the most abundant species in autumn, when Natrix maura has a low feeding activity. Statistical comparisons between viperine snake diet and prey availability showed that males selected small carp, immature snakes selected tadpoles and, in spring, females selected frogs. The selection of small carp by males may reflect a sexual divergence of trophic niche related to sexual size dimorphism, as females are larger than males. As tadpoles are presumably easier to catch than fish, tadpole selection by immature individuals may reflect variance in capture abilities. In spring, the selection of frogs by females overlapped with vitellogenesis, suggesting that females compensate for the cost of reproduction by selecting green frogs, which have a greater biomass and higher energy content than fish. Carps eaten in spring were smaller than in summer. Moreover, in summer viperine snakes selected smaller carp than the available mean size. This divergent tendency between carp size selection and carp size availability reveals how seasonal diet shifts in prey size selection may be a response to an increase in prey size.     

Some physiological and morphological responses of Pyrus boissieriana to flooding

European pear is a flooding-sensitive species, and for its cultivation in lowland areas, it is necessary to carry out the grafting of scions of commercial pear varieties into rootstocks belonging to flooding-tolerant wild pear species. Flooding tolerance of Pyrus boissieriana—a type of wild pear—was studied as a promissory rootstock for commercial pear. For this purpose, 3-month-old plants of P. boissieriana were subjected for 30 days to control (C), well-irrigated treatment, short-term (15 days) flooding plus 15 days recovery (F + R) and long-term (30 days) continuous flooding (F). Physiological performance, plant morphological changes and biomass accumulation were assessed. Results showed that, although stomatal conductance, transpiration and photosynthesis were progressively decreased by flooding, when flooding was short term (i.e., 2 weeks, F + R treatment) plants were able to adequately recover their physiological activity (50–74 % with respect to controls). In contrast, when plants continued to be flooded (F treatment), the physiological activity became null and the plants died quickly after the water subsided. Adventitious rooting was the most conspicuous registered morphological response to flooding, despite that flooded plants had shorter shoots and roots than control plants. Leaf and root biomass were 63 and 89 % higher under short-term flooding (F + R) than under continuous flooding (F), condition in which plants did not survive. In conclusion, P. boissieriana appears to be a promising species for its use as rootstock of commercial pear in lowland areas prone to flooding of up to 2 weeks. However, if the flooding period is extended, plants of this species are at risk of perishing.