A. L. Pereira

Morphological and genetic diversity of the family Azollaceae inferred from vegetative characters and RAPD markers

Family Azollaceae has seven species with a controversial taxonomy. The identification of species without reproductive structures relies on vegetative characters but some are variable, leading to misinterpretations. The molecular methods may be helpful, but until now, they did not provide a conclusive Azolla taxonomy. Therefore, we studied the family Azollaceae at vegetative and molecular levels. Analysis of vegetative, random amplified polymorphic DNA (RAPD) and combined data showed a comparable grouping of the Azolla species in two main clusters: cluster I, referred to as section Rhizosperma (A. pinnata and A. nilotica) and cluster II, referred to as section Azolla (A. filiculoides, A. microphylla, A. caroliniana and A. mexicana), with the exception of A. rubra, which clustered differently depending on the method. All the Azolla species were distinguished by the 13 polymorphic vegetative characters, the 211 RAPD markers or the combined data, with the latest showing the highest discrimination. The Shannon Index diversity was greater with RAPD (2.276) than with vegetative characters (0.054), highlighting the higher discriminating power of the molecular data. The partitioning of diversity was, as expected, high among species for all the types of data and low within species, with the lowest diversity obtained for morphological data. Both data sets (vegetative and RAPD) allowed the distinction of all the species and their clustering into sections Rhizosperma and Azolla, suggesting this as the most correct for this family. The dendrogram from the combined data was the most accurate, highlighting the benefit of integrating different types of data to study the family Azollaceae.

Taxonomic re-evaluation of the Azolla genus in Portugal

ABSTRACT The Portuguese and the European Flora refer to the presence of two or three Azolla species in Portugal: A. filiculoides Lam., A. caroliniana Willd. and/or Azolla mexicana Presl., the latter included in the last edition of Flora Europaea. In the present work, the taxonomy of Azolla species is reviewed using the two most important characters that can distinguish between these two/three species: papillae in the dorsal leaf lobe and perine architecture of the megaspore apparatus. Other characteristics, such as the hyaline border cells of the dorsal leaf lobes and the number of glochidia septa in microsporangium massulae, are also used. All the Azolla specimens, collected from several locations in Portugal, were identified as Azolla filiculoides Lam. This identification disagrees with previous published reports on Azolla taxonomy in Portugal as well as with herbarium identification.

Histochemistry of simple hairs from the foliar cavities of Azolla filiculoides

Abstract The foliar cavities of the water fern Azolla filiculoides have as many as 20 – 25 simple hairs (SH) protruding from the epidermal cells that delimit the cavity. These SH have a transfer-like ultrastructure normally associated with secretion of metabolites. The aim of this study was the chemical characterization of the compounds that accumulated in the SH of the zones F1-12 (from 1st to 12th leaves) and F13 (from 13th until the end of the sporophyte) throughout the seasons during a 1-year study. The histochemical tests show that the vacuoles of simple hairs contain a mixture of lipids, unsaturated lipids, polysaccharides, polyphenols (o-dihydroxyphenols, phenols with free ‒OH groups and tannins) and alkaloids or alkaloid-like compounds. These substances do not show seasonal variation, having been present throughout the one-year study. The histochemical analysis demonstrated that the SH always have a variety of metabolites. The function within the Azolla-Anabaena symbiosis is not known.

Culture of Azolla filiculoides in artificial conditions

Abstract Azolla filiculoides showed a planar development in four culture media, but with overlapping of sporophytes after 28 days, and curled roots in all cases except for IRRI2. The difference in biomass between the media IRRI2 and IRRI1‐Fe10x was statistically significant at Days 14, 21 and 28 by ANOVA. Medium IRRI2 gave the highest duplication time.

Volatile compounds from the symbiotic system Azolla filiculoides‐Anabaena azollae bacteria

Abstract Azolla filiculoides is an aquatic pteridophyte that may be used as animal food, biofertilizer and phytoremediation. Its volatile composition was never studied although several phytochemical analyses were performed. The volatile composition of A. filiculoides grown outdoors in a pond at the Botanical Garden of Lisbon University (BGLU) or in culture conditions as well as the effect of different harvesting times and the storage type were evaluated. The volatiles isolated by hydrodistillation and distillation‐extraction were analysed by gas chromatography and gas chromatography‐mass spectrometry. The oil of all the A. filiculoides samples studied affords a yellowish colour and an unpleasant odour in a yield of 0.01% (v/fw). Alcohols, aldehydes, alkanes and ketones dominated the culture samples, while aldehydes, alcohols, terpenoids and alkanes represented the main volatiles of the BGLU samples. Some quantitative differences were detected in seasonal and type of storage (fresh, dry or frozen at −20°C) studies of A. filiculoides from the BGLU. The BGLU and culture volatiles showed qualitative differences: 2‐ethyl‐1‐hexanol was only identified in the fern culture, whereas acetophenone, pentylfuran, acetylpyridine and 2‐octanone were only detected in BGLU samples. The dendrogram showed two distinct clusters (culture and BGLU samples). The possible biological origin and bioactivity of some of the volatile compounds is discussed. Abbreviations: FID, flame ionization detector; i.d., internal diameter; v/fw, volume by fresh weight; GC, gas chromatography; GC‐MS, gas chromatography‐mass spectrometry; u, unified atomic mass unit

Diagnosis and repair of gypsum plaster coatings: statistical characterization and lessons learned from a field survey

AbstractThis paper provides the statistical characterization of the pathological situation of 119 gypsum plaster coatings applied to partition walls and ceilings (inner gypsum plasters – IGP), the diagnosis methods that can be used to characterize the defects and confirm their causes, and the most suitable repair solutions. The results presented in this paper were achieved via the use of an expert system developed by the authors in an extensive inspection programme covering 23 buildings. A comprehensive set of charts and their detailed statistical analysis describe the results achieved, including the characteristics (temporal, spatial and severity) and frequency of the defects in the sample and the main causes of their occurrence in walls and ceilings. The most appropriate diagnosis methods, preventive measures and repair solutions prescribed for these defects in the sample are also analyzed and the most significant correlations presented. Even though in some instances the pathological situation of IGP is...

Winged stems in Pterospartum tridentatum: morphoanatomical study

Abstract Some members of the subtribe Genistinae show winged stems instead of leaves. Using techniques of light and scanning microscopy, the mor- phoanatomy and some microcharacters of the winged stem of Pterospartum. tridentatum are described and compared with those of other close taxa, also inserted in the Genistinae and with whom P. tridentatum is mistaken: Chamaespartium tridentatum (L.) Gibbs, C. sagittale (L.) Gibbs and G. florida L. P. tridentatum winged stem presents a peculiar anatomy, with characteristics of a dicot stem and leaf. The central vein is organized as a secondary stem and vascular tissues are surrounded by a ring of mechanical elements. Some epidermal microcharacters, such as the predominant type of stornata and their way of insertion, are unique and are not found in the other Genistinae studied. These characters were not described in P. tridentatum and support its delimitation as a distinct and natural taxon.

Oxidative Stress Function in Women over 40 Years of Age, Considering Their Lifestyle

Aging is dependent on biological processes that determine the aging of the organism at the cellular level. The Oxidative Stress Theory of Aging might explain some of the age-related changes in cell macromolecules. Moreover, exposome and lifestyle may also induce changes in cell damage induced by oxidative stress. The aim of the present study was to analyze the related redox changes in lymphocyte function of healthy women over 40 years old. Three groups: younger (YG: 40–49 years), middle aged (MAG: 50–59 years), and older (OG: ≥60 years) were evaluated on anthropometric variables, blood pressure, cardiovascular fitness, lifestyle habits, perceived stress, DNA damage, malondialdehyde, catalase activity, and total antioxidant capacity. Physical activity and cardiovascular fitness were significantly higher in YG and MAG as compared to the OG. Systolic blood pressure increased significantly with group age. Frequency and total amount of alcohol intake were lower in the OG and higher in the MAG. No significant differences were observed between the three groups in oxidative stress parameters. Only alcohol consumption was associated with the higher DNA FPG-sensitive sites, and only in the YG (p < 0.05). Healthy lifestyle is critical to avoiding major ailments associated with aging. This may be inferred from the lack of significant differences in the various oxidative stress parameters measured in the healthy women over the age of 40 who took part in the study. Conscious lifestyle behaviors (decrease in alcohol and smoking habits) could have impaired the expected age-related oxidative stress increase.

An extra sheath around the heterocysts of Anabaena azollae from the aquatic macrophyte Azolla filiculoides Lamarck

Abstract The fern Azolla filiculoides Lamarck (family Azollaceae) harbours a heterocystous nitrogen-fixing cyanobacterium Anabaena azollae Strasburger (Nostocales: Cyanobacteria) inside cavities on the dorsal lobes of the leaves. A new extra sheath was detected under scanning electron microscopy surrounding only the heterocysts of the cyanobiont and their chemical characterization by histochemical tests has pointed to the presence of proteins. The function of this extra sheath is unknown.

Random start local search and tabu search for a discrete lot-sizing and scheduling problem

In this paper we describe random start local search and tabu search for solving a multi-item, multi-machine discrete lot sizing and scheduling problem with sequence dependent changeover costs. We present two construction heuristics with a random component; one of them is purely random and another is based on the linear programming relaxation of the mixed integer programming model. They are used to generate initial solutions for random start local search and tabu search. We also propose two ways of exploring the neighborhoods, one based on a random subset of the neighborhood, and another based on exploring the whole neighborhood. Construction and improvement methods were combined on random start local search and tabu search, leading to a total of eight different methods. We present results of extensive computer experiments for analyzing the performance of all methods and their comparison with branch-and-bound, and conclude with some remarks on the different approaches to the problem.