Natural rock roughness as a key parameter for optimizing seedling adhesion and restoration of the seagrass Posidonia oceanica in its native environment

Seagrasses provide various ecosystem functions in coastal areas of the world. In the Mediterranean Sea, Posidonia oceanica is an endemic species threatened by several activities despite being protected by national and international laws. Currently, several transplanting initiatives have been carried out using different methods, among which those including seeds and seedlings are considered the most ecological and low-cost ones. Beach-cast fruits and seeds can be found in spring and their appearance can easily be reported, through a citizen science approach, by the community. One of the obstacles in using these methods is identifying the best substrate in which to place P. oceanica seeds to facilitate root adhesion of the seedlings prior to their transplantation into the sea. In the present study, we analyzed, using a 3D surface optical microscope, the roughness of natural rocks to identify the availability of specific roughness ranges suitable for adhesion and root anchoring of P. oceanica seedlings. Conventional roughness parameters and roughness power spectral density were calculated for the inner and outer surfaces of 9 different rock samples. Among the rock samples examined, the calcarenitic ones and in particular marsala calcarenite, due to the presence of the “ideal roughness for seedlings” can be considered one of the best consolidated substrates to be used for the construction of ad hoc devices on which plantlet of P. oceanica can grow for the purpose of restoration.     

Relationships between short and fast brain timescales

Brain electric activity exhibits two important features: oscillations with different timescales, characterized by diverse functional and psychological outcomes, and a temporal power law distribution. In order to further investigate the relationships between low- and high- frequency spikes in the brain, we used a variant of the Borsuk–Ulam theorem which states that, when we assess the nervous activity as embedded in a sphere equipped with a fractal dimension, we achieve two antipodal points with similar features (the slow and fast, scale-free oscillations). We demonstrate that slow and fast nervous oscillations mirror each other over time via a sinusoid relationship and provide, through the Bloch theorem from solid-state physics, the possible equation which links the two timescale activities. We show that, based on topological findings, nervous activities occurring in micro-levels are projected to single activities at meso- and macro-levels. This means that brain functions assessed at the higher scale of the whole brain necessarily display a counterpart in the lower ones, and vice versa. Our topological approach makes it possible to assess brain functions both based on entropy, and in the general terms of particle trajectories taking place on donut-like manifolds. Condensed brain activities might give rise to ideas and concepts by combination of different functional and anatomical levels. Furthermore, cognitive phenomena, as well as social activity can be described by the laws of quantum mechanics; memories and decisions exhibit holographic organization. In physics, the term duality refers to a case where two seemingly different systems turn out to be equivalent. This topological duality holds for all the types of spatio-temporal brain activities, independent of their inter- and intra-level relationships, strength, magnitude and boundaries, allowing us to connect the physiological manifestations of consciousness to the electric activities of the brain.     

Neurosecretory cells in the optic lobes of the brain and activity rhythms in Lycosa tarentula (Araneae: Lycosidae)

Several paired groups of neurosecretory cells (NS) were identified in the dorsal cortical neurons of the optic lobes of the brain of Lycosa tarentula (Araneae). Two large bottle-shaped cells (NS A1, A2) and a cluster of ca. 20 smaller cells (NS B) were found between the lamina and medulla of the anterior median eyes (AM). The forward oriented bundles of NS B axons run alongside large fibres linked to the synaptic zones of the indirect eyes. In front of the arcuate body, an islet of about 10 fusiform cells (NS C1) sends short axons close to the internal cortical border. Other large cells (NS C2, C3) are found from the medulla of the AM to the anterior border of the central body. Their long axons end deeply in the brain neuropil. NS B and C1 function synchronously. The secretory cycles of NS A1 and A2 seem to be in opposition. The activity of these three types of NS depends on the phase of the day. Anatomical relationships of NS A, B and C1 with visual afferent/efferent fibres via synaptic buttons indicate a role of these cells in the modulation of circadian rhythms of visual and locomotor activity. On the other hand, NS C2 and C3, the functioning of which is not synchronous, might be involved in the modulation or control of the elementary movements of L. tarentula when active or at rest.     

Use of kenaf fibre in the elaboration of specific substrates for Pleurotus ostreatus (Jacq. ex Fr.) Kummer cultivation

In this study, the viability of the kenaf fibre use, alone or combined with cereal straw, vine shoots and olive mill dried waste, in the elaboration of specific substrates for the cultivation of Pleurotus ostreatus (Jacq. ex Fr.) Kummer, second mushroom in importance cultivated in Spain, is described. Furthermore, three different methods of preparation of the substrate have been considered in order to obtain selectivity for the growth and later fruiting of Pleurotus sporophore. As for the production parameters, the best results have been provided by the substrates that combined kenaf with straw and with vine shoots, being unfavourable the substrates based in just kenaf or combined with olive mill dried waste. As for the treatment applied to the materials, the immersion in water alone and subsequent pasteurization and thermophilic conditioning, together with the semi-anaerobic fermentation, has been favoured in front of the immersion in water with fungicide and later pasteurization.     

Phylogenetic analysis of the archaeal community in an alkaline-saline soil of the former lake Texcoco (Mexico)

The soil of the former lake Texcoco is an extreme environment localized in the valley of Mexico City, Mexico. It is highly saline and alkaline, where Na⁺, Cl⁻, HCO₃⁻ and CO₃²⁻ are the predominant ions, with a pH ranging from 9.8 to 11.7 and electrolytic conductivities in saturation extracts from 22 to 150 dS m⁻¹. Metagenomic DNA from the archaeal community was extracted directly from soil and used as template to amplify 16S ribosomal gene by PCR. PCR products were used to construct gene libraries. The ribosomal library showed that the archaeal diversity included Natronococcus sp., Natronolimnobius sp., Natronobacterium sp., Natrinema sp., Natronomonas sp., Halovivax sp., “Halalkalicoccus jeotgali” and novel clades within the family of Halobacteriaceae. Four clones could not be classified. It was found that the archaeal diversity in an alkaline-saline soil of the former lake Texcoco, Mexico, was low, but showed yet uncharacterized and unclassified species. César Valenzuela-Encinas and Isabel Neria-González contributed equally to this publication.     

Targeting telomeres to enforce cancer cells to senesce

The telomeres protect the end of chromosomes from being recognized and processed as an accidental double stranded break. In human somatic cells, telomeres shorten progressively with every round of DNA replication, leading to dysfunctional telomeres that trigger cellular senescence or apoptosis depending on the cell type. This telomere erosion appears to play a role in cell renewal, ageing and cancer. Two recent studies demonstrated in mouse that eroded telomeres in cancer cells blocked for apoptosis limit cancer formation by triggering senescence. These results suggest that provoking senescence may provide a way to cure cancer and point to new therapeutical strategies targeting specific telomeric functions. Nevertheless, an important question remains unanswered: does replicative senescence limit tumor formation in human?     

Growth of the Pacific jack Caranx caninus (Pisces: Carangidae) from the coast of Colima, México

The Pacific jack Caranx caninus is a common species fished by artisanal fishermen off the coast of Colima, México. During 2002, monthly samples of morphometric data and otoliths were taken to determine age and growth. Seven age groups were identified. The highest growth, 14.4 cm, takes place during the first year of life. During the second year, C caninus grows 11.76 cm; the third year 9.61 cm; the fourth 7.85 cm; the fifth 6.41 cm and sixth year 5.24 cm. The constants of von Bertalanffy's growth equation were: L(infinity) = 83.26 cm, W(infinity) = 18.138 g, K = 0.202, t(0) = -0.283 and A(0.95) = 15 years. Growth curves of other species of the same genus were calculated in order to compare them with the one obtained in the present work. The gonadosomatic index presented higher values during November and May. The periods of more intensive feeding are from August to February.     

Murine interferon-gamma inducible protein-10 (IP-10) secreted by Lactococcus lactis chemo-attracts human CD3+ lymphocytes

Chemokines are members of the super family of cytokines necessary for leukocyte recruitment in tissues and lymphoid organs. The interferon-gamma inducible protein-10 (IP-10) chemo-attracts CXCR3-expressing cells, such as activated T lymphocytes and monocytes. We have genetically engineered a strain of Lactococcus lactis to secrete a biologically active murine IP-10 that interacts with human CXCR3, its homolog receptor, and chemo-attracts human CD3+ T lymphocytes.