Evidence That Calls-Based and Mobility Networks Are Isomorphic

Social relations involve both face-to-face interaction as well as telecommunications. We can observe the geography of phone calls and of the mobility of cell phones in space. These two phenomena can be described as networks of connections between different points in space. We use a dataset that includes billions of phone calls made in Colombia during a six-month period. We draw the two networks and find that the call-based network resembles a higher order aggregation of the mobility network and that both are isomorphic except for a higher spatial decay coefficient of the mobility network relative to the call-based network: when we discount distance effects on the call connections with the same decay observed for mobility connections, the two networks are virtually indistinguishable.     

'Locked-on' and 'locked-off' signal transduction mutations in the periplasmic domain of the Escherichia coli NarQ and NarX sensors affect nitrate- and nitrite-dependent regulation by NarL and NarP

The Escherichia coli NarX, NarQ, NarL and NarP proteins comprise a two-component regulatory system that controls the expression of many anaerobic electron-transport and fermentation-related genes in response to nitrate and nitrite. Either of the two sensor-transmitter proteins, NarX and NarQ, can activate the response-regulator proteins, NarL and NarP, which in turn are able to bind at their respective DNA regulatory sites to modulate gene expression. NarX contains a conserved 17 amino acid sequence, designated the ‘P-box’ element, that is essential for nitrate sensing. In this study we characterize narQ mutants that also confer altered nitrate control of NarL-dependent nitrate reductase (narGHJI ) and fumarate reductase (frdABCD) gene expression. While some narQ mutations cause the constitutive activation or repression of reporter-gene expression even when the cells are grown in the absence of the nitrate signal (i.e. a ‘locked-on’ phenotype), other mutations abolish nitrate-dependent control (i.e. a ‘locked-off’ phenotype). Interestingly the narQ (A42→T) and narQ (R50→Q) mutations along with the analogous narX18 (A46→T) and narX902 (R54→E) mutations also confer a ‘locked-on’ or a ‘locked-off’ phenotype in response to nitrite, the second environmental signal detected by NarQ and NarX. Furthermore, these narQ and narX mutations also affect NarP-dependent gene regulation of nitrite reductase (nrfABCDEFG) and aeg-46.5 gene expression in response to nitrite. We therefore propose that the NarQ sensor-transmitter protein also detects nitrate and nitrite in the periplasmic space via its periplasmic domain. A signal transduction model, which we previously proposed for NarX, is now extended to NarQ, in which a nitrate- or nitrite-detection event in the periplasmic region of the cell is followed by a signal transduction event through the inner membrane to the cytoplasmic domain of NarQ and NarX proteins to modulate their protein kinase/phosphatase activities.     

Early cretaceous serpulid limestones: Chachao formation,Neuquen basin,Argentina

Summary Colonial serpulids (Sarcinella) are common within some limestones of the lower Chachao Formation (Valanginian) near Malargüe city at the northern border of the Neuquem basin, Argentina. The shallowing-upwards sequence is characterized by low-energetic micritic carbonates. The serpulid limestones mark the transition from a carbonate ramp stage to a platform stage.     

The economics of monocropping and intercropping by smallholders: The case of coconuts in Indonesia

This article contains a comparison of the profits of cultivating modern and traditional varieties of coconuts as a monocrop and as an intercrop, in ideal and in average growing conditions, with good and with average management. We carry out the analysis from a private (financial) and from a national (economic) perspective. The results show that intercropping generates more income than monocropping. In the conclusion we discuss why development organizations and Third World countries encourage monocropping.     

A short-range endemic species from south-eastern Atlantic Rain Forest shows deep signature of historical events: phylogeography of harvestmen Acutisoma longipes (Arachnida: Opiliones)

The Brazilian Atlantic Rain Forest is amongst the most diverse biomes in the world, but the processes that shaped its biodiversity are still poorly understood. We used one mitochondrial and two nuclear markers to evaluate the phylogeographic patterns of the endemic harvestman Acutisoma longipes and its closely related species to investigate the biogeographic history of this biome. The results showed low intrapopulation diversity and strong population structure, suggesting poor dispersion amongst locations. Phylogenetic analyses pointed to three main mitochondrial lineages congruent with the geomorphology of the south-eastern region of Brazil (Serra do Mar, Serra da Mantiqueira, and interior plateau). These older divergences occurred in the middle-Neogene, suggesting that events in this period drove the diversification of the species, but Quaternary events also affected the populations locally. We detected some congruence between A. longipes demographic patterns and the areas of endemism delimited for harvestmen, suggesting that some regions of the distribution could have been more stable in the past (especially in Serra da Mantiqueira). Our findings corroborate that harvestmen are a suitable group for the study of ancient biogeographic events in the Atlantic Rain Forest, even at small-scale ranges. Acutisoma hamatum is here considered as a new junior synonym of A. longipes.     

Cell death induction in Giardia lamblia: Effect of beta-lapachone and starvation

Giardia lamblia is a protozoan that parasitizes the small intestine of vertebrates. It is a cause of intestinal infection and diarrhea and infects millions of people worldwide. This protozoan presents many characteristics common to eukaryotic cells but it lacks organelles found in most eukaryotes (e.g., peroxisomes, typical Golgi complex and mitochondria). Also it presents mitosomes, a relic organelle that appears to be a mitochondrial remnant. Cell death in Giardia was induced by the drug β-Lapachone and by starvation. Giardia behavior was followed by scanning, transmission and fluorescence microscopy, quantification of cell metabolism using MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide), changes in lipid rafts, using DiIC₁₆ and cholera toxin. Cell shrinkage, chromatin condensation, membrane blebbing and vacuolization provided ultrastructural evidence of apoptosis, whereas the myelinic figures in large vacuoles and LC-3 staining suggested an autophagic process. Lipids rafts were altered by drug treatment and co-localized with regions containing membrane blebbing. The treatment with β-Lap induced encystation. A search for sequence similarities in databases and protein alignments was carried out. Although Giardia is an amitochondrial organism, it presented some autophagic-like cell death characteristics and several, but not all, apoptotic characteristics, induced by β-Lapachone and starvation.     

Bringing Dicynodonts Back to Life: Paleobiology and Anatomy of a New Emydopoid Genus from the Upper Permian of Mozambique

Dicynodontia represent the most diverse tetrapod group during the Late Permian. They survived the Permo-Triassic extinction and are central to understanding Permo-Triassic terrestrial ecosystems. Although extensively studied, several aspects of dicynodont paleobiology such as, neuroanatomy, inner ear morphology and internal cranial anatomy remain obscure. Here we describe a new dicynodont (Therapsida, Anomodontia) from northern Mozambique: Niassodon mfumukasi gen. et sp. nov. The holotype ML1620 was collected from the Late Permian K5 formation, Metangula Graben, Niassa Province northern Mozambique, an almost completely unexplored basin and country for vertebrate paleontology. Synchrotron radiation based micro-computed tomography (SRµCT), combined with a phylogenetic analysis, demonstrates a set of characters shared with Emydopoidea. All individual bones were digitally segmented allowing a 3D visualization of each element. In addition, we reconstructed the osseous labyrinth, endocast, cranial nerves and vasculature. The brain is narrow and the cerebellum is broader than the forebrain, resembling the conservative, “reptilian-grade” morphology of other non-mammalian therapsids, but the enlarged paraflocculi occupy the same relative volume as in birds. The orientation of the horizontal semicircular canals indicates a slightly more dorsally tilted head posture than previously assumed in other dicynodonts. In addition, synchrotron data shows a secondary center of ossification in the femur. Thus ML1620 represents, to our knowledge, the oldest fossil evidence of a secondary center of ossification, pushing back the evolutionary origins of this feature. The fact that the specimen represents a new species indicates that the Late Permian tetrapod fauna of east Africa is still incompletely known.     

A Novel Immunomodulatory Hemocyanin from the Limpet Fissurella latimarginata Promotes Potent Anti-Tumor Activity in Melanoma

Hemocyanins, the huge oxygen-transporting glycoproteins of some mollusks, are used as immunomodulatory proteins with proven anti-cancer properties. The biodiversity of hemocyanins has promoted interest in identifying new anti-cancer candidates with improved immunological properties. Hemocyanins promote Th1 responses without known side effects, which make them ideal for long-term sustained treatment of cancer. In this study, we evaluated a novel hemocyanin from the limpet/gastropod Fissurella latimarginata (FLH). This protein has the typical hollow, cylindrical structure of other known hemocyanins, such as the keyhole limpet hemocyanin (KLH) and the Concholepas hemocyanin (CCH). FLH, like the KLH isoforms, is composed of a single type of polypeptide with exposed N- and O-linked oligosaccharides. However, its immunogenicity was significantly greater than that of KLH and CCH, as FLH induced a stronger humoral immune response and had more potent anti-tumor activity, delaying tumor growth and increasing the survival of mice challenged with B16F10 melanoma cells, in prophylactic and therapeutic settings. Additionally, FLH-treated mice demonstrated increased IFN-γ production and higher numbers of tumor-infiltrating CD4⁺ lymphocytes. Furthermore, in vitro assays demonstrated that FLH, but not CCH or KLH, stimulated the rapid production of pro-inflammatory cytokines (IL-6, IL-12, IL-23 and TNF-α) by dendritic cells, triggering a pro-inflammatory milieu that may explain its enhanced immunological activity. Moreover, this effect was abolished when deglycosylated FLH was used, suggesting that carbohydrates play a crucial role in the innate immune recognition of this protein. Altogether, our data demonstrate that FLH possesses increased anti-tumor activity in part because it activates a more potent innate immune response in comparison to other known hemocyanins. In conclusion, FLH is a potential new marine adjuvant for immunization and possible cancer immunotherapy.     

Reduced Serum Levels of Neuron Specific Enolase (NSE) in Drug-Naïve Subjects with Major Depression and Bipolar Disorder

Several biological factors have been recently related with major depression and bipolar disorder. The aim of our paper was to investigate the peripheral levels of the protein neuronal specific enolase (NSE), a putative marker of neuronal damage, comparing patients with major depressive disorder and bipolar disorder to control subjects. This is a case–control study nested in a cross-sectional population-based survey. Psychopathology screen was performed using the Mini-International Neuropsychiatric Interview 5.0 and blood samples were collected from 108 young adults. Three groups were selected, 36 healthy controls, 36 subjects with major depression disorder and 36 subjects with bipolar disorder. Serum levels of NSE significantly decreased (p = 0.002) in major depression disorder (2.19 ± 1.78 ng/mL) and bipolar disorder subjects (2.53 ± 2.61 ng/mL) compared to the control group (3.55 ± 2.19 ng/mL). In conclusion, peripheral neuronal specific enolase may be a useful marker drug-naïve major depression disorder and bipolar disorder, but its pathophysiological significance and response to treatment should be further investigated.