High Levels Of Alpha Research Articles

Timber plantations do not homogenize soil arthropod diversity but do alter species composition

Landscape transformation for agriculture threatens global biodiversity through simplification of ecosystems. We determine whether large-scale timber plantations contribute to biotic homogenization of soil biodiversity relative to remnant natural vegetation. We examined ant and springtail alpha- and beta-diversity, and assemblage composition, among biotopes in two different climatic and soil regions in a subtropical area of South Africa. Surprisingly, we observed equally high levels of alpha- and beta-diversity in plantations (Eucalyptus and Pinus) as in natural biotopes (indigenous forest and grassland) for both taxa in both regions, except in the inland sites where ant species richness was highest in grassland. Furthermore, beta-diversity in all biotopes was mainly due to species replacement rather than nestedness. The high diversity in plantations is likely due to high environmental variation among plantation sites, likely providing diverse niche opportunities across plantations. A possible mechanism for the large proportion of shared species between natural areas and plantations is colonization of arthropods from natural areas into plantations and/or source populations surviving harvesting and tree planting and then their populations growing during long periods of tree maturation. Plantations and natural areas supported complementary assemblages, which builds on the idea that remnant natural vegetation in production landscapes is essential for conserving not only unique aboveground biodiversity, but also unique belowground biodiversity. Furthermore, timber plantations do not homogenize soil arthropod taxonomic diversity as expected. This contrasts with global trends on biodiversity response to land-use change and emphasizes that conservation principles for soil biodiversity may differ from those aimed at aboveground biodiversity.

Yellow Lamb Disease (Clostridium perfringens Type A Enterotoxemia of Sheep): A Review.

Simple SummaryYellow lamb disease is a poorly researched and understood condition that seems to affect young sheep. The disease is characterized by hemolysis and is thought to be caused by alpha toxin-producing Clostridium perfringens type A, although a definitive association with this microorganism has not been confirmed. This is due, in part, to the ubiquitous nature of C. perfringens type A, which is naturally present in the intestine of healthy sheep, a fact that complicates the diagnosis. In this review, we summarize the available information on the etiology, clinical signs, lesions, diagnosis, prevention and prophylaxis of yellow lamb disease.Yellow lamb disease is an infrequent disease in sheep for which there is scant literature, and that has been reported in the US, Australia, New Zealand, South Africa and Europe, although anecdotal evidence indicates that it may have also been diagnosed in South America. The disease is produced by some strains of Clostridium perfringens type A that produce unusually high levels of alpha- toxin. Because C. perfringens type A is ubiquitous and is found in the intestine of most clinically healthy sheep, diagnosis of yellow lamb disease is challenging and requires quantitating the amount of this microorganism present in feces and/or intestinal content. Clinically, yellow lamb disease is characterized by depression, anemia, icterus and hemoglobinuria. Occasionally, sudden death may occur. Gross findings include generalized icterus, red urine in the bladder, enlarged, pale, and friable spleen, enlarged liver with an acinar pattern, and dark, swollen kidneys. Microscopically, yellow lamb disease is characterized by centrilobular necrosis of the liver, hemoglobinuria-associated acute tubular injury, splenic congestion, pulmonary congestion and edema. Although there are no vaccines specifically designed to prevent yellow lamb disease, several vaccines against the different types of C. perfringens may afford at least some level of protection against yellow lamb disease.

Time matters: Resilience of a post-disturbance forest landscape

Present-day disturbances are transforming European forest landscapes, and their legacies determine the vulnerability and resilience of the emergent forest generation. To understand these legacy effects, we investigated the resilience of the aboveground forest biomass (Babg) to a sequence of disturbances affecting the forest in different recovery phases from the initial large-scale impact. We used the model iLand to simulate windthrows that affected 13–24% of the Babg in a Central European forest landscape. An additional wind event was simulated 20, 40, 60, or 80 years after the initial impact (i.e., sequences of two windthrows were defined). Each windthrow triggered an outbreak of bark beetles that interacted with the recovery processes. We evaluated the resistance of the Babg to and recovery after the impact. Random Forest models were used to identify factors influencing resilience. We found that Babg resistance was the lowest 20 years after the initial impact when the increased proportion of emergent wind-exposed forest edges prevailed the disturbance-dampening effect of reduced biomass levels and increased landscape heterogeneity. This forest had a remarkably high recovery rate and reached the pre-disturbance Babg within 28 years. The forest exhibited a higher resistance and a slower recovery rate in the more advanced recovery phases, reaching the pre-disturbance Babg within 60–80 years. The recovery was enhanced by higher levels of alpha and beta diversity. Under elevated air temperature, the bark beetle outbreak triggered by windthrow delayed the recovery. However, the positive effect of increased temperature on forest productivity caused the recovery rate to be higher under the warming scenario than under the reference climate.We conclude that resilience is not a static property, but its magnitude and drivers vary in time, depending on vegetation feedbacks, interactions between disturbances, and climate. Understanding these mechanisms is an essential step towards the operationalization of resilience-oriented stewardship.

Multi-taxa environmental DNA inventories reveal distinct taxonomic and functional diversity in urban tropical forest fragments

Urban expansion and associated habitat transformation drives shifts in biodiversity, with declines in taxonomic and functional diversity. Forests fragments within urban landscapes offer a number of ecosystem services, and help to maintain biodiversity and ecosystem functions. Here, we focus on a tropical forest environment, and on the soil biota. Using eDNA metabarcoding, we compare forest fragments within the city of Cayenne, French Guiana, with a neighbouring continuous undisturbed forest. We wished to determine if urban forest fragments conserve high levels of alpha and beta diversity as well as similar functional composition for plants, soil animals, fungi and bacteria. We found that alpha diversity is similar across habitats for plants and fungi, lower in urban forests for metazoans and higher for bacteria. We also found that urban forests communities differ from undisturbed forests in their taxonomic composition, with urban forests exhibiting greater turnover between fragments potentially caused by ecological drift and limited dispersal. However, their functional composition exhibited limited differences, with an enrichment of palms, arbuscular mycorrhizal fungi and bacteria and a depletion of climber plants and termites. Thus, although urban forest fragments do shelter soil biodiversity that differs from native forests, the losses of soil functions may be relatively limited. This study demonstrates the strong potential of a multi-taxa eDNA approach for rapid inventories across taxonomic kingdoms, in particular for cryptic soil diversity. It also demonstrates the key role of urban forest fragments in conserving biodiversity and ecosystem function, and points to a need for more systematic monitoring of these areas in urban management plans.

НЕЙРОФИЗИОЛОГИЧЕСКИЕ МЕХАНИЗМЫ ВОСПРИЯТИЯ РЕЧИ И ИХ ОСОБЕННОСТИ У ДЕТЕЙ В НОРМЕ И ПРИ НАРУШЕНИЯХ РАЗВИТИЯ

Neuronal synchronization, reflected in the EEG pattern, is the mechanism by which the brain integrates different types of information contained in a speech message and presented in different areas of the brain (for example, phonological, spelling, semantic and syntactic information). The process of understanding a sentence consists of two groups of interrelated cognitive operations: it begins with searching in memory for phonological, syntactic and semantic properties of words, which is followed by integrating information into a general idea of the sentence meaning. The stage of searching for words in adults results in an increase in the theta rhythm power. The stage of integrating words into a sentence results in the growth of theta, beta, and gamma rhythms. At the same time, the growth of theta rhythm is more typical for children than for adults. Higher rhythms reactivity during speech perception indicates better developed speech skills in children. Under conditions of relative relaxation, the EEG of children with a high level of speech development is characterized by a moderate power level of theta and beta rhythms and a high level of alpha and mu rhythms. It is assumed that a key role in the process of understanding speech is played by the so-called «action perception circuits», surrounding the Sylvian sulcus of the left hemisphere. The «action perception circuits» are composed of nerve cells capable of providing the speech signals perception and generation. The most important subgroup of neurons included in the «action perception circuits» are mirror neurons that are activated when performing and observing actions. The desynchronization of the EEG mu rhythm is considered as mirror neurons activation marker. In several studies, it revealed that the level of mirror neurons activation and the level of speech understanding in children are connected. It is a topic of great interest to research the mu rhythm alpha and beta components reactivity both during the production of speech and during the perception of another person speech. At present, it is becoming obvious that analyzing the EEG rhythms power changes during the speech understanding in different scenarios could be used to identify the mechanisms of the brain language network and speech disorders. The revealed patterns make it possible to propose ways of correcting the children speech development using EEG biological feedback methods.

Advanced Identification and Quantification of Pesticide Residues in Vegetables by GC-ToFMS Technique

The identification and quantification of a large range of pesticide residues (e.g. fungicides, insecticides, acaricides) in vegetables from Romania markets, in Maramures, Alba Iulia and Botosani region, was performed by gas-chromatography coupled with time-of-flight mass spectrometry (GC-ToFMS) to better assess the impact of agricultural practices that may result from `accidental` application of higher doses of treatment solutions. The ion chromatograms obtained by GC-ToFMS enabled us to easily quantify at ppb level and to record the entire spectrum at high speeds (up to 500 spectra/second) without losing of the data quality. Although, most of the pesticide residues detected were below the limits set by the law, the results highlighted concentrations that exceeded the maximum allowed for toclofos-methyl and malathion from recent treatments and still high levels of alpha- and beta-hexachlorocyclohexane (mostly in green lettuce) from the historical treatments. It was also evidenced that green lettuce accumulated more than 77% higher amount of pesticides than cucumber, green beans and tomatoes.

Real-time monitoring and regulating auditory cortex alpha activity in patients with chronic tinnitus

Objective. Low levels of alpha activity (8–13Hz) mirror a state of enhanced responsiveness, whereas high levels of alpha are a state of reduced responsiveness. Tinnitus is accompanied by reduction of alpha activity in the perisylvian regions compared to normal hearing controls. This reduction might be a key mechanism in the chain of reactions leading to tinnitus. We devised a novel spatial filter as an on-line source monitoring method, which can be used to control alpha activity in the primary auditory cortex. In addition, we designed an innovative experimental procedure to enable suppression of visual and somatosensory alpha, facilitating auditory alpha control during alpha neurofeedback. Approach. An amplitude-modulated auditory stimulation with 40 Hz modulation frequency and 1000 Hz carrier frequency specifically activates the primary auditory cortex. The topography of 40 Hz oscillation depicts the activity of the auditory cortices. We used this map as a spatial filter, which passes the activity originating from the auditory cortex. To suppress superposition of auditory alpha by somatosensory and visual alpha, we used a continuous tactile jaw-stimulation and visual stimulation protocol to suppress somatosensory alpha of regions adjacent to the auditory cortex and visual alpha for local regulation of auditory alpha activity only. Main results. This novel spatial filter for online detection of auditory alpha activity and the usage of multi-sensory stimulation facilitate the appearance of alpha activity from the auditory cortex at the sensor level. Significance. The proposed procedure can be used in an EEG-neurofeedback-treatment approach allowing online auditory alpha self-regulation training in patients with chronic tinnitus.

Changes and clinical significance of electroencephalogram in patients with acute cerebral infarction

Objective To observe the changes of electroencephalogram (EEG) and its clinical significance in patients with acute cerebral infarction. Methods From January 2017 to January 2019, 96 patients with acute cerebral infarction treated in Zhejiang Xiaoshan Hospital were randomly selected as observation group, and 96 healthy persons of the same age from the same period in our hospital were selected as control group.All the participants were given EEG examination.The values of alpha, beta, delta, theta and DTABR were compared between the two groups.The focal cerebral infarction and large area cerebral infarction in observation group were compared.The values of alpha, beta, delta, theta and DTABR of the dead patients were observed, and the factors affecting the prognosis of the patients with good prognosis and poor prognosis were observed.Logistic multivariate regression analysis was carried out with the prognosis of the patients as a strain to analyze the factors affecting the prognosis of the patients. Results The values of delta, theta and DTABR of patients in the observation group were (43.26±10.51)Hz, (29.30±9.88)Hz, (1.14±0.40), respectively, which were higher than those in the control group[(22.49±5.37)Hz, (26.42±5.73)Hz, (0.92±0.37)](t=17.243, P=0.000; t=2.471, P=0.014, P=0.014; t=3.956, P=0.000). The alpha and theta of patients with focal cerebral infarction were (15.94±5.33)Hz and (30.76±10.02)Hz, respectively, which were higher than those of patients with large cerebral infarction[(11.37±4.06)Hz and (27.55±7.75)Hz](t=6.683, P=0.000; t=2.483, P=0.014). Delta and DTABR in patients with focal cerebral infarction were (37.42±5.33)Hz and (1.03±0.52)Hz, which were lower than those of patients with massive cerebral infarction[(52.36±5.21)Hz and (1.48±0.45)Hz](t=19.640, P=0.000; t=6.412, P=0.000). There was no significant difference in beta between the two groups (P>0.05). The patients with good prognosis had higher levels of alpha and beta on the affected side[(27.18 ±9.65)Hz and (14.83±5.06)Hz] than those with poor prognosis[(14.06 ±3.94)Hz and 9.03±4.33)Hz](t=8.034, P=0.000; t=5.841, P=0.000). The delta, theta, DTABR of affected side, affected side DTABR/contralateral DTABR were (31.42±9.83)Hz, (32.19 ±8.57)Hz, (0.916±0.371)Hz, (1.051±0.246), respectively, which were lower than those of patients with poor prognosis[(40.13±14.37)Hz, (37.44±10.11)Hz, (1.331±0.712)Hz, (1.376±0.352)](t=3.529, P=0.001; t=2.739, P=0.007; t=3.728, P=0.000; t=5.329, P=0.000). Logistic multivariate regression analysis was used to analyze the prognosis of patients with acute cerebral infarction.DTABR on the affected/healthy side was the factor influencing the prognosis of patients with acute cerebral infarction. Conclusion EEG in patients with acute cerebral infarction may increase the value of delta, theta and DTABR, and decrease the value of alpha and beta.DTABR in the affected side and the contralateral side is the prognostic factor. Key words: Brain infarction; Electroencephalography; Prognosis; Risk factors; logistic models

Studying the effect of Heartfulness Meditation on Brain Activity

Long-term meditation practice is increasingly recognized for its health benefits. Heartfulness meditation represents a quickly growing set of practices that is largely unstudied. Heartfulness is unique in that it is a meditation practice that focuses on the Heart. It helps individuals to connect to themselves and find inner peace. In order to deepen ones’ meditation, the element of Yogic Energy (‘pranahuti’) is used as an aid during meditation. The purpose of this study was to determine whether consistent EEG effects of Heartfulness meditation be observed in sixty experienced Heartfulness meditators, each of whom attended 6 testing sessions. In each session, participants performed three conditions: a set of cognitive tasks, Heartfulness guided relaxation, and Heartfulness Meditation. Participants during the cognitive portion were required to answer questions that tested their logical thinking (Cognitive Reflective Test) and creative thinking skills. (Random Associative Test) The order of condition was randomly counter balanced across six sessions. It was hypothesized that Heartfulness meditation would bring increased alpha (8-12Hz) brain activity during meditation and better cognitive task scores in sessions where the tasks followed meditation. Heartfulness meditation produces a significant decrease in brain activity (as indexed by higher levels of alpha during the early stages of meditation. As the meditation progressed deep meditative state (as indexed by higher levels of delta) were observed until the end of the condition. This lead to the conclusion that Heartfulness Meditation produces a state that is clearly distinguishable from effortful problem solving.

12. Studying the effect of Heartfulness Meditation on Brain Activity

Long-term meditation practice is increasingly recognized for its health benefits. Heartfulness meditation represents a quickly growing set of practices that is largely unstudied. Heartfulness is unique in that it is a meditation practice that focuses on the Heart. It helps individuals to connect to themselves and find inner peace. In order to deepen ones’ meditation, the element of Yogic Energy (‘pranahuti’) is used as an aid during meditation. The purpose of this study was to determine whether consistent EEG effects of Heartfulness meditation be observed in sixty experienced Heartfulness meditators, each of whom attended 6 testing sessions. In each session, participants performed three conditions: a set of cognitive tasks, Heartfulness guided relaxation, and Heartfulness Meditation. Participants during the cognitive portion were required to answer questions that tested their logical thinking (Cognitive Reflective Test) and creative thinking skills. (Random Associative Test) The order of condition was randomly counter balanced across six sessions. It was hypothesized that Heartfulness meditation would bring increased alpha (8-12Hz) brain activity during meditation and better cognitive task scores in sessions where the tasks followed meditation. Heartfulness meditation produces a significant decrease in brain activity (as indexed by higher levels of alpha during the early stages of meditation. As the meditation progressed deep meditative state (as indexed by higher levels of delta) were observed until the end of the condition. This lead to the conclusion that Heartfulness Meditation produces a state that is clearly distinguishable from effortful problem solving.

Word-wide meta-analysis of Quercus forests ectomycorrhizal fungal diversity reveals southwestern Mexico as a hotspot.

Quercus is the most diverse genus of ectomycorrhizal (ECM) host plants; it is distributed in the Northern and Southern Hemispheres, from temperate to tropical regions. However, their ECM communities have been scarcely studied in comparison to those of conifers. The objectives of this study were to determine the richness of ECM fungi associated with oak forests in the Cuitzeo basin in southwestern Mexico; and to determine the level of richness, potential endemism and species similarity among ECM fungal communities associated with natural oak forests worldwide through a meta-analysis. The ITS DNA sequences of ECM root tips from 14 studies were included in the meta-analysis. In total, 1065 species of ECM fungi have been documented worldwide; however, 812 species have been only found at one site. Oak forests in Europe contain 416 species, Mexico 307, USA 285, and China 151. Species with wider distributions are Sebacinaceae sp. SH197130, Amanita subjunquillea, Cenococcum geophilum, Cortinarius decipiens, Russula hortensis, R. risigallina, R. subrubescens, Sebacinaceae sp. SH214607, Tomentella ferruginea, and T. lapida. The meta-analysis revealed (1) that Mexico is not only a hotspot for oak species but also for their ECM mycobionts. (2) There is a particularly high diversity of ECM Pezizales in oak seasonal forests from western USA to southwestern Mexico. (3) The oak forests in southwestern Mexico have the largest number of potential endemic species. (4) Globally, there is a high turnover of ECM fungal species associated with oaks, which indicates high levels of alpha and beta diversity in these communities.

Plant diversity, forest dependency, and alien plant invasions in tropical agricultural landscapes

Land-use change and intensification in tropical rainforest regions is generally linked to a loss in species diversity that especially affects forest-dependent species. Indonesia is currently the country with the highest deforestation rates worldwide with potentially devastating effects on its diverse and highly endemic flora and fauna. Here we present a comprehensive assessment of the varied effects of forest conversion and land-use intensification on vascular plant diversity across the four dominant land-use systems in the lowlands of Sumatra: rainforest, jungle rubber agroforest, rubber plantations, and oil palm plantations. We conducted plot-based species inventories in Jambi Province and assessed a total of 156,006 individuals and 1382 plant species. Forest had the highest levels of alpha, beta, and gamma diversity, followed by jungle rubber. Plant communities in oil palm plantations were characterized by a high density of herbaceous weeds, but low species numbers and low beta diversity. Species numbers were comparable in oil palm and rubber plantations, but the latter showed slightly higher beta diversity. Forest had a clearly distinct floristic composition while the floristic composition of the other systems - and especially the two plantation systems - converged. Alien species were almost completely absent from forest, but the number and relative abundance of alien species increased with increasing land-use intensity and was highest in oil palm plantations where 25% of the species and 62% of the individuals belonged to alien species. Our results represent a first quantitative baseline for how forest conversion in Southeast Asia causes loss in species richness, changes in floristic composition and vegetation structure, as well as a shift from native to alien-dominated plant communities.

Comparison of Microbial Communities Isolated from Feces of Asymptomatic Salmonella-Shedding and Non-Salmonella Shedding Dairy Cows

In the United States Salmonella enterica subsp. enterica serotypes Kentucky and Cerro are frequently isolated from asymptomatic dairy cows. However, factors that contribute to colonization of the bovine gut by these two serotypes have not been identified. To investigate associations between Salmonella status and bacterial diversity, as well as the diversity of the microbial community in the dairy cow hindgut, the bacterial and archaeal communities of fecal samples from cows on a single dairy farm were determined by high-throughput sequencing of 16S rRNA gene amplicons. Fecal grab samples were collected from two Salmonella-positive cows and two Salmonella-negative cows on five sampling dates (n = 20 cows), and 16S rRNA gene amplicons from these samples were sequenced on the Illumina MiSeq platform. A high level of alpha (within) and beta diversity (between) samples demonstrated that microbial profiles of dairy cow hindguts are quite diverse. To determine whether Salmonella presence, sampling year, or sampling date explained a significant amount of the variation in microbial diversity, we performed constrained ordination analyses (distance based RDA) on the unifrac distance matrix produced with QIIME. Results indicated that there was not a significant difference in the microbial diversity associated with Salmonella presence (P > 0.05), but there were significant differences between sampling dates and years (Pseudo-F = 2.157 to 4.385, P < 0.05). Based on these data, it appears that commensal Salmonella infections with serotypes Cerro and Kentucky in dairy cows have little or no association with changes in the abundance of major bacterial groups in the hindgut. Rather, our results indicated that temporal dynamics and other undescribed parameters associated with them were the most influential drivers of the differences in microbial diversity and community structure in the dairy cow hindgut.

Assessing risks to ecosystems within biodiversity hotspots: a case study from southwestern Australia

AbstractThe south west of Western Australia is a global biodiversity hotspot that contains a suite of highly restricted and threatened ecosystems. In common with some other global hotspots, this region has high levels of alpha, beta and gamma diversity characterized by local endemism and spatial turnover of species. The region therefore includes a suite of highly localized species assemblages in complex mosaics across the landscape. Such landscapes pose particular challenges for assessing risks to biodiversity because the status of the most extensive species assemblages within broad scale assessment units tends to mask the status of those that are most restricted. Hence, risk assessments at different thematic scales may sometimes reveal different outcomes and salient threats. We examined these expectations by applying the IUCN Red List criteria for ecosystems at a fine thematic scale to assess risks to shrublands on southern Swan Coastal Plain ironstones, one of the most restricted ecosystems in the region, distinguished by its component suite of endemic flora. The ecosystem was found to be critically endangered due to its declining distribution and restricted current extent in combination with threats, particularly weed invasion. These outcomes suggest two scaling effects when a broader suite of assemblages in the region are considered; the perceived levels of risk may be less extreme; and the main threatening processes that influence risk assessment outcomes rank differently in importance. Both effects are critical to future management to promote persistence of ecosystems, as the priorities and actions will vary between local and regional scales, as will their conservation outcomes. In this case the major needs are to limit vegetation clearing and water extraction and mitigate the invasion of weeds and impacts of disease. The relative emphasis on these strategies varies between local and regional scales.

Susceptibility to chlorpyrifos in pyrethroid-resistant populations of Aedes aegypti (Diptera: Culicidae) from Mexico.

Resistance to the organophosphate insecticide chlorpyrifos was evaluated in females from six strains of Aedes aegypti (L.) that expressed high levels of cross-resistance to eight pyrethroid insecticides. Relative to LC50 and LC90 at 24 h of a susceptible New Orleans (NO) strain, three strains were highly resistant to chlorpyrifos (Coatzacoalcos, resistance ratio [RRLC90 = 11.97; Pozarica, RRLC90 = 12.98; and Cosoleacaque, RRLC50 = 13.94 and RRLC90 = 17.57), one strain was moderately resistant (Veracruz, RRLC90 = 5.92), and two strains were susceptible (Tantoyuca and Martinez de la Torre, RRLC50 and RRLC90 < 5) in bottle bioassays according to Centers for Disease Control and Prevention. Furthermore, high levels of alpha- or beta-esterase activity in the sample populations were correlated with resistance, suggesting that esterase activity may be a mechanism causing the development of organophosphate resistance in these populations. Overall, the populations in this study were less resistant to chlorpyrifos than to pyrethroids. Rotation of insecticides used in control activities is recommended to delay or minimize the occurrence of high levels of resistance to chlorpyrifos among local populations of Ae. aegypti. The diagnostic dose and diagnostic time for chlorpyrifos resistance monitoring was determined to be 85 microg per bottle and 30 min, respectively, using the susceptible NO strain.

Phylogenetic Diversities and Community Structure of Members of the Extremely Halophilic Archaea (Order Halobacteriales) in Multiple Saline Sediment Habitats

We investigated the phylogenetic diversity and community structure of members of the halophilic Archaea (order Halobacteriales) in five distinct sediment habitats that experience various levels of salinity and salinity fluctuations (sediments from Great Salt Plains and Zodletone Spring in Oklahoma, mangrove tree sediments in Puerto Rico, sediment underneath salt heaps in a salt-processing plant, and sediments from the Great Salt Lake northern arm) using Halobacteriales-specific 16S rRNA gene primers. Extremely diverse Halobacteriales communities were encountered in all habitats, with 27 (Zodletone) to 37 (mangrove) different genera identified per sample, out of the currently described 38 Halobacteriales genera. With the exception of Zodletone Spring, where the prevalent geochemical conditions are extremely inhospitable to Halobacteriales survival, habitats with fluctuating salinity levels were more diverse than permanently saline habitats. Sequences affiliated with the recently described genera Halogranum, Halolamina, Haloplanus, Halosarcina, and Halorientalis, in addition to the genera Halorubrum, Haloferax, and Halobacterium, were among the most abundant and ubiquitous genera, suggesting a wide distribution of these poorly studied genera in saline sediments. The Halobacteriales sediment communities analyzed in this study were more diverse than and completely distinct from communities from typical hypersaline water bodies. Finally, sequences unaffiliated with currently described genera represented a small fraction of the total Halobacteriales communities, ranging between 2.5% (Zodletone) to 7.0% (mangrove and Great Salt Lake). However, these novel sequences were characterized by remarkably high levels of alpha and beta diversities, suggesting the presence of an enormous, yet-untapped supply of novel Halobacteriales genera within the rare biosphere of various saline ecosystems.

The CAAT‐binding transcription factor 1/nuclear factor 1 binding site is important in β‐myosin heavy chain antisense promoter regulation in rats

The rat heart expresses two myosin heavy chain (MHC) isoforms, beta and alpha; these genes are arranged in tandem on the same chromosome. We have reported that an antisense (AS) beta RNA starts in the intergenic (IG) region between beta and alpha genes and extends to overlap the beta gene. We propose that in adult rats, both the alpha sense and IG betaAS RNA expression are activated by an IG bidirectional promoter and that the transcription of betaAS RNA interferes with the sense beta, resulting in low levels of beta mRNA and high levels of alpha, a phenotype seen in a typical rat heart. A previous report examined the activity of the betaAS promoter and showed that a 559 bp fragment of the betaAS promoter (-2285 to -1726; relative to alphaMHC gene start site) injected into rat ventricle was activated in control heart, and decreased significantly in response to hypothyroidism (propylthiouracil induced) and diabetes (streptozotocin induced) and increased in hyperthyroid rats (T(3) induced), similar in pattern to the endogenous betaAS RNA. In the present paper, we demonstrate with electrophoretic mobility shift analyses that ventricular nuclear proteins are interacting with a nuclear factor 1/CAAT-binding transcription factor 1 (NF1/CTF1) binding site, and a supershift assay indicates that the protein binding at this site is antigenetically related to the CTF1/NF1 factor. Moreover, a mutation of the CTF1/NF1 site within the 559 bp promoter region nearly abolished promoter activity in vivo in control, STZ- and PTU-treated rats. Based on these findings, we conclude that the NF1 site is critical to betaAS promoter regulation.

Caveolae Contribute to the Apoptosis Resistance Induced by the α1A-Adrenoceptor in Androgen-Independent Prostate Cancer Cells

BackgroundDuring androgen ablation prostate cancer cells' growth and survival become independent of normal regulatory mechanisms. These androgen-independent cells acquire the remarkable ability to adapt to the surrounding microenvironment whose factors, such as neurotransmitters, influence their survival. Although findings are becoming evident about the expression of α1A-adrenoceptors in prostate cancer epithelial cells, their exact functional role in androgen-independent cells has yet to be established. Previous work has demonstrated that membrane lipid rafts associated with key signalling proteins mediate growth and survival signalling pathways in prostate cancer cells.Methodology/Principal FindingsIn order to analyze the membrane topology of the α1A-adrenoceptor we explored its presence by a biochemical approach in purified detergent resistant membrane fractions of the androgen-independent prostate cancer cell line DU145. Electron microscopy observations demonstrated the colocalisation of the α1A-adrenoceptor with caveolin-1, the major protein component of caveolae. In addition, we showed that agonist stimulation of the α1A-adrenoceptor induced resistance to thapsigargin-induced apoptosis and that caveolin-1 was necessary for this process. Further, immunohistofluorescence revealed the relation between high levels of α1A-adrenoceptor and caveolin-1 expression with advanced stage prostate cancer. We also show by immunoblotting that the TG-induced apoptosis resistance described in DU145 cells is mediated by extracellular signal-regulated kinases (ERK).Conclusions/SignificanceIn conclusion, we propose that α1A-adrenoceptor stimulation in androgen-independent prostate cancer cells via caveolae constitutes one of the mechanisms contributing to their protection from TG-induced apoptosis.

Autoradiographic characterization of α2C‐adrenoceptors in the human striatum

Indirect experimental evidence suggests that drugs acting on the alpha(2C)-adrenoceptor could be useful in the treatment of neuropsychiatric disorders such as depression and schizophrenia. In rodent brain, the highest levels of alpha(2C)-adrenoceptors are found in the striatum, with lower levels in cerebral cortex and hippocampus. In human brain, because of the poor subtype-selectivity of the available alpha(2)-adrenoceptor ligands, the localization of alpha(2C)-adrenoceptors has remained unknown. Recently, a selective alpha(2C)-adrenoceptor antagonist, JP-1302, was characterized, and to assess the presence of alpha(2C)-adrenoceptors in human brain, we performed competition binding in vitro receptor autoradiography with JP-1302 and the alpha(2)-adrenoceptor subtype nonselective antagonist [ethyl-(3)H]RS79948-197 on rat and human postmortem brain sections. In striatum of both species, JP-1302 vs. [ethyl-(3)H]RS79948-197 competition binding was biphasic, identifying high- and low-affinity binding sites, whereas in cortex and cerebellum, only low-affinity binding sites were detected. The results indicate that a significant portion of the alpha(2)-adrenoceptors in striatum is of the alpha(2C) subtype, whereas non-alpha(2C)-adreocneptors predominate in cortex and cerebellum. Because the alpha(2C)-adrenoceptor subtype distribution pattern appears to be conserved between rodents and humans, results obtained from studies on the role of the alpha(2C)-adrenoceptor in rodent models of neuropsychiatric disorders may be relevant also for human diseases.

Vers la caractérisation des cellules souches de la glande mammaire murine adulte

The postnatal mammary morphogenesis comprises two steps, first, formation of a system of branching ducts at puberty and second, alveologenesis during pregnancy. The mammary epithelium is organized as a bilayer, composed of two cellular types, basal myoepithelial and luminal epithelial. The remarkable regenerative properties revealed in serial transplantation experiments suggest that the adult mammary epithelium harbors stem cells. Various strategies including analysis of DNA label-retaining cells, transgenic approach, and in vivo transplantation assay, have been used to isolate and characterize murine mammary stem and progenitor cells. Their molecular characteristics remain to be defined precisely but notable progress have been already made in the enrichment and identification of these cells. Current studies favor the hypothesis of a basal-type mammary stem cells expressing high levels of alpha 6, beta1 and beta 3 integrin chains, the major receptors of extracellular matrix proteins. Luminal-type progenitors may participate in the establishment of the bilayered alveolar epithelium during pregnancy.