Transcriptional landscape of Aspergillus niger at breaking of conidial dormancy revealed by RNA-sequencing

Background Genome-wide analysis was performed to assess the transcriptional landscape of germinating A. niger conidia using both next generation RNA-sequencing and GeneChips. The metabolism of storage compounds during conidial germination was also examined and compared to the transcript levels from associated genes. Results The transcriptome of dormant conidia was shown to be highly differentiated from that of germinating conidia and major changes in response to environmental shift occurred within the first hour of germination. The breaking of dormancy was associated with increased transcript levels of genes involved in the biosynthesis of proteins, RNA turnover and respiratory metabolism. Increased transcript levels of genes involved in metabolism of nitrate at the onset of germination implies its use as a source of nitrogen. The transcriptome of dormant conidia contained a significant component of antisense transcripts that changed during germination. Conclusion Dormant conidia contained transcripts of genes involved in fermentation, gluconeogenesis and the glyoxylate cycle. The presence of such transcripts in dormant conidia may indicate the generation of energy from non-carbohydrate substrates during starvation-induced conidiation or for maintenance purposes during dormancy. The immediate onset of metabolism of internal storage compounds after the onset of germination, and the presence of transcripts of relevant genes, suggest that conidia are primed for the onset of germination. For some genes, antisense transcription is regulated in the transition from resting conidia to fully active germinants

Modernizing persistence–bioaccumulation–toxicity (PBT) assessment with high throughput animal-free methods

The assessment of persistence (P), bioaccumulation (B), and toxicity (T) of a chemical is a crucial first step at ensuring chemical safety and is a cornerstone of the European Union’s chemicals regulation REACH (Registration, Evaluation, Authorization, and Restriction of Chemicals). Existing methods for PBT assessment are overly complex and cumbersome, have produced incorrect conclusions, and rely heavily on animal-intensive testing. We explore how new-approach methodologies (NAMs) can overcome the limitations of current PBT assessment. We propose two innovative hazard indicators, termed cumulative toxicity equivalents (CTE) and persistent toxicity equivalents (PTE). Together they are intended to replace existing PBT indicators and can also accommodate the emerging concept of PMT (where M stands for mobility). The proposed “toxicity equivalents” can be measured with high throughput in vitro bioassays. CTE refers to the toxic effects measured directly in any given sample, including single chemicals, substitution products, or mixtures. PTE is the equivalent measure of cumulative toxicity equivalents measured after simulated environmental degradation of the sample. With an appropriate panel of animal-free or alternative in vitro bioassays, CTE and PTE comprise key environmental and human health hazard indicators. CTE and PTE do not require analytical identification of transformation products and mixture components but instead prompt two key questions: is the chemical or mixture toxic, and is this toxicity persistent or can it be attenuated by environmental degradation? Taken together, the proposed hazard indicators CTE and PTE have the potential to integrate P, B/M and T assessment into one high-throughput experimental workflow that sidesteps the need for analytical measurements and will support the Chemicals Strategy for Sustainability of the European Union

Modernizing persistence–bioaccumulation–toxicity (PBT) assessment with high throughput animal-free methods

The assessment of persistence (P), bioaccumulation (B), and toxicity (T) of a chemical is a crucial first step at ensuring chemical safety and is a cornerstone of the European Union’s chemicals regulation REACH (Registration, Evaluation, Authorization, and Restriction of Chemicals). Existing methods for PBT assessment are overly complex and cumbersome, have produced incorrect conclusions, and rely heavily on animal-intensive testing. We explore how new-approach methodologies (NAMs) can overcome the limitations of current PBT assessment. We propose two innovative hazard indicators, termed cumulative toxicity equivalents (CTE) and persistent toxicity equivalents (PTE). Together they are intended to replace existing PBT indicators and can also accommodate the emerging concept of PMT (where M stands for mobility). The proposed “toxicity equivalents” can be measured with high throughput in vitro bioassays. CTE refers to the toxic effects measured directly in any given sample, including single chemicals, substitution products, or mixtures. PTE is the equivalent measure of cumulative toxicity equivalents measured after simulated environmental degradation of the sample. With an appropriate panel of animal-free or alternative in vitro bioassays, CTE and PTE comprise key environmental and human health hazard indicators. CTE and PTE do not require analytical identification of transformation products and mixture components but instead prompt two key questions: is the chemical or mixture toxic, and is this toxicity persistent or can it be attenuated by environmental degradation? Taken together, the proposed hazard indicators CTE and PTE have the potential to integrate P, B/M and T assessment into one high-throughput experimental workflow that sidesteps the need for analytical measurements and will support the Chemicals Strategy for Sustainability of the European Union.ISSN:0340-5761ISSN:1432-073

Host dispersal shapes the population structure of a tick-borne bacterial pathogen

Birds are hosts for several zoonotic pathogens. Because of their high mobility, especially of longdistance migrants, birds can disperse these pathogens, affecting their distribution and phylogeography. We focused on Borrelia burgdorferi sensu lato, which includes the causative agents of Lyme borreliosis, as an example for tick-borne pathogens, to address the role of birds as propagation hosts of zoonotic agents at a large geographical scale. We collected ticks from passerine birds in 11 European countries. B. burgdorferi s.l. prevalence in Ixodes spp. was 37% and increased with latitude. The fieldfare Turdus pilaris and the blackbird T. merula carried ticks with the highest Borrelia prevalence (92 and 58%, respectively), whereas robin Erithacus rubecula ticks were the least infected (3.8%). Borrelia garinii was the most prevalent genospecies (61%), followed by B. valaisiana (24%), B. afzelii (9%), B. turdi (5%) and B. lusitaniae (0.5%). A novel Borrelia genospecies "Candidatus Borrelia aligera" was also detected. Multilocus sequence typing (MLST) analysis of B. garinii isolates together with the global collection of B. garinii genotypes obtained from the Borrelia MLST public database revealed that: (a) there was little overlap among genotypes from different continents, (b) there was no geographical structuring within Europe, and (c) there was no evident association pattern detectable among B. garinii genotypes from ticks feeding on birds, questing ticks or human isolates. These findings strengthen the hypothesis that the population structure and evolutionary biology of tick-borne pathogens are shaped by their host associations and the movement patterns of these hosts.Peer reviewe

La Prospección de placeres del oro y otros minerales densos

[eng] Alluvial prospecting is the most widely used method in heavy mineral exploration. Heavy minerals are resistant to meteoric agents. Economically, the most important heavy minerals are: precious metals (gold, silver and platinum group minerals), gems (diamonds, rubies, sapphires, emeralds, etc), the tin base metal group (cassiterite), technologic metals such as titanium (ilmenite and rutile), tungsten (wolframite and scheelite), zirconium (zircon) and the rare earths. The most usual techniques used in alluvial prospecting and the different criteria employed in exploration, mineral benefit and evaluation of alluvial ore deposits known as placers are presented.[cat] La prospecció al.luvionar es un mètode excepcional per la recerca de minerals de interès econòmic, com los minerals densos d'elevada resistència física i química. Entre ells son d' interès els metalls preciosos (or, plata i platí), gemmes (diamant, rubí, zèfirs, maragdes, aigua-marina, etc.), metalls de base com l'estany (cassiterites), minerals tecnològics com el titani (ilmenites i rutils), wolfram (volframita i scheelita), zirconi (zircó), de terres rares (monacites), etc.. En aquest text, és presenten las tècniques mas usuals en Prospecció al.luvionar com la batea, així com els distints criteris a seguir per dur a termini una prospecció, un benefici i una avaluació dels seus jaciments que es coneixen com ¿placeres¿.[spa] La prospección aluvionar es un método excepcional para la búsqueda de minerales de interés económico, como los minerales densos de elevada resistencia físico-química. Entre ellos son de interés los metales preciosos (oro, plata y platinoides), gemas (diamante, rubíes, zafiros, esmeraldas, aguamarinas, etc.), metales de base como el estaño (casiteritas), minerales tecnológicos como el titanio (ilmenitas y rutilos), wólfram (volframita y scheelita), circonio (circón), de tierras raras (monacitas), etc.. En este texto, se presentan las técnicas mas usuales en prospección aluvionar como la batea, así como los distintos criterios a seguir para llevar a cabo una prospección, un beneficio y una evaluación de sus yacimientos que se conocen como ¿placeres¿

Strategies in vocabulary acquisition: a case study of male students

Telah banyak penelitian mengenai proses akuisisi bahasa. Secara umum, ahli bahasa mengelompokkan proses akuisisi bahasa ke dalam akuisisi bahasa pertama dan kedua. Sebagai tambahan, ada juga yang disebut proses akuisisi kosa kata. Faktanya, istilah akuisisi dapat ditafsirkan berbeda-beda oleh para ahli bahasa. Beberapa di antaranya membedakan antara mengakuisisi dan mempelajari. Yang lainnya menganggap kedua hal tersebut sama. Pada penelitian ini, peneliti mengacu pada pendapat bahwa keduanya setara. Proses akuisisi kosa kata sendiri dipengaruhi oleh banyak faktor. Beberapa diantaranya yang ditemukan oleh para ahli bahasa adalah latar belakang bahasa pertama, motivasi, dan strategi belajar. Strategi belajar sendiri dapat dibagi menjadi beberapa jenis. Para peneliti menemukan berbagai strategi pada penelitiannya dalam strategi pembelajaran bahasa. Salah satunya adalah Shirahata dkk. (1999, pada Azumi 2008) yang membagi strategi belajar bahasa ke ‘langsung’ dan ‘tidak langsung’ di mana setiap kelompok tersebut mengandung tiga tiga bagian. Azumi (2008), dengan strategi yang digagas oleh Shirahata dkk., menemukan bahwa strategi dalam pembelajaran bahasa lebih digunakan oleh pelajar tingkat lanjut daripada pelajar tingkat menengah dan dasar. Dengan penelitian ini, peneliti mencoba untuk mengetahui strategi yang paling sering digunakan, alasan penggunaan, pengaruh penggunaan, serta kekuatan dan kelemahan setiap strategi berdasarkan penggunanya, di mana hal tersebut tidak dilakukan pada penelitian milih Azumi. Pada akhir penelitian ini, peneliti menemukan bahwa hasilnya berbeda pada setiap kasus. Setiap dari hasilnya berbeda bergantung pada faktor yang mempengaruhi setiap subyek. Akhirnya, peneliti berharap penemuan dari penelitian ini dapat bermanfaat untuk perkembangan ilmu pada bidang akuisisi bahasa, khususnya akuisisi kosa kata, dan membantu pembaca yang ingin menyelidiki pengetahuan mengenai ini

Associations between life stress and subclinical cardiovascular disease are partly mediated by depressive and anxiety symptoms

AbstractBackgroundStress experienced during childhood or adulthood has been associated with cardiovascular disease (CVD), but it is not clear whether associations are already prevalent on a subclinical cardiovascular level. This study investigates associations between indicators of life stress and subclinical CVD, and whether these are mediated by depression and anxiety.MethodsSubjects were 650 participants of the Netherlands Study of Depression and Anxiety, aged 20–66years, with or without (27.5%) depressive and anxiety disorders. Life stress included childhood trauma, negative life events and recently experienced daily hassles or job strain. Subclinical CVD was measured as 1) carotid atherosclerosis (intima–media thickness and the presence of plaques) using B-mode ultrasonography, and 2) central arterial stiffness (heart rate normalized augmentation index) using calibrated radial applanation tonometry.ResultsIncreased central arterial stiffness was shown in subjects who had experienced childhood trauma (per SD increase: β=.07; p=.01), or reported recently experienced daily hassles (per SD increase: β=.06; p=.02), negative life events (per SD increase: β=.05; p=.03), or job strain (high versus low: β=.09; p=.01). Associations between life stress and arterial stiffness appeared to be partly mediated by severity of depressive and anxiety symptoms. No significant associations were found for childhood life events, nor between indicators of life stress and carotid atherosclerosis.ConclusionsChildhood trauma and recent life stress were associated with increased central arterial stiffness. This suggests that life stress – partly via depression and anxiety – might enhance the development and progression of CVD