Seismic Imaging of the Main Frontal Thrust in Nepal Reveals a Shallow Décollement and Blind Thrusting

Because great earthquakes in the Himalaya have an average recurrence interval exceeding 500 yr, most of what we know about past earthquakes comes from paleoseismology and tectonic geomorphology studies of the youngest fault system there, the Main Frontal Thrust (MFT). However, these data are sparse relative to fault segmentation and length, and interpretations are often hard to validate in the absence of information about fault geometry. Here, we image the upper two km of strata in the vicinity of the fault tip of the MFT in central Nepal (around the town of Bardibas) applying a pre-stack migration approach to two new seismic reflection profiles that we interpret using quantitative fault-bend folding theory. Our results provide direct evidence that a shallow décollement produces both emergent (Patu thrust) and blind (Bardibas thrust) fault strands. We show that the décollement lies about 2 km below the land surface near the fault tip, and steps down to a regional 5 km deep décollement level to the north. This implies that there is significant variation in the depth of the décollement. We demonstrate that some active faults do not reach the surface, and therefore paleoseismic trenching alone cannot characterize the earthquake history at these locations. Although blind, these faults have associated growth strata that allow us to infer their most recent displacement history. We present the first direct evidence of fault dip on two fault strands of the MFT at depth that can allow terrace uplift measurements to be more accurately converted to fault slip. We identify a beveled erosional surface buried beneath Quaternary sediments, indicating that strath surface formation is modulated by both climate-related base level changes and tectonics. Together, these results indicate that subsurface imaging, in conjunction with traditional paleoseismological tools, can best characterize the history of fault slip in the Himalaya and other similar thrust fault systems

Constraints on the Shallow Deformation Around the Main Frontal Thrust in Central Nepal from Refraction Velocities

The youngest fault system in the Himalayan orogeny is the Main Frontal Thrust (MFT), the frontal ramp of the Main Himalayan Thrust, which is expected to host the largest and most damaging earthquakes in Nepal. We characterize the upper few hundred meters below the surface across two MFT fault strands using ten high-resolution seismic profiles that we acquired in 2014 and 2015 with a 6-tonne Vibroseis source. We use first arrival picks from 625,416 seismic traces to derive P-wave seismic velocity models using a wavepath eikonal traveltime inversion method, and derive estimates of alluvium thickness and water table depth across these faults (the Patu and Bardibas thrusts), allowing us to constrain the subsurface geometry of the MFT. Our results show that 1) seismic velocities range from 255 to 3660 m/s, consistent with dry and saturated alluvium, and Siwalik bedrock; 2) low-velocity alluvium varies between ~20–50 and ~80–120 m thick in the hanging wall and footwall of the Bardibas thrust, respectively, corresponding to ~60–70 m of uplift of the hanging wall since deposition; 3) the two thrusts are soft-linked, and the western tip of the Bardibas thrust lies ~6 km west of its surface expression; 4) during the dry season, the water table is ~25–100 m higher in the hanging walls of the faults than in their footwalls, due to the larger thickness of permeable alluvium in the footwalls, and the water table shallows towards the east in the hanging wall of the Bardibas thrust; and 5) consistent with previous studies, the Patu thrust breaches the surface, while the Bardibas thrust is blind at Ratu Khola. These results also demonstrate that it should be possible to constrain the rate of uplift above the Bardibas thrust by drilling and dating sediments on both sides, which would complement existing measurements from terrace uplift

Distance Functions and Normalization Under Stream Scenarios

Data normalization is an essential task when modeling a classification system. When dealing with data streams, data normalization becomes especially challenging since we may not know in advance the properties of the features, such as their minimum/maximum values, and these properties may change over time. We compare the accuracies generated by eight well-known distance functions in data streams without normalization, normalized considering the statistics of the first batch of data received, and considering the previous batch received. We argue that experimental protocols for streams that consider the full stream as normalized are unrealistic and can lead to biased and poor results. Our results indicate that using the original data stream without applying normalization, and the Canberra distance, can be a good combination when no information about the data stream is known beforehand.Comment: Paper accepted to the 2023 International Joint Conference on Neural Network

Role of the Proteasome in Excitotoxicity-Induced Cleavage of Glutamic Acid Decarboxylase in Cultured Hippocampal Neurons

Glutamic acid decarboxylase is responsible for synthesizing GABA, the major inhibitory neurotransmitter, and exists in two isoforms—GAD65 and GAD67. The enzyme is cleaved under excitotoxic conditions, but the mechanisms involved and the functional consequences are not fully elucidated. We found that excitotoxic stimulation of cultured hippocampal neurons with glutamate leads to a time-dependent cleavage of GAD65 and GAD67 in the N-terminal region of the proteins, and decrease the corresponding mRNAs. The cleavage of GAD67 was sensitive to the proteasome inhibitors MG132, YU102 and lactacystin, and was also abrogated by the E1 ubiquitin ligase inhibitor UBEI-41. In contrast, MG132 and UBEI-41 were the only inhibitors tested that showed an effect on GAD65 cleavage. Excitotoxic stimulation with glutamate also increased the amount of GAD captured in experiments where ubiquitinated proteins and their binding partners were isolated. However, no evidences were found for direct GADs ubiquitination in cultured hippocampal neurons, and recombinant GAD65 was not cleaved by purified 20S or 26S proteasome preparations. Since calpains, a group of calcium activated proteases, play a key role in GAD65/67 cleavage under excitotoxic conditions the results suggest that GADs are cleaved after ubiquitination and degradation of an unknown binding partner by the proteasome. The characteristic punctate distribution of GAD65 along neurites of differentiated cultured hippocampal neurons was significantly reduced after excitotoxic injury, and the total GAD activity measured in extracts from the cerebellum or cerebral cortex at 24h postmortem (when there is a partial cleavage of GADs) was also decreased. The results show a role of the UPS in the cleavage of GAD65/67 and point out the deregulation of GADs under excitotoxic conditions, which is likely to affect GABAergic neurotransmission. This is the first time that the UPS has been implicated in the events triggered during excitotoxicity and the first molecular target of the UPS affected in this cell death process

Valores de referência para selecionados testes oftálmicos para a arara canindé (Ara araruna)

Objetivou-se determinar os valores normais para testes oftálmicos diagnósticos selecionados para a Arara Canindé. Trinta e cinco Ara ararauna (70 olhos), de sexo indeterminado, adultas, com peso médio de 1kg e provenientes de cativeiro no Distrito Federal, foram avaliadas. Aferiram-se a produção lacrimal pelo Teste lacrimal de Schirmer (TLS), a avaliação microbiológica da conjuntiva ocular, a pressão intra-ocular (PIO) utilizando a tonometria de rebote e o comprimento horizontal da rima palpebral Neste estudo 84.1% das amostras analisadas foram positivas para crescimento microbiológico. Bactérias, fungos e hifas foram isolados e Staphylococcus spp. (21.9%) e Bacillus spp. (26.8%) foram isolados mais frequentemente. Os valores médios do teste de Lacrimal de Schirmer (TLS) foram de 7.6±4.6 e 6.6±4.4mm/min para olhos direito (OD) e esquerdo (OE), respectivamente (média = 7,11±0,76mm/min). A pressão intraocular média foi de 11.4±2.5 (OD) e 11.6±1.8mmHg (OE) anteriormente à anestesia (média 11,49±0,22 mmHg) e 7.6 ± 2.4 mmHg (OD) e 7.8 ± 1.8 mm Hg (OE) (média 7,71±0,08mm Hg) após a anestesia, verificando-se que a PIO foi significativamente menor quando os animais se encontravam sob anestesia comparativamente ao momento em que não estavam anestesiados. O comprimento horizontal da rima horizontal palpebral foi de 11.7±0.1mm OD e de 11.8±0.1mm OE (média 11,72±0,07mm). Verificou-se correlação positiva do TLS com o comprimento da fissura palpebral para a espécie estudada. Estes valores de referencia serão úteis no diagnóstico de alterações oculares da Arara Canindé.The aim of this study was to establish reference values for selected ophthalmic diagnostic tests in healthy blue-and-yellow macaws. We investigated a total of 35 adult macaws (70 eyes) of undetermined sex and with an average weight of 1 kg, who were living in captivity in the Federal District, Brazil. Tear production using the Schirmer tear test (STT), normal conjunctival flora, intraocular pressure (IOP) using a rebound tonometer and horizontal palpebral fissure length (HPFL) were evaluated. In this study, 84.1% of samples were positive for microbial growth. Bacteria, fungi and yeasts were isolated, and Staphylococcus spp. (21.9%) and Bacillus spp. (26.8%) were the most frequently isolated microorganisms. The mean value for STT was 7.6±4.6mm/min in the right eye (OD) and 6.6±4.4mm/min in the left eye (OS) (median = 7,11±0,76mm/min). Mean IOP was 11.4±2.5mm Hg OD and 11.6±1.8mm Hg OS (median = 11.49±0.22mm Hg), prior to anesthesia, and 7.6±2.4mm Hg OD and 7.8±1.8mm Hg OS (median 7.71±0.08mmHg) after anesthesia. The IOP was significantly lower when the animals were under anesthesia as compared to when they were conscious (p≤0.05). Horizontal palpebral fissure length was 11.7±0.1mm OD and 11.8±0.1mm OS (median = 11.72±0.07mm). The STT showed a positive correlation with palpebral fissure measurement for this species. These selected ophthalmic reference values will be particularly useful in diagnosing pathological changes in the eyes of blue-and-yellow macaws

Dectin-1 Activation Exacerbates Obesity and Insulin Resistance in the Absence of MyD88

This work was supported by Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP, grant numbers 11/15682-4, 12/02270-2, 15/18121-4), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq, Regenera INCT Process Grant 465656/2014-5). JL is funded by the NIH/NIDDK R01DK106210. GDB is funded by the Wellcome Trust and the MRC Centre for Medical Mycology. Open access journalPeer reviewedPublisher PD

Dimensionamento de turbina pelton para aplicações sustentáveis / Size of a pelton turbine for application in rural areas

Hoje podemos ver que o desenvolvimento de um País é ligado diretamente o seu consumo e fornecimento de energia, como e dito por Abreu e Azevedo (2009, p.10): “O crescimento econômico, a industrialização e a urbanização estão intimamente ligadas a um aumento da demanda de energia.”. Ela também se tornou um bem essencial para todos, como diz Abreu e Azevedo (2009, P. 10 e 11): “Sendo a energia em bem essencial e primordial ao desenvolvimento de uma nação, ela permeia todos os níveis sociais e políticos do país.”Com isto temos o dever de pensarmos também à forma que esta energia elétrica e gerada, pois devemos diminuir o máximo possível o impacto no meio ambiente com a sua produção, tendo em vista que hoje a maior parte da energia elétrica e gerada por meio de materiais não renováveis, foi visto a necessidade de se atender esta população com uma forma alternativa de produção de energia, aproveitando os recursos disponíveis. 

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors

Cognitive impairment induced by delta9-tetrahydrocannabinol occurs through heteromers between cannabinoid CB1 and serotonin 5-HT2A receptors

Delta-9-tetrahydrocannabinol (THC), the main psychoactive compound of marijuana, induces numerous undesirable effects, including memory impairments, anxiety, and dependence. Conversely, THC also has potentially therapeutic effects, including analgesia, muscle relaxation, and neuroprotection. However, the mechanisms that dissociate these responses are still not known. Using mice lacking the serotonin receptor 5-HT2A, we revealed that the analgesic and amnesic effects of THC are independent of each other: while amnesia induced by THC disappears in the mutant mice, THC can still promote analgesia in these animals. In subsequent molecular studies, we showed that in specific brain regions involved in memory formation, the receptors for THC and the 5-HT2A receptors work together by physically interacting with each other. Experimentally interfering with this interaction prevented the memory deficits induced by THC, but not its analgesic properties. Our results highlight a novel mechanism by which the beneficial analgesic properties of THC can be dissociated from its cognitive side effects