The Transients: Five Generations of a Southern Family Volume III

L, Jade, breaches near Kellett Bluff. L, Jade, with another tail lob. L with her calf, L T60 and T60C high speed porpoising away from the Resident orcas. Cormorant Colony on Mandarte Island, Canada. Pelagic Cormorant flying towards the colony up on the rocky cliff. Mandarte Island — Cormorant colony on the cliff face.

Canadian Geese headed for Canada. Oligonucleotides used for the cloning of localization plasmids are listed in S1 Table. Transformation and microscopic analyses were performed as described before [ 50 ]. Germination and appressorium formation were assayed on polystyrene and on onion epidermis.

Segments of the third leaf of day-old maize Zea mays cv. Golden Jubilee plants cultivated in an air-conditioned greenhouse were excised and incubated to assess virulence of C. Comparison with the genomic regions revealed that each of the genes comprises four exons of varying length Fig 1A. The genomic sequences and the gene numbers can be found in S2 File.

B Artistic representation forged steel of the TRP channel core structure containing six transmembrane TM domains and a pore loop between TM domain 5 and 6. Cytosolic amino acid residues are indicated in light green, TM domains are shown in yellow, luminal amino acid residues are depicted in light blue, and the predicted pore loop is marked in dark blue. Acidic amino acid residues [Asp D or Glu E ] are indicated by a red edge, which is boldfaced in motifs of 4 or more consecutive acidic amino acid residues.

One circle represents one amino acid residue. The first and the last amino acid of the whole protein, as well as of each TM domain, are enumerated. There is also a high degree of conservation in the length of the luminal and cytosolic linkers of the TM domains as well as of the putative pore loop S2 Table [ 18 ]. Hence, the C-terminus of those proteins is predicted to reside in the lumen. The obtained sequences were aligned, trimmed, and a phylogenetic tree was generated that comprised six major branches Fig 2.

Species belonging to the Saccharomycotina harboured only one putative TRP protein and clustered on a distinct branch. The fifth branch comprises only predicted proteins from Basidiomycota.

1. Grocery Whore: BDSM Flash Fiction;
2. ;
3. The GOD CiPHER?
4. .

In general, all examined filamentous fungi carry one to four predicted TRPF proteins. Colletotrichum higginsianum and Neurospora crassa are the only of the analyzed species containing predicted proteins with similarity to all four CgTRPFs. There is no apparent correlation between nutritional lifestyle or pathogenicity and the number of TRPF proteins per species.

TRPF groups 1, 2, 3, and 4, each containing a C. TRPF group not containing a C. To determine whether the four CgTRPF genes may play a role during growth, we first determined their expression in spores and in colonies cultivated on a membrane overlying mLCM agar, as described by Lange and co-workers [ 41 ]. Full-length transcripts for all four genes were detectable in vegetative hyphae and conidial spores Fig 3A.

To determine transcript abundance throughout the infection process on maize, two independent methods were applied on two different cultivars Mikado, Golden Jubilee. Transcript levels were assessed from 0 to hours post inoculation hpi. Compared to 0 hpi, transcript levels of CgTRPF1 were induced from 12 hpi onward by up to 13 fold in both data sets. Transcript abundances of CgTRPF4 were also consistently elevated throughout earlier stages of the infection process, albeit to a lesser extent Fig 3B and 3C. The transcriptomic data indicate that all four CgTRPF genes may play a role in all stages of growth and infection.

B, C Expression during the infection process relative to the expression in spores 0 hours post infection, hpi ; black: CgTRPF1 , dark grey: CgTRPF2 , light grey: B Detached third leaves of 2. C Third leaf of intact two-week-old drop-infected plants cv. TRP channels of animals localize either at the plasma membrane or at membranes of intracellular organelles, while the S.

Resident orcas meet Transients

Because CgTRPF1 through 3 exhibited a similar localization pattern, we investigated whether they are present in the same compartment. To this end, the respective genes were fused to mCherry and combined with EGFPf fusion constructs in a dual-tag plasmid system [ 50 ]. As all CgTRPF genes were expressed in spores, plate cultures, and throughout the infection process, and since mutants of other fungi for TRPY1 homologues show severe defects [ 37 , 38 ], we analysed the role of CgTRPF1 through 4 in growth and pathogenicity.

To this end, we created deletion strains for each gene by homologous recombination. For further analysis of this gene, three individual strains were chosen that showed different Southern blot patterns for one additional integration event S1 Fig. This may be indicated by an increased expression of the remaining CgTRPF genes in the deletion strains. In the deletion strains, an occasional weak upregulation of other family members was observed. However, this alteration was always well below two-fold, which does not indicate a strong compensatory response.

Therefore, germination was tested on polystyrene Fig 5A and on onion epidermis Fig 5B. In both types of assay, germination of the deletion strains was not reduced compared to the wild type, indicating either no role of the CgTRPF genes in this process or a functional redundancy of the genes. On onion epidermis, only appressoria were counted. To utilize those, the fungus has to secrete hydrolytic enzymes by exocytosis, allowing the uptake of low-molecular compounds.

To test whether CgTRPFs may function in this process or in the utilization of diverse carbon sources, wild type and deletion strains for all of the four genes were assayed for growth on mLCM and PDA, as well as on minimal media supplemented with glucose, sucrose, raffinose, sorbitol, mannitol, malate, pectate, or cellulose. The strains did not show any consistent and reproducible growth differences on any of the tested media Fig 6.

Hence, CgTRPF genes are either not required for those secretion events, or the genes are functionally redundant in this process. All values were normalized to the growth of the wild type on the respective medium. Colony diameter was measured hours post inoculation. This decrease in growth was also apparent, but not exacerbated, in the Cgtrpf mutant strains Fig 7. As reported previously [ 45 ], the C. It has been suggested that in N.

Kymographs of individual hyphae of wild type and deletion mutants. ROIs of subsequent images, acquired every 2 sec, were plotted one below the other. The slope of the kymographs, read from top to bottom, thus indicates the growth rate. All measurements were performed on hyphae growing at an mLCM agar-glass interface [ 45 ]. The rate of spike occurrence was not reduced in any of the deletion strains S3 Fig. TRPY1 is known to act as a sensor for osmotic disturbance in S. As expected, growth of the C.

1. Resident orcas meet Transients.
2. Direito da Comunicação Social (Portuguese Edition);
3. Resident orcas meet Transients - All Aboard Sailing.
4. A Beginners Guide to Making Money Online from Scratch.
5. No Longer Strangers: The Practice of Radical Hospitality.

All deletion mutants of the four CgTRPF genes were inhibited similar to the wild type on medium containing 0. A, B Mycelial growth of C. A Colony diameter of wild type stressed with varying concentrations of glycerol, normalized to unstressed colonies. B Wild type and deletion strains stressed with 0. Colony diameters were determined hours post inoculation. Treatment was started at 1 min. Treatment solutions were added after 1 min of recording. Replicate measurements can be found in S4 Fig. To test if any of the C. To this end, we employed the apoaequorin-harbouring wild type strain.

Treatment of whole colonies with buffer alone caused a short and small response that phased out entirely after about 3 min Fig 9D , grey line. Treatment with a solution containing 1. This indicates that, in contrast to S. As all assays failed to identify a possible involvement of C. In a detached leaf segment assay, none of the mutants exhibited symptoms that differed noticeably from those of the wild type Fig Sections of the third leaf of two-week-old maize plants cv.

Associated Data

Golden Jubilee were infected with 10 4 spores of C. Representative images of three biological replicates are shown; the experiment was repeated twice with similar results. In support of a pivotal role of this class of ion channels in fungi, the knock-down of a TRPY1 homologue in M. We therefore considered this family as a potential target for plant protection strategies against the devastating maize pathogen C. Our initial database queries revealed that this gene family was expanded in most filamentous fungi, with up to four members in the examined genomes, while the genomes of all examined yeasts contain only a single TRPY1 homologue.

This is in good agreement with a comparative genomic analysis pointing to a possible expansion of the TRP family in filamentous fungi [ 18 ]. The members in filamentous fungi, which we denominate TRPF s, cluster in five subgroups. In the genome of C. All were expressed throughout development and infection, and all encoded proteins were localized in intracellular organelles.

Further on, the proteins display a membrane topology similar to the yeast TRPY1 channel, albeit with a variable number of TM domains additional to the core of six TM domains. These motifs are predicted to reside in cytosolic or luminal termini. This might indicate that technical problems of the heterologous expression system e. However, we consider this as not very likely because other TRP channels are functional in this system. To further test this presumption, the response of C. Horizontal lines in panels b and c indicate the time period in which the quantities are calculated, markers are placed in the middle point of the time window.

Therefore, the increase in the average size of events i. In general, a Poissonian model fits seismicity well only when main shocks are considered, while aftershocks or swarm-like sequences introduce clustering in the earthquake sequences. By means of the coefficient of variation CV , that is the ratio between the standard deviation and mean of the population of interevent times, we check when interevent times depart from an exponential distribution. As expected, we find a high degree of clustering when we use all data in the sequence Fig.

In detail, CV is close to one before the onset of the swarm i. For all the other phases, CV takes values larger than 1, with empirical distribution of interevent time compatible with a power-law model see Fig. This explanation may apply also to the Pollino sequence. Probability density for interevent times IETs of each phase of the sequence.

Colours and symbols are for the phases 0—6 in Fig. Dot-dashed line are IETs for all data. Coefficient of variation CV are reported together with the number of data above the catalogue completeness. In the inset same as the main plot but IETs of each sequence are normalized by their mean values. Earthquakes swarms are usually the result of the interplay between aseismic forcing acting on tectonically loaded structures and earthquake—earthquake self-interaction.

In this way, the observed seismicity results from the contribution of two processes: One is related to stress changes related to aseismic processes, the other one is related to earthquake-induced stress changes. While the second one is interesting for studying earthquake interactions, the first process is of major interest for exploring the initiation mechanism of the whole sequence.

The smoothing window is crucial: For weak smoothing, the model favours a strong time dependence with a large fraction of the earthquakes associated with it, while the time dependence becomes negligible for strong smoothing. We deliberately increase the cut-off magnitude for this analysis since both the inversion and optimization of ETAS parameters are more sensitive to catalogue incompleteness than the statistical analyses previously performed.

The latter model is clearly superior based on its AIC value and indicates that a large number of events were directly driven by an aseismic forcing. The estimated ETAS parameters are all in the range of typical values observed in other regions e. The optimized fit is shown in Fig. After a small increase of the seismicity rate at the beginning of the swarm in October , the first considerable acceleration coincides with phase 3 of the sequence almost one year before the main shock in Fall An even faster acceleration on the transient forcing occurred in the three months before the main shock.

Cumulative plot of seismicity versus time. Red curve are observed earthquakes, blue curve indicates the number of events predicted by ETAS model with time dependent background rate and grey shaded curve are expected events related to the transient background rate. One of the major advantages of long lasting seismic sequences is that they allow us to image in detail the hosting tectonic structures.

Here, we confirm a possible heterogeneity in the stress field resulting in a more complex transtensional regime with a large component of extension. Two alternatives are conceivable at this stage for the tectonic structure s activated by the swarm: In case the first scenario applies, this would point at interesting properties of the activated fault. On the other hand, a system of normal faults, as in scenario 2, was mapped in the northern part of the Mercure basin and was activated by the main shock-aftershocks sequence of the September M w 5.

In particular, our ETAS-based modelling of the seismicity shows that a large proportion of the events, about 75 per cent, are not aftershocks. For some swarm sequences it was possible to observe deformation not justified by the energy released seismically. A large role played by fluids either due to increase of pore pressure or fluid infiltration within the seismogenic zone may favour aseismic slip by lowering the normal stress on the fault plane. Interestingly, the fastest acceleration in the seismic rate occurred in the three months before the largest event in October This was accompanied by a decrease of the b -value, leading to a predicted increased likelihood of a larger magnitude earthquake.

In the present case, a high seismicity rate coupled with a low b -value may indicate a change in the dynamics of the aseismic forcing for example a transient decrease of pore pressure or, alternatively, the activation of regions with different rock rheology and thus different seismogenic characteristics. The relation between maximum observed magnitude, b -values and seismic rate should be better investigated in future analyses of seismic swarms.

Resident orcas meet Transients - All Aboard Sailing

At the time of the discovery of palaeoseismicity on the Castrovillari fault the lack of large historical earthquakes was explained with a lack of historical data. The faults may therefore now be loaded with large strain. Episodes of transient slip, releasing the majority of the moment are accompanied by seismic swarms, that release only a small fraction of the energy through seismic waves. High resolution geodetic monitoring can indicate which one of the two scenarios is the most likely by simply budgeting the total geodetic moment accumulated and that released seismically by the sequence.

A large aseismic release of geodetic moment during the seismic swarm in the Mercure Basin fault is not inconsistent with the low seismic activity on the Castrovillari fault. At present, without precise locations and no constraints from deformation data, it is difficult to say if the swarm was accompanied by a large aseismic release of geodetic moment and if the low-seismicity fault portions are linked to creeping or to increased locking.

Traditional hazard estimation methods are based on the knowledge of the structures involved and on estimates of the parameters of the Gutenberg—Richter relation, maximum magnitude and ground motion prediction. Regardless of the physical mechanism in place, during seismic swarms and certainly during the Pollino sequence all these quantities are poorly known or strongly time-dependent and in general affected by large uncertainties. This makes it difficult to estimate the seismic hazard with traditional methods.

A possible strategy to decrease uncertainties is to develop methods to incorporate, beside the seismicity and tectonic loading of the area, the monitoring of a large number of parameters: Deformation, changes of velocity of seismic wave in the crust, physico-chemical properties of fluids in wells and thermal- and hot-springs. Understanding co-variation of those signals with the seismic rate is of crucial importance to better estimate the hazard due to natural and man-made fluid-related seismic activity.

In this work, we have examined the geometrical, mechanical and statistical characteristics of the seismic swarm striking the Pollino range region. We interpret this as a result of the transtensional stress field acting in the southern part of the Mercure Basin. Due to a lack of resolution on the hypocentres of the events, we cannot definitively discriminate the tectonic structures hosting the sequence but we discuss two possible alternative scenarios: One single curved structure or a system of subparallel faults.

It is difficult to explain the spatial and temporal evolution of the sequence only in terms of static stress transfer due to the larger earthquakes within the sequence, so we argue for an external forcing as a driving mechanism of the swarm. The external forcing is confirmed by analysis of the sequence using the ETAS model. Results indicate 75 per cent of the earthquakes in the sequence may be attributed to a transient forcing and the rest is normal aftershock activity.

Changes of b -values in time throughout the sequence also support the external forcing hypothesis since low b -values correlate with the period of highest seismicity rate and with the occurrence of the largest shock. Yet, whether the external forcing is due to transient and aseismic slip episodes can only be resolved by linking high precision earthquake locations and high resolution geodetic monitoring. The comments of Rodolfo Console, an anonymous reviewer and the associate editor Egill Hauksson helped improve the manuscript.

The authors thank Marybeth Rice for revising the English.

INTRODUCTION

Oxford University Press is a department of the University of Oxford. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide. Sign In or Create an Account. Close mobile search navigation Article navigation. Aseismic transient driving the swarm-like seismic sequence in the Pollino range, Southern Italy Luigi Passarelli.

Abstract Tectonic earthquake swarms challenge our understanding of earthquake processes since it is difficult to link observations to the underlying physical mechanisms and to assess the hazard they pose. Seismicity and tectonics , Statistical seismology , Dynamics: View large Download slide. We model the causative fault as a square dislocation Okada of side 4. The fault strike o , dip 54 o and rake —79 o were set according to the focal mechanism solution in Fig. A source study of the 9 September M w 5. Analysis of the 9 September M w 5. Materiali per un catalogo dei terremoti italiani: Eventi sconosciuti, rivalutati o riscoperti.

Pleistocene strike—slip tectonics in the Lucanian Apennine Southern Italy. Automated procedure for point and kinematic source inversion at regional distances. Discrimination of induced seismicity by full moment tensor inversion and decomposition. New constraints on the seismic history of the Castrovillari fault in the Pollino gap Calabria, southern Italy. Velocity ratio variations in the source region of earthquake swarms in NW Bohemia obtained from arrival time double-differences.

Bidirectional and unidirectional fracture growth during hydrofracturing: A constitutive law for rate of earthquakeproduction and its application to earthquake clustering. Topography of the Calabria subduction zone southern Italy: Active transpression in the northern Calabria Apennines, southern Italy, Tectonophysics.