Twenty-Five Years of Domoic Acid Monitoring in Galicia (NW Spain): Spatial, Temporal and Interspecific Variations

Prevalence, impact on shellfish resources and interspecific, spatial, and temporal variabilities of domoic acid (DA) in bivalves from Galicia (NW Spain) have been studied based on more than 25 years of monitoring data. The maximum prevalence (samples in which DA was detected) (100%) and incidence (samples with DA levels above the regulatory limit) (97.4%) were recorded in Pecten maximus, and the minimum ones in Mytilus galloprovincialis (12.6 and 1.1%, respectively). The maximum DA concentrations were 663.9 mg kg−1 in P. maximus and 316 mg kg−1 in Venerupis corrugata. After excluding scallop P. maximus data, DA was found (prevalence) in 13.3% of bivalve samples, with 1.3% being over the regulatory limit. In general, the prevalence of this toxin decreased towards the North but not the magnitude of its episodes. The seasonal distribution was characterized by two maxima, in spring and autumn, with the later decreasing in intensity towards the north. DA levels decreased slightly over the studied period, although this decreasing trend was not linear. A cyclic pattern was observed in the interannual variability, with cycles of 4 and 11 years. Intoxication and detoxification rates were slower than those expected from laboratory experiments, suggesting the supply of DA during these phases plays an important role.

Mistakes can stabilise the dynamics of rock-paper-scissors games

A game of rock-paper-scissors is an interesting example of an interaction where none of the pure strategies strictly dominates all others, leading to a cyclic pattern. In this work, we consider an unstable version of rock-paper-scissors dynamics and allow individuals to make behavioural mistakes during the strategy execution. We show that such an assumption can break a cyclic relationship leading to a stable equilibrium emerging with only one strategy surviving. We consider two cases: completely random mistakes when individuals have no bias towards any strategy and a general form of mistakes. Then, we determine conditions for a strategy to dominate all other strategies. However, given that individuals who adopt a dominating strategy are still prone to behavioural mistakes in the observed behaviour, we may still observe extinct strategies. That is, behavioural mistakes in strategy execution stabilise evolutionary dynamics leading to an evolutionary stable and, potentially, mixed co-existence equilibrium.

Life-Saving Emergency Adrenalectomy in a Pheochromocytoma Crisis with Cardiogenic Shock

Cardiogenic shock during a pheochromocytoma crisis is a life-threatening disorder. This case report illustrates a 49-year-old male with profound cardiogenic shock, extreme hemodynamic instability (systolic blood pressure ranging from 45 up to 290 mmHg in a cyclic pattern), and progressive multiple organ failure in the presence of a unilateral adrenal mass. Emergency adrenalectomy led to rapid hemodynamic stabilization. Histological investigation confirmed the diagnosis of pheochromocytoma. This case indicates that emergency adrenalectomy, although usually not considered first choice, is a valid option in cardiogenic shock and extremely fluctuating hemodynamics due to a pheochromcytoma-induced catecholamine storm.

The Mansurov Effect: Real or a statistical artefact?

<p>The Mansurov Effect is related to the interplanetary magnetic field (IMF) and its ability to modulate the global electric circuit, which is further hypothesized to impact the polar troposphere through cloud generation processes. In this paper we investigate the connection between IMF By-component and polar surface pressure by using daily ERA5 reanalysis for geopotential height since 1980. Previous studies have shown to produce a significant 27-day cyclic response during solar cycle 23. However, when appropriate statistical tests are applied, the correlation is not significant at the 95% level. Our results also show that data from three other solar cycles, which have not been investigated before, produce similar cyclic responses as during solar cycle 23, but with seemingly random offset in the timing of the signal. We examine the origin of the cyclic pattern occurring in the super epoch/lead lag regression methods commonly used to support the Mansurov hypothesis in all recent papers, as well as other phenomena in this community. By generating random normally distributed noise with different levels of temporal autocorrelation, and using the real IMF By-index as forcing, we show that the methods applied to support the Mansurov hypothesis up to now, are highly susceptible, as cyclic patterns always occurs as artefacts of the methods. This, in addition to the lack of significance, suggests that there is no adequate evidence in support of the Mansurov Effect.</p>

Trends and Periodicities in Rainfall, Temperature, and Relative Humidity Datasets Over Ghana

This paper analyzed trends and periodicities in annual and seasonal rainfall, temperature, and relative humidity (RH) over Ghana using climatological datasets for twelve (12) synoptic stations spanning the periods of 30 to 52 years (1961–2010), obtained from the Ghana Meteorological Agency (GMet). The datasets were normalized by dividing with the long time mean, and grouped in decades. Findings show that 1961-1970 and 2001-2010 decades recorded significant wetter years, while 1981-1990 recorded relatively drier years within in the zones with bimodal rainfall seasons. However in the zone with mono-modal rainfall seasons wetter years occurred within the decades of 1981-1990 and 2001-2010. Furthermore, it is realised that, there is a cyclic pattern noted in the rainfall time series and a cycle of about 5 to 8 months for the Northern zone, 6 – 8 month for the middle belt and approximately 8 months for the coastal zone in the rainfall, temperature and humidity datasets suggesting a coherence in their relationship.

Mistakes can stabilise the dynamics of rock-paper-scissors games

A game of rock-paper-scissors is an interesting example of an interaction where none of the pure strategies strictly dominates all others, leading to a cyclic pattern. In this work, we consider an unstable version of rock-paper-scissors dynamics and allow individuals to make behavioural mistakes during the strategy execution. We show that such an assumption can break a cyclic relationship leading to a stable equilibrium emerging with only one strategy surviving. We consider two cases: completely random mistakes when individuals have no bias towards any strategy and a general form of mistakes. Then, we determine conditions for a strategy to dominate all other strategies. However, given that individuals who adopt a dominating strategy are still prone to behavioural mistakes in the observed behaviour, we may still observe extinct strategies. That is, behavioural mistakes in strategy execution stabilise evolutionary dynamics leading to an evolutionary stable and, potentially, mixed co-existence equilibrium.Author summaryA game of rock-paper-scissors is more than just a children’s game. This type of interactions is often used to describe competition among animals or humans. A special feature of such an interaction is that none of the pure strategies dominates, resulting in a cyclic pattern. However, in wild communities such interactions are rarely observed by biologists. Our results suggest that this lack of cyclicity may stem from imperfectness of interacting individuals. In other words, we show analytically that heterogeneity in behavioural patterns may break a cyclic relationship and lead to a stable equilibrium in pure or mixed strategies.

Loss of polycystins suppresses deciliation via the activation of the centrosomal integrity pathway

The primary cilium is a microtubule-based, antenna-like organelle housing several signaling pathways. It follows a cyclic pattern of assembly and deciliation (disassembly and/or shedding), as cells exit and re-enter the cell cycle, respectively. In general, primary cilia loss leads to kidney cystogenesis. However, in animal models of autosomal dominant polycystic kidney disease, a major disease caused by mutations in the polycystin genes (Pkd1 or Pkd2), primary cilia ablation or acceleration of deciliation suppresses cystic growth, whereas deceleration of deciliation enhances cystogenesis. Here, we show that deciliation is delayed in the cystic epithelium of a mouse model of postnatal deletion of Pkd1 and in Pkd1- or Pkd2-null cells in culture. Mechanistic experiments show that PKD1 depletion activates the centrosomal integrity/mitotic surveillance pathway involving 53BP1, USP28, and p53 leading to a delay in deciliation. Reduced deciliation rate causes prolonged activation of cilia-based signaling pathways that could promote cystic growth. Our study links polycystins to cilia dynamics, identifies cellular deciliation downstream of the centrosomal integrity pathway, and helps explain pro-cystic effects of primary cilia in autosomal dominant polycystic kidney disease.

Prediction of seasonal patterns of porcine reproductive and respiratory syndrome virus RNA detection in the U.S. swine industry

We developed a model to predict the cyclic pattern of porcine reproductive and respiratory syndrome virus (PRRSV) RNA detection by reverse-transcription real-time PCR (RT-rtPCR) from 4 major swine-centric veterinary diagnostic laboratories (VDLs) in the United States and to use historical data to forecast the upcoming year’s weekly percentage of positive submissions and issue outbreak signals when the pattern of detection was not as expected. Standardized submission data and test results were used. Historical data (2015–2017) composed of the weekly percentage of PCR-positive submissions were used to fit a cyclic robust regression model. The findings were used to forecast the expected weekly percentage of PCR-positive submissions, with a 95% confidence interval (CI), for 2018. During 2018, the proportion of PRRSV-positive submissions crossed 95% CI boundaries at week 2, 14–25, and 48. The relatively higher detection on week 2 and 48 were mostly from submissions containing samples from wean-to-market pigs, and for week 14–25 originated mostly from samples from adult/sow farms. There was a recurring yearly pattern of detection, wherein an increased proportion of PRRSV RNA detection in submissions originating from wean-to-finish farms was followed by increased detection in samples from adult/sow farms. Results from the model described herein confirm the seasonal cyclic pattern of PRRSV detection using test results consolidated from 4 VDLs. Wave crests occurred consistently during winter, and wave troughs occurred consistently during the summer months. Our model was able to correctly identify statistically significant outbreak signals in PRRSV RNA detection at 3 instances during 2018.