Cycle Events Research Articles

Greening‐Induced Biophysical Impacts Lead to Earlier Spring and Autumn Phenology in Temperate and Boreal Forests

AbstractTree phenology, the timing of periodic biological events in trees, is highly sensitive to climate change. Previous studies have indicated that forest greening can impact the local climate by modifying the seasonal surface energy budget. However, the understanding of tree phenological responses to forest greening at large spatial scales remains limited. Utilizing satellite‐derived phenological and leaf area index data spanning from 2001 to 2021, herein we show that forest greening led to earlier spring and autumn phenology in both temperate and boreal forests. Our findings demonstrated that forest greening during winter and spring contributed to a reduction in surface albedo, resulting in biophysical warming and consequently advancing spring leaf phenology. Conversely, forest greening in summer and autumn induced biophysical cooling through increased evapotranspiration, leading to an earlier onset of autumn leaf phenology. Our findings highlight the significant impact of forest greening‐induced local seasonal climate changes on shaping tree phenology in temperate and boreal forests. It is crucial to consider these greening‐induced alterations in microclimate conditions when modeling changes in tree phenology under future climate warming scenarios.

Viral RNA Interactome: The Ultimate Researcher’s Guide to RNA–Protein Interactions

RNA molecules in the cell are bound by a multitude of RNA-binding proteins (RBPs) with a variety of regulatory consequences. Often, interactions with these RNA-binding proteins are facilitated by the complex secondary and tertiary structures of RNA molecules. Viral RNAs especially are known to be heavily structured and interact with many RBPs, with roles including genome packaging, immune evasion, enhancing replication and transcription, and increasing translation efficiency. As such, the RNA–protein interactome represents a critical facet of the viral replication cycle. Characterization of these interactions is necessary for the development of novel therapeutics targeted at the disruption of essential replication cycle events. In this review, we aim to summarize the various roles of RNA structures in shaping the RNA–protein interactome, the regulatory roles of these interactions, as well as up-to-date methods developed for the characterization of the interactome and directions for novel, RNA-directed therapeutics.

An Artificial Intelligence approach to monitor infectious diseases: lessons learned from COVID-19

Abstract Background The World Health Organization declared the start (March 11th 2020) and the end (May 5th 2023) of COVID19 pandemic, while in Italy it has been present since February 2020. Indicators such as number of new positive cases, deaths and hospitalizations are used to monitor epidemiological trends, but they suffer from biases limiting their effectiveness. Methods We used data from the Emergency Medical Services Activities as an alternative and studied three types of contributions: COVID19, flu and baseline during three time frames: -period 1 (July 1st-Oct 11th 2016; Feb 10th-May 20th 2017) used to model the baseline, when flu contribution should be negligible. -Period 2: (Dec 15th-Feb 14th 2017), when flu in 2017 is very evident. -Period 3: (March 11th-31st 2020), when the first COVID19 wave is dominant. To extract the pure contribution from flu and COVID19, the baseline contribution was properly subtracted. Results From these data we developed a machine learning approach (MLA) that offers a simple and powerful tool to monitor COVID19 or future infectious diseases. To maximize the identification power of COVID19, we used the Toolkit for multivariate analysis package. An artificial neural network, multilayer perceptron, deep neural network and boosted decision tree methods have been trained, considering the events in period 3 as signal and period 1 as background. To avoid overtraining, the samples were divided in two: one half to train the algorithm, and the other to check the performance. The results are stable over time and able to efficiently discriminate COVID19. With 50% efficiency of accepting COVID19 patients, roughly 95% of baseline patients can be rejected. Conclusions MLA can be used to early assign a probability of COVID19 without specific test, only relying on standard triage and emergency call details. This tool could be very useful to early detect the presence of new pandemics and tag positive patients before the official healthcare reporting system. Key messages • AI model using data from Emergency Medical Services Activities can be a useful tool to early detect new pandemics and tag positive patients before the official healthcare reporting system. • Covid19 pandemic gave us the possibility to develop new digital tools to use in the analysis of epidemiological trends.

Ablation outcome in elderly women with atrial fibrillation undergoing pulsed-field ablation for electrical isolation of pulmonary veins and left atrial posterior wall

Abstract Background Documented evidences indicate higher prevalence of non-paroxysmal atrial fibrillation (AF) as well as in elderly women but also demonstrate the need to go beyond the pulmonary veins (PV) when treating these patients. Objective We compared the ablation outcome in elderly women (>70 years) with that in men in the same age group as well as in younger women (≤70 years) undergoing pulsed-field ablation (PFA) for persistent AF (PerAF). Methods This multicenter study included consecutive PerAF patients undergoing PFA as their first procedure. Patients were divided into 3 groups: Group 1: women >70 years, Group 2: men ≥70 years and Group 3: women ≤70 years. All received PV isolation (PVI) and isolation of left atrial posterior wall (LAPWI). Concentric overlapping lesions were placed in the LAPW. Number of applications were determined on a case-by-case basis. Isolation was confirmed by electrograms recorded on the multispline catheter. In all patients, ICE and fluoroscopy were used to optimize contact between the PFA catheter and the targeted tissue. Arrhythmia-monitoring was performed for 1-year with periodic clinic visits, event recorders and 7-day Holter monitoring. Results A total of 229 patients (group 1: 73; group 2: 47 and group 3: 109) were included in this analysis. Baseline characteristics of the study population is presented in table 1. At 1-year follow-up, 15 (20.5%), 3 (6.38%) and 10 (9.17%) from group 1, 2 and 3 respectively, experienced arrhythmia recurrence off-antiarrhythmic drugs. Recurrence rate in group 1 was significantly higher than that in group 2 (p=0.034) and group 3 (p=0.029). Conclusion In women aged ≤70 years and in elderly men (>70 years), PVI plus isolation of LAPW using ICE-guided PFA was associated with significantly lower recurrence rate compared to that in the elderly women. Given the higher recurrence rate following PVI+LAPWI in the elderly females, the operators should consider addressing all other AF-initiating extra-PV triggers for better ablation-outcome in this subset of the AF population.

Ablation outcome in patients with atrial fibrillation undergoing ICE-guided pulsed-field ablation

Abstract Background Prior experiences from preclinical studies indicate the critical need of catheter-tissue- contact for creation of consistent transmural lesions in pulsed-field ablation (PFA). Intracardiac echocardiography (ICE) not only provide real-time visualization of cardiac structures, but also ensure adequate contact with the tissue. Objective We evaluated ablation outcome and reconnection rate following ICE-guided PFA procedure in patients with atrial fibrillation (AF). Methods Consecutive patients receiving ICE-guided PFA procedure were included in this multi-center analysis. All patients received isolation of PVs (PVI). Additional ablation of left atrial posterior wall (LAPW) was decided based on operator’s discretion. Concentric overlapping lesions were placed in the LAPW. Number of applications were determined on a case-by-case basis. ICE and fluoroscopy were used to optimize contact between the PFA catheter and the targeted tissue. All procedures were performed under uninterrupted anticoagulation. Mapping was done before and after ablation to confirm electrical isolation. Arrhythmia-monitoring was done for 1-year with periodic clinic visits, event recorders and 7-day Holter monitoring. Results A total of 372 patients [age: 62.69 ± 10.41 years, male: 201 (71.3%), paroxysmal AF: 67 (18%)] were included in this analysis of which 48 (12.9%) underwent PVI-only and the remaining subjects received additional ablation of LAPW. Mean number of applications were 34.67 ± 8.88 and 73.65 ± 37.21 for PVI-only and PVI+LAPWI cohorts respectively (p<0.001). No major procedural complications such as esophageal injury, atrio-esophageal fistula, pericardial effusion requiring drainage or cerebrovascular accidents were reported. During 1-year follow-up, 38 (10.2%) patients underwent repeat procedure for recurrence. Reconnection of PV and LAPW were found in only 2 (5.2%) patients. In all 38 patients, new triggers initiating AF were detected to be originating from interatrial septum: 25 (65.8%), superior vena cava: 9 (23.7%), coronary sinus: 7 (18.4%) and left atrial appendage: 6 (15.8%). Conclusion ICE-guided PFA procedures are safe and produce durable lesions leading to very low reconnection rate. The recurrence was mostly due to new triggers initiating AF.

Alternative splicing in the genome of HPV and its regulation.

Persistent infection with high-risk human papillomavirus (HR-HPV) is the main cause of cervical cancer. These chronic infections are characterized by high expression of the HPV E6 and E7 oncogenes and the absence of the L1 and L2 capsid proteins. The regulation of HPV gene expression plays a crucial role in both the viral life cycle and rare oncogenic events. Alternative splicing of HPV mRNA is a key mechanism in post-transcriptional regulation. Through alternative splicing, HPV mRNA is diversified into various splice isoforms with distinct coding potentials, encoding multiple proteins and influencing the expression of HPV genes. The spliced mRNAs derived from a donor splicing site within the E6 ORF and one of the different acceptor sites located in the early mRNA contain E6 truncated mRNAs, named E6*. E6* is one of the extensively studied splicing isoforms. However, the role of E6* proteins in cancer progression remains controversial. Here, we reviewed and compared the alternative splicing events occurring in the genomes of HR-HPV and LR-HPV. Recently, new HPV alternative splicing regulatory proteins have been continuously discovered, and we have updated the regulation of HPV alternative splicing. In addition, we summarized the functions of known splice isoforms from three aspects: anti-tumorigenic, tumorigenic, and other cancer-related functions, including not only E6*, but also E6^E7, E8^E2, and so on. Comprehending their contributions to cancer development enhances insights into the carcinogenic mechanisms of HPV and explores the potential utility of alternative splicing in the diagnosis and treatment of cervical cancer.

The proliferation and viability of human periodontal ligament stem cells cultured on polymeric scaffolds can be improved by low-level laser irradiation.

This study assessed the impact of low-level laser irradiation on the viability and proliferation of human periodontal ligament stem cells (hPDLSCs) cultivated on polylactic acid (PLA) scaffolds. hPDLSCs were obtained, characterized, and grown on the surface of PLA films produced via the solvent casting technique. The study involved two groups: the control group, which was not exposed to radiation, and the laser group, which was irradiated with a diode laser (InGaAIP) with a power of 30 mW, a wavelength of 660 nm, and a single dose of 1 J/cm² emitted continuously. Cell viability was assessed 24 and 48 hours after irradiation using the Alamar blue and Live/Dead assays. Flow cytometry was used to assess cell cycle events, and scanning electron microscopy (SEM) was used to evaluate the interaction between cells and the biomaterial. The results revealed a statistically significant increase in cell metabolic activity in the laser group compared with the control group at 24 hours (p <0.05) and 48 hours (p <0.001), as indicated by the Alamar blue assay. The Live/Dead assay also revealed a greater density of viable cells in the laser group. The cell cycle analysis revealed a significant increase in the number of cells in the proliferative phase (G2/M) in the laser group compared with the control group (p <0.001). The SEM images demonstrated that the irradiated group had a greater concentration of cells while still maintaining their cell shape and projections. This study demonstrated that photobiomodulation can increase the viability and proliferation of periodontal stem cells cultured on PLA scaffolds, suggesting the potential of this protocol for future studies on periodontal tissue engineering.

Capacity Assessment of a Combined Sewer Network under Different Weather Conditions: Using Nature-Based Solutions to Increase Resilience

Severe weather conditions and urban intensification are key factors affecting the response of combined sewer systems, especially during storm events. In this regard, the capacity assessment of combined sewer networks under the impact of rainfall storm events of different return periods was the focus of this work. The selected case study area was a mixed-use catchment in the city centre of Thessaloniki, Greece. The hydraulic performance of the examined sewer network was assessed using an InfoWorks ICM model. The results indicated that mitigation strategies, such as the application of nature-based solutions (NBSs) or low-impact developments (LIDs) are considered essential for controlling combined sewer overflows. A multicriteria analysis was conducted to select the most appropriate NBSs/LIDs to be located in the study area to enhance the system’s capacity. The results of this multicriteria analysis were used to propose a combined sewer overflow mitigation scenario, based on the installation of green roofs, as the most highly ranked solution in the analysis performed. Incorporating the proposed NBS/LID in the hydrologic-hydraulic model significantly increased the performance of the studied combined sewer network.

Insurance loss model vs. meteorological loss index – how comparable are their loss estimates for European windstorms?

Abstract. Windstorms affecting Europe are among the natural hazards with the largest socio-economic impacts. Therefore, many sectors like society, the economy, or the insurance industry are highly interested in reliable information on associated impacts and losses. In this study, we compare – for the first time – estimated windstorm losses using a simplified meteorological loss index (LI) with losses obtained from a complex insurance loss (catastrophe) model, namely the European Windstorm Model of Aon Impact Forecasting. To test the sensitivity of LI to different meteorological input data, we furthermore contrast LI based on the reanalysis dataset ERA5 and its predecessor ERA-Interim. We focus on similarities and differences between the datasets in terms of loss values and storm rank for specific historical storm events in the common reanalysis period across 11 European countries. Our results reveal higher LI values for ERA5 than for ERA-Interim for all of Europe (by roughly a factor of 10), coming mostly from the higher spatial resolution in ERA5. The storm ranking is comparable for western and central European countries for both reanalyses, confirmed by high correlation values between 0.6 and 0.89. Compared to the Aon Impact Forecasting model, LI ERA5 shows comparable storm ranks, with correlation values ranging between 0.45 and 0.8. In terms of normalized loss, LI exhibits overall lower values and smaller regional differences. Compared to the market perspective represented by the insurance loss model, LI seems to have particular difficulty in distinguishing between high-impact events at the tail of the wind gust distribution and moderate-impact events. Thus, the loss distribution in LI is likely not steep enough, and the tail is probably underestimated. Nevertheless, it is an effective index that is suitable for estimating the impacts of storm events and ranking storm events, precisely because of its simplicity.

Sweet Bread Teaching Factory's Feasibility Projection at Banyuwangi State Polytechnic

This study aims to provide an overview of sweet bread production as an alternative in planning and developing teaching factories based on business feasibility projection analysis. A quantitative technique was applied in this research. Survey techniques and statistical tests were used to examine the hypotheses. To demonstrate that an institution can and should continue its sweet bread business, several variables were measured, including the Internal Rate of Return (IRR), Net Present Value (NPV), Return on Investment (ROI), Benefit–Cost Ratio (B/C ratio), Payback Period (PBP), and Break Event Point (BEP), providing further information for Business Model Canvas analysis of a business model. Based on the BMC, the value propositions are a variety of sweet bread, ease of access, affordable prices, quality, and taste. Key activities include sweetbread production, stock management, marketing and promotion, and customer service. Customer segmentation involves students, lecturers, staff, and institutional visitors. An analysis of financial projections reveals that business is feasible. This can be seen from IRR = 53,19%; the NPV &gt; 0 is equal to IDR 85,222,327; ROI = 216.69%; B/C ratio =1.07; BCR &gt; 1; PBP = 41 months; and BEP = IDR 5,528,669.25. Keywords: teaching factory, sweet bread production, business feasibility, financial projection

Evidence for biomolecular condensates of MatP in spatiotemporal regulation of the bacterial cell division cycle.

An increasing number of proteins involved in bacterial cell cycle events have been recently shown to undergo phase separation. The resulting biomolecular condensates play an important role in cell cycle protein function and may be involved in development of persister cells tolerant to antibiotics. Here we report that the E. coli chromosomal Ter macrodomain organizer MatP, a division site selection protein implicated in the coordination of chromosome segregation with cell division, forms biomolecular condensates in cytomimetic systems. These condensates are favored by crowding and preferentially localize at the membrane of microfluidics droplets, a behavior probably mediated by MatP-lipid binding. Condensates are negatively regulated and partially dislodged from the membrane by DNA sequences recognized by MatP ( matS ), which partition into them. Unexpectedly, MatP condensation is enhanced by FtsZ, a core component of the division machinery previously described to undergo phase separation. Our biophysical analyses uncover a direct interaction between the two proteins, disrupted by matS sequences. This binding might have implications for FtsZ ring positioning at mid-cell by the Ter linkage, which comprises MatP and two other proteins that bridge the canonical MatP/FtsZ interaction. FtsZ/MatP condensates interconvert with bundles in response to GTP addition, providing additional levels of regulation. Consistent with discrete foci reported in cells, MatP biomolecular condensates may facilitate MatP's role in chromosome organization and spatiotemporal regulation of cytokinesis and DNA segregation. Moreover, sequestration of MatP in these membraneless compartments, with or without FtsZ, could promote cell entry into dormant states that are able to survive antibiotic treatments.

Probabilistic risk analysis of local verification of Load Model 1 in Eurocode for Soil-Steel Composite bridges in Sweden

Bridges must be designed to ensure safety for all users. At the same time, the design should be performed with an appropriate risk level. In Sweden, Soil-Steel Composite bridges (SSCB) are the most common bridge type. For SSCB, local verification of Load Model 1 in Eurocode is most often governing the design. The objective of this study was to investigate whether local verification of LM1 load case could be modified without decreasing the agreed risk level in Eurocode. Weight in motion measurements from real traffic were extrapolated with Rice formula. Monte Carlo simulations were used to simulate the 1000-year return period event to obtain the acceptable risk level as prescribed in Eurocode. The results show that the local verification of LM1 is conservative, considering the acceptable risk level in Eurocode. With a modified implementation of local verification, this paper shows that a potential saving of up to 14% in terms of economic cost and CO2-equivalents is possible. A modified implementation of local verification of LM1 in Eurocode for SSCB is proposed, which could reduce the climate impact by up to 14% associated to the construction of new SSCB in Sweden.

Demonstration of a physical inversion scheme for all-sky, day-night IASI observations and application to the analysis of the onset of the Antarctica ozone hole: Assessment of retrievals and consistency of forward modeling

Based on a recently developed all-sky forward model (σ-IASI/F2N) for the computation of spectral radiances in the range 100 to 2760 cm-1, the paper addresses the spring onset of the Antarctica ozone hole with infrared observations from the IASI (Infrared Atmospheric Sounder Interferometer) satellite sounder. The Antarctica ozone hole is a cyclic event that grows in normal conditions in late August and collapses in late November/early December. Because of climate change (cooling of the stratosphere), the O3 hole is expected to become deeper. Indeed, 2021 and 2023 have been characterized by very spatially extensive and deep ozone hole. To demonstrate that we can gain further insights into these phenomena with the help of infrared nadir viewing observations, we have developed an all-sky retrieval tool, which inverts the whole IASI infrared spectrum to simultaneously estimate thermodynamic and geophysical parameters, including ozone and nitric acid, which are key parameters in analyzing the Antarctic ozone hole. Infrared sounders acquire data day and night, unlike visible and ultraviolet sounders, which are only operational during daytime. This enables us to acquire data also during the polar night, which is a critical time for O3 hole formation. Ice polar stratospheric clouds have been identified and fitted with our scheme. Maps of atmospheric ozone, complemented with those of nitric acid, temperature, and lower stratosphere height, have been retrieved for July, September, and October 2021 and 2023. Results are compared to those derived from TROPOMI (TROPOspheric Monitoring Instrument) and OMI (Ozone Monitoring Instrument), showing a very good agreement. The comparison of simultaneously retrieved O3 and HNO3 shows that the onset of the ozone hole is associated with relevant denitrification in the Antarctica Stratosphere. For 2023, our findings also show that O3 depletion episodes began as early as July. Although demonstrative, our analysis evidences the importance of Numerical Weather Prediction centers to assimilating all-sky infrared radiances (day, night, clear, or with ice or water clouds) to get insights into providing a more comprehensive picture of the Southern Spring ozone depletion over Antarctica.

Fluctuations and extreme events in the public attention on Italian legislative elections

The share of social media attention to political candidates was shown to be a good predictor of election outcomes in several studies. This attention to individual candidates fluctuates due to incoming daily news and sometimes reflects long-term trends. By analyzing Twitter data in the 2013 and 2022 election campaign we observe that, on short timescales, the dynamics can be effectively characterized by a mean-reverting diffusion process on a logarithmic scale. This implies that the response to news and the exchange of opinions on Twitter lead to attention fluctuations spanning orders of magnitudes. However, these fluctuations remain centered around certain average levels of popularity, which change slowly in contrast to the rapid daily and hourly variations driven by Twitter trends and news. In particular, on our 2013 data we are able to estimate the dominant timescale of fluctuations at around three hours. Finally, by considering the extreme data points in the tail of the attention variation distribution, we could identify critical events in the electoral campaign period and extract useful information from the flow of data.

Paleoenvironmental Evolution and Organic Matter Enrichment Genesis of the Late Turonian Black Shale in the Southern Songliao Basin, NE China

AbstractThe Upper Cretaceous Qingshankou Formation black shales, deposited in the late Turonian (LTB shales), are the main source rocks of the Songliao Basin. The origins of organic matter enrichment of the shales is a contentious subject fuelling many ongoing debates. This study investigates the genesis of the organic matter‐rich shale by using molecular geochemistry. The LTB shales can be divided into three sections. The Section I shales were deposited in saline, stratified and anoxic water conditions, which are related to seawater incursion events. At least three episodic and periodic seawater incursion events were recognized during Section I shale deposition. The Section II shales deposited in brackish to fresh and deep lake‐level conditions with high primary productivity, which are related to lake‐level transgression. The Section III shales were deposited under fresh and slightly oxidized water conditions, which are related to lake‐level regression. Two organic matter enrichment models for the LTB shales are identified, that is, the seawater incursion model and the maximum lake‐level transgression sedimentation model, which act on different shale sections, both playing significant roles in the enrichment of organic matter.

Cross-environmental cycling of antimicrobial resistance in agricultural areas fertilized with poultry litter: A one health approach

Poultry litter, commonly used as an organic fertilizer, can contain antimicrobial residues, resistant bacteria, and/or antimicrobial resistance genes. After application to soil, these contaminants can reach crops and be transported to aquatic systems through leaching and runoff. Once in water bodies, they can return to soil and crops through irrigation, establishing a cycle that promotes the selection, spread and persistence of antimicrobial resistance. To investigate the hypothesis of a cyclical event, samples of poultry litter, cultivable soil fertilized with this organic residue, rhizosphere soil from Sechium edule (chayote), water, and sediments from irrigation ponds were collected across two agricultural and poultry-producing areas during the dry and rainy seasons. Clinically significant bacteria, especially bacteria belonging to the Enterobacteriaceae family, were isolated. Fifty-three strains exhibited one or more antimicrobial resistance genes, as detected by PCR amplification, including those conferring resistance to sulfonamides (sul1 and sul2), fluoroquinolones (qnrB, qnrA, and qnrS), and β-lactams (blaGES, blaTEM, blaSHV, blaCTX-M-1/2,blaCTX-M-8, and blaCTX-M-14). Genes encoding integrases related to class-1 and 2 integrons (intI1 and intI2) were also observed. A rare occurrence of the blaGES gene was observed in Stenotrophomonas sp. and Brevundimonas sp. Strains of Escherichia sp. were multidrug resistant. Sequencing of the 16S rRNA encoding gene indicated unique operational taxonomic units (OTUs) originating from poultry litter and found in the soil, rhizosphere, water, and sediment, highlighting the dissemination of this material across agricultural substrates. These findings strongly suggest the spread of antimicrobial-resistant bacteria in agricultural environments, posing potential risks to both human and animal health.

Multicenter comparative study of polysomnography outcomes in children with the monogenic disorder sickle cell disease.

Sleep-disordered breathing (SDB) is prevalent in children with sickle cell disease (SCD) and is associated with worse outcomes. This study aims to compare the outcomes of polysomnography (PSG) performed for pediatric patients with SCD at three United States centers. We included children with SCD aged 0-21 who underwent PSG at three American Academy of Sleep Medicine accredited centers: the University of Alabama at Birmingham (UAB), the University of Florida (UF), and Duke University Hospital (DUH), between 2012 and 2022. Descriptive statistics were used as appropriate to compare the baseline characters and PSG outcomes among the different centers. A total of 210 children with SCD from the three centers were included, with comparable sex, SCD genotypes, hemoglobin, hematocrit levels, and chronic transfusion. Children from the different centers exhibited variations in age (P < .001), BMI (P < .05), mean corpuscular volume (P < .05), and hydroxyurea use (P < .05) at the time of the PSG. Overall, the three centers showed significantly different PSG outcomes. Patients from UF had worse obstructive sleep apnea, oxygenation, and periodic leg movement events, together with lower hydroxyurea usage. While those from DUH showed higher hypoventilation and arousal indices. This multicenter study underscores variations in PSG outcomes among pediatric SCD patients at different centers in the Southeast United States. These findings emphasize the need for standardized approaches to screen for SDB, refer to PSG, and interpret the results in children with SCD. These conclusions may apply to other genetic disorders associated with an increased risk of sleep-disordered breathing.

Remotely Sensed Comparative Spatiotemporal Analysis of Drought and Wet Periods in Distinct Mediterranean Agroecosystems

Drought is a widespread natural hazard resulting from an extended period of reduced rainfall, with significant socioeconomic and ecological consequences. Drought severity can impact food security globally due to its high spatial and temporal coverage. The primary objective of this paper consists of a comparative spatiotemporal analysis of environmental extremes (drought/wetness) through the estimation of a twelve-month Standardized Precipitation Index (SPI12) between three distinct vulnerable agricultural regions in the Mediterranean basin (i.e., Spain, Lebanon and Tunisia), under a climate change environment in the last 38 years (1982–2020). The added value of this paper lies in the simultaneous estimation of temporal and spatial variability of drought and wetness periodic events, paying special attention to the geographical patterns of these extremes both in annual and interannual (seasonal) time scales. The results indicated that Spain and Tunisia (western Mediterranean) exhibit similar patterns over the studied period, while Lebanon demonstrates contrasting trends. Comparing the two extreme dry hydrological years, the Spanish study area faced the highest drought intensity, areal extent and duration (SPI12 = −1.18; −1.84; 28–78%; 9–12 months), followed by the Lebanese (SPI12 = −1.28; −1.39; 37–50%; 7–12 months) and the Tunisian ones (SPI12 = −1.05; −1.08; 10–34%; 8 months). Concerning the wettest hydrological years, the Lebanese study domain has recorded the highest SPI12 values, areal extent and duration (SPI12 = 1.58; 2.28; 66–83%; 8–11 months), followed by the Tunisian (SPI12 = 1.55; 1.79; 49–73%; 7–10 months) and Spanish one (SPI12 = 1.07; 1.99; 21–73%; 4–11 months). The periodicity of drought/wetness episodes is about 20 years in Spanish area and 10 years in the Lebanese area (for drought events), whereas there seems no periodicity in the Tunisian one. Understanding the spatial distribution of drought is crucial for targeted mitigation strategies in high-risk areas, potentially avoiding broad, resource-intensive measures across entire regions.

Germination responses to changing rainfall timing reveal potential climate vulnerability in a clade of wildflowers.

The seasonal timing of life history transitions is often critical to fitness, and many organisms rely upon environmental cues to match life cycle events with favorable conditions. In plants, the timing of seed germination is mediated by seasonal cues such as rainfall and temperature. Variation in cue responses among species can reflect evolutionary processes and adaptation to local climate and can affect vulnerability to changing conditions. Indeed, climate change is altering the timing of precipitation, and germination responses to such change can have consequences for individual fitness, population dynamics, and species distributions. Here, we assessed responses to the seasonal timing of germination-triggering rains for eleven species spanning the Streptanthus/Caulanthus clade (Brassicaceae). To do so, we experimentally manipulated the onset date of rainfall events, measured effects on germination fraction, and evaluated whether responses were constrained by evolutionary relationships across the phylogeny. We then explored the possible consequences of these responses to contemporary shifts in precipitation timing. Germination fractions decreased with later onset of rains and cooler temperatures for all but three Caulanthus species. Species' germination responses to the timing of rainfall and seasonal temperatures were phylogenetically constrained, with Caulanthus species appearing less responsive. Further, four species are likely already experiencing significant decreases in germination fractions with observed climate change, which has shifted the timing of rainfall towards the cooler, winter months in California. Overall, our findings emphasize the sensitivity of germination to seasonal conditions, underscore the importance of interacting environmental cues, and highlight vulnerability to shifting precipitation patterns with climate change, particularly in more northern, mesic species.

Arrival-breeding interval is flexible in a songbird and is not constrained by migration carry-over effects.

As spring phenology advances with climate change, so too must the timing of life cycle events. Breeding at the right time is critical in many species as it maximizes fitness. For long-distance migratory birds, flexibility in the duration of the arrival-breeding interval (pre-breeding period) may allow populations to adjust their timing of breeding. However, whether first egg-lay dates are flexible to local environmental conditions after arrival, and if they are constrained by the time needed to replenish energy lost during migration, remains unclear. We investigated the regional flexibility of the arrival-breeding interval in an avian migrant, the purple martin, Progne subis, across their breeding range. We evaluated whether the duration of the arrival-breeding interval was flexible to temperature and precipitation at breeding sites, and if timing was limited by migration rate and stopover duration. We also tested if longer interval durations were associated with higher fledging success. To address our hypotheses, we used a combination of migration tracking, weather and breeding data collected from four regions across eastern North America (26.1° N to 52.4° N latitude). We found the arrival-breeding interval to be shortest in the north and longest in the south. Across all regions, warmer temperatures encountered at breeding grounds were associated with shorter intervals, and faster migration rates led to longer intervals. The length of the interval was not influenced by precipitation or stopover duration. Finally, longer intervals were not associated with higher fledge success. Currently, the longer arrival-breeding intervals in this study system, on average 28.3 days, may provide both early and late-arriving birds with ample time for recovery so birds can lay eggs according to temperature. Any negative effects of faster migration may have been buffered by longer arrival-breeding intervals, as interval length did not determine fledge success. With ongoing climate change, further research is needed to examine if arrival-breeding intervals become constrained by migration timing, which may limit opportunities for migrants to match the timing of breeding with key resources.