Season Interaction Research Articles

Seasonal coral-algae interactions drive White Mat Syndrome coral disease outbreaks

Ocean warming drives not only the increase of known coral disease prevalence but facilitates the emergence of new undescribed ones too. As climate change is restructuring coral ecosystems, novel biological interactions could lead to an increase in coral disease in both tropical and marginal coral communities. White Mat Syndrome (WMS) represents one such emerging coral disease, with outbreaks associated with high algal interactions and seasonal summer temperatures. However, the mechanisms behind its pathogenesis, modes of transmission and causative pathogens remain to be identified. Ex situ infection experiments pairing the coral Porites heronensis together with local potential contributory factors show that the macroalga Gelidium elegans hosts and proliferates the WMS microbial mat. This pathogenic consortium then infects adjacent corals, leading to their mortality. WMS was also observed to transmit following the fragmentation of the microbial mat, which was able to infect healthy corals. Sulfur-cycling bacteria (i.e., Beggiatoa, Desulfobacter sp., Arcobacteraceae species) and the free-living spirochete Oceanospirochaeta sediminicola were found consistently in both WMS and G. elegans consortia, suggesting they are putative pathogens of WMS. The predicted functional roles of these pathogenic consortia showed degradative processes, hinting that tissue lyses could drive mat formation and spread. Coral-algae interactions will rise due to ongoing ocean warming and coral ecosystem degradation, likely promoting the virulence and prevalence of algal-driven coral diseases.

Exploring Effective Detection and Spatial Pattern of Prickly Pear Cactus (Opuntia Genus) from Airborne Imagery before and after Prescribed Fires in the Edwards Plateau

Over the past century, prickly pear (PP) cactus (e.g., genus Opuntia; subgenus Platyopuntia) has increased on semi-arid rangelands. Effective detection of cacti abundance and spatial pattern is challenging due to the inherent heterogeneity of rangeland landscapes. In this study, high-resolution multispectral imageries (0.21 m) were used to test object-based (OB) feature extraction, random forest (RF) machine learning, and spectral endmember (n-D) classification methods to map PP and evaluate its spatial pattern. We trained and tested classification methods using field-collected GPS location, plant cover, and spectrometry from 288 2 m radius polygons before a prescribed burn and 480 samples after the burn within a 69.2-ha burn unit. The most accurate classification method was then used to map PP distribution and quantify abundance before and after fire. As a case study, we assessed the spatial pattern of mapped PP cover, considering topoedaphic setting and burn conditions. The results showed that the endmember classification method, spectral angle mapper (SAM), outperformed the RF and OB classifications with higher kappa coefficients (KC) (0.93 vs. 0.82 and 0.23, respectively) and overall accuracies (OA) (0.96 vs. 0.91 and 0.49) from pre-fire imagery. KC and OA metrics of post-fire imagery were lower, but rankings among classification methods were similar. SAM classifications revealed that fire reduced PP abundance by 46.5%, but reductions varied by soil type, with deeper soils having greater decreases (61%). Kolmogorov-Smirnov tests indicated significant changes before and after fire in the frequency distribution of PP cover within deeper soils (D = 0.64, p = 0.02). A two-way ANOVA revealed that the interaction of season (pre- vs. post-fire) and soils significantly (p < 0.00001) influenced the spatial pattern of PP patches. Fire also reduced the size and shape of PP patches depending on the topoedaphic settings. This study provides an innovative and effective approach for integrating field data collection, remote sensing, and endmember classification methods to map prickly pear and assess the effects of prescribed fire on prickly pear spatial patterns. Accurate mapping of PP can aid in the design and implementation of spatially explicit rangeland management strategies, such as fire, that can help reduce and mitigate the ecological and economic impacts of prickly pear expansion.

Species traits drive responses of forest birds to agriculturally‐modified habitats throughout the annual cycle

The conversion of forest to agriculture is considered one of the greatest threats to avian biodiversity, yet how species respond to habitat modification throughout the annual cycle remains unknown. We examined whether forest bird associations with agricultural habitats vary throughout the year, and if species traits influence these relationships. Using data from the eBird community‐science program, we investigated associations between agriculturally‐modified land cover and the occurrence of 238 forest bird species based on three sets of avian traits: migratory strategy, dietary guild, and foraging strategy. We found that the influence of agriculturally‐modified land cover on species distributions varied widely across periods and trait groups but highlighting several broad findings. First, migratory species showed strong seasonal differences in their response to agricultural land cover while resident species did not. Second, there was a migratory strategy by season interaction; Neotropical migrants were most negatively influenced by agricultural land cover during the breeding period while short‐distance migrants were most negatively influenced during the non‐breeding period. Third, regardless of season, some dietary (e.g. insectivores) and foraging guilds (e.g. bark foragers) consistently responded more negatively to agricultural land cover than others (e.g. omnivores and ground foragers, respectively). Fourth, there were greater differences among dietary guilds in their responses to agricultural land cover during the breeding period than during the non‐breeding period, perhaps reflecting how different habitat and ecological requirements enhance the susceptibility of some guilds during reproduction. These results suggest that management efforts across the annual cycle may be oversimplified and thus ineffective when based on broad ecological generalisations that are static in space and time.

Species Complex of Leaf Roller Infesting Litchi (<i>Litchi chinensis</i> Sonn.) In West Bengal with their Seasonal Incidence

An experiment was conducted at Fruit Research Station, Mandauri, Bidhan Chandra Krishi Viswavidyalaya with a view to rule out the leaf roller species complex associated with litchi (Litchi chinensis) in West Bengal. The result revealed that three species namely litchi leaf roller, Gatesclarkeana sp. (Lepidoptera: Tortricidae); leaf webber, Dudua aprobola Meyrick (Lepidoptera: Tortricidae); litchi leaf roller, Statherotis leucaspis Meyrick (Lepidoptera: Tortricidae) were associated with the crop and hence their seasonal incidence and interaction with abiotic factors have also been studied. Among the species Gatesclarkeana sp. was found least abundant and occasionally observed during fruiting season while Dudua aprobola observed only in copper leaf stage or in soft tender leaves. Statherotis leucaspis was observed as most dominant species in basin of West Bengal which has not yet been reported from the state. The pest remained very active from 26th standard meteorological week and continued upto 47th standard week. Interestingly the same pest was observed during panicle initiation stage to flowering stage, attacking the panicle (maximum 23.75%) which led direct yield loss.

Transvaluate of genotype × environment × season interaction of agronomic traits and bioactive compounds of Withania somnifera (L.) Dunal in the Deccan plateau region

The exegesis of ashwagandha (Withania somnifera L.) types related to various seasons was the focus of the current investigation. A field study was conducted at the CSIR-Central Institute of Medicinal and Aromatic Plants experimental field in Hyderabad, India, using a factorial randomized block design with three replicates over two years and four seasons (Kharif and Rabi). The all three factors were made up of with two years (2020–2021 and 2021–2022), eight varieties (Red berry, JA-134, Poshita, CIMAP-Pratap, CIMAP-Chetak, NMITLI-118, NMITLI-101, CIM-Pushti), and two seasons (Kharif and Rabi) respectively. Plant growth indices (plant height, number of branches plant–1), phenological parameters (day to flower initiation and days to root harvest), yield attributes (main root length, root diameter, dry root yield hectare–1, and seed yield hectare–1) quality traits (starch content, fiber content, starch fiber ratio, and total alkaloid estimation) were evaluated. Research findings contribute to understanding of how seasons influence the characteristics of ashwagandha cultivars and their overall agronomic performance. Understanding how environmental factors, such as seasons, affect plant growth and development is crucial for optimizing agricultural practices and improving crop yields. The results obtained in this study can be used to select specific varieties for specific seasonal conditions and identify varieties that perform better in both states. Irrespective of the variety used, both seasons (Kharif and Rabi) produce higher dry root yield per hectare, and the rabi season yields superior results in terms of starch fiber ratio and total alkaloid content in ashwagandha. CIM-Pushti, NMITLI-101, and Poshita achieved good results concerning yield and quality aspects in the Kharif season. CIM-Pushti, NMITLI-101, and CIMAP-Pratap performed admirably during the Rabi season. CIM-Pushti and NMITLI-101 provide superior agronomic performance in both seasons (Kharif and Rabi).

Diagnosing the compound seasonal soil moisture-hydroclimate interaction regime on the Tibetan Plateau using multi-high-resolution reanalysis products and one regional climate model

Land-atmosphere energy and moisture exchanges exert great impacts on local and regional climate. However, high uncertainties exist in the recent land–atmosphere interactions due to scarce observations and difficulties in modeling at high elevations and cold regions. This study applied multiple high-resolution reanalysis products (ERA5-land, GLDAS Noah and CLSM products) and one regional climate model, RegCM4, to diagnose the interaction pattern and strength of seasonal soil moisture and hydroclimate on the Tibetan Plateau (TP) using a conditional correlation coefficient method and the global land–atmosphere coupling experimental modeling approach. A compound aggregation method is applied to recognize hot spots with strong soil moisture-hydroclimate interactions among multiple data. As a result, the Changtang Plateau in the inner TP, the sources of the Yellow, Yangtze, Mekong, Salween, and Lancang Rivers and part of the Brahmaputra River basin in the south-southeastern TP are diagnosed with strong land–atmosphere interactions in most seasons. In summer, the coupling strength is stronger, and the covered area is much wider and spatially continuous as the climate turns warm. All applied data indicate a positive dominant soil moisture-precipitation feedback, and a negative soil moisture-temperature feedback at the hot spots. Meanwhile, the soil moisture-runoff feedback is strong and positive at most parts of the TP, especially at the hot spots and in summer. Evapotranspiration acts as a positive linkage in the soil moisture-precipitation-temperature interactions, while the nexus of soil moisture, evapotranspiration and runoff is complicated. This study contributes to understanding local land-hydroclimate interactions in the high elevation and cold climate of the TP. Additionally, the found the proposed compound aggregation method efficient for compound studies.

Differences in body temperature regulation during heat stress and seasonal depression in milk yield between Holstein, Brown Swiss, and crossbred cows

It is not clear whether cattle that are genetically superior in regulation of body temperature during heat stress are also better able to sustain milk production during hot conditions. Objectives were to evaluate differences in body temperature regulation during heat stress between Holstein, Brown Swiss, and crossbred cows under semi-tropical conditions and test whether the seasonal depression in milk yield was greater for genetic groups less able to regulate body temperature. For the first objective, conducted during heat stress, vaginal temperature was measured at 15-min intervals for 5 d in 133 pregnant lactating cows. Vaginal temperatures were affected by time and interaction between genetic group and time. Vaginal temperatures were higher for Holsteins for most times of the day. Moreover, the maximum daily vaginal temperature was higher for Holstein (39.8 ± 0.1°C) than for Brown Swiss (39.3 ± 0.2°C) or crossbreds (39.2 ± 0.1°C). For the second objective, 6,179 lactation records from 2,976 cows were analyzed to determine effects of genetic group and season of calving (cool season = Oct to March; warm season = April to Sept) on 305-d milk yield. Milk yield was affected by genetic group and season but not by the interaction of genetic group and season. The difference in average 305-d milk yield between cows calving in cool versus hot weather was 310 kg (4% decrease) for Holstein, 480 kg (7% decrease) for Brown Swiss, and 420 kg (6% decrease) for crossbreds. In conclusion, Brown Swiss and crossbreds regulated body temperature during heat stress better than Holsteins but these breeds were not more resistant to heat stress with respect to milk yield. Thus, genetic differences in thermotolerance are likely to exist that are independent of regulation of body temperature.

Total and Differential Somatic Cell Count in Italian Local Cattle Breeds: Phenotypic Variability and Effect on Milk Yield and Composition.

Milk differential somatic cell count (DSCC) represents the percentage of polymorphonuclear neutrophils and lymphocytes out of the total somatic cell count (SCC) and has been proposed in recent years as a proxy for udder health in dairy cows. We investigated phenotypic factors affecting SCC and DSCC using 3978 records of 212 Alpine Grey and 426 Burlina cows farmed in Northern Italy. The linear mixed model accounted for the fixed effects of breed, parity, lactation stage, sampling season, and first-order interactions of breed with the other effects. Cow, herd-test-date nested within breed were random. Subsequently, four udder health status groups (UHS) were created by combining SCC and DSCC to assess the UHS impact on milk yield and quality. DSCC was greater in Alpine Grey (66.2 ± 0.8%) than Burlina cows (63.2 ± 0.6%) and, similarly to SCC, it increased with days in milk and parity regardless of breed. Milk yield and composition were affected by UHS in both breeds. These results suggest that also udder health of local breeds can be monitored on a large scale through SCC and DSCC for reduction in biodiversity loss and increased farm profitability. However, in addition to milk data, the introduction of mastitis recording and monitoring plans is advisable.

Ecohydrological niche segregation among desert shrubs in a gypsum-calcareous formation, north-western Iran

ABSTRACT Background Xerophilic subshrubs exhibit multiple functional types and frequently show hydrological niche segregation. In the poorly studied Irano-Turanian gypsum deserts, knowledge of the ecohydrological strategies of different plant species is essential to understand community complexity in these vulnerable ecosystems. Aim We studied the ecohydrological strategies of five co-existing subshrub members of Caryophyllales, ascertaining if their rooting architecture, gypsum affinity or photosynthetic pathway determined their water uptake, and if gypsum crystallisation water could be a relevant water source for plants in different seasons. Methods We conducted soil and xylem sampling for isotope analyses in spring and summer and extracted water by cryogenic vacuum distillation. Oxygen and hydrogen isotope compositions were determined and compared with visual representation and Bayesian Mixing Models to determine species ecohydrological strategies. Results Species – season interactions were related to differences in xylem sap isotopic composition. Three basic strategies relying on contrasting the use of free topsoil moisture and deep soil water could be detected and were in part explained by rooting architecture. Plant gypsum affinity and photosynthetic pathways did not have a significant effect on the water sources used by the plants. Conclusions Ecohydrological niche segregation was explained partly by rooting architecture and species-specific traits. Gypsum crystallisation water was not used in summer by the studied species.

Cowpea Yield Under Water Stress Scenarios

Cowpea is considered a subsistence crop, so it is generally cultivated by family farming in the rainy season and, outside this season, with the aid of irrigation. Its yield is reduced if there is water stress due to the lack of rainfall or irrigation water. Objective of this study was to evaluate the influence of water stress in the rainy and dry seasons on grain yield, biomass, harvest index and water use efficiency in the ‘Costela de Vaca’ cowpea variety cultivated in no-tillage system using crop residues present in the experimental area. Experimental design used was randomized blocks, in a 2 x 5 factorial scheme (cropping season x water stress), with four replicates. Treatments consisted of two cropping seasons (rainy and dry) and five forms of water stress (without water stress, water suspension for 5, 10 and 15 days, and rainfed cultivation). Biomass was the only parameter influenced by the cropping season versus water stress interaction. Regardless of the cowpea cropping season, water stress reduced grain yield and biomass. Harvest index showed no sensitivity to water stress and cropping season. Water use efficiency was influenced by the cropping season. Soil cover promoted maintenance of soil moisture during cowpea cultivation in both periods.

Feeding habit and intensity of Periophthalmus variabilis caught from some coastal provinces in the Mekong Delta, Vietnam

Dusky-gilled mudskipper Periophthalmus variabilis, a member of the family Gobiidae, is a potential aquarium pet in the Mekong Delta (MD), Vietnam; however, data on its feeding habit and intensity has been limited. Therefore, this study aims to evaluate the relative gut length (RGL) and gastro-somatic index (GI) of Periophthalmus variabilis in order to determine the feeding habit and intensity of this mudskipper and its variation regarding sex, size, season, site, and their interaction. One thousand one hundred seventy mudskipper samples were collected monthly in four locations: Duyen Hai-Tra Vinh, Tran De-Soc Trang, Hoa Binh-Bac Lieu, and Dam Doi-Ca Mau from January 2022 to December 2022. The analysis showed that Periophthalmus variabilis was a carnivorous fish with an average RGL value of 0.52±0.01 SE (<1). In addition, the RGL of this species varied and depended on size, sampling site, season, and the interaction of both size and season with locations. The GI of the mudskipper was 4.27±0.29 SE, indicating that its feeding intensity belonged to the moderate category and varied with size and site but not sex, season, and interactions. These results supplement novel knowledge on its feeding habit and intensity, a basis for researching the aquaculture of Periophthalmus variabilis in MD.

Assessing pregnancy outcomes in cow-calf operations after administration of modified-live or killed virus vaccinations at the initiation of synchronization for fixed-time AI

The objective of this study was to compare the reproductive outcomes (artificial insemination [AI] pregnancy rates, season pregnancy rates, AI pregnancy losses) and calf traits (birth and weaning weights) after vaccination of suckled beef cows against bovine herpesvirus 1 and bovine viral diarrhea virus using commercially-available modified-live virus (MLV) or killed virus (KV) vaccine at the initiation of a fixed-time AI program. Previously-vaccinated cows (n = 2138) on 14 farms throughout Virginia were enrolled in the study during the Fall 2017 and Spring 2018 breeding seasons. Animals received a single vaccination injection at 10 d pre-breeding, corresponding with time of CIDR insertion at initiation of the 7-d CO-Synch + CIDR synchronization protocol. Cows were inseminated at a fixed time (60–66 h after removal of the CIDR insert) and subsequently turned out with bulls approximately 1 wk after insemination for a natural service. Cows treated with the MLV vaccine had greater AI pregnancy rates than cows treated with the KV vaccine during the fall (P = 0.008; 54% vs. 46%, respectively), but not during the spring breeding season (P = 0.62; 48 vs. 49%). Season pregnancy rates were greater (P = 0.01) in the fall (95–96%) than in the spring breeding season (89–90%), but were not affected by vaccine treatment (P = 0.49) or treatment by season (P = 0.30) interactions. Percentage of AI pregnancy losses was not affected by season (P = 0.85), vaccine treatment (P = 0.83), or treatment by season interactions (P = 0.68). The number of cycles it took for cows to become pregnant by natural service differed by season (P = 0.006) but not treatment (P = 0.87) or treatment by season interaction (P = 0.997). Cows treated with the MLV vaccine gave birth earlier in the calving season (8.36 ± 0.6 d) than those treated with the KV vaccine (10.31 ± 0.6 d; P = 0.02). There was a main effect of season on birth weights (P = 0.008), weaning weights (P < 0.001), and ADG at weaning (P < 0.001), but no effects of treatment (P ≥ 0.26) or treatment by season interaction (P ≥ 0.10) on any of these parameters. Overall, this study demonstrated that the administration of an MLV vaccine at 10 d before fixed-time AI did not have any adverse effects on pregnancy or calf outcomes compared with KV vaccine administration.

Seed dormancy revisited: Dormancy‐release pathways and environmental interactions

Abstract Many internal (inherent) and environmental (imposed) factors control seed dormancy and germination that we divide into three basic dormancy‐release pathways: Maternal structures and embryo physiology control inherent dormancy that is broken by various types of scarification and physiological changes, followed by imposed‐dormancy release when the prevailing environment is replaced by certain ‘standard’ conditions that stimulate germination (Pathway 1); imposed dormancy prevails even if inherent dormancy is broken or not applicable that is released when replaced by certain ‘standard’ environmental conditions which stimulate germination (Pathway 2); and release from inherent dormancy by light/dark or cold stratification is contingent on the pre‐existence of certain environmental conditions that stimulate germination (Pathway 3). On‐plant seed storage (serotiny) and frugivorous seeds are recognized here as representing special types of physical dormancy, as their properties are consistent with those of hard diaspores. Warm stratification does not require seeds to be moist as it is just a physical response. Heat may promote germination of non‐hard, as well as hard, seeds as it may increase their permeability further. Levels of germination gauge the net effect of inherent‐ and imposed‐dormancy release so that it is only possible to identify the extent of inherent‐dormancy release when conditions for germination are optimal (imposed dormancy has been annulled). While imposed dormancy may be protracted after inherent dormancy is broken by heat or chilling during the dry or cold seasons, release from both states may effectively coincide if smoke chemicals or light are received during the (wet) growing season. We suggest reserving the term secondary dormancy for seeds that return to (inherent or imposed) dormancy due to changed environmental conditions. Under seasonal climates, fluctuations in environmental conditions can lead to secondary dormancy and even dormancy cycling. We recognize four types of functional interactions between any two environmental factors that induce inherent‐dormancy release: binary interactions are ineffective, only one stimulus is effective, both are effective but non‐additive, or both are additive/synergistic. Two environmental stimuli that individually break dormancy but have no additive effect must be affecting the same process; this was demonstrated here for some interactions between heat and smoke. The three dormancy‐release pathways, together with internal, seasonal and stochastic interactions, are coordinated by the non‐dormant seed to ensure maximum germination under optimal conditions. To ignore any aspect outlined here leads to an impoverished understanding of the disparate seed ecology of species adapted to different stressful and disturbance‐prone habitats. Read the free Plain Language Summary for this article on the Journal blog.

Contrasting Mechanisms Determine the Microeukaryotic and Syndiniales Community Assembly in a Eutrophic bay.

Syndiniales is a diverse parasitic group, increasingly gaining attention owing to its high taxonomic diversity in marine ecosystems and inhibitory effects on the dinoflagellate blooms. However, their seasonal dynamics, host interactions, and mechanisms of community assembly are largely unknown, particularly in eutrophic waters. Here, using 18S rRNA gene amplicon sequencing, we intended to elucidate the interactions between Syndiniales and microeukaryotes, as well as community assembly processes in a eutrophic bay. The results showed that Syndiniales group II was dominating throughout the year, with substantially higher abundance in the winter and spring, whereas Syndiniales group I was more abundant in the summer and autumn. Temperature and Dinoflagellata were the most important abiotic and biotic factors driving variations of the Syndiniales community, respectively. The assembly processes of microeukaryotes and Syndiniales were completely different, with the former being controlled by a balance between homogeneous selection and drift and the latter being solely governed by drift. Network analysis revealed that Syndiniales group II had the largest number of interactions with microeukaryotes, and they primarily associated with Dinoflagellata in the winter, while interactions with Chlorophyta and Bacillariophyta increased dramatically in summer and autumn. These findings provide significant insights in understanding the interactions and assembly processes of Syndiniales throughout the year, which is critical in revealing the roles of single-celled parasites in driving protist dynamics in eutrophic waters.

Assessing chronic stress in wild mammals using claw-derived cortisol: a validation using European badgers (Meles meles).

Measuring stress experienced by wild mammals is increasingly important in the context of human-induced rapid environmental change and initiatives to mitigate human-wildlife conflicts. Glucocorticoids (GC), such as cortisol, mediate responses by promoting physiological adjustments during environmental perturbations. Measuring cortisol is a popular technique; however, this often reveals only recent short-term stress such as that incurred by restraining the animal to sample blood, corrupting the veracity of this approach. Here we present a protocol using claw cortisol, compared with hair cortisol, as a long-term stress bio-indicator, which circumvents this constraint, where claw tissue archives the individual's GC concentration over preceding weeks. We then correlate our findings against detailed knowledge of European badger life history stressors. Based on a solid-phase extraction method, we assessed how claw cortisol concentrations related to season and badger sex, age and body-condition using a combination of generalized linear mixed models (GLMM) (n= 668 samples from 273 unique individuals) followed by finer scale mixed models for repeated measures (MMRM) (n= 152 re-captured individuals). Claw and hair cortisol assays achieved high accuracy, precision and repeatability, with similar sensitivity. The top GLMM model for claw cortisol included age, sex, season and the sex*season interaction. Overall, claw cortisol levels were significantly higher among males than females, but strongly influenced by season, where females had higher levels than males in autumn. The top fine scale MMRM model included sex, age and body condition, with claw cortisol significantly higher in males, older and thinner individuals. Hair cortisol was more variable than claw; nevertheless, there was a positive correlation after removing 34 outliers. We discuss strong support for these stress-related claw cortisol patterns from previous studies of badger biology. Given the potential of this technique, we conclude that it has broad application in conservation biology.

Automated identification system for ships data as a proxy for marine vessel related stressors

An increasing number of marine conservation initiatives rely on data from Automatic Identification System (AIS) to inform marine vessel traffic associated impact assessments and mitigation policy. However, a considerable proportion of vessel traffic is not captured by AIS in many regions of the world. Here we introduce two complementary techniques for collecting traffic data in the Canadian Salish Sea that rely on optical imagery. Vessel data pulled from imagery captured using a shore-based autonomous camera system (“Photobot”) were used for temporal analyses, and data from imagery collected by the National Aerial Surveillance Program (NASP) were used for spatial analyses. The photobot imagery captured vessel passages through Boundary Pass every minute (Jan–Dec 2017), and NASP data collection occurred opportunistically across most of the Canadian Salish Sea (2017–2018). Based on photobot imagery data, we found that up to 72 % of total vessel passages through Boundary Pass were not broadcasting AIS, and in some vessel categories this proportion was much higher (i.e., 96 %). We fit negative binomial General Linearized Models to our photobot data and found a strong seasonal variation in non-AIS, and a weekend/weekday component that also varied by season (interaction term p < 0.0001). Non-AIS traffic was much higher during the summer (Apr–Sep) and during the weekend (Sat-Sun), reflecting patterns in recreational vessel traffic not obligated to broadcast AIS. Negative binomial General Additive Models based on the NASP data revealed strong spatial associations with distance from shore (up to 10 km) and non-AIS vessel traffic for both summer and winter seasons. There were also associations between non-AIS vessels and marina and anchorage densities, particularly during the winter, which again reflect seasonal recreational vessel traffic patterns. Overall, our GAMs explained 20–37 % of all vessel traffic during the summer and winter, and highlighted subregions where vessel traffic is under represented by AIS.

Hydrologic Control on Arsenic Cycling at the Groundwater-Surface Water Interface of a Tidal Channel.

Historical industrial activities have resulted in soil contamination at sites globally. Many of these sites are located along coastlines, making them vulnerable to hydrologic and biogeochemical alterations due to climate change and sea-level rise. However, the impact of hydrologic dynamics on contaminant mobility in tidal environments has not been well studied. Here, we collected data from pressure transducers in wells, multi-level redox sensors, and porewater samplers at an As-contaminated site adjacent to a freshwater tidal channel. Results indicate that sharp redox gradients exist and that redox conditions vary on tidal to seasonal timescales due to sub-daily water level fluctuations in the channel and seasonal groundwater-surface water interactions. The As and Fe2+ concentrations decreased during seasonal periods of net discharge to the channel. The seasonal changes were greater than tidal variations in both Eh and As concentrations, indicating that impacts of the seasonal mechanism are stronger than those of sub-daily water table fluctuations. A conceptual model describing tidal and seasonal hydro-biogeochemical coupling is presented. These findings have broad implications for understanding the impacts of sea-level rise on the mobility of natural and anthropogenic coastal solutes.

The accuracy of 8-hour ambulatory blood pressure monitoring, adjusted to seasons.

Ambulatory blood pressure monitoring (ABPM) is considered the most reliable and accurate measurement of blood pressure (BP). However, the use of ABPM has some limitations, which make it difficult to complete for the entire 24 h. We aimed to establish in which part of the day BP measurements are in highest correlation with full ABPM (over 24 h) results. We performed a retrospective cross-sectional study which included 3113 full ABPM. Each ABPM was divided into 6- and 8-hour segments, and mean BP in each time segment was calculated. Linear mix models for describing BP by BP in each time segment were performed. A total of 3113 ABPM measurements carried out on 2676 patients (mean age 57.78 ± 14.74) were included in the study. Linear mix models demonstrated significant association between mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) in full ABPM, and SBP and DBP between 2-10 PM, respectively (SBP: β = 0.902, p < 0.001; DBP: β = 0.839, p < 0.001), adjusted for gender, age, season, and relevant interactions. This section had higher coefficient correlations than other sections which were examined. The study findings indicate high correlation between BP between 2-10 PM, and BP in full-ABPM, by each season. This time segment may be ideal for short-term BP monitoring as an initial screening test and for patients who are unable to complete full ABPM. However, since this time segment does not include nighttime hours, there is a risk of underdiagnosis of non-dipper.

Conservation agriculture practices lead to diverse weed communities and higher maize grain yield in Southern Africa

Weed development is one of the major constraints to cereal cropping systems in Southern Africa with potential severe crop losses. Understanding weed community responses to different conservation agriculture (CA) components ( i.e ., no-tillage, NT; crop rotation, R; and mulching, M) and/or their combinations is crucial in Southern Africa where farmers apply different combinations depending on local context. Here, for the first time, we assessed how weed density, community diversity and structure respond to different combinations of CA components [conventional tillage (CT), CT+M, CT+R, CT+M+R, NT, NT+M, NT+R, NT+M+R]. The study was carried out over three seasons at two locations with contrasting soil textures i.e ., clayish, and sandy. At the sandy location, across seasons, weed density (number of individuals per unit area) and community diversity (distribution of individuals within the species) were significantly and positively affected by precipitation and not by cropping system. Weed richness (number of species) was affected by the interaction of season and cropping system, with the highest number of weed species being recorded in the NT+M+R system in the seasons with medium to high precipitation. At the clayish location, an opposite pattern was observed, and weed density was lower in seasons with medium-high precipitation than under low precipitation. Weed community diversity was 50 % higher under NT+M than under CT+R, whereas weed species richness decreased with the increase of precipitation. At both locations, the implementation of rotation and mulching either in NT or CT systems resulted in the modification of the structure of weed community with respect to CT and NT alone, and these CA combinations were associated with highest maize grain yield. Overall, eight weed species common to both locations were responsible for most of the community structure differences among cropping systems. Structural equation modelling showed that at the sandy location precipitation did not affect grain yield, but positively affected weed density, diversity, evenness, and richness. By contrast, at the clay location, precipitation positively affected grain yield, but did not modify weed density and evenness, and reduced weed community diversity and richness. At this location, weed density negatively affected grain yield. The differential weed-crop relationship supports the need to find a site-specific equilibrium between the control of weeds and the maintenance of their diversity. • Rotation & mulch in no-tillage-NT & conventional tillage-CT modified weed community. • In sandy soil rainfall positively affected weed density & diversity and not yield. • In sandy soil weed diversity positively affected grain yield. • In clay soil rainfall positively affected yield & reduced weed diversity & richness. • In clay soil, weed density negatively affected grain yield.

Türkiye’ye Ait Yerel Ekmeklik Buğday Çeşitlerinden Seçilen Saf Hatlar ile Bazı Tescilli Çeşitlerin Tane Kalite Özelliklerinin Belirlenmesi

Bread wheat landraces are considered among important gene sources for quality breeding programs. This study aims to compare thousand kernel weight crude protein ratio, dry gluten ratio, grain hardness and zeleny sedimentation results of 20 bread wheat lines selected from landraces to 5 registered cultivars in order to determine future candidates for quality breeding programs. Field experiments were conducted in the consequent 2012-2013 and 2013-2014 growing seasons in Çanakkale (Türkiye), according to randomized complete block design with three replications. ANOVA results indicated significant difference among genotypes, means were compared with Duncan’s test. Additionally, genotype × growing season interaction were significant for all parameters. Results of cluster and PCA Biplot analysis revealed a significant and positive relationship between crude protein ratio and dry gluten ratio while allowing for the selection of superior landrace pure lines. Our findings suggested that bread wheat varieties had higher TKW compared to landrace pure lines when pure lines had higher crude protein ratio, dry gluten ratio, sedimentation value with generally softer grains. Bread wheat landraces were concluded as being important variation sources.