Faster Rate Of Development Research Articles

Влияние различных факторов риска на формирование вторичных органических психических расстройств у лиц пожилого возраста с алкогольной зависимостью, сформированной в среднем и пожилом возрасте

Background. Alcohol slows down the work of the brain and central nervous system, leads to deterioration of memory and concentration, cognitive disorders, and the formation of organic mental disorders. Due to the retirement of elderly people, some of them resort to taking alcohol as an adaptogen to alleviate various social, mental and psychological disorders, which can lead to the emergence of new or exacerbation of existing somatic disorders, the formation of alcoholism, as well as organic mental disorders. Aim. To investigate the risk factors (RF) for the formation of secondary organic mental disorders (SOMD) in elderly people with alcohol dependence (AD), formed in middle and old age. Patients and methods. The study included only male patients for the purity of the study aged 60 to 74 years (average age 67.5±7.2), who were divided into 2 groups depending on the age of occurrence of AD: group 1 – 21 people (36.2%), AD occurred at the age of 51.6±1.2 years, and the symptoms of SOMD at 61.8±2.1 years; group 2 – 37 people (63.8%), AD occurred at the age of 64.5±2.5 years, and SOMD at 71.3±2.8 years. The following methods were used: questionnaire – using the developed "Anamnestic chart", clinical (anamnesis collection), statistical (parametric and nonparametric). Results. The main factors of the formation of SOMD in people with formed AD in middle and old age are combinations of various RF, as well as a monofactor in the form of chronic alcohol abuse, the proportion of which varies depending on the age of AD formation. Conclusion. When AD is formed in old age, combinations of RF have a greater influence on the development of SOMD. And in the formation of AD in middle age, both alcohol, as an exogenous mono-damaging factor, and a combination of RF contribute to the formation of SOMD. Hereditary burden of alcoholism affects the progrediency of alcoholism, but does not play a role in the rate of formation of SOMD. The formation of alcoholism in middle age is combined with a relatively slow rate of formation of SOMD and a smaller number of associated somatic pathology, and when formed in old age – with a relatively fast rate of development of SOMD and a large number of associated somatic pathology.

Effects of parental diet on Mormon cricket egg diapause, embryonic development rate, and periodic outbreaks

Transgenerational phenotypic modification can alter organismal fitness, population demographics, and community interactions. For ectotherms, both dietary composition and temperature have important effects on organismal fitness, but they are rarely investigated together. Mormon crickets Anabrus simplex are capable of diapausing as eggs in the soil for multiple years with duration largely dependent on cumulative heat units or degree days. Because Mormon crickets can be abundant in the landscape in one year and disappear suddenly the next, I asked: does parental nutrition affect the duration of egg diapause? Beginning in the ultimate nymphal instar, Mormon crickets were fed a diet high in protein, one equal in protein to carbohydrate, or a diet high in carbohydrates and the time for eggs to develop after they were laid was measured. If parental nutrition affects temperature-sensitive egg diapause, then that change in sensitivity to temperature might also alter the relationship between embryonic development rate and temperature. I asked: does parental nutrition affect embryonic development rate as a function of temperature? To this end, I manipulated densities of Mormon cricket nymphs and protein-rich prey (grasshoppers) in field cages, collected eggs from the adult Mormon crickets, and measured the optimal temperature, maximum development rate, and thermal breadth for embryonic development of the offspring. I found that Mormon crickets fed a high protein diet laid eggs with shorter diapause. Consistent with this long-term result, those housed with the most grasshoppers to eat laid eggs that had the fastest maximum development rate, whereas those without grasshoppers laid eggs with slower maximum developmental rates but the broadest thermal breadth. Eggs from Mormon crickets housed with intermediate levels of grasshopper densities had a decline in peak development rate with an increase in density. In addition, Mormon crickets housed with more conspecifics laid eggs with faster development rates, whereas thermal breadth and the temperature optima were not affected by cricket density. As predicted, Mormon cricket diets significantly affected egg diapause and development rates. Contrary to expectations based on observed changes in diet preferences during a Mormon cricket outbreak, Mormon crickets fed high protein diets laid eggs with significantly shorter egg diapause and significantly faster egg development rates. Interestingly, doubling of Mormon cricket density caused eggs to develop in nearly half the time. This latter result indicates that Mormon cricket aggregations promote rapid development of progeny. Moreover, the tight, linear structure of migratory bands in which females intermittently stop to lay eggs assures that the progeny hatch and develop in dense cohorts. In this manner, the banding behavior might carry-over into subsequent generations as long as cohorts are dense and protein is available. With band thinning or protein restriction, females spread their bet-hedging and progeny remain longer as eggs in the soil.

Novel Mito-Nuclear Combinations Facilitate the Global Invasion of a Major Agricultural Crop Pest.

A fundamental understanding of the underlying mechanisms involved in biological invasions is crucial to developing effective risk assessment and control measures against invasive species. The fall armyworm (FAW), Spodoptera frugiperda, is a highly invasive pest that has rapidly spread from its native Americas into much of the Eastern Hemisphere, with a highly homogeneous nuclear genetic background. However, the exact mechanism behind its rapid introduction and propagation remains unclear. Here, a systematic investigation is conducted into the population dynamics of FAW in China from 2019 to 2021 and found that FAW individuals carrying "rice" mitochondria (FAW-mR) are more prevalent (>98%) than that with "corn" mitochondria (FAW-mC) at the initial stage of the invasion and in newly-occupied non-overwintering areas. Further fitness experiments show that the two hybrid-strains of FAW exhibit different adaptions in the new environment in China, and this may have been facilitated by amino acid changes in mitochondrial-encoded proteins. FAW-mR used increases energy metabolism, faster wing-beat frequencies, and lower wing loadings to drive greater flight performance and subsequent rapid colonization of new habitats. In contrast, FAW-mC individuals adapt with more relaxed mitochondria and shuttle energetics into maternal investment, observed as faster development rate and higher fecundity. The presence of two different mitochondria types within FAW has the potential to significantly expand the range of damage and enhance competitive advantage. Overall, the study describes a novel invasion mechanism displayed by the FAW population that facilitates its expansion and establishment in new environments.

Two Old Wild-Type Strains of Drosophila melanogaster Can Serve as an Animal Model of Faster and Slower Aging Processes.

Drosophila melanogaster provides a powerful platform to study the physiology and genetics of aging, i.e., the mechanisms underpinnings healthy aging, age-associated disorders, and acceleration of the aging process under adverse environmental conditions. Here, we tested the responses of daily rhythms to age-accelerated factors in two wild-type laboratory-adapted strains, Canton-S and Harwich. On the example of the 24 h patterns of locomotor activity and sleep, we documented the responses of these two strains to such factors as aging, high temperature, carbohydrate diet, and diet with different doses of caffeine-benzoate sodium. The strains demonstrated differential responses to these factors. Moreover, compared to Canton-S, Harwich showed a reduced locomotor activity, larger amount of sleep, faster rate of development, smaller body weight, lower concentrations of main sugars, lower fecundity, and shorter lifespan. It might be recommended to use at least two strains, one with a relatively fast and another with a relatively slow aging process, for the experimental elaboration of relationships between genes, environment, behavior, physiology, and health.

Antibiose de genótipos de morangueiro ao ácaro-rajado

ABSTRACT: The spotted spider mite, Tetranychus urticae (Koch, 1836), is one of the most important pests of strawberry production systems worldwide. Because plant resistance is an important integrated management strategy, the present study investigated the effects of 12 strawberry genotypes on the biological characteristics of this pest under laboratory conditions (25 ± 2 °C and RH 60 ± 10%; 12:12-hour photophase). The experiment was carried using 12 treatments (genotypes), divided into 20 replications each, in a completely randomized design. The response variables were the biological parameters of the spider mite and its survival rate. The development and survival of T. urticae were influenced by different strawberry genotypes. The Camarosa cultivar together with genotypes Selection 05 and 2017-04-03 negatively affected the development and survival of T. urticae. The Selection 02 genotype had greatest susceptibility to the spider mite, which allowed fast development and high survival rate. The reproductive parameters of T. urticae were affected differently as a function of the strawberry genotype, with the Camarosa cultivar and the genotypes Selection 05 and 2017-04-03 being unfavorable to development, suggesting a possible resistance based on antibiosis.

Which temperature matters? Effects of origin, rearing and test conditions on the chemical sensitivity of Pardosa amentata

AbstractSpiders may be adversely affected by pesticides, yet they are not included in regulatory risk assessment and a related standard guideline to test their sensitivity to chemicals is lacking. Different laboratory setups, including test temperature and relative humidity, have been shown to influence the sensitivity of spiders. The climate from which spiders originate and the rearing conditions in the laboratory prior to ecotoxicological testing may also alter their sensitivity to chemicals, potentially in interaction with test conditions. We investigated the influence of population origin, rearing and test temperature on the chemical sensitivity of the spider Pardosa amentata towards lambda‐cyhalothrin. We collected female P. amentata carrying egg sacs from two climates, i.e., boreal and cool temperate. Spiders were kept in the laboratory and their offspring were reared and tested at 15, 20 and 25°C. Hatching of egg sacs largely failed at 15°C, while a moderate spiderling mortality (40%) was recorded at 20°C. At 25°C, mortality increased (63%) and a faster developmental rate was observed. Rearing and test temperature had no significant effects on spider chemical sensitivity. However, spider chemical sensitivity differed between populations, with spiders from boreal climate being 38% more sensitive than spiders from cool temperate climate. A higher sensitivity towards lambda‐cyhalothrin increases the risk of population reduction in treated areas, with potential alterations of ecosystem functions such as biological control. Our results suggest that the climatic origin of test organisms deserves stronger attention in ecotoxicological research.

Stochastic modeling of Dalbulus maidis, vector of maize diseases

We developed a simple linear stochastic model for Dalbulus maidis dependent exclusively on temperature, whose parameters were determined from published field and laboratory studies performed at different temperatures. This model takes into account the principal stages and events of the life cycle of this pest, which is vector of maize diseases. We implemented the effect of distributed delays or Linear Chain Trick (LCT) considering a fixed number of sub-stages for egg and nymph stages of Dalbulus maidis in order to accurately represent what is observed in nature. A sensitivity analysis allows us to observe that the speed of the dynamics is sensitive to changes in the development rates, but not to the longevity of each stage or the fecundity, which almost exclusively affect insect abundance. We used our model to study its predictive and explanatory capacity considering a published experiment as a case study. Although the simulation results show a behavior qualitatively equivalent to that observed in the experimental results it is not possible to explain accurately the magnitude, nor the times in which the maximum abundances of second-generation nymphs and adults are reached. Therefore, we evaluated three possible scenarios for the insect that allow us to glimpse some of the advantages of having a computational model in order to find out what processes, taken into account in the model, may explain the differences observed between published experimental results and model results. The three proposed scenarios, based on variations in the parameterized rates of the model, can satisfactorily explain the experimental observations. We observed that in order to better simulate the experimental results it is not necessary to modify fecundity or mortality rates. However, it is necessary to accelerate the average development rates of our model by 20 to 40 %, compatible with extreme values of the rates close to the upper edges of the confidence bands of our parameterization rate curves, according to insects with faster development rates already reported in literature.

Effects of incubation temperature and maternal phenotype on Baltic herring (Clupea harengus membras) eggs and larvae: an experimental study

Temperature modifies the reproductive success of fish, yet, in many species, we lack the information on its role in the early development. In this study, the effect of temperature on the relation between maternal traits (length, age, somatic condition, and muscle lipid and ovarian thyroid hormone concentrations), egg quality (fertilization success, development rate, mortality, and hatching success), and offspring traits (size-at-hatch, yolk sac size, and proportion of malformations) were studied in Baltic herring ( Clupea harengus membras) in the northern Baltic Sea. The experiments were conducted at an ambient temperature of 7 °C and at an elevated temperature of 14 °C using 5 to 10 females and 3 replicates per female. The results indicate that elevated temperature may result in a faster developmental rate, a lower early-stage mortality and hatching success, smaller size-at-hatch, a larger yolk sac size, and a higher amount of larval malformations when compared to an ambient temperature. The egg and offspring traits were also associated with the maternal traits, indicating especially that thyroid hormones play a mediating role in the physiological processes.

Impact of temperature on Downs herring (Clupea harengus) embryonic stages: First insights from an experimental approach.

Among all human-induced pressures, ocean warming is expected to be one of the major drivers of change in marine ecosystems. Fish species are particularly vulnerable during embryogenesis. Here, the impact of temperature was assessed on embryonic stages of Atlantic herring (Clupea harengus), a species of high socio-economic interest, with a particular focus on the under-studied eastern English Channel winter-spawning component (Downs herring). Key traits linked to growth and development were experimentally evaluated at three temperatures (8°C, 10°C and 14°C), from fertilization to hatching, in standardized controlled conditions. Overall negative impacts of increased temperature were observed on fertilization rate, mean egg diameter at eyed stage, hatching rate and yolk sac volume. A faster developmental rate and a change in development stage frequency of newly hatched larvae were also observed at higher temperature. Potential parental effects were detected for four key traits (i.e. fertilization rate, eyed survival rate, mean egg diameter and hatching rate), despite a limited number of families. For instance, a large variability among families was shown in survival rate at eyed stage (between 0 and 63%). Potential relationships between maternal characteristics and embryo traits were therefore explored. We show that a substantial proportion of variance (between 31 and 70%) could be explained by the female attributes considered. More particularly, age, traits linked to life history (i.e. asymptotic average length and Brody growth rate coefficient), condition and length were important predictors of embryonic key traits. Overall, this study constitutes a stepping-stone to investigate potential consequences of warming on Downs herring recruitment and provides first insights on potential parental effects.

High sensitivity to dietary imidacloprid exposure in early life stages of Folsomia quadrioculata (Collembola) populations from contrasting climates

Survival of early life stages is critical for population growth. Understanding the vulnerability of these sensitive stages can therefore improve ecological risk predictions. The globally-used neonicotinoid insecticide imidacloprid does not degrade easily in soil and occurs at concentrations potentially toxic to non-target soil organisms, such as Collembola. Here, we studied the effects of dietary exposure to imidacloprid on the survival of juveniles in an arctic and a temperate population of Folsomia quadrioculata (Collembola), a commonly-occurring litter-dwelling species in the Northern Hemisphere. The exposure lasted from <24 h to 30 days since hatching at 15 °C. We assessed whether (1) the arctic population of the test species with faster development rates could be more vulnerable than the temperate population, (2) cumulative mortality could increase substantially with exposure time, and (3) the mortality risk experienced during the juvenile stage could be greater than that experienced by the adults. We found a strong concentration-dependent decline in survival in both populations, with small but significantly different LC50s, despite large differences in multiple life-history traits. Applying a General Unified Threshold model for Survival (GUTS) showed a low threshold for effects, slow damage dynamics, a 6–11-fold decrease in LC50 from 14 to 30 days of exposure, and saturation of damage at the three highest concentrations. In addition, exposure starting soon after hatching caused much more mortality than that starting in the adult stages. Our findings suggest that toxicity tests not emphasizing the neonate stages or not lasting long enough can underestimate the implications for populations of naturally abundant non-target organisms.

Evaluating the impact of a 2.5–3°C increase in temperature on drought-stressed German wheat cultivars under natural stress conditions

Climate change in Central Europe is expected to influence crop growth through frequent drought and heat extremes. Wheat contributing about 20% of the total dietary calories and proteins worldwide, is sensitive to heat and drought, especially during its reproductive stages. To develop strategies to improve climate resilience in wheat, a comprehensive field evaluation was carried out under drier and warmer field conditions in Moldova from 2016 to 2019 for forty winter wheat varieties from Germany and Eastern Europe. The grain yield of German cultivars grown in Moldova ranged from 4.46–6.58 t/ha from 2016 to 2019 and was 40% lower compared to the same cultivars grown in Southern Germany. This is significantly more than the reduction predicted by current process-based crop yield models considering only seasonal temperature effects and not combined drought effects. Among all the wheat varieties tested in Moldova, Eastern European varieties and German hybrids achieved the best yield performance across the years. The lower grain yield of German wheat varieties was mainly due to the reduction in grain filling duration, which led to a decrease in the grain filling rate and thousand-grain weight. A higher grain filling rate contributed to a higher grain yield in the Eastern European varieties. These results suggest that well-adapted varieties with a faster rate of development and an earlier start of grain filling have a notable advantage under drought and heat conditions, providing a useful genetic source to increase heat and drought tolerance in future plant breeding programs. The space-for-time approach used in this study allows for the investigation of combined heat and drought, reflecting anticipated or future climate conditions without taking into account CO2 effects.

Regenerative ability and micropropagation of &lt;I&gt;Petunia hybrid&lt;/I&gt; in vitro

Scientific relevance. The garden petunia, Petunia hybrida, is a popular and wide spread ornamental crop from the family Solanaceae. It is a promising model plant for molecular and genetic research. In vitro micropropagation plays an important role in the distribution of the garden petunia because the survivability and quality of seed material decreases significantly in every subsequent generation. Besides, micropropagation reduces the cost of production substantially. Considering that very few researchers addressed this question in the Russian Federation, this direction of research is still worthy of attention.Materials and methods. The experiments were conducted by the Laboratory of Breeding and Genetic Research on Field Crops at FSBSI “Federal Scientific Center of Agricultural Biotechnology of the Far East named after A.K. Chaiki”. Seeds of Petunia hybrida (double-flowered) were used as primary explants. Liquid bleacher ACE diluted with distilled water in the proportion 1:9 was used as a sterilizing agent (the working solution contained 0.50% NaOCl). The total time of exposure was 15 minutes. The primary explants were subcultured onto a hormone-free Murashige and Skoog basal medium containing 20 g/L sucrose and 6 g/L agar. Isolated in vitro objects were cultured in test tubes with cotton-gauze plugs at an illuminance of 4000 lx, a temperature of 22–25 °C, and a 16h photoperiod in a culture room. The duration of one passage was 60 days. Micropropagation was carried out using 7- 10 mm cuttings with one or two nodes. The pot culture of the regenerants was established under controlled conditions in a light room (photoperiod was 16 hours, temperature was 23°С).Results. The optimal method for introducing Petunia hybrida into cell culture is the use of seeds treated with the solution of bleacher ACE that was diluted with distilled water in the proportion 1:9. The optimal time of exposure is 15 minutes. Petunia hybrida demonstrated a high regeneration rate on the hormone-free MS medium – it had a fast growth and development rate, and good rhizogenesis; the reproductive rate was 8.77. For the micropropagation of the garden petunia, it is advisable to use cuttings of test tube plants, which should be placed onto a hormone-free MS medium. The test tube plants of Petunia hybrida acclimatized successfully on a soil substrate. This shows the high plasticity of the culture.

Harnessing heterosis and male sterility in soybean [Glycine max (L.) Merrill]: A critical revisit.

Soybean is a predominantly self-pollinated crop. It is also one of the important oilseed legumes. Soybean is an excellent crop having industrial, traditional, culinary, feeding, and cultural roles. Genetic diversity in breeding programs is of prime importance as it ensures the success of any breeding by enhancing the outcomes and results of the plants. The phenomenon wherein the progeny exhibits greater biomass (yield) and a faster rate of development and fertility than its parents is referred to as heterosis. As of now, heterosis is mainly limited to the trait of seed yield and is considered the basis for the development of better (superior) varieties. Male sterility (MS) is extensively used for the production of seeds and the improvement of crops coupled with the traditional breeding programs and molecular technology. Therefore, deployment of MS and heterosis in breeding soybean could yield better outcomes. This review aims to focus on two aspects, namely, MS and heterosis in soybean with its scope for crop improvement.

The comprehensive study of the urbanization development and environmental damage response mechanism

With the acceleration of economic globalization and trade liberalization, environmental issues have attracted more and more attention from the world and become one of the major issues facing mankind. A series of global environmental problems that have emerged under the background of economic globalization have become barriers restricting the sustainable development of the economy and society. As one of the key issues in network research, BP neural network provides an effective tool for studying the multi-objective and multi-dimensional interaction between networks. During training, the BP neural network can adaptively memorize the learning content in the weights of the network through learning. That is, the BP neural network has a high self-learning and self-adaptive ability.This paper fully contrasts and studies several neural networks and deep learning models at this stage,This paper fully contrasts and studies several neural networks and deep learning models at this stage, and forms a new type of network model. In this paper, through the construction of BP neural network training model for experimental simulation, the experimental results show that our city's urban expansion phenomenon in 2019 is still showing a growth momentum. The urbanization and eco-environment system of our city are developing in a good level with fast and stable development rate, which indicates that the development under the existing development conditions can realize the coordinated development of urbanization and environment. In order to protect the damaged ecological environment, it is necessary to improve the path of ecological environment damage compensation responsibility and diversified ecological environment damage compensation relief procedures. Academic and legal practitioners can distinguish clearly from the elements of tort construction and environmental tort, improve the system of environmental tort liability, and strengthen China's environmental legislation.

Formation of the yield of oil crops of the Brassicaceae family in the Middle Cis-Urals

The article presents data on the study of the formation of the seed yield of spring oil crops in the conditions of the Middle Cis-Urals. The work is based on the results of a two-factor microfield experiment, where factor A - crops - rape and camelina, factor B - varieties of crops - rape Accord and Podmoskovny, camelina Veles and Yubilyar. The relevance of the study is related to the growing interest in oil crops. The research methodology is generally accepted in agronomy. Camelina was characterized by a faster rate of development, its growing season was 89-109 days, rape - 109-147 days. Morphological and biological features of crops were revealed – a large height of rape plants, their damage by blossom weevil and diamondback moth and the associated lower (50%) survival rate of plants during vegetation; lower seed content (by 44 pcs.) and the formation of smaller seeds (the weight of 1000 seeds was 2.08 g inferior to the same indicator of rape) in camelina. With such a yield structure, camelina had an advantage of 18 g/m2. The crops did not differ in the content of crude protein and fat in the seeds.

Single Cell Protein: A Potential Substitute in Human and Animal Nutrition

Single cell protein (SCP) is the first product of the fermentation process and has proven to be a good protein alternative. Food competition is becoming more intense as the world’s population continues to grow. Soon, SCP may be able to compensate for a protein deficit. Various global businesses are focusing on SCP production, and the scope of its application is expanding as time and knowledge increases. High quantities of SCP can be produced by microorganisms, such as algae, yeast, fungi and bacteria, due to their fast development rate and the significant level of protein in their chemical structure. Beside proteins, SCP contains carbohydrates, nucleic acids, lipids, minerals, vitamins and several important amino acids. SCP has been an effective substitute for more expensive protein sources such as fish and soybean products. In conclusion, SCP can easily replace traditional protein sources in human and animal feed without detrimental effects. Potential substrate candidates and optimization strategies for SCP production have been extensively studied. This review article focuses on the various aspects of SCP, from its production, using different substrates, player microorganisms and nutritional benefits, to its economic aspects.

Evolution of cold tolerance and thermal plasticity in life history, behaviour and physiology during a poleward range expansion

Many species that are moving polewards encounter novel thermal regimes to which they have to adapt. Therefore, rapid evolution of thermal tolerance and of thermal plasticity in fitness-related traits in edge populations can be crucial for the success and speed of range expansions. We tested for adaptation in cold tolerance and in life history, behavioural and physiological traits and their thermal plasticity during a poleward range expansion. We reconstructed the thermal performance curves of life history (survival, growth and development rates), behaviour (food intake) and cold tolerance (chill coma recovery time) in the aquatic larval stage of the damselfly Ischnura elegans that is currently showing a poleward range expansion in northern Europe. We studied larvae from three edge and three core populations using a common-garden experiment. Consistent with the colder annual temperatures, larvae at the expansion front evolved an improved cold tolerance. The edge populations showed no overall (across temperatures) evolution of a faster life history that would improve their range-shifting ability. Moreover, consistent with damselfly edge populations from colder latitudes, edge populations evolved at the highest rearing temperature (28°C) a faster development rate, likely to better exploit the rare periods with higher temperatures. This was associated with a higher food intake and a lower metabolic rate. In conclusion, our results suggest that the edge populations rapidly evolved adaptive changes in trait means and thermal plasticity to the novel thermal conditions at the edge front. Our results highlight the importance of considering besides trait plasticity and the evolution of trait means, also the evolution of trait plasticity to improve forecasts of responses to climate change.

Natural variation in plant telomere length is associated with flowering time.

Telomeres are highly repetitive DNA sequences found at the ends of chromosomes that protect the chromosomes from deterioration duringcell division. Here, using whole-genome re-sequencing and terminal restriction fragment assays, we found substantial natural intraspecific variation in telomere length in Arabidopsis thaliana, rice (Oryza sativa), and maize (Zea mays). Genome-wide association study (GWAS) mapping in A. thaliana identified 13 regions with GWAS-significant associations underlying telomere length variation, including a region that harbors the telomerase reverse transcriptase (TERT) gene. Population genomic analysis provided evidence for a selective sweep at the TERT region associated with longer telomeres. We found that telomere length is negatively correlated with flowering time variation not only in A. thaliana, but also in maize and rice, indicating a link between life-history traits and chromosome integrity. Our results point to several possible reasons for this correlation, including the possibility that longer telomeres may be more adaptive in plants that have faster developmental rates (and therefore flower earlier). Our work suggests that chromosomal structure itself might be an adaptive trait associated with plant life-history strategies.

Milk losses and dynamics during perturbations in dairy cows differ with parity and lactation stage

Milk yield dynamics during perturbations reflect how cows respond to challenges. This study investigated the characteristics of 62,406 perturbations from 16,604 lactation curves of dairy cows milked with an automated milking system at 50 Belgian, Dutch, and English farms. The unperturbed lactation curve representing the theoretical milk yield dynamics was estimated with an iterative procedure fitting a model on the daily milk yield data that was not part of a perturbation. Perturbations were defined as periods of at least 5 d of negative residuals having at least 1 day that the total daily milk production was below 80% of the estimated unperturbed lactation curve. Every perturbation was characterized and split in a development and a recovery phase. Based hereon, we calculated both the characteristics of the perturbation as a whole, and the duration, slopes, and milk losses in the phases separately. A 2-way ANOVA followed by a pairwise comparison of group means was carried out to detect differences between these characteristics in different lactation stages (early, mid-early, mid-late, and late) and parities (first, second, and third or higher). On average, 3.8 ± 1.9 (mean ± standard deviation) perturbations were detected per lactation in the first 305 d after calving, corresponding to an estimated 92.1 ± 135.8 kg of milk loss. Only 1% of the lactations had no perturbations. On average, 2.3 kg of milk was lost per day in the development phase, while the recovery phase corresponded to an average increase in milk production of 1.5 kg/d, and these phases lasted an average of 10.1 and 11.6 d, respectively. Perturbation characteristics were significantly different across parity and lactation stage groups, and early and mid-early perturbations in higher parities were found to be more severe with faster development rates, slower recovery rates, and higher milk losses. The method to characterize perturbations can be used for precision phenotyping purposes that look into the response of cows to challenges or that monitor applications (e.g., to evaluate the development and recovery of diseases and how these are affected by preventive actions or treatments).

The older plant gets the sun: Age‐related changes in Miscanthus × giganteus phenology

AbstractAge‐related changes are usually overlooked in perennial grass research; when they are considered it is usually as a change in plant size (e.g., biomass). Whether other physiological or developmental aspects change as stands age, and how those aspects may impact long‐term stand dynamics, remains unclear. Conventional experimental designs study a single stand over multiple growing seasons and thereby confound age‐related changes with growing season conditions. Here we used a staggered‐start experimental design with three repeated planting years over two growing seasons to isolate growing season effects. We studied changes in Miscanthus × giganteus phenology during its yield‐building stage (first 3 years) and estimated age, growing season and nitrogen (N) effects on development using nonlinear regression parameters. Stand age clearly changed plant growth; faster developmental rates were usually seen in 1‐year‐old stands (young), but because 2‐ and 3‐year‐old stands (mature) emerged 3 months earlier than newly planted stands they produced 30% more stems with 30%–60% more leaves. Nitrogen fertilization modulated some age‐related phenological changes. Fertilized 2‐year‐old stands reached similar stem densities as unfertilized 3‐year‐old stands and had fewer number of senesced leaves like 1‐year‐old stands. In addition, N fertilization had no effect on young M. × giganteus, but extended mature stands’ growing season more than 2 weeks by hastening emergence and delaying senescence. It also delayed flowering regardless of stand age. Our results suggest that, along with changes in size, M. × giganteus stands showed shifts in developmental strategies: young stands emerged later and developed faster, while mature stands grew for longer but more slowly. In temperate regions, where hard frost events are likely to interrupt development in late autumn, rapid early development is critical to plant survival. Nonlinear regression parameter differences proved effective in identifying phenological shifts.