Several lines of evidence point to an increase in the activity of the terrestrial biosphere over recent decades, impacting the global net land carbon sink (NLS) and its control on the growth of ...atmospheric carbon dioxide (ca). Global terrestrial gross primary production (GPP)—the rate of carbon fixation by photosynthesis—is estimated to have risen by (31 ± 5)% since 1900, but the relative contributions of different putative drivers to this increase are not well known. Here we identify the rising atmospheric CO2 concentration as the dominant driver. We reconcile leaf‐level and global atmospheric constraints on trends in modeled biospheric activity to reveal a global CO2 fertilization effect on photosynthesis of 30% since 1900, or 47% for a doubling of ca above the pre‐industrial level. Our historic value is nearly twice as high as current estimates (17 ± 4)% that do not use the full range of available constraints. Consequently, under a future low‐emission scenario, we project a land carbon sink (174 PgC, 2006–2099) that is 57 PgC larger than if a lower CO2 fertilization effect comparable with current estimates is assumed. These findings suggest a larger beneficial role of the land carbon sink in modulating future excess anthropogenic CO2 consistent with the target of the Paris Agreement to stay below 2°C warming, and underscore the importance of preserving terrestrial carbon sinks.
CO2 concentrations in the global atmosphere will continue to rise for decades ahead. Plants grow faster under elevated CO2, but the current generation of carbon cycle models, including those embedded in Earth system models used for climate assessment, diverge in their representation and future projections of this response. By invoking long‐standing theory on how plants use a limited supply of nitrogen in order to optimize photosynthesis and growth, we reconcile leaf‐level and recent global atmospheric constraints on CO2 fertilization.
To provide an updated comparison of pregnancy-related complications and adverse perinatal outcomes of pregnancies conceived after frozen embryo transfer (FET) versus fresh embryo transfer (fresh ET).
...Meta-analysis.
University.
Pregnancies resulting from FET versus fresh ET.
Pubmed, Embase, Cochrane Library, Google Scholar, and Chinese databases, including the China National Knowledge Infrastructure Database, Wanfang, and Chinese Scientific Journals Full-Text Database were searched by two independent reviewers from January 1980 to September 2017. The results were expressed as risk ratios with 95% confidence intervals.
Pregnancy-related complications and perinatal outcomes.
Our search retrieved 1,397 articles, of which 31 studies were included. Pregnancies resulting from FET were associated with lower relative risks of placenta previa, placental abruption, low birth weight, very low birth weight, very preterm birth, small for gestational age, and perinatal mortality compared with fresh ET. Pregnancies occurring from FET were associated with increased risks of pregnancy-induced hypertension, postpartum hemorrhage, and large for gestational age compared with fresh ET. The risks of gestational diabetes mellitus, preterm premature rupture of the membranes, and preterm birth (PTB) showed no differences between the two groups.
Our analysis demonstrated that FET results in lower risks of placenta previa, placental abruption, low birth weight, very low birth weight, very preterm birth, small for gestational age, and perinatal mortality than fresh ET, some differences that are attributed to the increased risks of pregnancy-induced hypertension, large for gestational age, and postpartum hemorrhage. Although cryotechnology keeps improving, for comprehensive consideration, individual approaches remain appropriate to balance the options of FET or fresh ET at present.
The shift from outcrossing to selfing is common in flowering plants, but the genomic consequences and the speed at which they emerge remain poorly understood. An excellent model for understanding the ...evolution of self fertilization is provided by Capsella rubella, which became self compatible <200,000 years ago. We report a C. rubella reference genome sequence and compare RNA expression and polymorphism patterns between C. rubella and its outcrossing progenitor Capsella grandiflora. We found a clear shift in the expression of genes associated with flowering phenotypes, similar to that seen in Arabidopsis, in which self fertilization evolved about 1 million years ago. Comparisons of the two Capsella species showed evidence of rapid genome-wide relaxation of purifying selection in C. rubella without a concomitant change in transposable element abundance. Overall we document that the transition to selfing may be typified by parallel shifts in gene expression, along with a measurable reduction of purifying selection.
Summary
Plant microbiomes are essential to host health and productivity but the ecological processes that govern crop microbiome assembly are not fully known.
Here we examined bacterial communities ...across 684 samples from soils (rhizosphere and bulk soil) and multiple compartment niches (rhizoplane, root endosphere, phylloplane, and leaf endosphere) in maize (Zea mays)‐wheat (Triticum aestivum)/barley (Hordeum vulgare) rotation system under different fertilization practices at two contrasting sites.
Our results demonstrate that microbiome assembly along the soil‐plant continuum is shaped predominantly by compartment niche and host species rather than by site or fertilization practice. From soils to epiphytes to endophytes, host selection pressure sequentially increased and bacterial diversity and network complexity consequently reduced, with the strongest host effect in leaf endosphere. Source tracking indicates that crop microbiome is mainly derived from soils and gradually enriched and filtered at different plant compartment niches. Moreover, crop microbiomes were dominated by a few dominant taxa (c. 0.5% of bacterial phylotypes), with bacilli identified as the important biomarker taxa for wheat and barley and Methylobacteriaceae for maize.
Our work provides comprehensive empirical evidence on host selection, potential sources and enrichment processes for crop microbiome assembly, and has important implications for future crop management and manipulation of crop microbiome for sustainable agriculture.
The rising atmospheric CO2 concentration leads to a CO2 fertilization effect on plants—that is, increased photosynthetic uptake of CO2 by leaves and enhanced water‐use efficiency (WUE). Yet, the ...resulting net impact of CO2 fertilization on plant growth and soil moisture (SM) savings at large scale is poorly understood. Drylands provide a natural experimental setting to detect the CO2 fertilization effect on plant growth since foliage amount, plant water‐use and photosynthesis are all tightly coupled in water‐limited ecosystems. A long‐term change in the response of leaf area index (LAI, a measure of foliage amount) to changes in SM is likely to stem from changing water demand of primary productivity in water‐limited ecosystems and is a proxy for changes in WUE. Using 34‐year satellite observations of LAI and SM over tropical and subtropical drylands, we identify that a 1% increment in SM leads to 0.15% (±0.008, 95% confidence interval) and 0.51% (±0.01, 95% confidence interval) increments in LAI during 1982‒1998 and 1999‒2015, respectively. The increasing response of LAI to SM has contributed 7.2% (±3.0%, 95% confidence interval) to total dryland greening during 1999‒2015 compared to 1982‒1998. The increasing response of LAI to SM is consistent with the CO2 fertilization effect on WUE in water‐limited ecosystems, indicating that a given amount of SM has sustained greater amounts of photosynthetic foliage over time. The LAI responses to changes in SM from seven dynamic global vegetation models are not always consistent with observations, highlighting the need for improved process knowledge of terrestrial ecosystem responses to rising atmospheric CO2 concentration.
Drylands provide a natural experimental setting to detect the CO2 fertilization effect on plant growth since foliage amount, plant water‐use and photosynthesis are all tightly coupled in water‐limited ecosystems. Using 34‐year satellite observations of leaf area index (LAI) and soil moisture (SM) over drylands, we identify that an equivalent increment in SM leads to a larger increase in LAI during 1999‒2015 compared to 1982‒1998. This finding suggests that a given amount of SM has sustained greater amounts of photosynthetic foliage biomass over time due to decreasing transpiration per unit leaf area with increasing CO2 concentration.
Abstract
STUDY QUESTION
What is the impact of day after rescue ICSI (r-ICSI) on success of fresh and frozen embryo transfers?
SUMMARY ANSWER
The use of r-ICSI can virtually allay fears of total ...fertilization failure (TFF) after conventional IVF (C-IVF) and achieve high live birth rates after frozen blastocyst transfer.
WHAT IS KNOWN ALREADY
More infertility clinics have resorted to the use of ICSI in place of C-IVF in IVF treatment owing to fear of TFF or a low fertilization rate. r-ICSI has been attempted either on the day of IVF or the day after. Day after r-ICSI has proved unsuccessful in the past.
STUDY DESIGN, SIZE, DURATION
A retrospective data analysis was performed of 16 608 qualifying cases between April 2010 and July 2021 conducted at a single private academically affiliated fertility clinic.
PARTICIPANTS/MATERIALS, SETTING, METHODS
r-ICSI was performed principally on patients with >4 metaphase II oocytes, showing no signs of fertilization 18 h after C-IVF. C-IVF was performed on patients who had >4 million total motile sperm after preparation. r-ICSI was then performed 18–24 h after insemination, using the sperm sample from the previous day. r-ICSI fertilization rates, cryopreservation of cleavage and blastocysts embryos, and pregnancy rates after fresh or frozen transfer were then assessed.
MAIN RESULTS AND THE ROLE OF CHANCE
r-ICSI was performed on 377 patients (2.3% of eligible retrieval cycles) who had a mean (±SD) female and male age of 35.9 ± 4.5 and 38.1 ± 9.1 years, respectively. A total of 5459 oocytes were initially retrieved. Of the oocytes undergoing r-ICSI, 2389 (49.5%) fertilized normally, and 205 (54.4%) patients underwent a fresh embryo transfer. The live birth rates were 23/186 (12.3%) for fresh cleavage and 5/19 (26.3%) for fresh blastocyst stage transfers. In 145 cycles a blastocyst was frozen, and 137 transfers were performed with a 64/137 (46.7%) live birth rate. Of the 377 cycles receiving r-ICSI only, 25 of the qualifying cases failed to have any fertilization, reducing TFF to 25/16 608 (0.15%).
LIMITATIONS, REASONS FOR CAUTION
This was a single-center retrospective study on a specific subset of patients, which may limit its generalizability to other clinics.
WIDER IMPLICATIONS OF THE FINDINGS
r-ICSI allows a second opportunity to fertilize oocytes despite poor initial outcomes. Patients who had a frozen blastocyst transfer achieved high live birth rates, indicating that a resynchronization of the embryo with the endometrium can optimize r-ICSI cases. r-ICSI allays fears of TFF when using C-IVF, providing evidence that the overuse of ICSI in patients without male factor may not be warranted.
STUDY FUNDING/COMPETING INTEREST(S)
The study was internally funded by Boston IVF. The authors declare that they have no conflict of interest in relation to the data published in the article.
TRIAL REGISTRATION NUMBER
N/A.
•The effect of 3-year fertilizations on soil bacterial community in 3 agroecosystems.•Geographic location was a main factor shaping soil bacterial community structure.•Short-term effect of chemical N ...fertilizer on bacterial community was much stronger.•N fertilizer reduced bacterial network complexity and connectivity in upland soil.
Nitrogen (N) fertilization is a pivotal contributor to increasing crop yields. The substantial long-term effects of fertilization on soil microbial communities have been clearly verified. However, the short-term impacts of inorganic and organic fertilization are more stochastic and less deterministic in different agroecosystems, especially at a large spatial scale. Here, we examined the effect of 3 years of different fertilization strategies (i.e., no N fertilizer, inorganic N fertilization, and total or partial replacement of inorganic N by organic manure) on the soil bacterial community in three agroecosystem types spanning the middle temperate zone to the subtropical zone. The results showed that the main contribution to the changes in soil bacterial community structure were dominated by geographic location, which accounted for 61.60% of structural variation, while sampling season and fertilization practice explained 1.52% and 0.61%, respectively. Across three contrasting agroecosystem types, the inorganic N-alone application had greater impacts on the bacterial community structure than organic N fertilization, but the changes in composition were dependent on geographic location. Further, N fertilizer addition reduced soil bacterial network complexity and connectivity; specifically, some key module hubs belonging to non-dominant taxa were lost in N-fertilized upland soils, indicating reduced diversity and stability of the soil micro-ecosystem. Together, our results suggest that, when compared with the mild organic N source, the short-term stimulatory effect of chemical N fertilizer tended not to be beneficial for agroecosystem stability and sustainability.
To evaluate the impact of a poor quality embryo (PQE) during double ET (DET) with a top quality embryo (TQE) on IVF outcome.
A review of prospectively collected data.
Tertiary level fertility clinic.
...All patients undergoing blastocyst transfers as part of fresh IVF (n = 939) and frozen ET (n = 1,009) cycles performed between 2010 and 2016.
Single ET (SET) with TQE (group 1) was set as control and compared with outcomes for SET with PQE (group 2), DET with 2 TQEs (group 3), PQE plus TQE (group 4), and 2 PQE (group 5).
Live births and multiple births.
The live birth rates for group 4 were statistically similar to group 1 during fresh IVF (26.5% vs. 33.7%; odds ratio OR, 0.95; 95% confidence interval CI 0.53–1.7) and frozen ET (24.2% vs. 32.7%; OR, 0.75; 95% CI 0.48–1.2), although there was a trend for lower success. Conversely, multiple births were higher in group 4 for fresh IVF (19% vs. 4.7%; OR, 2.9; 95% CI 1.3–6.6) and frozen ET (10.3% vs. 2.6%; OR, 2.4; 95% CI 1.2–4.9). The live birth rates for group 2 (12.2% for fresh IVF and 14.6% for frozen ET) and group 5 (21.2% for fresh IVF and 14% for frozen ET) were lower and for group 3 were higher (40.8% for fresh IVF and 40.3% for frozen ET) when compared with group 1. Multiple births were significantly higher with DET.
This study does not support DET with one PQE along with a TQE, when there is only one TQE and one or more PQEs available for fresh IVF or frozen ET.
Efecto de la transferencia de un embrión de calidad deficiente junto con uno de calidad superior en el resultado de los ciclos de fecundación in vitro frescos y congelados
evaluar el impacto de la transferencia de un embrión de baja calidad (PQE) en transferencias embrionarias (ET) dobles (DET), junto con un embrión de máxima calidad (TQE) en el resultado de fecundación in vitro (IVF).
Revisión de datos recogidos de manera prospectiva.
Clínica de fertilidad de nivel terciario.
Todas las pacientes sometidas a transferencias de blastocistos como parte de ciclos frescos de IVF (n=939) y ET de congelados (n=1009) realizados entre 2010 y 2016.
ET única (SET) con TQE (grupo 1) fue establecido como control y se comparó con los resultados para SET con PQE (grupo 2), DET con 2 TQE (grupo 3), PQE más TQE (grupo 4) y 2 PQE (grupo 5).
Nacidos vivos y nacimientos múltiples.
Las tasas de nacidos vivos para el grupo 4 fueron estadísticamente similares al grupo 1 en ciclos frescos de FIV (26.5% vs 33.7%; odds ratio OR, 0.95; intervalo de confianza del 95% IC 0.53-1.7) y ET congelados (24.2% vs 32.7%; OR, 0.75; IC del 95%: 0.48-1.2), aunque hubo una tendencia a menor tasa de éxito. Por el contrario, los partos múltiples fueron más altos en el grupo 4 para FIV en fresco (19% vs 4.7%); OR, 2.9; IC del 95%: 1.3-6.6) y ET congelados (10.3 vs 2.6%; OR, 2.4; IC del 95%: 1.2-4.9). Las tasas de nacidos vivos para el grupo 2 (12.2% para FIV en fresco y 14.6% para ET congelados) y el grupo 5 (21.2% para FIV en fresco y 14% para ET congelados) fueron menores, y para el grupo 3 fueron mayores (40.8% para FIV en fresco y 40.3% para ET congelados) cuando se compararon con el grupo 1. Los partos múltiples fueron significativamente más altos con DET.
Este estudio no avala la realización de un DET con un PQE junto con un TQE, cuando sólo hay un TQE y uno o más PQE disponibles para IVF frescos o ET de congelados.
Pollination and Floral Ecology is the most comprehensive single-volume reference to all aspects of pollination biology--and the first fully up-to-date resource of its kind to appear in decades. This ...beautifully illustrated book describes how flowers use colors, shapes, and scents to advertise themselves; how they offer pollen and nectar as rewards; and how they share complex interactions with beetles, birds, bats, bees, and other creatures. The ecology of these interactions is covered in depth, including the timing and patterning of flowering, competition among flowering plants to attract certain visitors and deter others, and the many ways plants and animals can cheat each other.
Farmers must carefully plan their fertilization programs, including conducting soil tests before planting. Investing in soil testing and adhering to BMPs can lead to substantial long-term benefits. ...This publication addresses vegetable fertilization in Florida, offering principles and methods for effective fertilization programs applicable to various crops. This document was first published in June 1996.
PDF
