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The birth of the first test tube baby in 1978 focused attention on the sweeping advances in assisted reproductive technology (ART), which is now a multi-billion-dollar business in the United States. Sperm and eggs are bought and sold in a market that has few barriers to its skyrocketing growth. While ART has been an invaluable gift to thousands of people, creating new families, the use of someone else's genetic material raises complex legal and public policy issues that touch on technological anxiety, eugenics, reproductive autonomy, identity, and family structure. How should the use of gametic material be regulated? Should recipients be able to choose the \"best\" sperm and eggs? Should a child ever be able to discover the identity of her gamete donor? Who can claim parental rights?Naomi R. Cahn explores these issues and many more in Test Tube Families, noting that although such questions are fundamental to the new reproductive technologies, there are few definitive answers currently provided by the law, ethics, or cultural norms. As a new generation of \"donor kids\" comes of age, Cahn calls for better regulation of ART, exhorting legal and policy-making communities to cease applying piecemeal laws and instead create legislation that sustains the fertility industry while simultaneously protecting the interests of donors, recipients, and the children that result from successful transfers.

Contemporary Dutch policy and legislation facilitate the use of high quality, accessible and affordable assisted reproductive technologies (ARTs) to all citizens in need of them, while at the same time setting some strict boundaries on their use in daily clinical practices. Through the ethnographic study of a single clinic in this national context,Patient-Centred IVF examines how this particular form of medicine, aiming to empower its patients, co-shapes the experiences, views and decisions of those using these technologies. Gerrits contends that to understand the use of reproductive technologies in practice and the complexity of processes of medicalization, we need to go beyond 'easy assumptions' about the hegemony of biomedicine and the expected impact of patient-centredness.

The use of intracytoplasmic sperm injection has increased substantially worldwide, primarily in couples with non-male factor infertility. However, there is a paucity of evidence from randomised trials supporting this approach compared with conventional in-vitro fertilisation (IVF). We aimed to investigate whether intracytoplasmic sperm injection would result in a higher livebirth rate compared with conventional IVF. This open-label, multicentre, randomised trial was done at two IVF centres in Ho Chi Minh City, Vietnam (IVFMD, My Duc Hospital and IVFAS, An Sinh Hospital). Eligible couples were aged at least 18 years and the male partner's sperm count and motility (progressive motility) were normal based on WHO 2010 criteria. Couples had to have undergone two or fewer previous conventional IVF or intracytoplasmic sperm injection attempts, have used an antagonist protocol for ovarian stimulation, and agree to have two or fewer embryos transferred. Couples were randomly assigned (1:1) to undergo either intracytoplasmic sperm injection or conventional IVF, using block randomisation with variable block size of 2, 4, or 8 and a telephone-based central randomisation method. The computer-generated randomisation list was prepared by an independent statistician who had no other involvement in the study. Embryologists and couples were not masked to study groups because of the type of interventions and differences in hospital fees, but clinicians performing embryo transfer were unaware of study group allocation. The primary outcome was livebirth after the first embryo transfer from the initiated cycle. Analyses were done on an intention-to-treat basis. The trial is registered with ClinicalTrials.gov, NCT03428919. Between March 16, 2018, and Aug 12, 2019, we randomly assigned 1064 couples to intracytoplasmic sperm injection (n=532) or conventional IVF (n=532). Livebirth after the first embryo transfer from the initiated cycle occurred in 184 (35%) of 532 couples randomly assigned to intracytoplasmic sperm injection and in 166 (31%) of 532 couples randomly assigned to conventional IVF (absolute difference 3·4%, 95% CI −2·4 to 9·2; risk ratio [RR] 1·11, 95% CI 0·93 to 1·32; p=0·27). 29 (5%) couples in the intracytoplasmic sperm injection group and 34 (6%) couples in the conventional IVF group had fertilisation failure (absolute difference −0·9%, −4·0 to 2·1, RR 0·85, 95% CI 0·53 to 1·38; p=0·60). In couples with infertility in whom the male partner has a normal total sperm count and motility, intracytoplasmic sperm injection did not improve the livebirth rate compared with conventional IVF. Our results challenge the value of the routine use of intracytoplasmic sperm injection in assisted reproduction techniques for this population. My Duc Hospital and Merck Sharp and Dohme.

Tree mortality rates appear to be increasing in moist tropical forests (MTFs) with significant carbon cycle consequences. Here, we review the state of knowledge regarding MTF tree mortality, create a conceptual framework with testable hypotheses regarding the drivers, mechanisms and interactions that may underlie increasing MTF mortality rates, and identify the next steps for improved understanding and reduced prediction. Increasing mortality rates are associated with rising temperature and vapor pressure deficit, liana abundance, drought, wind events, fire and, possibly, CO2 fertilization-induced increases in stand thinning or acceleration of trees reaching larger, more vulnerable heights. The majority of these mortality drivers may kill trees in part through carbon starvation and hydraulic failure. The relative importance of each driver is unknown. High species diversity may buffer MTFs against large-scale mortality events, but recent and expected trends in mortality drivers give reason for concern regarding increasing mortality within MTFs. Models of tropical tree mortality are advancing the representation of hydraulics, carbon and demography, but require more empirical knowledge regarding the most common drivers and their subsequent mechanisms. We outline critical datasets and model developments required to test hypotheses regarding the underlying causes of increasing MTF mortality rates, and improve prediction of future mortality under climate change.

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 Atmospheric carbon dioxide concentration ([CO2]) is increasing, which increases leaf‐scale photosynthesis and intrinsic water‐use efficiency. These direct responses have the potential to increase plant growth, vegetation biomass, and soil organic matter; transferring carbon from the atmosphere into terrestrial ecosystems (a carbon sink). A substantial global terrestrial carbon sink would slow the rate of [CO2] increase and thus climate change. However, ecosystem CO2 responses are complex or confounded by concurrent changes in multiple agents of global change and evidence for a [CO2]‐driven terrestrial carbon sink can appear contradictory. Here we synthesize theory and broad, multidisciplinary evidence for the effects of increasing [CO2] (iCO2) on the global terrestrial carbon sink. Evidence suggests a substantial increase in global photosynthesis since pre‐industrial times. Established theory, supported by experiments, indicates that iCO2 is likely responsible for about half of the increase. Global carbon budgeting, atmospheric data, and forest inventories indicate a historical carbon sink, and these apparent iCO2 responses are high in comparison to experiments and predictions from theory. Plant mortality and soil carbon iCO2 responses are highly uncertain. In conclusion, a range of evidence supports a positive terrestrial carbon sink in response to iCO2, albeit with uncertain magnitude and strong suggestion of a role for additional agents of global change. See also the Commentary on this article by Way et al., 229: 2383–2385.

Introduced in 1992, intracytoplasmic sperm injection (ICSI) was initially indicated for severe male infertility; however, its use has since been expanded to non-severe male infertility. We aimed to compare the efficacy and safety of ICSI versus conventional in-vitro fertilisation (IVF) in couples with infertility with non-severe male factor. We conducted an investigator-initiated, multicentre, open-label, randomised controlled trial in ten reproductive medicine centres across China. Couples with infertility with non-severe male factor without a history of poor fertilisation were randomly assigned (1:1) to undergo either ICSI or conventional IVF. The primary outcome was live birth after first embryo transfer. We performed the primary analysis in the intention-to-treat population using log-binomial regression models for categorical outcomes or linear regression models for continuous outcomes, adjusting for centre. This trial is registered with Clinicaltrials.gov, NCT03298633, and is completed. Between April 4, 2018, and Nov 15, 2021, 3879 couples were screened, of whom 2387 (61·5%) couples were randomly assigned (1184 [49·6%] to the ICSI group and 1203 [50·4%] to the conventional IVF group). After excluding couples who were ineligible, randomised twice, or withdrew consent, 1154 (97·5%) in the ICSI group and 1175 (97·7%) in the conventional IVF group were included in the primary analysis. Live birth after first embryo transfer occurred in 390 (33·8%) couples in the ICSI group and in 430 (36·6%) couples in the conventional IVF group (adjusted risk ratio [RR] 0·92 [95% CI 0·83–1·03]; p=0·16). Two (0·2%) neonatal deaths were reported in the ICSI group and one (0·1%) in the conventional IVF group. In couples with infertility with non-severe male factor, ICSI did not improve live birth rate compared with conventional IVF. Given that ICSI is an invasive procedure associated with additional costs and potential increased risks to offspring health, routine use is not recommended in this population. National Natural Science Foundation of China, National Key Research and Development Program, Beijing Municipal Science & Technology Commission, and Peking University Third Hospital.

The effectiveness of PIEZO-ICSI (P-ICSI) compared to conventional ICSI (C-ICSI) is still controversial. The only confirmed effectiveness of P-ICSI compared to C-ICSI is that it can reduce the number of degenerated oocytes after ICSI. This study included 100 patients undergoing their first IVF cycle. The patients were randomly assigned to C-ICSI group and P-ICSI group, 50 patients per each group. A total of 2,434 oocytes were retrieved from 100 patients. Among them, 1,527 oocytes with visible meiotic spindle were inseminated by C-ICSI or P-ICSI (778 by C-ICSI, 749 by P-ICSI). Fertilization, degeneration after ICSI and blastocyst development were compared between the C-ICSI group and P-ICSI group. Among the embryos developed to blastocysts, good quality blastocysts were vitrified. The frozen-thawed embryo transfer (FET) cycles were carried out in 42 patients of C-ICSI group and in 45 patients of P-ICSI group. Clinical pregnancy outcomes were analyzed. The differences between C-ICSI group and P-ICSI group were statistically analyzed using Mann-Whitney U test or chi-Square test. Patient age was not different between C-ICSI group and P-ICSI group (33.5 ± 2.7 vs. 32.9 ± 2.4, P = 0.12114). Normal fertilization rate of P-ICSI group (584/749, 78.0%) was significantly higher than that of C-ICSI group (565/778, 72.6%, P = 0.0176). The oocyte degeneration rate after ICSI was significantly higher in C-ICSI group (49/778, 6.3%) than in P-ICSI group (24/749, 3.2%, P = 0.0055). Among the fertilized oocytes, 21 did not cleave; 14 were from C-ICSI group (2.48%) and 7 from P-ICSI group (1.20%, P = 0.1250). Blastocyst formation rate (65.5% vs. 67.8%, P = 0.4485) and the rates of blastocyst that were available for vitrification (59.3% vs. 62.6%, P = 0.2724) were not different between C-ICSI group and P-ICSI group. Blastocyst formation rate on day 5 was significantly higher in P-ICSI group (50.3%) than in C-ICSI group (43.9%, P = 0.0367). In FET cycles, average age of patients was 33.6 ± 2.6 years old in C-ICSI group and that was 32.9 ± 2.3 years old in P-ICSI group. The average number of transferred embryos was 1.5 ± 0.5 in C-ICSI group and 1.2 ± 0.4 in P-ICSI group. The clinical pregnancy rate and the abortion rate of C-ICSI group were 64.3% and 18.5%, respectively. Those of P-ICSI group were 66.7% and 23.3%, respectively. This study showed that normal fertilization rate, the survival of oocytes after ICSI and blastocyst formation rate on day 5 were significantly higher in P-ICSI group than in C-ICSI group. Developmental arrest of zygotes was lower in P-ICSI group than in C-ICSI group. The number of embryos available for vitrification can be increased by implementing P-ICSI. P-ICSI has the potential to improve the development of zygotes into blastocysts.

• Soil nutrient availability can strongly affect root traits. In tropical forests, phosphorus (P) is often considered the main limiting nutrient for plants. However, support for the P paradigm is limited, and N and cations might also control tropical forests functioning. • We used a large-scale experiment to determine how the factorial addition of nitrogen (N), P and cations affected root productivity and traits related to nutrient acquisition strategies (morphological traits, phosphatase activity, arbuscular mycorrhizal colonisation and nutrient contents) in a primary rainforest growing on low-fertility soils in Central Amazonia after 1 yr of fertilisation. • Multiple root traits and productivity were affected. Phosphorus additions increased annual root productivity and root diameter, but decreased root phosphatase activity. Cation additions increased root productivity at certain times of year, also increasing root diameter and mycorrhizal colonisation. P and cation additions increased their element concentrations in root tissues. No responses were detected with N addition. • Here we showed that rock-derived nutrients determined root functioning in low-fertility Amazonian soils, demonstrating not only the hypothesised importance of P, but also highlighting the role of cations. The changes in fine root traits and productivity indicated that even slow-growing tropical rainforests can respond rapidly to changes in resource availability.