Search results for "fertilization"
showing 10 items of 326 documents
Soil Quality as Affected by Intensive Versus Conservative Agricultural Managements
2017
Soils, the earth’s skin, are at the intersection of the lithosphere, hydrosphere, atmosphere, and biosphere. The persistence of life on our planet depends on the maintenance of soils as they constitute the biological engines of earth. Human population has increased exponentially in recent decades, along with the demand for food, materials, and energy, which have caused a shift from low-yield and subsistence agriculture to a more productive, high-cost, and intensive agriculture. However, soils are very fragile ecosystems and require centuries for their development, thus within the human timescale they are not renewable resources. Modern and intensive agriculture implies serious concern about…
Aberrant methylation patterns at the two-cell stage as an indicator of early developmental failure
2002
The fertilized mouse egg actively demethylates the paternal genome within a few hours after fertilization, whereas the maternal genome is only passively demethylated by a replication-dependent mechanism after the two-cell stage. This evolutionarily conserved assymetry in the early diploid mammalian embryo may have a role in methylation reprogramming of the two very different sets of sperm and egg chromatin for somatic development and formation of totipotent cells. Immunofluorescence staining with an antibody against 5-methylcytosine (MeC) showed that the incidence of abnormal methylation patterns differs between mouse two-cell embryos from superovulated females, nonsuperovulated matings, an…
Factors which influence sperm ability to fertilize.
2005
Different facrors influence animal sperm abiÌiry ro fertilizc- Some ofthem are revieu'ed here, spermmotiliry block to polyspermy, chemioattracrìon, sperm cornpetition lor fcrtilization. Old and new data are report-ed, as lor exanplc the new notions on sperm moriliry derived from sitc directed mutagenesis in rodents, the newnotions on thc odour receptors in m:rrnmalian sperm attr-action and ncw notions on sperm competìtion, which isvariable in diflerent species
Effects of sewage sludge addition to Norway spruce seedlings on nitrogen availability and soil fauna in clear-cut areas
2012
Anaerobically digested and composted sewage sludge (CSS) has been suggested to be a slow-release fertilizer in forestry and an alternative to quick-release inorganic fertilizers. The effects of CSS with or without added carbohydrate on inorganic nitrogen availability and on soil animals were tested in two Norway spruce plantations. Half of the seedlings were individually fertilized with CSS, and the rest were left as controls. Solid sucrose was added to half of the fertilized and untreated seedlings. Soil samples were taken in the autumn in the first and the second year after the treatments. CSS increased soil NH4-N (2100%), the proportion of soil NO3-N, and the N concentration of spruce ne…
Surrogate Motherhood in Italy
2011
Lo studio ricostruisce in chiave critica e comparata la normativa italiana sulla fecondazione artificiale tra pregi (pochi) e difetti (molti)
Impact of Endocrine Disorders on IVF Outcomes: Results from a Large, Single-Centre, Prospective Study
2022
Abstract Endocrine disorders negatively influence the ovarian function, and increasing incidence of endocrine diseases with age may have further negative effects on pregnancy rate. Prospective cohort study of 231 consecutively enrolled patients underwent IVF treatment. In patients with known endocrine disorders, the laboratory parameters were corrected before IVF treatment. One hundred sixty one patients (69.7%) had at least one known and treated endocrine disorder (study group), and 70 patients were endocrine negative (control group). Endocrine disorders diagnosed were thyroid disorders (32.5%), diminished ovarian reserve (23.8%), insulin resistance (22.5%), PCOS (15.2%), hyperprolactinaem…
Effect of thyroid function on assisted reproduction outcomes in euthyroid infertile women: A single center retrospective data analysis and a systemat…
2022
BackgroundThe influence of thyroid-stimulating hormone (TSH) on gestational outcomes have been studied and checked whether differing TSH levels are relevant on human reproduction outcomes. International guidelines recommend TSH values <2.5 mIU/L in women trying to conceive, since values above this level are related to a higher frequency of adverse reproductive outcomes. This study aimed to evaluate whether TSH values correlate with different gestational outcomes in euthyroid infertile women without autoimmune thyroid disease.MethodsA retrospective cohort study was conducted involving 256 women who underwent in vitro fertilization (IVF) treatment. The participants were divided into tw…
Constitutive hsp70 is essential to mitosis during early cleavage of Paracentrotus lividus embryos: The blockage of constitutive hsp70 impairs mitosis
1999
Localization of constitutive hsp70 in eggs and early embryos of sea urchin Paracentrotus lividus is shown by means of in situ immunostaining. An accumulation of this protein is shown in the mitotic structures (asters, spindles and centrosomes). Microinjection of anti-hsp70 antibodies into eggs causes impairment of formation of mitotic structures and of cell division. This impairment goes from a complete mitotic block, to irregular mitotic apparatus formation with irregular cleavage, depending upon the antibody concentration. The localization of hsp70 after antibody microinjection is also described. Blockage of mitotic apparatus formation by nocodazole also blocks the concentration of hsp70 …
Role of rotation and nitrogen fertilization on the productive and qualitative response of durum wheat (Triticum durum Desf.)
2012
Correct soil management can improve and/or sometimes restore the fertility of agricultural land. Crop rotations are important to maintain adequate soil organic matter content and to reduce chemical nutritional intake. Qualitative and productive durum wheat response is strongly influenced by soil nutrient availability, necessary for plant growth and development. Nitrogen availability, mainly during the first stage of growth, determines the uptake rate and total nitrogen uptake; later is also responsible of nitrogen translocation from vegetative to reproductive organs, determining yield and grain qualitative characteristics. The aim of the trial was to evaluate cropping system effects and nit…
Impact of FIGO type 3 uterine fibroids on in vitro fertilization outcomes: A systematic review and meta‐analysis
2023
Background: The effect of FIGO (the International Federation of Gynecology & Obstetrics) type 3 myomas on in vitro fertilization (IVF) is uncertain. Objectives: To evaluate whether FIGO type 3 myomas affect IVF outcomes, through a systematic review and meta-analysis (CRD42022379700). Search strategy: Electronic databases were searched until November 15, 2022. Selection criteria: Studies evaluating the effects of FIGO type 3 myomas on IVF outcome. Data collection and analysis: Pooled results were expressed as odds ratios (OR) with 95% confidence intervals (CI). Heterogeneity was assessed using Higgins I2 . Sources of heterogeneity were explored with sensitivity and subgroup analyses. Mai…