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Dairy cows enter the negative energy balance in the early post-partum period, which negatively affects milk yield, health status and reproduction. This study aimed to determine if milk yield (MY) and fat/protein (F/P) ratio could be used as reliable indicators for predicting the quality of aspirated oocytes and their further use for in vitro fertilisation. A secondary goal was to compare different periods before oocyte aspiration to determine which period had the most significant impact on the oocyte development in donor cows. All tested Holstein cows were at their first lactation (n = 68). The first ultrasound-guided follicular aspiration in donor cows was done on average at 58.7 days in milk (DIM). Usually, a second aspiration followed a week later if no problems were detected. In total, 102 aspirations were performed. Three model equations with different F/P ratio distributions and variants of MY production were tested in statistical evaluation. On average, 3.6 oocytes were retrieved per donor per aspiration, with a minimum of 1 and a maximum of 12. The maturation rate was 62.2%, with a high probability of reaching metaphase II (90.45%). The highest number of oocytes was obtained from low-yielding cows with a low F/P ratio in all evaluated periods (P < 0.01). The quality and expansion of cumulus-oocyte complexes were unaffected by the metabolic status. However, a tendency for better quality oocytes in donors with lower MY and F/P ratios was observed in all models. Our preliminary results showed that the prediction of oocyte quality in a homogeneous group of the first-lactation cows was related to the chosen data acquisition model. Data about milk yield and F/P ratio obtained from on-farm systems provide a valuable source of information for the selection of oocyte donors.

Dairy cows enter the negative energy balance in the early post-partum period, which negatively affects milk yield, health status and reproduction. This study aimed to determine if milk yield (MY) and fat/protein (F/P) ratio could be used as reliable indicators for predicting the quality of aspirated oocytes and their further use for in vitro fertilisation. A secondary goal was to compare different periods before oocyte aspiration to determine which period had the most significant impact on the oocyte development in donor cows. All tested Holstein cows were at their first lactation (n = 68). The first ultrasound-guided follicular aspiration in donor cows was done on average at 58.7 days in milk (DIM). Usually, a second aspiration followed a week later if no problems were detected. In total, 102 aspirations were performed. Three model equations with different F/P ratio distributions and variants of MY production were tested in statistical evaluation. On average, 3.6 oocytes were retrieved per donor per aspiration, with a minimum of 1 and a maximum of 12. The maturation rate was 62.2%, with a high probability of reaching metaphase II (90.45%). The highest number of oocytes was obtained from low-yielding cows with a low F/P ratio in all evaluated periods (P < 0.01). The quality and expansion of cumulus-oocyte complexes were unaffected by the metabolic status. However, a tendency for better quality oocytes in donors with lower MY and F/P ratios was observed in all models. Our preliminary results showed that the prediction of oocyte quality in a homogeneous group of the first-lactation cows was related to the chosen data acquisition model. Data about milk yield and F/P ratio obtained from on-farm systems provide a valuable source of information for the selection of oocyte donors. [ABSTRACT FROM AUTHOR]

This study aims to find a suitable feed for the maturation of snakehead (Channa lucius) cultured in pond systems. The experiment was designed randomly in two different treatments, trash fish (treatment 1) and pellet feed (treatment 2), respectively. Each treatment was repeated three times. The weight of females selected for the experiment was about 102 ± 3,12g. Environmental factors were controlled in an appropriate range for fish growth and mature during the experiment. After 120 days of rearing, the final values of gonad somatic index of fish in treatment 1 and treatment 2 were respectively 3.61 ± 1.1 and 3.54 ± 1.8%. Condition factors of fish in treatment 1 and treatment 2 were 0.0093 ± 0.0013; 0.0095 ± 0.0008, respectively. Absolute fecundity of the fish in treatment 1 was 41,951 ± 7,820 eggs/kg, whereas this value in treatment 2 was 42,106 ± 7,201 eggs/kg. Relative fecundity of the fish in treatment 1 and treatment 2 were 5,762 ± 1,580 and 4,296 ± 737 eggs/fish, respectively. There was no significant difference (p>0.05) in the maturity rate of fish in treatment 1 and treatment 2, which were 75.0 ± 0.38% and 72.7 ± 0.28%, respectively. The results gained from this study indicated that both treatments (treatment 1 and treatment 2) were equally good for fish maturational characteristics of snakehead (Channa lucius).

Copyright of Vascular Access is the property of Canadian Vascular Access Association and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Here we study how the structure and growth of a cellular population vary with the distribution of maturation times from each stage. We consider two cell cycle stages. The first represents early G1. The second includes late G1, S, G2, and mitosis. Passage between the two reflects passage of an important cell cycle checkpoint known as the restriction point. We model the population as a system of partial differential equations. After establishing the existence of solutions, we characterize the maturation rates and derive the steady-state age and stage distributions as well as the asymptotic growth rates for models with exponential and inverse Gaussian maturation time distributions. We find that the stable age and stage distributions, transient dynamics, and asymptotic growth rates are substantially different for these two maturation models. We conclude that researchers modeling cellular populations should take care when choosing a maturation time distribution, as the population growth rate and stage structure can be heavily impacted by this choice. Furthermore, differences in the models' transient dynamics constitute testable predictions that can help further our understanding of the fundamental process of cellular proliferation. We hope that our numerical methods and programs will provide a scaffold for future research on cellular proliferation.

The brachiobasilic transposition (BBT) arteriovenous fistula (AVF) is a valuable option especially for dialysis patients with previously failed vascular access. We aim to report factors affecting the maturation of BBT‐AVF created with either one‐stage or two‐stage technique. BBT‐AVF procedures between January 2015 and May 2019 by a dedicated vascular access team were investigated retrospectively. A total of 122 patients (63 males, 59 females), with 6 to 12 weeks of follow‐up after the BBT‐AVF procedure were included in the study. Patients of one‐stage and two‐stage techniques were compared for maturation rates. Patients with successful and failed maturation were compared for baseline characteristics and anatomic factors. Of 122 BBT‐AVF procedures, 54 were created with the one‐stage and 68 were created with the two‐stage technique. The mean age of the patients was 58.2 ± 13.8, the mean brachial artery and basilic vein diameters were 3.91 ± 1.02 mm, and 3.39 ± 1.16 mm. Of 122 included patients, 88 (72.1%) had mature AVFs at follow‐up. The AVF maturation rates were similar between the one‐ and two‐stage groups (70.4% vs 73.5%; P =.699). Lower age (62.8 ± 12.5 vs 56.5 ± 13.9; P =.023) and greater brachial artery diameter (3.09 ± 0.84 mm vs 4.23 ± 1.76 mm; P <.048) were the only factors affecting the AVF maturation in univariate analysis. Gender, extremity side, diabetes mellitus, hypertension, and targeted vein diameter were not found to affect the AVF maturation (P =.301, P =.084, P =.134, P =.858, P =.127). Target artery diameter (P =.049) was the only significant factor affecting BBT‐AVF maturation in multivariate analysis. One‐stage and two‐stage BBT‐AVFs are similar in terms of maturation rates. Targeted artery diameter was the only factor important in BBT‐AVF maturation in our study group. The two‐stage technique can be preferred considering smaller incision size and lower complication rate in patients with suitable anatomy. [ABSTRACT FROM AUTHOR]

Abstract Fetal bovine serum (FBS) is widely used in cell cultures due to its high stability and easy access. It was also used as a substitute for porcine follicular fluid (PFF) in previous studies. However, FBS components are unclear, and the presence of FBS in culture media may introduce a variation from batch to batch. This study aimed to establish an effective method to screen FBS in place of PFF in the culture media for porcine oocytes in vitro. We screened FBS from different sources by using porcine fetal fibroblast cells. The effects of six FBS samples on porcine fetal fibroblast cell growth were tested via frozen cell survival assay, cell clone formation assay, cell growth curve, and cell passage activity assay. The best serum that we called GFBS (heat‐inactivated FBS, cat. no. 10500‐64; Gibco) showed a similar effect on the maturation and development of porcine oocytes to that of PFF and can be used as a good substitute for PFF. These results suggested that the porcine fetal fibroblast cell culture test can be used as a valuable method to screen FBS for porcine oocyte maturation and embryonic development in vitro.

Background In vitro maturation (IVM) of immature oocytes retrieved from ovarian tissue has been considered as a valuable approach for fertility preservation in cancerous patients. Objective To evaluate the efficacy of vitrification on oocyte maturation, survival rates, as well as the subcellular oocyte quality post IVM. Materials and Methods The ovarian cortexes from 19 women with cervix and uterine malignancy aged 21–39 yr were collected. Cumulus-oocyte complexes were aspirated from all visible antral follicles. 102 immature oocytes were collected, and 43 oocytes were detected appropriately for IVM (control group). Also, 59 immature oocytes were vitrified, then matured in vitro (IVM) in two groups: with Growth/differentiation factor 9 (GDF9) (group 1) and without GDF9 (group 2) supplementation. Rates of oocytes viability, maturation, and survival along with meiotic spindle visualization and zona pellucida birefringence were assessed with Polyscope. Results The rate of maturation was significantly higher in controls (55.8%) compared to the other groups. Maturation rate was 23.3% in oocytes cultured in IVM medium enriched with GDF9, and 27.6% in those cultured in IVM medium lacking GDF9 (p = 0.86). Also, the meiotic spindle was present in 74.4% of control oocytes which was significantly higher than the other groups. The proportion of high zona pellucida birefringence was higher in the controls when compared with group 1 (51.2% vs. 23.3%, respectively, p = 0.04). Conclusion Vitrification had a detrimental effect on oocyte maturation, viability as well as the subcellular quality of the oocytes after IVM in cancerous women.

Background: The existing literature lacks consensus on the effectiveness of utilizing polymorphisms to enhance outcomes in in vitro fertilization (IVF), particularly regarding ovulation induction protocols, oocyte and embryo quality, and pregnancy rates. Therefore, the present pilot study aims to assess whether the composition of different gonadotropin preparations affects the ovarian stimulation protocol concerning follicle-stimulating hormone receptor ( FSHR ) Ser680Asn genotypes (Ser/Ser, Ser/Asn, and Asn/Asn), in terms of ovulation induction parameters, including oocyte maturation rate, embryo quality, and pregnancy rate., Methodology: A total of 94 IVF patients underwent treatment using a GnRH antagonist protocol with four distinct gonadotropin preparations: HMG, HMG/hCG, rFSH, and rFSH/hCG. Follicular fluid (FF) samples were pooled for each patient for analysis., Results: No statistical differences in the FF hormonal profile (progesterone, testosterone, androstenedione, estradiol, FSH, hCG) among the FSHR genotypes were reported either separately for each protocol or in combination for the four different preparations of gonadotropins. The maturation rate of MII oocytes and embryo quality did not differ among women carrying either Ser/Ser, Ser/Asn, or Asn/Asn genotype (p-value=0.475, and p-value=1.000, respectively). Moreover, no statistically significant correlation was revealed among Ser/Ser, Ser/Asn, and Asn/Asn carriers and pregnancy rate (p = 0.588)., Conclusions: FF hormonal analysis of women undergoing IVF using different ovulation induction protocols and carrying either Ser/Ser, Ser/Asn, or Asn/Asn genotype revealed no significant correlations, in terms of maturation rate of MII oocytes, embryo quality, and pregnancy rate, indicating that the FSHR Ser680Asn genotype does not constitute a biomarker for a positive pregnancy outcome. Therefore, the existence of a different mechanism for the expression of FSHR  Ser680Asn genotypes in the FF hormonal profile related to stimulated cycles is implied., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Papamentzelopoulou et al.)

Abstract Solid organic matter (OM) in sedimentary rocks produces petroleum and solid bitumen when it undergoes thermal maturation. The solid OM is a 'geomacromolecule', usually representing a mixture of various organisms with distinct biogenic origins, and can have high heterogeneity in composition. Programmed pyrolysis is a common method to reveal bulk geochemical characteristics of the dominant OM, while detailed organic petrography is required to reveal information about the biogenic origin of contributing macerals. Despite the advantages of programmed pyrolysis, it cannot provide information about the heterogeneity of chemical compositions present in the individual OM types. Therefore, other analytical techniques such as Raman spectroscopy are necessary. In this study, we compared geochemical characteristics and Raman spectra of two sets of naturally and artificially matured Bakken source rock samples. A continuous Raman spectral map on solid bitumen particles was created from the artificially matured hydrous pyrolysis residues, in particular, to show the systematic chemical modifications in microscale. Spectroscopic data was plotted for both sets against thermal maturity to compare maturation rate/path for these two separate groups. The outcome showed that artificial maturation through hydrous pyrolysis does not follow the same trend as naturally-matured samples although having similar solid bitumen reflectance values (%SBRo). Furthermore, Raman spectroscopy of solid bitumen from artificially matured samples indicated the heterogeneity of OM decreases as maturity increases. This may represent an alteration in chemical structure towards more uniform compounds at higher maturity. This study may emphasize the necessity of using analytical methods such as Raman spectroscopy along with conventional geochemical methods to better reveal the underlying chemical structure of OM. Finally, observation by Raman spectroscopy of chemical alteration of OM during artificial maturation may assist in the proposal of improved pyrolysis protocols to better resemble natural geologic processes. Highlights • Hydrous Pyrolysis although known as the best thermal maturity simulation method, did not necessarily follow natural maturation conditions. • The result can help to propose protocols and adjust experimental parameters for HP based on those cross-plots for more accurate thermal maturity progression steps in the lab. • It was also found and shown by Raman mapping mode that as maturity increases, heterogeneity of organic matter decreases. [ABSTRACT FROM AUTHOR]

Background: In vitro maturation (IVM) of immature oocytes retrieved from ovarian tissue has been considered as a valuable approach for fertility preservation in cancerous patients. Objective: To evaluate the efficacy of vitrification on oocyte maturation, survival rates, as well as the subcellular oocyte quality post IVM. Materials and Methods: The ovarian cortexes from 19 women with cervix and uterine malignancy aged 21-39 yr were collected. Cumulus-oocyte complexes were aspirated from all visible antral follicles. 102 immature oocytes were collected, and 43 oocytes were detected appropriately for IVM (control group). Also, 59 immature oocytes were vitrified, then matured in vitro (IVM) in two groups: with Growth/differentiation factor 9 (GDF9) (group 1) and without GDF9 (group 2) supplementation. Rates of oocytes viability, maturation, and survival along with meiotic spindle visualization and zona pellucida birefringence were assessed with Polyscope. Results: The rate of maturation was significantly higher in controls (55.8%) compared to the other groups. Maturation rate was 23.3% in oocytes cultured in IVM medium enriched with GDF9, and 27.6% in those cultured in IVM medium lacking GDF9 (p = 0.86). Also, the meiotic spindle was present in 74.4% of control oocytes which was significantly higher than the other groups. The proportion of high zona pellucida birefringence was higher in the controls when compared with group 1 (51.2% vs. 23.3%, respectively, p = 0.04). Conclusion: Vitrification had a detrimental effect on oocyte maturation, viability as well as the subcellular quality of the oocytes after IVM in cancerous women. [ABSTRACT FROM AUTHOR]

[Objectives] This study was conducted to investigate the effects of lamb age and in vitro culture system of oocytes on the results of juvenile in vitro embryo transfer (JIVET). [Methods] Ten Dorper x small-tailed Han lambs aged 5 to 10 weeks were induced to superovulate via i. p. injection of pregnant mare's serum gonadotropin (PMSG). The oocytes were matured in basal maturation solution or modified maturation solution, which was prepared by adding 200 µmol/L cysteine to the basal maturation solution. Then, the oocytes were fertilized in fertilization medium I containing 2% estrus sheep serum (ESS) or fertilization medium II containing 3 mg/ml bull serum albumin (BSA). Finally, the number of oocytes, oocyte maturation rate and cleavage rate of the lambs of different ages were determined. [Results] The average number of oocytes recovered per lamb was (111.00 ± 16.97), (139.50 ± 28.99), (108.50 ± 17.68) and (42.00 ± 11.31) for 5-, 7-, 8- and 10-week-old Dorper x small-tailed Han lambs, respectively. The number of oocytes obtained from 5-, 7- and 8-week-old lambs was significantly higher than that from 10-week-old lambs (1 < 0.05), but there was no significant difference among 5 -, 7- and 8-week-old lambs (1 > 0.05). The maturation rate of oocytes cultured in modified maturation solution was 3.64% higher than that in basal maturation solution. The cleavage rate of oocytes in fertilization medium I was very significantly higher than that in fertilization medium II (1 < 0.01). [Conclusions] The results of JIVET can be improved by harvesting oocytes from lambs aged 5-8 weeks, adding a certain amount of cysteine into oocyte maturation solution, and a certain amount of ESS into fertilization medium. [ABSTRACT FROM AUTHOR]

Background and Objective: With respect to the antioxidant role of melatonin and retinoic acid, it seems to be effective both in the maturation and embryonic development. This study was done to investigate the effect of combination of melatonin and All-Trans retinoic acid (RA) on maturation, fertilization and embryonic development of immature mouse oocytes. Methods: In this experimental study, cumulus - oocyte complex (COCs) were recovered from 4-6 week old female mice NMRI and were divided into 6 maturation medium groups including control, sham, experiment 1(melatonin 100 nM, 1 and 2 µM), experiment 2 (retinoic acid 1, 2, 4, 6 µM), experiment 3 (melatonin 2 µM+RA 4 µM), experiment 4 (Mel 100nM + retinoic acid 4µM). The maturation rate was recorded after 24 hours of culture in a humidified atmosphere of 5% CO2 at 37°C. The matured oocytes were fertilized with sperm. Fertilization and embryonic development rates to the blastocyst stage were recorded. Results: Maturation rate in the control and sham groups were 50.6% and 49.4%, respectively. Maturation rate were 54.3%, 54.8%, 59.9% in melatonin group with concentrations of 100 nM, 1 and 2 µM, respectively. Maturation rate were 51.6%, 51%, 59% and 49.6% in t-RA group with concentrations of 1, 2, 4, 6 μM. Maturation rate were 60.4% and 54.2% in the experiment 3 and 4 groups, respectively. The maturation rates in the melatonin 2 µM, retinoic acid 4 µM and experiment 3 significantly increased in compare to control (P

Abstract Microalgae provide a wealthy natural resource of bioactive compounds, which have many biological activities. Monosodium glutamate is a food additive that acts either as food preservatives or as tastiness enhancer. It was confirmed that monosodium glutamate poses a serious responsibility in the pathogenesis of anovulatory infertility. Therefore, the idea of this research was directed to reveal efficiency of Chlorella vulgaris and Spirulina platensis extracts against the ovarian dysfunction resulted due to monosodium glutamate consumption. Adult female albino mice were gavages orally monosodium glutamate alone or with either Chlorella vulgaris or Spirulina platensis aqueous extracts for 28 days. Female mice were subjected to superovulation to study the oocytes nuclear maturation stages. Histological and quantitative investigation was carried on ovaries. Biochemical assessment to measure the sex hormones level and ovarian enzymatic antioxidants was done. In addition, ovarian antioxidant mRNA genes were determined using quantitative PCR and Glyceraldehyde-3-phosphate dehydrogenase was used as an internal control. The result revealed that monosodium glutamate reduced the oocytes quality and maturation rate, while, both algae improve the oocyte quality and maturation rate than in monosodium glutamate group. Chlorella vulgaris and Spirulina platensis improved the monosodium glutamate ovarian tissue histological alteration, sex hormones content and raised the ovarian enzymatic antioxidants level. In addition, monosodium glutamate markedly diminished the Glutathione peroxidase, superoxide dismutase and catalase mRNA expressions, However, Chlorella vulgaris or Spirulina platensis upregulated the expression of genes close to control. In conclusion, Chlorella vulgaris and Spirulina platensis showed potential alleviative role against the monosodium glutamate ovarian dysfunction. [ABSTRACT FROM AUTHOR]

Combination of in vitro maturation (IVM) and cryopreservation offers new opportunities for women with contraindication in ovarian stimulation, and females who desire to postpone the childbearing due to different problems. There are still controversies regarding IVM procedure and its impact on oocytes fertilization capability. This systematic review and meta-analysis were conducted to evaluate the impact of vitrification on human oocyte maturation rate during IVM procedure. In this review, we searched Medline, Embase, Scopus and ISI web of science to identify English-language studies. The last search was implemented on 3 February 2018. The original articles which assessed maturation rate after vitrification of MI or GV oocytes were included. Animal trials and the studies that performed cryopreservation using slow-freeze method were excluded. Bias and quality assessments were performed. 2476 articles were screened primarily. After duplication removing and the application of inclusion and exclusion criteria, 14 studies included for the analysis. All studies compared maturation rate between the oocytes that were vitrified at the GV or MI stage before maturation and oocytes which were matured in vitro without vitrification. Meta-analysis showed that oocyte vitrification at GV stage had a significant negative impact on maturation rate (RR = 0.76, 95% CI: 0.66–0.88); I 2  = 85.2%; P = 0.000). Finally, based on our results, oocyte vitrification decreases the maturation rate by 24%. [ABSTRACT FROM AUTHOR]

A lower number of metaphase II oocytes eligible for vitrification after controlled stimulation in cancer patients has recently been reported, suggesting that cancer may impair the dynamics and quality of follicular growth. In this prospective, non-interventional study, the pattern of follicular growth and oocyte cohort after ovarian stimulation in cancer patients was analysed. Ninety cancer patients, recruited before starting chemotherapy, were compared with 180 time- and age-matched healthy controls undergoing intracytoplasmic sperm injection. Primary outcome was total number of metaphase II oocytes and metaphase II /total oocytes rate. Basal anti-Müllerian hormone levels ( P < 0.05) and antral follicle count ( P < 0.0001) were significantly lower in cancer patients. Recombinant FSH total dose was significantly higher in the cancer group ( P < 0.0001). No differences were found in duration of stimulation, mean number of mature follicles on day of ovulation induction and total oocyte number after retrieval; the number of metaphase II oocytes retrieved (6.2 ± 4.7 versus 8.8 ± 4.2; P < 0.0001) and number of metaphase II oocytes–total oocytes ratio were significantly lower in cancer patients (56% versus 78%, P < 0.0001). Fewer metaphase II oocytes were eligible for vitrification and lower maturation rate in the cancer group. [ABSTRACT FROM AUTHOR]

Abstract: Structured compartmental models in mathematical biology track age classes, stage classes, or size classes of a population. Structured modeling becomes important when mechanistic formulations or intraspecific interactions are class‐dependent. The classic derivation of such models from partial differential equations produces time delays in the transition rates between classes. In particular, the transition from juvenile to adult has a delay equal to the maturation period of the organism. In the literature, many structured compartmental models, posed as ordinary differential equations, omit this delay. We reviewed occurrences of continuous‐time compartmental models for age‐ and stage‐structured populations in the recent literature (2000–2016) to discover which papers did so. About half of the 249 papers we reviewed used a maturation delay. Papers with ecological models were more likely to have the delay than papers with disease models, and mathematically focused papers were more likely to have the delay than biologically focused papers. Recommendations for Resource Managers: Interacting populations often are modeled with systems of ordinary differential equations in which the state variables are numbers of individuals of each species and interaction terms depend only on the current state of the system. Single‐population continuous‐time models with age‐ or stage‐structure, in which state variables represent numbers of individuals in classes such as juveniles and adults, often but not always contain maturation time delays in the transition rates between classes. The exclusion of the delay typically changes the model dynamics. Managers should be aware of the maturation delay issue when considering the results of continuous‐time models of structured populations. Discrete‐time models have an inherent time delay, set by the census time step chosen by the modeler, and for that reason are convenient for modeling maturation and other biological delays. [ABSTRACT FROM AUTHOR]

Background Left–right asymmetry is a fundamental organizing feature of the human brain, and neuropsychiatric disorders such as schizophrenia sometimes involve alterations of brain asymmetry. As early as 8 weeks postconception, the majority of human fetuses move their right arms more than their left arms, but because nerve fiber tracts are still descending from the forebrain at this stage, spinal–muscular asymmetries are likely to play an important developmental role. Methods We used RNA sequencing to measure gene expression levels in the left and right spinal cords, and the left and right hindbrains, of 18 postmortem human embryos aged 4 to 8 weeks postconception. Genes showing embryonic lateralization were tested for an enrichment of signals in genome-wide association data for schizophrenia. Results The left side of the embryonic spinal cord was found to mature faster than the right side. Both sides transitioned from transcriptional profiles associated with cell division and proliferation at earlier stages to neuronal differentiation and function at later stages, but the two sides were not in synchrony ( p = 2.2 E-161). The hindbrain showed a left–right mirrored pattern compared with the spinal cord, consistent with the well-known crossing over of function between these two structures. Genes that showed lateralization in the embryonic spinal cord were enriched for association signals with schizophrenia ( p = 4.3 E-05). Conclusions These are the earliest stage left–right differences of human neural development ever reported. Disruption of the lateralized developmental program may play a role in the genetic susceptibility to schizophrenia. [ABSTRACT FROM AUTHOR]

Matrix population models are widely used to describe the growth of stage-structured populations. The variability in stage duration among individuals is one of the important parameters affecting population growth. Despite that importance, studies frequently focus only on the average duration and (perhaps unknowingly) make specific assumptions regarding the variation in stage duration that likely contradicts with the data. Furthermore, although there are methods for modeling variable stage duration, they are not sufficiently flexible to encompass the diversity of potential distributions. This study discusses problems associated with the existing methods and describes approaches to deal with the problems. [ABSTRACT FROM AUTHOR]

Copyright of Collegium Antropologicum is the property of Croatian Anthropological Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

With the objective of to adjust nonlinear models for the growth curves for a buffaloes herd raised in floodable lands in Rio Grande do Sul state, monthly records measured from birth to two years-old of 64 males and 63 females born between 1982 and 1989 were used. The models used were: Von Bertalanffy, Brody, Gompertz and Logistic. The parameters were estimated by NLIN procedure and the criteria used to evaluate the adjustment given by the models were: asymptotic standard deviation; coefficient of determination; average absolute deviation of residues and asymptotic index. Von Bertalanffy and Brody models overestimated the male asymptotic weight (A) in 15.9 and 171.3kg, respectively, and the Gompertz and Logistic models underestimated it in 4.5 and 13.4kg, respectively. For females, the Logistic model underestimated the asymptotic weight (-2.09kg), and Gompertz, Von Bertalanffy and Brody overestimated this parameter in 8.04, 17.7, and 280.33kg, respectively. The biggest average deviation was estimated by Brody model for both sexes, characterizing the biggest index. Considering the criteria, it is recommended the Gompertz and Logistic models for adjust females and males Murrah buffaloes breed growth curves.Com o objetivo de ajustar modelos não-lineares ao crescimento ponderal para búfalos criados em terras baixas no Estado do Rio Grande do Sul, foram utilizados registros mensais mensurados do nascimento aos dois anos de idade de 64 machos e 63 fêmeas, nascidos no período de 1982 a 1989. Utilizaram-se os modelos: Von Bertalanffy, Brody, Gompertz e Logístico. Os parâmetros foram estimados usando o procedimento NLIN e os critérios utilizados para verificar o ajuste dos modelos foram: desvio padrão assintótico; coeficiente de determinação; desvio médio absoluto dos resíduos e o índice assintótico. Os modelos Von Bertalanffy e Brody superestimaram o peso assintótico (A) para os machos em 15,9 e 171,3kg, respectivamente, e os modelos Gompertz e Logístico, subestimaram em 4,5 e 13,4kg, respectivamente. Para as fêmeas, o modelo Logístico subestimou o peso assintótico (-2,09kg) e os modelos Gompertz, Von Bertalanffy e Brody superestimaram esse parâmetro em: 8,04; 17,7 e 280,33kg, respectivamente. O maior desvio médio absoluto foi estimado pelo modelo Brody para ambos os sexos, caracterizando o melhor índice. Considerando os critérios, recomenda-se o modelo Gompertz e o modelo Logístico para ajustar a curva de crescimento de fêmeas e machos da raça Murrah.

Background and Objective: To determine the results of autogenous arteriovenous fistula (AVF) performed by a general surgeon at secondary-level hospital, in terms of maturation rate, primary patency rate, and complication rate. Material and Methods: Between October 2011 and November 2014, 64 patients with indications for hemodialysis (HD) were considered for permanent venous access at Phetchabun Hospital. Fifty AVFs were performed on 47 patients who had been selected on physical examination to have adequate vessels. Patients were followed until June 2015. Results: Of 64 patients, 47 patients (73%) underwent 50 AVFs which composed of 3 radiocephalic AVF (6%), 46 brachiocephalic AVF (92%) and 1 brachiobasilic AVF (2%). Overall maturation rate was 90%. Mean time of maturation was 8.6 weeks. Primary patency rate was analyzed by descriptive survival analysis. Primary patency rate of AVF at 6th month, 1st, 2nd and 3rd year was 89%, 87%, 82% and 82%, respectively. Post-operative hematoma was the only complication seen (8%). Conclusion: General surgeons in the setting of secondary-level hospital can perform AVF effectively in selected patients, selecting appropriate types of AVF, with proper time of initiation hemodialysis. [ABSTRACT FROM AUTHOR]

There are few studies on weight covering the full life cycle of Zebu cattle, and there is no entire growth description or mean growth pattern for animals belonging to this breed. In order to provide such data, 1,158 Nelore females born between 1985 and 1995 were weighed 14,563 times from birth to full growth maturity, in ten herds spread over seven Brazilian states. The Von Bertalanffy, Brody, logistic and Gompertz non-linear models were used to obtain the asymptotic weights (A) and the maturation rates (K). The (co)variance and breeding value components for A and K were obtained by using the multiple trait derivative free restricted maximum likelihood method under the animal model. Genetic trends were calculated in function of the mean expected progeny differences (EPD) for the trait (A or K) divided by the number of animals according to their year of birth. The genetic trends of the expected progeny difference with reference to the date of birth of the cows were, on average, -6.5g y-1 for A and 2.0g y-1 for K, close to zero as confirmed by the low (0.0023 to 0.003) coefficient of regression values. The curve parameters are recommended as a selection criterion to reach precocity and avoid adult weight increase in the female herd.

Background and Objective: With respect to the antioxidant role of melatonin and retinoic acid, it seems to be effective both in the maturation and embryonic development. This study was done to investigate the effect of combination of melatonin and All-Trans retinoic acid (RA) on maturation, fertilization and embryonic development of immature mouse oocytes. Methods: In this experimental study, cumulus - oocyte complex (COCs) were recovered from 4-6 week old female mice NMRI and were divided into 6 maturation medium groups including control, sham, experiment 1(melatonin 100 nM, 1 and 2 μM), experiment 2 (retinoic acid 1, 2, 4, 6 μM), experiment 3 (melatonin 2 μM+RA 4 μM), experiment 4 (Mel 100nM + retinoic acid 4μM). The maturation rate was recorded after 24 hours of culture in a humidified atmosphere of 5% CO2 at 37°C. The matured oocytes were fertilized with sperm. Fertilization and embryonic development rates to the blastocyst stage were recorded. Results: Maturation rate in the control and sham groups were 50.6% and 49.4%, respectively. Maturation rate were 54.3%, 54.8%, 59.9% in melatonin group with concentrations of 100 nM, 1 and 2 μM, respectively. Maturation rate were 51.6%, 51%, 59% and 49.6% in t-RA group with concentrations of 1, 2, 4, 6 μM. Maturation rate were 60.4% and 54.2% in the experiment 3 and 4 groups, respectively. The maturation rates in the melatonin 2 μM, retinoic acid 4 μM and experiment 3 significantly increased in compare to control (P<0.05). The embryonic development rate in the melatonin with 100nM concentration and 4 μM of retinoic acid increased significantly compared to controls (P<0.05). Although, embryonic development rate in experiment 3 was higher than control, but lower in compare to melatonin 100 nM and the retinoic acid 4 μM. The embryonic development rate in experiment 4 significantly increased in compare to control (P<0.05). Conclusion: Combination of melatonin and All-Trans retinoic acid in medium culture increase maturation rate and improved embryonic development in dose dependent manner. [ABSTRACT FROM AUTHOR]

Maturation is a critical developmental process, and the age and size at which it occurs have important fitness consequences. Although maturation is remarkably variable, certain mechanisms, including a minimum size or state threshold, are proposed to underlie the process across a broad diversity of taxa. Recent evidence suggests that thresholds may themselves be developmentally plastic, and in the crustacean Daphnia pulex it is unclear whether maturation follows a threshold or is a gradual process more akin to a rate. Changes in gene expression across four instars before and during maturation were compared in a cDNA microarray experiment. Developmental stage was treated statistically both as a discontinuous and as a continuous variable, to determine whether genes showed gradual or discrete changes in expression. The continuous analysis identified a greater number of genes with significant differential expression (45) than the discontinuous analysis (11). The majority of genes, including those coding for histones, factors relating to transcription and cell cycle processes, and a putative developmental hormone showed continuous increases or decreases in expression from the first to the fourth instars that were studied, suggestive of a prolonged and gradual maturation process. Three genes coding for a fused vitellogenin/superoxide dismutase showed increases in expression following the second instar and coincided with the posited maturation threshold, but even their expression increased in a continuous fashion. [ABSTRACT FROM AUTHOR]

In Burkina Faso, the cyclical vectors of African animal trypanosomoses (AAT) are riverine tsetse species, namely Glossina palpalis gambiensis Vanderplank (G.p.g.) and Glossina tachinoides Westwood (G. t.) (Diptera: Glossinidae). Experimental work demonstrated that environmental stress can increase the sensitivity of tsetse to trypanosome infection. Seasonal variations of the tsetse infection rates were monitored monthly over 17 months (May 2006-Sept 2007) in two sites (Douroula and Kadomba). In total, 1,423 flies were dissected and the infection of the proboscis, middle intestine and salivary glands was noted. All the positive organs were analyzed using monospecific polymerase chain reaction (PCR) primers. To investigate the role of different environmental factors, fly infection rates were analyzed using generalized linear mixed binomial models using the species, sex, and monthly averages of the maximum, minimum and mean daily temperatures, rainfalls, Land Surface Temperature day (LSTd) and night (LSTn) as fixed effects and the trap position as a random effect. The overall infection rate was 10% from which the predominant species was T. congolense (7.6% of the flies), followed by T. vivax (2.2% of the flies). The best model (lowest AICc) for the global infection rates was the one with the maximum daily temperature only as fixed effect (p<0.001). For T. congolense, the best model was the one with the tsetse species, sex, maximum daily temperature and rainfalls as fixed effect, where the maximum daily temperature was the main effect (p<0.001). The number of T. vivax infections was too low to allow the models to converge. The maturation rate of T. congolense was very high (94%), and G. t. harbored a higher maturation rate (p=0.03). The results are discussed in view of former laboratory studies showing that temperature stress can increase the susceptibility of tsetse to trypanosomes, as well as the possibility to improve AAT risk mapping using satellite images. [ABSTRACT FROM AUTHOR]

Question Fire management practices aimed at biodiversity conservation are often in conflict with hazard reduction requirements. Particularly in protected areas where such conflict of interest exists, the question is asked: what are the ecological thresholds within which fire should be managed? Location Montane proteoid fynbos shrublands, eastern coastal part of the Cape Floral Kingdom; coastal slopes of the Tsitsikamma and Outeniqua Mountains, South Africa. Methods Estimates of optimal fire frequencies are often based on the relationship between plant age and the rate of seed accumulation of the slowest-maturing species. We established juvenile periods and recruitment success (measured as the ratio of post-fire recruits to the pre-burn population) after fires at different intervals, of serotinous, reseeding shrubs in the Proteaceae. From this we estimated minimum fire return intervals ( FRIs) that would allow for their persistence in eastern coastal fynbos shrublands. Results Juvenile periods ranged from 4 to 9 yr, which are comparable to ecologically similar proteoids elsewhere in fynbos and SE and SW Australian shrublands. There was large variability among sites and within species in the degree of flowering at given plant ages, some of which seemed related to the moisture regime. There were no consistent differences among species in their rate of maturation. Post-fire recruitment success was near zero following a fire in 5-yr-old vegetation, always above replacement levels following fires in ≥7-yr-old vegetation, and at a maximum in old (38 yr) fynbos. There was considerable variation in post-fire recruitment success for any particular FRI, species or site. The lack of a significant relationship between recruitment success and pre-fire vegetation age, suggests that once a critical post-fire age is attained, factors other than seed abundance affect recruitment success. Conclusions From an ecological perspective, our findings imply a minimum FRI of 9 yr for eastern coastal fynbos. This is not intended to prescribe rigid management of fire according to a fixed rotation and does not negate the need to consider site- or species-specific requirements. Instead it provides a lower threshold for a range of acceptable FRIs below which a significant decline of species populations is predicted. [ABSTRACT FROM AUTHOR]

With the objective of to adjust nonlinear models for the growth curves for a buffaloes herd raised in floodable lands in Rio Grande do Sul state, monthly records measured from birth to two years-old of 64 males and 63 females born between 1982 and 1989 were used. The models used were: Von Bertalanffy, Brody, Gompertz and Logistic. The parameters were estimated by NLIN procedure and the criteria used to evaluate the adjustment given by the models were: asymptotic standard deviation; coefficient of determination; average absolute deviation of residues and asymptotic index. Von Bertalanffy and Brody models overestimated the male asymptotic weight (A) in 15.9 and 171.3kg, respectively, and the Gompertz and Logistic models underestimated it in 4.5 and 13.4kg, respectively. For females, the Logistic model underestimated the asymptotic weight (-2.09kg), and Gompertz, Von Bertalanffy and Brody overestimated this parameter in 8.04, 17.7, and 280.33kg, respectively. The biggest average deviation was estimated by Brody model for both sexes, characterizing the biggest index. Considering the criteria, it is recommended the Gompertz and Logistic models for adjust females and males Murrah buffaloes breed growth curves. [ABSTRACT FROM AUTHOR]

Abstract: Most theoretical studies on character displacement and the coexistence of competing species have focused attention on the evolution of competitive traits driven by inter-specific competition. We investigated the evolution of the maturation rate which is not directly related to competition and trades off with the birth rate and how it influences competitive outcomes. Evolution may result in the superior competitor becoming extinct if, initially, the inferior competitor has a lower, and the superior one a higher, maturation rate at the coexistence equilibrium. This counterintuitive result is explained by an explosive increase in the adult population of the inferior competitor as a result of the more rapid evolution of its maturation rate, which is caused by differences in the intensity and direction of selection on the maturation rates of the two species and in their adult densities, which are related to differences in their life histories. Thus, a life history trait trade-off with a competitive trait may cause a competitive ecological coexistence to collapse. [Copyright &y& Elsevier]

Reaction norms for age and size at maturity are being analyzed to answer important questions about the evolution of life histories. A new statistical method is developed in the framework of time-to-event data analysis, which circumvents shortcomings in currently available approaches. The method emphasizes the estimation of age and size-dependent maturation rates. Individual probabilities of maturation during any given time interval follow by integrating maturation rate along the growth curve. The integration may be performed in different ways, over ages or sizes or both, corresponding to different assumptions on how individuals store the operational history of the maturation process. Data analysis amounts to fitting generalized nonlinear regression models to a maturation status variable. This technique has three main advantages over existing methods: (1) treating maturation as a stochastic process enables one to specify a rate of maturation; (2) age and size at which maturation occurs do not have to be observed exactly, and bias arising from approximations and interpolations is avoided; (3) ages at which sizes are measured and maturation status are observed can differ between individuals. An application to data on the springtail Folsomia candida is presented. Models with age-dependent integration of maturation rates were preferred. The analysis demonstrates a significant size dependence of the maturation rate but no age dependence. [ABSTRACT FROM AUTHOR]

Here we study how the structure and growth of a cellular population vary with the distribution of maturation times from each stage. We consider two cell cycle stages. The first represents early G1. The second includes late G1, S, G2, and mitosis. Passage between the two reflects passage of an important cell cycle checkpoint known as the restriction point. We model the population as a system of partial differential equations. After establishing the existence of solutions, we characterize the maturation rates and derive the steady-state age and stage distributions as well as the asymptotic growth rates for models with exponential and inverse Gaussian maturation time distributions. We find that the stable age and stage distributions, transient dynamics, and asymptotic growth rates are substantially different for these two maturation models. We conclude that researchers modeling cellular populations should take care when choosing a maturation time distribution, as the population growth rate and stage structure can be heavily impacted by this choice. Furthermore, differences in the models' transient dynamics constitute testable predictions that can help further our understanding of the fundamental process of cellular proliferation. We hope that our numerical methods and programs will provide a scaffold for future research on cellular proliferation.