Enhancing seedling survival on former floodplain grazing land in the Capertee Valley, Australia

© 2017 Ecological Society of Australia and John Wiley & Sons Australia, Ltd Active revegetation is an essential component of biodiversity conservation for fragmented ecosystems and the species that depend on them. However, key knowledge gaps exist around the most cost-effective revegetation strategies to employ in different contexts. This article reports on a revegetation trial undertaken in the Capertee Valley of New South Wales, Australia, to assist the conservation of the critically endangered bird, the Regent Honeyeater (Anthochaera phrygia). Seven treatments were compared to assess their cost-effectiveness for enhancing plant survival at a floodplain site with a history of grazing on introduced pastures. While overall survival rates were low, treatments involving tree guards had higher survival rates and were more cost-effective than treatments without guards. Weed growth, animal activity and water stress all appeared to play a role in the low survival rates at this site, with enhanced weed control emerging as a priority for future trials at similar sites

Fertilization capacity with rainbow trout DNA-damaged sperm and embryo developmental success

Mammalian spermatozoa undergo a strong selection process along the female tract to guarantee fertilization by good quality cells, but risks of fertilization with DNA-damaged spermatozoa have been reported. In contrast, most external fertilizers such as fish seem to have weaker selection procedures. This fact, together with their high prolificacy and external embryo development, indicates that fish could be useful for the study of the effects of sperm DNA damage on embryo development. We cryopreserved sperm from rainbow trout using egg yolk and low-density lipoprotein as additives to promote different rates of DNA damage. DNA fragmentation and oxidization were analyzed using comet assay with and without digestion with restriction enzymes, and fertilization trials were performed. Some embryo batches were treated with 3-aminobenzamide (3AB) to inhibit DNA repair by the poly (ADP-ribose) polymerase, which is an enzyme of the base excision repair pathway. Results showed that all the spermatozoa cryopreserved with egg yolk carried more than 10% fragmented DNA, maintaining fertilization rates of 61.1+/-2.3 but a high rate of abortions, especially during gastrulation, and only 14.5+/-4.4 hatching success. Furthermore, after 3AB treatment, hatching dropped to 3.2+/-2.2, showing that at least 10% DNA fragmentation was repaired. We conclude that trout sperm maintains its ability to fertilize in spite of having DNA damage, but that embryo survival is affected. Damage is partially repaired by the oocyte during the first cleavage. Important advantages of using rainbow trout for the study of processes related to DNA damage and repair during development have been reported. Reproduction (2010) 139 989-997Junta de Castilla y Leon (Spain) [LE007A06]; University of Leoninfo:eu-repo/semantics/publishedVersio

Teaching Resilience: Enabling Factors for Effective Responses to COVID-19

The COVID-19 pandemic has disrupted higher education globally. Teaching staff have pivoted to online learning and employed a range of strategies to facilitate student success. Aside from offering a testing ground for innovative teaching strategies, the pandemic has also provided an opportunity to better understand the pre-existing conditions that enable higher education systems to be resilient - that is, to respond and adapt to disturbances in ways that retain the functions and structures essential for student success. This article presents a case study covering two transdisciplinary undergraduate courses at the University of Technology Sydney, Australia. The results highlight the importance of information flows, feedbacks, self-organisation, leadership, openness, trust, equity, diversity, reserves, social learning and nestedness. These results show that resilience frameworks developed by previous scholars are relevant to university teaching systems and offer guidance on which system features require protection and strengthening to enable effective responses to future disturbances

A novel locus for Meckel-Gruber syndrome, MKS3, maps to chromosome 8q24

Meckel-Gruber syndrome (MKS), the most common monogenic cause of neural tube defects, is an autosomal recessive disorder characterised by a combination of renal cysts and variably associated features, including developmental anomalies of the central nervous system (typically encephalcoele), hepatic ductal dysplasia and cysts, and polydactyly. Locus heterogeneity has been demonstrated by the mapping of the MKS1 locus to 17q21-24 in Finnish kindreds, and of MKS2 to 11q13 in North African-Middle Eastern cohorts. In the present study, we have investigated the genetic basis of MKS in eight consanguineous kindreds, originating from the Indian sub-continent, that do not show linkage to either MKS1 or MKS2. We report the localisation of a third MKS locus (MKS3) to chromosome 8q24 in this cohort by a genome-wide linkage search using autozygosity mapping. We identified a 26-cM region of autozygosity between D8S586 and D8S1108 with a maximum cumulative two-point LOD score at D8S1179 (Z(max)=3.04 at theta=0.06). A heterogeneity test provided evidence of one unlinked family. Exclusion of this family from multipoint analysis maximised the cumulative multipoint LOD score at locus D8S1128 (Z(max)=5.65). Furthermore, a heterozygous SNP in DDEF1, a putative candidate gene, suggested that MKS3 mapped within a 15-cM interval. Comparison of the clinical features of MKS3-linked cases with reports of MKS1- and MKS2-linked kindreds suggests that polydactyly (and possibly encephalocele) appear less common in MKS3-linked families

Development and internal validation of a model for postoperative morbidity in adults undergoing major elective colorectal surgery: the peri-operative quality improvement programme (PQIP) colorectal risk model

Over 1.5 million major surgical procedures take place in the UK NHS each year and approximately 25% of patients develop at least one complication. The most widely used risk-adjustment model for postoperative morbidity in the UK is the physiological and operative severity score for the enumeration of mortality and morbidity. However, this model was derived more than 30 years ago and now overestimates the risk of morbidity. In addition, contemporary definitions of some model predictors are markedly different compared with when the tool was developed. A second model used in clinical practice is the American College of Surgeons National Surgical Quality Improvement Programme risk model; this provides a risk estimate for a range of postoperative complications. This model, widely used in North America, is not open source and therefore cannot be applied to patient populations in other settings. Data from a prospective multicentre clinical dataset of 118 NHS hospitals (the peri-operative quality improvement programme) were used to develop a bespoke risk-adjustment model for postoperative morbidity. Patients aged ≥ 18 years who underwent colorectal surgery were eligible for inclusion. Postoperative morbidity was defined using the postoperative morbidity survey at postoperative day 7. Thirty-one candidate variables were considered for inclusion in the model. Death or morbidity occurred by postoperative day 7 in 3098 out of 11,646 patients (26.6%). Twelve variables were incorporated into the final model, including (among others): Rockwood clinical frailty scale; body mass index; and index of multiple deprivation quintile. The C-statistic was 0.672 (95%CI 0.660–0.684), with a bootstrap optimism corrected C-statistic of 0.666 at internal validation. The model demonstrated good calibration across the range of morbidity estimates with a mean slope gradient of predicted risk of 0.959 (95%CI 0.894–1.024) with an index-corrected intercept of −0.038 (95%CI −0.112–0.036) at internal validation. Our model provides parsimonious case-mix adjustment to quantify risk of morbidity on postoperative day 7 for a UK population of patients undergoing major colorectal surgery. Despite the C-statistic of < 0.7, our model outperformed existing risk-models in widespread use. We therefore recommend application in case-mix adjustment, where incorporation into a continuous monitoring tool such as the variable life adjusted display or exponentially-weighted moving average-chart could support high-level monitoring and quality improvement of risk-adjusted outcome at the population level

Mutations in FRMD7, a newly identified member of the FERM family, cause X-linked idiopathic congenital nystagmus.

Idiopathic congenital nystagmus is characterized by involuntary, periodic, predominantly horizontal oscillations of both eyes. We identified 22 mutations in FRMD7 in 26 families with X-linked idiopathic congenital nystagmus. Screening of 42 singleton cases of idiopathic congenital nystagmus (28 male, 14 females) yielded three mutations (7%). We found restricted expression of FRMD7 in human embryonic brain and developing neural retina, suggesting a specific role in the control of eye movement and gaze stability

Oxidative Stress in Zebrafish (Danio rerio) Sperm

Laboratories around the world have produced tens of thousands of mutant and transgenic zebrafish lines. As with mice, maintaining all of these valuable zebrafish genotypes is expensive, risky, and beyond the capacity of even the largest stock centers. Because reducing oxidative stress has become an important aspect of reducing the variability in mouse sperm cryopreservation, we examined whether antioxidants might improve cryopreservation of zebrafish sperm. Four experiments were conducted in this study. First, we used the xanthine-xanthine oxidase (X-XO) system to generate reactive oxygen species (ROS). The X-XO system was capable of producing a stress reaction in zebrafish sperm reducing its sperm motility in a concentration dependent manner (P<0.05). Second, we examined X-XO and the impact of antioxidants on sperm viability, ROS and motility. Catalase (CAT) mitigated stress and maintained viability and sperm motility (P>0.05), whereas superoxide dismutase (SOD) and vitamin E did not (P<0.05). Third, we evaluated ROS in zebrafish spermatozoa during cryopreservation and its effect on viability and motility. Methanol (8%) reduced viability and sperm motility (P<0.05), but the addition of CAT mitigated these effects (P>0.05), producing a mean 2.0 to 2.9-fold increase in post-thaw motility. Fourth, we examined the effect of additional cryoprotectants and CAT on fresh sperm motility. Cryoprotectants, 8% methanol and 10% dimethylacetamide (DMA), reduced the motility over the control value (P<0.5), whereas 10% dimethylformamide (DMF) with or without CAT did not (P>0.05). Zebrafish sperm protocols should be modified to improve the reliability of the cryopreservation process, perhaps using a different cryoprotectant. Regardless, the simple addition of CAT to present-day procedures will significantly improve this process, assuring increased and less variable fertilization success and allowing resource managers to dependably plan how many straws are needed to safely cryopreserve a genetic line

A comparison of cryopreservation methods: Slow-cooling vs. rapid-cooling based on cell viability, oxidative stress, apoptosis, and CD34+ enumeration of human umbilical cord blood mononucleated cells

<p>Abstract</p> <p>Background</p> <p>The finding of human umbilical cord blood as one of the most likely sources of hematopoietic stem cells offers a less invasive alternative for the need of hematopoietic stem cell transplantation. Due to the once-in-a-life time chance of collecting it, an optimum cryopreservation method that can preserve the life and function of the cells contained is critically needed.</p> <p>Methods</p> <p>Until now, slow-cooling has been the routine method of cryopreservation; however, rapid-cooling offers a simple, efficient, and harmless method for preserving the life and function of the desired cells. Therefore, this study was conducted to compare the effectiveness of slow- and rapid-cooling to preserve umbilical cord blood of mononucleated cells suspected of containing hematopoietic stem cells. The parameters used in this study were differences in cell viability, malondialdehyde content, and apoptosis level. The identification of hematopoietic stem cells themselves was carried out by enumerating CD34⁺in a flow cytometer.</p> <p>Results</p> <p>Our results showed that mononucleated cell viability after rapid-cooling (91.9%) was significantly higher than that after slow-cooling (75.5%), with a <it>p </it>value = 0.003. Interestingly, the malondialdehyde level in the mononucleated cell population after rapid-cooling (56.45 μM) was also significantly higher than that after slow-cooling (33.25 μM), with a <it>p </it>value < 0.001. The apoptosis level in rapid-cooling population (5.18%) was not significantly different from that of the mononucleated cell population that underwent slow-cooling (3.81%), with a <it>p </it>value = 0.138. However, CD34⁺enumeration was much higher in the population that underwent slow-cooling (23.32 cell/μl) than in the one that underwent rapid-cooling (2.47 cell/μl), with a <it>p </it>value = 0.001.</p> <p>Conclusions</p> <p>Rapid-cooling is a potential cryopreservation method to be used to preserve the umbilical cord blood of mononucleated cells, although further optimization of the number of CD34⁺cells after rapid-cooling is critically needed.</p

Thymus-Associated Parathyroid Hormone Has Two Cellular Origins with Distinct Endocrine and Immunological Functions

In mammals, parathyroid hormone (PTH) is a key regulator of extracellular calcium and inorganic phosphorus homeostasis. Although the parathyroid glands were thought to be the only source of PTH, extra-parathyroid PTH production in the thymus, which shares a common origin with parathyroids during organogenesis, has been proposed to provide an auxiliary source of PTH, resulting in a higher than expected survival rate for aparathyroid Gcm2−/− mutants. However, the developmental ontogeny and cellular identity of these “thymic” PTH–expressing cells is unknown. We found that the lethality of aparathyroid Gcm2−/− mutants was affected by genetic background without relation to serum PTH levels, suggesting a need to reconsider the physiological function of thymic PTH. We identified two sources of extra-parathyroid PTH in wild-type mice. Incomplete separation of the parathyroid and thymus organs during organogenesis resulted in misplaced, isolated parathyroid cells that were often attached to the thymus; this was the major source of thymic PTH in normal mice. Analysis of thymus and parathyroid organogenesis in human embryos showed a broadly similar result, indicating that these results may provide insight into human parathyroid development. In addition, medullary thymic epithelial cells (mTECs) express PTH in a Gcm2-independent manner that requires TEC differentiation and is consistent with expression as a self-antigen for negative selection. Genetic or surgical removal of the thymus indicated that thymus-derived PTH in Gcm2−/− mutants did not provide auxiliary endocrine function. Our data show conclusively that the thymus does not serve as an auxiliary source of either serum PTH or parathyroid function. We further show that the normal process of parathyroid organogenesis in both mice and humans leads to the generation of multiple small parathyroid clusters in addition to the main parathyroid glands, that are the likely source of physiologically relevant “thymic PTH.

Predicting severe pain after major surgery: a secondary analysis of the Peri-operative Quality Improvement Programme (PQIP) dataset

Acute postoperative pain is common, distressing and associated with increased morbidity. Targeted interventions can prevent its development. We aimed to develop and internally validate a predictive tool to pre-emptively identify patients at risk of severe pain following major surgery. We analysed data from the UK Peri-operative Quality Improvement Programme to develop and validate a logistic regression model to predict severe pain on the first postoperative day using pre-operative variables. Secondary analyses included the use of peri-operative variables. Data from 17,079 patients undergoing major surgery were included. Severe pain was reported by 3140 (18.4%) patients; this was more prevalent in females, patients with cancer or insulin-dependent diabetes, current smokers and in those taking baseline opioids. Our final model included 25 pre-operative predictors with an optimism-corrected c-statistic of 0.66 and good calibration (mean absolute error 0.005, p = 0.35). Decision-curve analysis suggested an optimal cut-off value of 20–30% predicted risk to identify high-risk individuals. Potentially modifiable risk factors included smoking status and patient-reported measures of psychological well-being. Non-modifiable factors included demographic and surgical factors. Discrimination was improved by the addition of intra-operative variables (likelihood ratio χ2 496.5, p < 0.001) but not by the addition of baseline opioid data. On internal validation, our pre-operative prediction model was well calibrated but discrimination was moderate. Performance was improved with the inclusion of peri-operative covariates suggesting pre-operative variables alone are not sufficient to adequately predict postoperative pain