324 research outputs found
Sexual coloration and sperm performance in the Australian painted dragon lizard, Ctenophorus pictus
Theory predicts trade-offs between pre- and post-copulatory sexually selected traits. This relationship may be mediated by the degree to which males are able to monopolize access to females, as this will place an upper limit on the strength of post-copulatory selection. Furthermore, traits that aid in mate monopolization may be costly to maintain and may limit investment in post-copulatory traits, such as sperm performance. Australian painted dragons are polymorphic for the presence or absence of a yellow gular patch (\u27bibs\u27), which may aid them to monopolize access to females. Previous work has shown that there are physiological costs of carrying this bib (greater loss of body condition in the wild). Here, we show that male painted dragons use this bright yellow bib as both an inter- and intrasexual signal, and we assess whether this signal is traded off against sperm performance within the same individuals. We found no relationship between aspects of bib colour and sperm swimming velocity or percentage of motile sperm and suggest that the bib polymorphism may be maintained by complex interactions between physiological or life-history traits including other sperm or ejaculate traits and environmental influences
Using new ways of working to attract millennials
Millennials are attracted to the new ways of working.
However, care needs to be taken as the new ways of working must be clearly aligned with opportunities to learn and grow
Remoción de contaminantes y crecimiento del alga Scenedesmus sp. en aguas residuales de curtiembres, comparación entre células libres e inmovilizadas
Tannery wastewater are a public health and ecosystem hazard, due to the high concentration of contaminants such as chrome, sulfides and others. One way to treat these waters is by the use of microorganisms such as microalgae due to their capacity to use the inorganic compounds, as well as to accumulate metals and other contaminant substances; ability that could be improve with cellular immobilization. In this paper, the growth and removal of nitrogen, phosphorus and chrome by the microalgae Scenedesmus sp. were evaluated, comparing the rates between free and immobilized cells in a Loofa matrix. In this way, a higher growth in the free cells was obtained, compared to the immobilized ones. However, there were no significant differences between removals of contaminants. In both cases, higher reductions than 90% for NO–3 , NH+4, PO34 and Chromium, as well as a significant reduction in BOD and COD (> 97%) were obtained, probably by a synergy effect between algae and bacteria presents in the culture. Finally, lipids in both cases were higher than 20%, showing that this biomass could present a high potential as a raw material for the generation of biodiesel.Las aguas residuales de curtiembres conllevan un problema ambiental y de salud, debido a las altas concentraciones de contaminantes como el cromo, sulfuros, entre otros. Una forma de realizar el tratamiento de estas aguas es por medio del uso de microorganismos tales como las microalgas, debido a su capacidad de utilizar los compuestos inorgánicos y acumular metales y otras sustancias contaminantes. Esta capacidad podría verse magnificada con la inmovilización celular en diferentes matrices. En este artículo se presenta una evaluación de la capacidad de crecimiento y de remoción de nitrógeno, fósforo y cromo por parte de la microalga Scenedesmus sp., comparando la eficiencia entre las células libres e inmovilizadas en una matriz de esponja de Luffa. De esta manera, se obtuvo un mayor crecimiento en las células libres en comparación a las inmovilizadas, aunque sin diferencias significativas entre ambos experimentos. En ambos casos se observaron remociones superiores al 90% para NO–3 , NH+4, PO34 y cromo total, así como una reducción importante de la DBO y DQO (> 97 %) que puede deberse a efecto sinérgico con las bacterias presentes en los cultivos de la microalga. Finalmente, los porcentajes de lípidos en ambos casos fueron superiores al 20% indicando que esta biomasa podría presentar un alto potencial como materia prima para la generación de biodiesel
The third way of umbilical cord blood banking
This paper analyses the current problems of public and private banks, and gives two hybrid models which facilitate the cell exchange and allocate resource more efficiently. One is the 'public and private combination' model, and the other is the 'donatable family banking' model. It analyzes these models in terms of cell exchange, quality and financial consideration. This paper provides an alternative perspective on how the cord blood industry can cooperate with stem cell science
Clustering and Alignment of Polymorphic Sequences for HLA-DRB1 Genotyping
Located on Chromosome 6p21, classical human leukocyte antigen genes are highly polymorphic. HLA alleles associate with a variety of phenotypes, such as narcolepsy, autoimmunity, as well as immunologic response to infectious disease. Moreover, high resolution genotyping of these loci is critical to achieving long-term survival of allogeneic transplants. Development of methods to obtain high resolution analysis of HLA genotypes will lead to improved understanding of how select alleles contribute to human health and disease risk. Genomic DNAs were obtained from a cohort of n = 383 subjects recruited as part of an Ulcerative Colitis study and analyzed for HLA-DRB1. HLA genotypes were determined using sequence specific oligonucleotide probes and by next-generation sequencing using the Roche/454 GSFLX instrument. The Clustering and Alignment of Polymorphic Sequences (CAPSeq) software application was developed to analyze next-generation sequencing data. The application generates HLA sequence specific 6-digit genotype information from next-generation sequencing data using MUMmer to align sequences and the R package diffusionMap to classify sequences into their respective allelic groups. The incorporation of Bootstrap Aggregating, Bagging to aid in sorting of sequences into allele classes resulted in improved genotyping accuracy. Using Bagging iterations equal to 60, the genotyping results obtained using CAPSeq when compared with sequence specific oligonucleotide probe characterized 4-digit genotypes exhibited high rates of concordance, matching at 759 out of 766 (99.1%) alleles. © 2013 Ringquist et al
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Prostaglandin E2 promotes survival of naive UCB T cells via the Wnt/β-catenin pathway and alters immune reconstitution after UCBT
The outcome of umbilical cord blood transplantation (UCBT) is compromised by low hematopoietic stem cell (HSC) doses leading to prolonged time to engraftment, delayed immunological reconstitution and late memory T-cell skewing. Exposure of UCB to dimethyl-prostaglandin E2 (dmPGE2) increases HSC in vivo. We determined that exposure of UCB T lymphocytes to dmPGE2 modified Wnt signaling resulting in T cell factor (TCF)-mediated transcription. Wnt signaling upregulated interleukin (IL)-7R and IL-2Rβ, resulting in enhanced survival mediated by the homeostatic cytokines IL-7 and IL-15. dmPGE2 also induced components of the Wnt pathway and Wnt receptors, thereby priming UCB T cells to receive signals via Wnt ligands in vivo. We observed that the Wnt transcription factor TCF7 and its target EOMES were elevated in the T cells of patients who received PGE2-treated UCBs. Consistent with the role of Wnt/β-catenin signaling to induce and maintain naive, memory precursors and long-lived central memory CD8+ cells, these patients also had increased fractions of CD8+CD45RO-CD62L+ plus CD8+CD45RO+CD62L+ subsets encompassing these T-cell populations. These effects of the PGE2/Wnt/β-catenin axis may have significant implications for harnessing immunity in the context of UCBT, where impaired immune reconstitution is associated with late memory T-cell skewing
Neonatal umbilical cord blood transplantation halts skeletal disease progression in the murine model of MPS-I
Umbilical cord blood (UCB) is a promising source of stem cells to use in early haematopoietic stem
cell transplantation (HSCT) approaches for several genetic diseases that can be diagnosed at birth. Mucopolysaccharidosis type I (MPS-I) is a progressive multi-system disorder caused by deficiency
of lysosomal enzyme α-L-iduronidase, and patients treated with allogeneic HSCT at the onset
have improved outcome, suggesting to administer such therapy as early as possible. Given that
the best characterized MPS-I murine model is an immunocompetent mouse, we here developed a transplantation system based on murine UCB. With the final aim of testing the therapeutic efficacy of UCB in MPS-I mice transplanted at birth, we first defined the features of murine UCB cells and demonstrated that they are capable of multi-lineage haematopoietic repopulation of myeloablated adult mice similarly to bone marrow cells. We then assessed the effectiveness of murine UCB cells transplantation in busulfan-conditioned newborn MPS-I mice. Twenty weeks after treatment, iduronidase activity was increased in visceral organs of MPS-I animals, glycosaminoglycans storage was reduced, and skeletal phenotype was ameliorated. This study explores a potential therapy for MPS-I at a very early stage in life and represents a novel model to test UCB-based transplantation approaches for various diseases
Ethical issues relating to the banking of umbilical cord blood in Mexico
<p>Abstract</p> <p>Background</p> <p>Umbilical cord banks are a central component, as umbilical cord tissue providers, in both medical treatment and scientific research with stem cells. But, whereas the creation of umbilical cord banks is seen as successful practice, it is perceived as a risky style of play by others. This article examines and discusses the ethical, medical and legal considerations that arise from the operation of umbilical cord banks in Mexico.</p> <p>Discussion</p> <p>A number of experts have stated that the use of umbilical cord goes beyond the mere utilization of human tissues for the purpose of treatment. This tissue is also used in research studies: genetic studies, studies to evaluate the effectiveness of new antibiotics, studies to identify new proteins, etc. Meanwhile, others claim that the law and other norms for the functioning of cord banks are not consistent and are poorly defined. Some of these critics point out that the confidentiality of donor information is handled differently in different places. The fact that private cord banks offer their services as "biological insurance" in order to obtain informed consent by promising the parents that the tissue that will be stored insures the health of their child in the future raises the issue of whether the consent is freely given or given under coercion. Another consideration that must be made in relation to privately owned cord banks has to do with the ownership of the stored umbilical cord.</p> <p>Summary</p> <p>Conflicts between moral principles and economic interests (non-moral principles) cause dilemmas in the clinical practice of umbilical cord blood storage and use especially in privately owned banks. This article presents a reflection and some of the guidelines that must be followed by umbilical cord banks in order to deal with these conflicts. This reflection is based on the fundamental notions of ethics and public health and seeks to be a contribution towards the improvement of umbilical cord banks' performance.</p
Meta-analysis of gender performance gaps in undergraduate natural science courses
To investigate patterns of gender-based performance gaps, we conducted a meta-analysis of published studies and unpublished data collected across 169 undergraduate biology and chemistry courses. While we did not detect an overall gender gap in performance, heterogeneity analyses suggested further analysis was warranted, so we investigated whether attributes of the learning environment impacted performance disparities on the basis of gender. Several factors moderated performance differences, including class size, assessment type, and pedagogy. Specifically, we found evidence that larger classes, reliance on exams, and undisrupted, traditional lecture were associated with lower grades for women. We discuss our results in the context of natural science courses and conclude by making recommendations for instructional practices and future research to promote gender equity
Increasing Use of Allogeneic Hematopoietic Cell Transplantation in Patients Aged 70 Years and Older in the United States
In this study, we evaluated trends and outcomes of allogeneic hematopoietic cell transplantation (HCT) in adults ≥ 70 years with hematologic malignancies across the United States. Adults ≥ 70 years with a hematologic malignancy undergoing first allogeneic HCT in the United States between 2000 and 2013 and reported to the Center for International Blood and Marrow Transplant Research were eligible. Transplant utilization and transplant outcomes, including overall survival (OS), progression-free survival (PFS), and transplant-related mortality (TRM) were studied. One thousand one hundred and six patients ≥ 70 years underwent HCT across 103 transplant centers. The number and proportion of allografts performed in this population rose markedly over the past decade, accounting for 0.1% of transplants in 2000 to 3.85% (N = 298) in 2013. Acute myeloid leukemia and myelodysplastic syndromes represented the most common disease indications. Two-year OS and PFS significantly improved over time (OS: 26% [95% confidence interval (CI), 21% to 33%] in 2000-2007 to 39% [95% CI, 35% to 42%] in 2008-2013, P \u3c .001; PFS: 22% [16% to 28%] in 2000-2007 to 32% [95% CI, 29% to 36%] in 2008-2013, P = .003). Two-year TRM ranged from 33% to 35% and was unchanged over time (P = .54). Multivariable analysis of OS in the modern era of 2008-2013 revealed higher comorbidity by HCT comorbidity index ≥ 3 (hazard ratio [HR], 1.27; P = .006), umbilical cord blood graft (HR, 1.97; P = .0002), and myeloablative conditioning (HR, 1.61; P = .0002) as adverse factors. Over the past decade, utilization and survival after allogeneic transplant have increased in patients ≥ 70 years. Select adults ≥70 years with hematologic malignancies should be considered for transplant
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