Availability of fresh water in cold climate regions

Challenges related to the availability of fresh water in cold climate regions are discussed with emphasis on possible degradation of the quality of drinking water. The permafrost in this region has been consistent in making sure there is little drainage in the ground. This is important, as fresh water is mainly supplied through melting water from snow and ice in the many winter months. Climate change and warmer weather plays a role in heating up the permafrost and increasing the rate of the melting snow. This has an impact on both the amount of water and potentially the drinking quality. In certain cold region areas, fresh water sources are located not far from the shore. With increased shorline erosion due to warming climate, the fresh water supply is in danger of being contaminated by salt water during large storm events. Furthermore, human activities such as road transport and sewage contamination do also have a significant impact on the water's quality. A bowtie diagram will be used to illustrate the different risk factors and suggestions on how to maintain the quality of fresh water supplies in cold climate areas. The primary focus areas will be Isdammen, near Longyearbyen on Svalbard and Utqiagvik (formerly Barrow), Alaska.publishedVersio

The National & State Context of STEM Education: Past, Present, and Future

N/

STEM II Initiative-Updates from Participating Institutions (Part 1)

STEM II Initiative – Updates from Participating Institutions (Part 1) is made up of a series of “sampler sessions” so that interested individuals can get an overview but not comprehensive coverage. Dr. Nathan Moon will introduce this session by telling a few important lessons gleaned from the STEM I evaluations. Second, Dr. Tim Howard will talk about the STEM II Initiative at Columbus State. Third, Dr. Judy Awong-Taylor will provide information concerning the STEM II Initiative at Georgia Gwinnett College. Fourth, Dr. Rosalie Richards will discuss what is happening with the STEM II Initiative at Georgia College & State University

Human CD8 T cells generated in vitro from hematopoietic stem cells are functionally mature

<p>Abstract</p> <p>Background</p> <p>T cell development occurs within the highly specialized thymus. Cytotoxic CD8 T cells are critical in adaptive immunity by targeting virally infected or tumor cells. In this study, we addressed whether functional CD8 T cells can be generated fully <it>in vitro </it>using human umbilical cord blood (UCB) hematopoietic stem cells (HSCs) in coculture with OP9-DL1 cells.</p> <p>Results</p> <p>HSC/OP9-DL1 cocultures supported the differentiation of CD8 T cells, which were TCR/CD3^hiCD27^hiCD1a^negand thus phenotypically resembled mature functional CD8 single positive thymocytes. These <it>in vitro</it>-generated T cells also appeared to be conventional CD8 cells, as they expressed high levels of <it>Eomes </it>and low levels of <it>Plzf</it>, albeit not identical to <it>ex vivo </it>UCB CD8 T cells. Consistent with the phenotypic and molecular characterization, upon TCR-stimulation, <it>in vitro</it>-generated CD8 T cells proliferated, expressed activation markers (MHC-II, CD25, CD38), secreted IFN-γ and expressed Granzyme B, a cytotoxic T-cell effector molecule.</p> <p>Conclusion</p> <p>Taken together, the ability to direct human hematopoietic stem cell or T-progenitor cells towards a mature functional phenotype raises the possibility of establishing cell-based treatments for T-immunodeficiencies by rapidly restoring CD8 effector function, thereby mitigating the risks associated with opportunistic infections.</p

Influencia del tensioactivo aniónico (LAS) sobre la actividad de la microbiota de los lodos activos

[ES] En el presente trabajo se estudia la influencia que ejerce el tensioactivo aniónico lineal alquil benceno sulfonato sódico, L.A.S., sobre la microbiota que existe en una unidad de lodos activos a escala de laboratorio de una Estación Depuradora de Aguas Residuales. Para ello, se han utilizado tanto los procedimientos tradicionales de control de dichas unidades (medida de sólidos volátiles en suspensión y demanda química de oxígeno) como técnicas específicas de medida de la actividad bacteriana (actividad deshidrogenasa y tasa de respiración específica) estableciéndose una comparación entre ellas. Los resultados obtenidos revelan que la medida de la tasa de respiración específica es el parámetro más sencillo y rápido para el control rutinario de la actividad de lodos activos, aunque para un control exhaustivo de los mismos, es sin embargo más adecuada la medida de la actividad deshidrogenasa.Coello Oviedo, MD.; Sales Márquez, D.; Quiroga Alonso, JM. (1998). Influencia del tensioactivo aniónico (LAS) sobre la actividad de la microbiota de los lodos activos. Ingeniería del Agua. 5(4):13-20. https://doi.org/10.4995/ia.1998.2767SWORD132054APHA; AWWA; WPCF (1989) Métodos Normalizados para el análisis de aguas potables y residuales. Editorial Díaz de Santos S. A. Edición en Español.MadridAwong, J.; Bitton, G. and Koopman, B. (1985) ATP, Oxygen Uptake Rate and INT-dehydrogenase activity of actinomycete foams. Water Research 7, 917-921.Berna, J., Moreno, A., and Ferrer, J. (1992) Anassesment of the ultimate biodegradation of LAS. C.E.S.I.O. International Surfactants Congress.Cavalli, L., Cassani, G. and Maraschin, C. (1996) Linear alkylbenzene sulphonate (LAS). Structure elucidation of the biodegradation intermediates. 4th World Surfactants Congress. Barcelona Vol 4, pp 448-462.Dicorcia, A, Marchetti, M, Samperi, R. and Marcomini, A. (1994) Liquid chromatographic detrrmination of linear alkylbenzene sulphonates in aqueous environmental samples. Anal. Chein. 63, pp 1179-1182.Edwards, G. L.; Sherrad, J.H. (1982) Measurement and viability of oxigen uptake rate as an activated sludge process control paramete. J. Water Pollut. Control Fed. 12, 1546-1552.García-Lara, J.; Perón, F.J.; González, J. and Vives-Rego, J.; (1991) Assessment of microbial activity by the INT-dehydrogenase assay during the degradation of linear alkylbenzene sulphonate in sea water and in the OECD screening method. Biomedical Letters 46: 151-157.Granados, J. (1996) Surfactans raw materials. Constant evolution and a solid future. 4th World Surfactants Congress. L, p p 100-123.Gray, N. F. (1989) Biology wastewater treatment. Oxford Science Pubications. Oxford (London)Harrigan, W.F. and McCance, M. (1975) Métodos de laboratorio en microbiología de alimentos y productos lácteos. Editorial Academia.Kikuchi, M., Tokay, A. and Yoshida, T. (1986) Determination of trace levels of linear alkvlbenzene sulphonate in the marine environment by high performance liquid chromatography. Water Research 20, 643-650.López, J.M., Kopman, B. and Bitton, G. (1985) INT-Dehydrogenase test for activated sludge process control. Biotechnology and Bioengineering. 28, 1080-1085.Madoni, P. (1994) A sludge biotic index (SBI) for the evaulation of the biológical performance of activated sludge plants based on the microfauna analysis. Water Research 1, 67-75.Mathijs, E. and De Henau, H. (1987) Determination of LAS. Tenside Surf. Det. 24,193-199.Mcavoy, J. and Giger, W. (1986) Determination of linear alkylbenzene sulphonate in sewage sludge by high-resolution gas cromatography/mass spectrometry. Env. Sci. Technol. 20, 376-378.Nakae E, A, Tsuji, K., and Yamanaka, M. (1981) Determination of alkyl chain distribution of alkylbenzenesulphonates by liquid chromatography. Anal. Chem. 53(12), 1818-1821.Quiroga, J. and Sales, D. (1991) Degradation kinetics of urfactants. Tenside Surf. Det. 28, 27-30.Rappaport, R., Hopping, W. and Echoff, W. (1987) Monitoring LAS in the environment. 8th Annual Meeting of the Soc. Env. Tox. and Chem. Peñascola. Florida.Raimundo, C.C. and Presión, M.R. (1992) The distribution of linear alkylbezenes in coastal and estuarine sediments of the western north sea. Marine Pollution Bulletin 24. 138-146.Swisher, R. (1981) The problem of the ultimate biodegradation of LAS: an extension. Tenside Surf. Det. 19, 298-299.Swisher, R (1963) The chemistry of surfactants benzene rings. J.Am.Oil Chem. Soc. 40, 648-656

T Lymphocyte Potential Marks the Emergence of Definitive Hematopoietic Progenitors in Human Pluripotent Stem Cell Differentiation Cultures

SummaryThe efficient generation of hematopoietic stem cells from human pluripotent stem cells is dependent on the appropriate specification of the definitive hematopoietic program during differentiation. In this study, we used T lymphocyte potential to track the onset of definitive hematopoiesis from human embryonic and induced pluripotent stem cells differentiated with specific morphogens in serum- and stromal-free cultures. We show that this program develops from a progenitor population with characteristics of hemogenic endothelium, including the expression of CD34, VE-cadherin, GATA2, LMO2, and RUNX1. Along with T cells, these progenitors display the capacity to generate myeloid and erythroid cells. Manipulation of Activin/Nodal signaling during early stages of differentiation revealed that development of the definitive hematopoietic progenitor population is not dependent on this pathway, distinguishing it from primitive hematopoiesis. Collectively, these findings demonstrate that it is possible to generate T lymphoid progenitors from pluripotent stem cells and that this lineage develops from a population whose emergence marks the onset of human definitive hematopoiesis

Loss of CD44dim expression from early progenitor cells marks T-cell lineage commitment in the human thymus

Human T-cell development is less well studied than its murine counterpart due to the lack of genetic tools and the difficulty of obtaining cells and tissues. Here, we report the transcriptional landscape of 11 immature, consecutive human T-cell developmental stages. The changes in gene expression of cultured stem cells on OP9-DL1 match those of ex vivo isolated murine and human thymocytes. These analyses led us to define evolutionary conserved gene signatures that represent pre- and post-αβ T-cell commitment stages. We found that loss of dim expression of CD44 marks human T-cell commitment in early CD7+CD5+CD45dim cells, before the acquisition of CD1a surface expression. The CD44-CD1a- post-committed thymocytes have initiated in frame T-cell receptor rearrangements that are accompanied by loss of capacity to differentiate toward myeloid, B- and NK-lineages, unlike uncommitted CD44dimCD1a- thymocytes. Therefore, loss of CD44 represents a previously unrecognized human thymocyte stage that defines the earliest committed T-cell population in the thymus

Notch signaling during human T cell development

Notch signaling is critical during multiple stages of T cell development in both mouse and human. Evidence has emerged in recent years that this pathway might regulate T-lineage differentiation differently between both species. Here, we review our current understanding of how Notch signaling is activated and used during human T cell development. First, we set the stage by describing the developmental steps that make up human T cell development before describing the expression profiles of Notch receptors, ligands, and target genes during this process. To delineate stage-specific roles for Notch signaling during human T cell development, we subsequently try to interpret the functional Notch studies that have been performed in light of these expression profiles and compare this to its suggested role in the mouse

A qualitative analysis to identify the elements that support department level change in the life sciences: The PULSE Vision & Change Recognition Program

The 2011 report, Vision and Change in Undergraduate Biology Education: A Call to Action, provided the impetus to mobilize the undergraduate life sciences education community to affect change in order to enhance the educational experiences of life sciences majors. The work of the appointed Partnership for Undergraduate Life Sciences Education (PULSE) Vision and Change (V&C) Leadership Fellows has focused on the development of programs and resources to support departmental change. In this report, we present a qualitative assessment of several documents generated from the PULSE V&C Leadership Fellow Recognition Team. The Recognition Team developed two initiatives to provide departments with feedback on their change process. The first initiative, the validated PULSE V&C Rubrics, enables departments to collaboratively self-assess their progress in enacting change. The second initiative, the PULSE Recognition Program, involves completion of the aforementioned Rubrics and a site-visit by two Recognition Team members to provide external insights and suggestions to foster a department’s change process. Eight departments participated in the Recognition Program in 2014. An evaluation of the documents yielded from the Recognition Program review of seven of the eight departments and a comparison of Rubric scores from before and three years following the site-visits uncovered several common elements required for successful department level change. These elements include an institutional culture that values and supports excellence in teaching and learning with resources and infrastructure, a departmental emphasis on program and course level assessment, and, most importantly, a departmental champion who actively supports endeavors that enhance teaching excellence