We present a high-resolution Holocene sedimentary record of environmental variability from the eastern Chukchi Sea. An ice-rafted debris bearing silty-clay marks the deglacial to post-glacial ...Holocene transition at this site and is dated at 9.7 ka. An interval of oscillating magnetic parameters from 9.5 to 8.7 ka coincides with the Holocene Thermal Maximum in the western Arctic, and is manifested at the study area as pulses of fine-grained magnetite input every 180–230 years, possibly from increased river discharge or stronger currents flowing over the core site. The magnetic mineral assemblage is very uniform over the last 8.2 ka and consists of a mixture of magnetite, titanomagnetite, and a magnetic phase that we tentatively identify as the magnetic iron sulfide greigite. The amount of magnetic iron sulfides increases up through the Holocene, a trend that is controlled by the amount of marine organic matter available to fuel bacterial sulfate reduction. The median destructive field of the Natural Remanent Magnetization (MDF
NRM) displays centennial to millennial scale cycles with significant variance at periods of 900–1300 and 1700–2700 years, with intervals of high MDF
NRM values coinciding with indicators of greater sea ice cover McKay, J., de Vernal, A., Hillaire-Marcel, C., Not, C., Polyak, L., Darby, D., 2008. Holocene fluctuations in Arctic sea-ice cover: Dinocyst-based reconstructions for the eastern Chukchi Sea. Can. J. Earth Sci. 45, 1399–1415. The MDF
NRM is controlled by the variable abundance of iron sulfides formed during early diagenesis. We interpret intervals of high MDF
NRM values as times of stronger water column stratification, during which the pyritization process was interrupted by the lack of marine organic matter and lack of reactive iron. Intervals of low MDF
NRM values, which coincide with indicators of reduced sea ice cover, are interpreted as times of stronger vertical mixing of the water column, which allows fresh marine organic matter and reactive iron to reach the seafloor, driving the pyritization process to completion.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Neglect has been linked to short-term and long-term deleterious outcomes in children, but has received little attention in the research literature.
Identify types, subtypes, and severity of child ...neglect in a sample of substantiated cases at 4 U.S. Army installations. Describe demographic correlates of victims and offenders by type and subtype.
Data were collected from archived clinical records. A stratified random sample of 100 substantiated child neglect case files were selected per site (N = 400). Data from a single child per case file were used.
5 types and 17 subtypes of neglect were represented, singly or in combination, with varying severity. Lack of Supervision was most common (n = 177, 35.3%), followed by Emotional Neglect (n = 159, 31.8%), Failure to Provide Physical Needs (n = 131, 26.2%), Moral-Legal Neglect (n = 20, 4%), and Educational Neglect (n = 13; 2.6%). Child neglect occurred mostly among young children and in young enlisted families.
Current results highlight the need to focus on types, subtypes, and severity of neglect incidents that provide specific understanding of child risk to better inform policy. Further study should examine specific risk factors and their relationship to neglect types and severity outcomes.
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DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK, VSZLJ
Recently, Y chromosome markers have begun to be used to study Native American origins. Available data have been interpreted as indicating that the colonizers of the New World carried a single founder ...haplotype. However, these early studies have been based on a few, mostly complex polymorphisms of insufficient resolution to determine whether observed diversity stems from admixture or diversity among the colonizers. Because the interpretation of Y chromosomal variation in the New World depends on founding diversity, it is important to develop marker systems with finer resolution. Here we evaluate the hypothesis of a single-founder Y haplotype for Amerinds by using 11 Y-specific markers in five Colombian Amerind populations. Two of these markers (DYS271, DYS287) are reliable indicators of admixture and detected three non-Amerind chromosomes in our sample. Two other markers (DYS199, M19) are single-nucleotide polymorphisms mostly restricted to Native Americans. The relatedness of chromosomes defined by these two markers was evaluated by constructing haplotypes with seven microsatellite loci (DYS388 to 394). The microsatellite backgrounds found on the two haplogroups defined by marker DYS199 demonstrate the existence of at least two Amerind founder haplotypes, one of them (carrying allele DYS199 T) largely restricted to Native Americans. The estimated age and distribution of these haplogroups places them among the founders of the New World.
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BFBNIB, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK
Las investigaciones paleoherpetológicas en la Universidad Nacional de Cuyo (Mendoza) se iniciaron en el año 2012 con el desarrollo del Laboratorio y Museo de Dinosaurios, el cual fue creado por ...Bernardo González Riga, recibiendo el apoyo de las autoridades de la Facultad de Ciencias Exactas y Naturales. Este “Laboratorio y Museo” desarrolla cuatro aspectos claves que se potencian entre sí: investigación, docencia universitaria, protección del patrimonio paleontológico y extensión social. Fue gestionado y construido por un equipo de investigadores, profesores, técnicos y estudiantes, destacándose el rol protagónico de L. Ortiz David, J. P. Coria, M.B. Tomaselli, C. Mercado y G. Sánchez Tiviroli. Para ello se desarrolló un trabajo colaborativo y solidario, teniendo como misión hacer ciencia y acercarla a la sociedad. Las investigaciones se centran en Sistemática, Filogenia, Paleoecología y Tafonomía de dinosaurios y pterosaurios, así también como en Icnología relacionada con aspectos anatómicos. Entre los descubrimientos más significativos se encuentran los primeros dinosaurios saurópodos de Mendoza: Mendozasaurus, Malarguesaurus, Quetecsaurus y Notocolossus, siendo este último uno de los dinosaurios más grandes del mundo. Asimismo, se destacan otros dos excepcionales descubrimientos: el pterosaurio más grande de América del Sur y el primer yacimiento de huellas fósiles de dinosaurios de Mendoza, el cual posee ca. 400 icnitas. Este yacimiento ha sido objeto durante 14 años de numerosas gestiones y labores en terreno para su protección, denominándose hoy Parque Cretácico Huellas de Dinosaurios de Malargüe. La formación del primer equipo mendocino especializado en dinosaurios contribuyó a la paleoherpetología argentina.
Streptomyces reticuli produces a mycelium-associated enzyme, CpeB, whose N-terminal and C-terminal portions mediate heme-dependent catalase-peroxidase and heme-independent manganese-peroxidase ...activities, respectively. The regulator FurS governs transcription of the furS- cpeB operon. The thiol form of FurS contains one zinc ion per monomer and binds in this state to its cognate operator. Oxidation of SH groups within FurS induces the release of the zinc ion. Substitution of the codons for the amino acids cysteine 96, histidine 92 and 93, and tyrosine 59 in furS disrupts the in vivo repressor activity of FurS and results in enhanced synthesis of CpeB in corresponding S. lividans transformants. Biochemical and footprinting studies with FurS and its mutant derivatives revealed that the cysteine residues 96 and 99 are involved in reversible S-S bond formation, while cysteine 96 and the histidine residues 92 and 93 are required for zinc coordination, and tyrosine 59 is necessary for the binding of FurS to DNA. On the basis of these data, functional predictions can be made for the mycobacterial regulator FurA, a close homologue of FurS.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Timely identification of color-producing agents (CPAs) in Lake Erie is a challenging, but vital aspect of monitoring harmful algal blooms (HABs). In particular, HABs that include large amounts of ...cyanobacteria (CyanoHABs) can be toxic to humans, posing a threat to drinking water, in addition to recreational and economic use of Lake Erie. The optical signal of Lake Erie is complex (Becker et al., 2009; Moore et al., 2017), typically comprised of phytoplankton, cyanobacteria, colored dissolved organic matter (CDOM), detritus, and terrigenous inorganic particles, varying in composition both spatially and temporally. The Kent State University (KSU) spectral decomposition method effectively partitions CPAs using a varimax-rotated, principal component analysis (VPCA) of visible reflectance spectra measured using lab, field or satellite instruments (Ali et al., 2013; Ortiz et al., 2017, 2013). We analyze 2015 imagery acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor and field samples collected during the early 2015 cyanoHAB season. We identified four primary CPA spectral signatures, and the spatial distribution of each identified CPA, in the reflectance spectra datasets of both the MODIS and lab-measured water samples. The KSU spectral decomposition method results in mixtures of specific pigments, pigment degradation products, and minerals that describe the optically complex water. We found very good agreement between the KSU VPCA spectral decomposition results and in situ measurements, indicating that this method may be a powerful tool for rapid CyanoHAB monitoring and assessment in large lakes using instruments that provide moderate resolution imagery (0.3 to 1 km2).
The mouse TCRalpha/TCRdelta/Dad1 gene locus bears a locus control region (LCR) that drives high-level, position-independent, thymic transgene expression in chromatin. It achieves this through DNA ...sequences that enhance transcription and protect transgene expression from integration site-dependent position effects. The former activity maps to a classical enhancer region (Ealpha). In contrast, the elements supporting the latter capacity that suppresses position effects are incompletely understood. Such elements likely play important roles in their native locus and may resemble insulator/boundary sequences. Insulators support enhancer blocking and/or chromatin barrier activity. Most vertebrate enhancer-blocking insulators are dependent on the CTCF transcription factor and its cognate DNA binding site. However, studies have also revealed CTCF-independent enhancer blocking and barrier insulator activity in the vertebrate genome. The TCRalpha LCR contains a CTCF-dependent and multiple CTCF-independent enhancer-blocking regions whose roles in LCR activity are unknown. Using randomly integrated reporter transgenes in mice, we find that the CTCF region plays a very minor role in LCR function. In contrast, we report the in vivo function of two additional downstream elements located in the region of the LCR that supports CTCF-independent enhancer-blocking activity in cell culture. Internal deletion of either of these elements significantly impairs LCR activity. These results reveal that the position-effect suppression region of the TCRalpha LCR harbors an array of CTCF-independent, positive-acting gene regulatory elements, some of which share characteristics with barrier-type insulators. These elements may help manage the separate regulatory programs of the TCRalpha and Dad1 genes.
The OP9/OP9-DL1 co-culture system has become a well-established method for deriving differentiated blood cell types from embryonic and hematopoietic progenitors of both mouse and human origin. It is ...now used to address a growing variety of complex genetic, cellular and molecular questions related to hematopoiesis, and is at the cutting edge of efforts to translate these basic findings to therapeutic applications. The procedures are straightforward and routinely yield robust results. However, achieving successful hematopoietic differentiation in vitro requires special attention to the details of reagent and cell culture maintenance. Furthermore, the protocol features technique sensitive steps that, while not difficult, take care and practice to master. Here we focus on the procedures for differentiation of T lymphocytes from mouse embryonic stem cells (mESC). We provide a detailed protocol with discussions of the critical steps and parameters that enable reproducibly robust cellular differentiation in vitro. It is in the interest of the field to consider wider adoption of this technology, as it has the potential to reduce animal use, lower the cost and shorten the timelines of both basic and translational experimentation.
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