Autochthonous outer ramp sedimentation: The Alamogordo Member of the Lake Valley Formation,New Mexico

Summary Paleozoic carbonate ramp sedimentation has generally been described in terms of downlapping clinoforms composed of allochthonous sediment derived from shallower environments. However, during transgressive episodes when carbonate sediment production is low and down slope sediment transport by gravity becomes inactive, autochthonous carbonate sediment accumulates in vertical stacks of essentially in situ sediment. Autochthonous outer ramp deposition is probably a part of many Paleozoic ramp strata, but has heretofore not been recognized because of the general absence of adequate exposures. Evidence of autochthonous, in situ deposition and preservation of sediments in a starved setting is well displayed in the Alamogordo Member of the Lake Valley Formation in south central New Mexico. This evidence includes: 1) beds and bed sets that are individually continuous and traceable along ramp slope for 32 km, 2) down-ramp sequential distributions of depth-sensitive organisms and assemblages but patchy distribution of rock types, 3) lack of sedimentary structures indicative of transport, 4) well preserved, unabraded fossils, 5) the common occurrence of fossils in life position, 6) beds traceable into and through mounds 7) bed thickness trends ascribed to biotic productivity, and 8) geopetal structures in original position. Integrated paleontologic, sedimentologic, and stratigraphic data provide information about depositional processes and setting. The depositional slope was approximately 0.5^o based on the distribution of fossil algae; this is comparable to dips reported for other Mississippian homoclinal ramps. An oxygen minimum zone may have impinged on the ramp during a major flooding event. Shifts in biotic gradients from bed to bed reveal transgressive-regressive patterns that would not be resolvable without detailed paleontological evidence. The Alamogordo Member formed as a result of transgressive and early highstand starved carbonate sedimentation along a narrow, homoclinal outer ramp. The surface of maximum flooding and the boundary between the TST and HST are within the Alamogordo Member.     

Plasma Membrane Profiling Defines an Expanded Class of Cell Surface Proteins Selectively Targeted for Degradation by HCMV US2 in Cooperation with UL141

Human cytomegalovirus (HCMV) US2, US3, US6 and US11 act in concert to prevent immune recognition of virally infected cells by CD8+ T-lymphocytes through downregulation of MHC class I molecules (MHC-I). Here we show that US2 function goes far beyond MHC-I degradation. A systematic proteomic study using Plasma Membrane Profiling revealed US2 was unique in downregulating additional cellular targets, including: five distinct integrin α-chains, CD112, the interleukin-12 receptor, PTPRJ and thrombomodulin. US2 recruited the cellular E3 ligase TRC8 to direct the proteasomal degradation of all its targets, reminiscent of its degradation of MHC-I. Whereas integrin α-chains were selectively degraded, their integrin β1 binding partner accumulated in the ER. Consequently integrin signaling, cell adhesion and migration were strongly suppressed. US2 was necessary and sufficient for degradation of the majority of its substrates, but remarkably, the HCMV NK cell evasion function UL141 requisitioned US2 to enhance downregulation of the NK cell ligand CD112. UL141 retained CD112 in the ER from where US2 promoted its TRC8-dependent retrotranslocation and degradation. These findings redefine US2 as a multifunctional degradation hub which, through recruitment of the cellular E3 ligase TRC8, modulates diverse immune pathways involved in antigen presentation, NK cell activation, migration and coagulation; and highlight US2’s impact on HCMV pathogenesis.     

Interferon production and tumor cell killing by human lymphocytes stimulated in mixed-lymphocyte culture

The in vitro synthesis of interferon (IFN) by human lymphocytes stimulated in mixed-lymphocyte culture (MLC) was examined. The production of IFN in MLC was restricted to T lymphocytes and maximum levels of IFN were detected in supernatants from cells incubated for 5 to 7 days. The IFN produced was identified as IFN-gamma by antibody neutralization. To identify the T cell responsible for IFN production, purified T lymphocytes were separated into subpopulations after incubation in 5 mM theophylline. Theophylline-resistant (T-res) T cells retain the ability to form sheep erythrocyte (SRBC) rosettes and are depleted in IgG Fc receptor-positive T cells (T gamma cells). Theophylline-sensitive (T-sens) T cells fail to form rosettes after theophylline treatment and are enriched in T gamma cells. In addition, analyses using monoclonal antibodies showed that T-sens cells were enriched in OKM1-, HNK-1-, and 7.2-positive cells and T-res cells contained increased numbers of 9.6- and OKT4-positive cells. Following MLC stimulation, equivalent levels of IFN-gamma were produced by T-res and T-sens cells and both subpopulations maintained natural killer (NK)-like cytotoxicity against K562 target cells. Addition of partially purified IFN-gamma to unstimulated T-res and T-sens cells resulted in the maintenance of NK-like cytotoxicity in a manner analogous to that observed after MLC. Additional experiments indicated that peripheral blood lymphocytes depleted of 9.6- or OKM1-positive cells by complement-mediated lysis were devoid of cytotoxicity against K562 cells. Furthermore, MLC stimulation of 9.6- or OKM1-depleted cells failed to restore cytotoxic activity. In summary, these experiments demonstrate that the maintenance of NK-like cytotoxicity by MLC-stimulated T cells is associated with the synthesis of IFN-gamma, that MLC stimulated T-res and T-sens T-cell subsets produce equivalent amounts of IFN, and that 9.6- or OKM1-positive cells are required for the maintenance of NK-like cytotoxicity in MLC.     

Early Social Networks Predict Survival in Wild Bottlenose Dolphins

A fundamental question concerning group-living species is what factors influence the evolution of sociality. Although several studies link adult social bonds to fitness, social patterns and relationships are often formed early in life and are also likely to have fitness consequences, particularly in species with lengthy developmental periods, extensive social learning, and early social bond-formation. In a longitudinal study of bottlenose dolphins (Tursiops sp.), calf social network structure, specifically the metric eigenvector centrality, predicted juvenile survival in males. Additionally, male calves that died post-weaning had stronger ties to juvenile males than surviving male calves, suggesting that juvenile males impose fitness costs on their younger counterparts. Our study indicates that selection is acting on social traits early in life and highlights the need to examine the costs and benefits of social bonds during formative life history stages.     

An optimized procedure for the capture,fractionation and proteomic analysis of proteins using hydrogel nanoparticles

We have developed an optimized procedure using dual size exclusion/affinity hydrogel nanoparticles to capture and comparatively analyze low molecular mass proteins directly from biological samples. The method described facilitates charge‐ and size‐dependent protein binding, direct analysis by MS or other means and is highly reproducible. A comparative analysis of the low molecular mass proteome of plasma following freeze–thaw immediately after venipuncture is used to illustrate proof‐of‐concept. The technique described is rapid and may be easily reproduced in any laboratory.     

The human cornea has a high incidence of acquired chromosome abnormalities

Structurally and functionally, the human cornea is a highly specialized tissue. The corneal stromal collagen matrix is uniquely transparent and yet maintains a mechanically tough and chemically impermeable barrier between the eye and environment. We report for the first time that stromal keratocytes of the human cornea show cytogenetic abnormalities with a frequency that is unprecedented among normal tissues. The abnormalities are acquired, clonal and nonclonal, primarily aneuploid in nature, and present in normal as well as diseased corneas. Received: 10 February 1997 / Accepted: 21 May 1997     

Climatic controls of the cool human thermal sensation in a summertime onshore wind

 Afternoon observations in summer comparing shoreline with inland atmospheric conditions were made during onshore winds at Victoria, British Columbia, Canada. The onshore wind came from a cool water surface. Mean monthly water temperatures near to shore were between 11 and 11.5° C. The onshore wind brought lower air, ground surface radiant and sky radiant temperatures; lower humidity and greater wind speed. All of these combine to produce a cooler human environment at the shoreline than inland. The relative importance of climatic elements in producing the cooler environment was assessed using sensitivity analyses with eight different human thermal exchange models/indices. Air temperature and wind speed had the greatest effect, followed by ground surface radiant temperature, sky radiant temperature and humidity. Wind speed is the most practical element to consider when trying to maximize human comfort along the shoreline. Received: 9 July 1996 / Revised: 31 March 1997 / Accepted: 14 April 1997