Caddisfly larvae construct underwater protective cases using surrounding materials, thus providing information on environmental conditions in both modern and ancient systems. Microbial bioherms ...associated with caddisfly cases are found in the Berriassian-Hauterivian (similar to 140-130 Ma) Shinekhudag Formation of Mongolia, and yield new insights into aspects of lacustrine paleoecosystems and paleoenvironments. This formation contains the earliest record of plant-armored caddisfly cases and a rare occurrence of microbial-caddisfly association from the Mesozoic. The bioherms are investigated within the context of stratigraphic correlations, depositional environment interpretations, and basin-evolution models of the sedimentary fill. The bioherms form 0.5-2.0 m diameter mound-shaped bodies and are concentrated within a single, oil shale-bound stratigraphic interval. Each bioherm is composed of up to 40% caddisfly cases along with stromatolites of millimeter-scale, micritic laminations. Petrographic analyses reveal these bioherms are composed of non-systematic associations of columnar and oncoidal microbialites, constructed around colonies of caddisfly cases. The cases are straight to curved, slightly tapered, and tube-shaped, with a progressively increasing length and width trend (7-21 mm by 1.5-2.5 mm). Despite these variations, the case architectures reveal similar construction materials; the particles used for cases are dominated by plant fragments, ostracod valves, carbonate rocks, and rare mica and feldspar grains. Allochems within the bioherms include ooids, ostracods, plant fragments, rare gastropods, feldspar grains bound in micritic matrices, and are consolidated by carbonate dominated cements. The combination of microbial-caddisfly association, plant fragment case particles, and ooids/oncoids are indicative of a shallow, littoral lake setting. Stratigraphic juxtaposition of nearshore bioherms and the bounding distal oil-shale facies suggests that the bioherms developed in an underfilled lake basin, resulting from an abrupt and short-lived lake desiccation event. Lake chemistry is believed to have been relatively alkaline, saline to hypersaline, and rich in Ca, Mg, and HCO3 ions. Through analyzing bioherm characteristics, caddisfly case architecture, carbonate microfacies, and stratigraphic variability, we infer larger-scale processes that controlled basin development during their formation.
•Deglacial history of Pope Glacier reconstructed using surface exposure dating.•560 m of early Holocene thinning at an average rate of 0.13 ± 0.09/0.04 m yr−1.•Thinning coincides with enhanced ...upwelling of warm water onto continental shelf.•Reduction in ice shelf buttressing may have triggered widespread glacier thinning.
The Amundsen Sea sector of the Antarctic ice sheet presently dominates the contribution from Antarctica to sea level rise. Several large ice streams that currently drain the sector have experienced rapid flow acceleration, grounding line retreat and thinning during the past few decades. However, little is known of their longer-term – millennial-scale – retreat history, despite the reliance of several ice sheet and glacial-isostatic adjustment models on such data for improving sea level prediction from this critical region. This study investigates the timing and extent of surface lowering of one of those ice streams, Pope Glacier, since the Last Glacial Maximum (LGM), using glacial-geological evidence for former ice cover. We present a new deglacial chronology for the glacier, derived from surface exposure dating of glacially-deposited cobbles and ice-scoured bedrock from Mount Murphy and its surrounding peaks. Cosmogenic 10Be exposure ages from 44 erratic cobbles and 5 bedrock samples, and in situ 14C exposure ages from one erratic and 8 bedrock samples are predominantly in the range 5.5-16 ka. Although 10Be inheritance from prior exposure is prevalent in some erratics and probably all bedrock samples, none of the ages pre-date the LGM. From these results we infer that the surface of Pope Glacier lowered by 560 m during the early- to mid-Holocene (9-6 ka), at an average rate of 0.13 ± 0.09/0.04 m yr−1. The lowering coincided with a period of enhanced upwelling of warm Circumpolar Deep Water onto the continental shelf in the region. A reduction in buttressing − facilitated by such upwelling − by an ice shelf that is thought to have spanned the embayment until 10.6 cal kyr BP could have triggered simultaneous early Holocene thinning of Pope Glacier and glaciers elsewhere in the Amundsen Sea Embayment.
Phosphorylation of proteins on tyrosine (Tyr) residues evolved in metazoan organisms as a mechanism of coordinating tissue growth
. Multicellular eukaryotes typically have more than 50 distinct ...protein Tyr kinases that catalyse the phosphorylation of thousands of Tyr residues throughout the proteome
. How a given Tyr kinase can phosphorylate a specific subset of proteins at unique Tyr sites is only partially understood
. Here we used combinatorial peptide arrays to profile the substrate sequence specificity of all human Tyr kinases. Globally, the Tyr kinases demonstrate considerable diversity in optimal patterns of residues surrounding the site of phosphorylation, revealing the functional organization of the human Tyr kinome by substrate motif preference. Using this information, Tyr kinases that are most compatible with phosphorylating any Tyr site can be identified. Analysis of mass spectrometry phosphoproteomic datasets using this compendium of kinase specificities accurately identifies specific Tyr kinases that are dysregulated in cells after stimulation with growth factors, treatment with anti-cancer drugs or expression of oncogenic variants. Furthermore, the topology of known Tyr signalling networks naturally emerged from a comparison of the sequence specificities of the Tyr kinases and the SH2 phosphotyrosine (pTyr)-binding domains. Finally we show that the intrinsic substrate specificity of Tyr kinases has remained fundamentally unchanged from worms to humans, suggesting that the fidelity between Tyr kinases and their protein substrate sequences has been maintained across hundreds of millions of years of evolution.
Public health laboratories (PHLs) continue to face internal and external challenges to their abilities to provide successful, timely responses to public health crises and emerging threats. These ...laboratories are mandated to maintain the health of their communities by identifying, diagnosing, and warning constituents of potential and real health emergencies. Due to the changing characteristics of public health threats and their cross-jurisdictional nature, laboratories are facing increased pressure to ensure that they respond in a consistent and coordinated manner. Here, the Association of Public Health Laboratories (APHL) Emerging Leader Program Cohort 11 members have compiled stories from subject matter experts (SMEs) at PHLs with direct involvement in crises to determine the characteristics of a successful response. Experts examined a diverse selection of emerging threats from across PHLs, including infectious diseases, opioids, natural disasters, and government shutdowns. While no public health crisis will be identical to another, overarching themes were consistent across subjects. Experiences from SMEs that could improve future responses to emerging threats are highlighted.
In the United States, transgender women are disproportionately affected by HIV. However, few evidence-based prevention interventions exist for this key population. We describe two promising, locally ...developed interventions that are currently being implemented and evaluated through the Centers for Disease Control and Prevention Combination HIV Prevention for Transgender Women Project: (a) ChiCAS, designed to promote the uptake of pre-exposure prophylaxis (PrEP), condom use, and medically supervised hormone therapy among Spanish-speaking transgender Latinas, and (b) TransLife Care, designed to address the structural drivers of HIV risk through access to housing, employment, legal services, and medical services, including HIV preventive care (e.g., PrEP use) among racially/ethnically diverse urban transgender women. If the evaluation trials determine that these interventions are effective, they will be among the first such interventions for use with transgender women incorporating PrEP, thereby contributing to the evidence-based resources that may be used to reduce HIV risk among this population.
The COVID-19 pandemic caused drastic social changes for many people, including separation from friends and coworkers, enforced close contact with family, and reductions in mobility. Here we assess ...the extent to which people's evolutionarily-relevant basic motivations and goals—fundamental social motives such as Affiliation and Kin Care—might have been affected. To address this question, we gathered data on fundamental social motives in 42 countries (N = 15,915) across two waves, including 19 countries (N = 10,907) for which data were gathered both before and during the pandemic (pre-pandemic wave: 32 countries, N = 8998; 3302 male, 5585 female; Mage = 24.43, SD = 7.91; mid-pandemic wave: 29 countries, N = 6917; 2249 male, 4218 female; Mage = 28.59, SD = 11.31). Samples include data collected online (e.g., Prolific, MTurk), at universities, and via community sampling. We found that Disease Avoidance motivation was substantially higher during the pandemic, and that most of the other fundamental social motives showed small, yet significant, differences across waves. Most sensibly, concern with caring for one's children was higher during the pandemic, and concerns with Mate Seeking and Status were lower. Earlier findings showing the prioritization of family motives over mating motives (and even over Disease Avoidance motives) were replicated during the pandemic. Finally, well-being remained positively associated with family-related motives and negatively associated with mating motives during the pandemic, as in the pre-pandemic samples. Our results provide further evidence for the robust primacy of family-related motivations even during this unique disruption of social life.
Peptide immunotherapy both activates and suppresses the T cell response against known peptide Ags. Although pretreatment with VP2(121-130) peptide inhibits the development of antiviral CTL specific ...for the immunodominant D(b):VP2(121-130) epitope expressed during acute Theiler's murine encephalomyelitis virus infection, i.v. injection of this same peptide or MHC tetramers containing the peptide during an ongoing antiviral CTL response results in a peptide-induced fatal syndrome (PIFS) within 48 h. Susceptibility to PIFS is dependent on peptide-specific CD8(+) T cells, varies among inbred strains of mice, and is not mediated by traditionally defined mechanisms of shock. Analyses using bone marrow chimeras and mutant mice demonstrate that susceptibility to PIFS is determined by the genotype of bone marrow-derived cells and requires the expression of perforin. Animals responding to peptide treatment with PIFS develop classical stress responses in the brain. These findings raise important considerations for the development of peptide therapies for active diseases to modify immune responses involving expanded populations of T cells. In summary, treatment with peptides or MHC-tetramers during a peptide-specific immune response can result in a fatal shock-like syndrome. Susceptibility to the syndrome is genetically determined, is mediated by CD8(+) T cells, and requires expression of perforin. These findings raise concerns about the use of peptides and MHC tetramers in therapeutic schemes.
To describe the HIV case finding strategies used by the Special Projects of National Significance (SPNS), Adolescent HIV Outreach and Treatment programs, the populations of youth they were able to ...reach, and the populations of HIV-positive youth they were able to identify.
Program specifications from five programs located in four major metropolitan centers were contrasted. Four of the programs also provided outcome data for HIV counseling and testing outcome numbers, demographic and risk profile data for youth who underwent HIV testing, and mode of infection of HIV-positive youth.
The program outcomes were discussed in terms of similarities and differences in outreach methods (e.g., peer workers, time of outreach, etc.), geographic settings (i.e., mobile van, institutional settings, community locations), individual characteristics (e.g., pregnant women) and youth subcultures (i.e., gay/transgendered, incarcerated juveniles, homeless).
Because HIV-positive adolescents will constitutionally remain a “hidden population,” a great deal of time and effort will continue to need to go into the front end of outreach, counseling and testing. Specific guidance and recommendations for locating HIV-positive youth were provided to program designers for each type of outreach strategy.
PDF
