Do focused interests support word learning? A study with autistic and nonautistic children

Although focused interests are often associated with a diagnosis of autism, they are common in nonautistic individuals as well. Previous studies have explored how these interests impact cognitive, social, and language development. While some research has suggested that strong interests can detract from learning (particularly for autistic children), newer research has indicated that they can be advantageous. In this pre-registered study, we asked whether focused interests support word learning in 44 autistic children and a vocabulary-matched sample of 44 nonautistic children (mean ages 58 and 34 months respectively). In a word-learning task administered over Zoom, children were exposed to an action labeled by a novel word. The action was either depicted by their focused interest or by a neutral image; stimuli were personalized for each child. At test, they were asked to identify the referent of the novel word, and their eye gaze was evaluated as a measure of learning. The preregistered analyses revealed an effect of focused interests, and post-hoc analyses clarified that autistic children learned the novel word in both the focused interest and neutral conditions, while nonautistic children only showed evidence of learning in the neutral condition. These results suggest that focused interests are not disruptive for vocabulary learning in autism, and thus they could be utilized in programming that supports early language learning in this population.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

Aqueously altered igneous rocks sampled on the floor of Jezero crater, Mars

The Perseverance rover landed in Jezero crater, Mars, to investigate ancient lake and river deposits. We report observations of the crater floor, below the crater's sedimentary delta, finding the floor consists of igneous rocks altered by water. The lowest exposed unit, informally named Séítah, is a coarsely crystalline olivine-rich rock, which accumulated at the base of a magma body. Fe-Mg carbonates along grain boundaries indicate reactions with CO₂-rich water, under water-poor conditions. Overlying Séítah is a unit informally named Máaz, which we interpret as lava flows or the chemical complement to Séítah in a layered igneous body. Voids in these rocks contain sulfates and perchlorates, likely introduced by later near-surface brine evaporation. Core samples of these rocks were stored aboard Perseverance for potential return to Earth.

An olivine cumulate outcrop on the floor of Jezero crater, Mars

The geological units on the floor of Jezero crater, Mars, are part of a wider regional stratigraphy of olivine-rich rocks, which extends well beyond the crater. We investigate the petrology of olivine and carbonate-bearing rocks of the Séítah formation in the floor of Jezero. Using multispectral images and x-ray fluorescence data, acquired by the Perseverance rover, we performed a petrographic analysis of the Bastide and Brac outcrops within this unit. We find that these outcrops are composed of igneous rock, moderately altered by aqueous fluid. The igneous rocks are mainly made of coarse-grained olivine, similar to some Martian meteorites. We interpret them as an olivine cumulate, formed by settling and enrichment of olivine through multi-stage cooling of a thick magma body.

Organic synthesis associated with serpentinization and carbonation on early Mars

Water-rock interactions are relevant to planetary habitability, influencing mineralogical diversity and the production of organic molecules. We examine carbonates and silicates in the martian meteorite Allan Hills 84001 (ALH 84001), using colocated nanoscale analyses, to characterize the nature of water-rock reactions on early Mars. We find complex refractory organic material associated with mineral assemblages that formed by mineral carbonation and serpentinization reactions. The organic molecules are colocated with nanophase magnetite; both formed in situ during water-rock interactions on Mars. Two potentially distinct mechanisms of abiotic organic synthesis operated on early Mars during the late Noachian period (3.9 to 4.1 billion years ago).

7 The Elephant in the Room: An Innovative and Effective Approach to Multidisciplinary Advance Care Planning Training

Background

Exploring patients’ preferences for future care is known to reduce adverse health outcomes, limit transfers between care settings institutionalisation and improve quality of life. Patients value opportunities to have honest conversations.

In the recent “Talking about Dying” report from the Royal College of Physicians (RCP), it was found that healthcare professionals (HCPs) find it challenging to start conversations with patients and families. Yet the report highlights a need for HCPs to be equipped with the skills and confidence to provide opportunities for advance care planning in primary care, inpatient and outpatient settings.

Methods

A multi-disciplinary faculty delivered simulation sessions to 115 candidates (50.4% doctors, 33% nurses and 16.5% allied health professionals) from primary and secondary care.

Eight half-day sessions have taken place across North London. Each session started with an introductory lecture, followed by simulated scenarios between a professional actor and candidate within small multi-disciplinary groups. Group discussion was facilitated and feedback given.

We focused on acknowledging the progressive, complex and unpredictable nature of frailty. Scenarios included resuscitation, re-admission to hospital, risk feeding, complex discharge planning and cultural values in older adults.

Results

100% would recommend this multidisciplinary simulation to teach advance care planning.

Only 15.6% of candidates felt confident or very confident with conversations; this improved to 90.5% following the simulation and was maintained at 69.5% three months later. Understanding when advance care planning is appropriate improved from 70% to 100%. Three months after the training, 86% stated they had a sustained change in practice in ACP as a result of the course.

Conclusion

We have demonstrated that our multidisciplinary simulation is an effective format of improving understanding and confidence in having advance care planning conversations. These results are evident both immediately after and at the three month follow up stage demonstrating a sustained change in practice.

A systematic review and meta-analysis of laparotomy compared with laparoscopic management of interstitial pregnancy

BACKGROUND

Interstitial pregnancy is a rare but life-threatening condition accounting for 1-4% of all types of tubal ectopic pregnancies. It can be managed by open and minimally invasive surgical techniques. Our goal was to compare laparoscopic and open surgery for managing interstitial pregnancy.

SEARCH STRATEGY

We searched PubMed, Scopus, Web of Science, and Cochrane up to May 2020.

SELECTION CRITERIA

1) Women with interstitial pregnancy, 2) Intervention: laparoscopic surgery, 3) Comparator: open surgery, 4) Outcomes: Hospital stay, operation time, pain scale, blood loss. Secondary outcomes: any other reported 5) Study designs: interventional and observational.

DATA COLLECTION AND ANALYSIS

Data was extracted from the relevant articles and was pooled as mean difference (MD) or relative risk (RR) with a 95% confidence interval (CI).

MAIN RESULTS

We included six studies, three of which provided eligible data. The duration of hospital stay was lower in the laparoscopic surgery group (MD = -1.42, 95% CI [-1.72, -0.76], P < 0.0001). There was no significant difference in operative time (MD = 5.90, 95% CI [-11.30, 23.09], P = 0.50, blood loss (MD = -9.43, 95% CI [-214.18, 195.32], P = 0.93), complications (RR = 1.54, 95% CI [0.20, 11.85], P = 0.68), or blood transfusions (RR = 0.77, 95% CI [0.50, 1.25], P = 0.30).

CONCLUSION

Laparoscopic surgery is associated with shorter hospital stay, with no difference in terms of blood loss, post-, and intraoperative complications, and need for blood transfusion compared with laparotomy.

Single-cell multiplexed proteomics to identify novel polyfunctional CD8+ T cell signatures induced by nivolumab in head and neck cancer patients after salvage surgery

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Background: Immune checkpoint inhibitors (ICIs) are FDA approved for use in head and neck squamous cell cancer (HNSCC), however, only ~20% patients achieve a response. Identification of biomarkers of response or toxicity remains a challenge. Polyfunctional T-cells, or T-cells producing multiple cytokines, have been recognized as contributors to durable immunity against various cancers. However, their role has not been studied prospectively in HNSCC patients receiving ICIs. To look for an early predictor of response, we used single-cell functional proteomic profiling (IsoPlexis) on blood samples pre- and post- first dose of nivolumab (nivo) in patients on our phase-II study of locally recurrent HNSCC (NCT03355560). Methods: HNSCC patients who failed definitive radiation +/-chemotherapy and were subsequently treated with curative intent salvage resection were enrolled to receive 6 months of nivo beginning 4 to 11 weeks after surgery. Blood samples were collected before and after the first dose of nivo. Peripheral blood mononuclear cells were isolated, enriched for CD8+ T cells and using the 32-plex IsoCode technology, single-cell cytokine signals were captured and polyfunctional strength of CD8+ T cells was evaluated across four groups (effector, stimulatory, regulatory, inflammatory). A comparison analysis was performed between pre- and post- nivo treatment and between patients who relapsed (non-responders) vs those who did not (responders). Results: Thirty-three of 39 planned patients have been enrolled, of which 28 are evaluable and 5/28 (18%) developed recurrence. Median age is 68 years (range 51-85), 9/28 (32%) patients are female, 26/28 (93%) are white, disease sites include oropharyngeal 6/28 (21%), oral cavity 11/28 (39%) and larynx 11/28 (39%). Samples were evaluated at a median follow up of 5.9 months from enrollment. Single-cell analysis demonstrated a strong upregulation of polyfunctional human CD8+ T cell subsets in responders. Polyfunctional Strength Index (PSI) was enhanced in CD8+ T cells across the responders’ samples, composed largely of effector cytokines (granzyme-β, IFN-γ, MIP-1α, perforin, TNF-α). Conclusions: Single-cell functional proteomic analysis revealed significantly upregulated polyfunctional profiles and an increase in effector cytokines in patients who responded to nivo. This data provides important insights into PD-1 inhibitor triggered T-cell activity and may be used to predict response to ICIs in HNSCC patients using a blood test. Clinical trial information: NCT03355560 .

Molecular identification of fungi microfossils in a Neoproterozoic shale rock

Precambrian fossils of fungi are sparse, and the knowledge of their early evolution and the role they played in the colonization of land surface are limited. Here, we report the discovery of fungi fossils in a 810 to 715 million year old dolomitic shale from the Mbuji-Mayi Supergroup, Democratic Republic of Congo. Syngenetically preserved in a transitional, subaerially exposed paleoenvironment, these carbonaceous filaments of ~5 μm in width exhibit low-frequency septation (pseudosepta) and high-angle branching that can form dense interconnected mycelium-like structures. Using an array of microscopic (SEM, TEM, and confocal laser scanning fluorescence microscopy) and spectroscopic techniques (Raman, FTIR, and XANES), we demonstrated the presence of vestigial chitin in these fossil filaments and document the eukaryotic nature of their precursor. Based on those combined evidences, these fossil filaments and mycelium-like structures are identified as remnants of fungal networks and represent the oldest, molecularly identified remains of Fungi.

Preliminary effects on the innate immune system with the combination of cetuximab and durvalumab in metastatic/ relapsed head and neck squamous cell carcinoma in a phase II trial

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Background: Cetuximab is a recombinant chimeric monoclonal IgG1 antibody which binds specifically to the epidermal growth factor receptor (EGFR) and stimulates an innate immune response by promoting natural killer (NK) cell mediated antibody-dependent cell-mediated cytotoxicity (ADCC). Cetuximab is approved as a single agent in relapsed/metastatic head and neck squamous cell carcinoma (R/M HNSCC). PD-1 check-point inhibitors which release the inhibition of the adaptive immune response, are also approved as single agents in this setting. However the response rates with these drugs, when used individually range from 10-20%. We hypothesized that adding a PD-L1 inhibitor, durvalumab to cetuximab would cause anti-tumor synergy by activating the innate as well as adaptive immune systems without compromising safety in this phase-2 trial in R/M HNSCC patients who have progressed on platinum based therapy. Methods: Blood samples were collected from the first six enrolled patients prior to starting treatment and 4 weeks after the first combined dose of cetuximab and durvalumab. PBMCs were isolated, stained with a live/dead stain as well as CD3, CD4, CD8, CD56, CD16 and NK2GD (natural killer group 2 member D activation receptor) antibodies and analyzed by flow cytometry. Cytokine levels in plasma were measured using standardized ELISA assay kits. Results: Compared to pre-treatment levels, post-treatment samples showed an increase in activated cytokine producing NK cells (CD56bright/CD16-) in all but one patient. Activated cytotoxic NK cell subpopulations (CD56dim/CD16+) showed variable results post-treatment. CD8+ T cells were similar pre and post-treatment in 5 patients. TGF-b levels increased in 5 patients and decreased in 1 patient post-treatment. Interestingly, the patient with decreased TGF-b levels post-treatment had an almost doubling of CD8+ T-cells and an increase in activated cytokine producing NK cells (CD56bright/CD16-). Conclusions: The clinical trial is ongoing and therefore, comparison to clinical response has not yet been analyzed. However, these findings support the combination of cetuximab and durvalumab in R/M HNSCC given the activation of an NK-cell mediated innate immune response in these patient samples. Clinical trial information: NCT03691714.

Organic synthesis on Mars by electrochemical reduction of CO2

The sources and nature of organic carbon on Mars have been a subject of intense research. Steele et al. (2012) showed that 10 martian meteorites contain macromolecular carbon phases contained within pyroxene- and olivine-hosted melt inclusions. Here, we show that martian meteorites Tissint, Nakhla, and NWA 1950 have an inventory of organic carbon species associated with fluid-mineral reactions that are remarkably consistent with those detected by the Mars Science Laboratory (MSL) mission. We advance the hypothesis that interactions among spinel-group minerals, sulfides, and a brine enable the electrochemical reduction of aqueous CO₂ to organic molecules. Although documented here in martian samples, a similar process likely occurs wherever igneous rocks containing spinel-group minerals and/or sulfides encounter brines.

Abstract P6-12-08: Healthcare barrier profiles in patients navigated for cancer screening and treatment and the impact of the affordable care act

Background: The underserved community experiences barriers to cancer screening that result in overall greater mortality rates across all cancers. Insurance coverage brought forth by the Affordable Care Act has the potential to significantly impact these barriers through reducing the burden of health care cost on the patient. In this study the authors observe the impact of the Affordable Care Act on the barrier profiles presented by the patients navigated for cancer screening and treatment.

Methods: Patient navigation encounters were recorded for a total of 1146 patients navigated for cancer screening and treatment at the Cleveland Clinic Foundation from the years 2012 through 2015. A total of 3259 encounters were classified into barrier types. Health care billed encounters were retrieved from EPIC for this group of patients from the time they entered patient navigation and classified in terms of insurance coverage. Patients were categorized according to their barrier profile. Appropriate generalized linear regression models were used to test for association of these profiles to number and types of navigation and health care encounters and cost, and to test for change in types of encounters and patient barrier profiles through time.

Results: The insurance barrier is present in 23% of all navigation encounters. Patients presenting with an insurance barrier had a greater mean number of navigation (p&lt;0.001) and health care encounters (p&lt;0.006), had a greater proportion of self-paid health care encounters (p&lt;0.001) and a lower total cost billed for health care encounters after controlling for number of encounters (p&lt;0.001) . The access barrier is present in 53% of navigation encounters while patients that present with only the access barrier account for 42% of the entire sample. Patients that present with only the access barrier have doubled every year (OR 2.2 per year, 95% CI [1.8 2.6]) from 2012 to 2015, while the proportion of self-paid health care encounters (OR 0.26 per year, 95% CI [0.25 0.28]) and the presence of the insurance barrier (OR 0.55 per year, 95% CI [ 0.49 0.62]) have more than halved during this time period.

Conclusion: Although the Affordable Care Act has clearly had an impact by lowering the number of insurance barrier navigation encounters through time, it has uncovered access as the predominant remaining barrier. Understanding and targeting the access barrier will be the most effective way to potentiate the effects of the ACA on patients being navigated for cancer screening and treatment.

Citation Format: Raska P, Ott MA, Steele A, Bailey A, Hickman D, Allen D, Urbanek D, Glass K, Bailey J, Bell K, Montero A, Abraham J. Healthcare barrier profiles in patients navigated for cancer screening and treatment and the impact of the affordable care act. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-12-08.

Raman Imaging Spectroscopy of a Putative Microfossil from the ∼3.46 Ga Apex Chert: Insights from Quartz Grain Orientation

The utility of nondestructive laser Raman for testing the biogenicity of microfossil-like structures in ancient rocks is promising, yet results from deposits like the ∼3.46 Ga Apex chert remain contentious. The essence of the debate is that associated microstructures, which are not purported to be microfossils, also contain reduced carbon that displays Raman D- and G-band peaks similar to those seen in the purported microfossils. This has led to the hypothesis that all features including reported microfossils are due to compression of nonfossil carbon during crystal growth around quartz spherulites or more angular crystals. In this scenario, the precursor to this macromolecular carbon may or may not have been of biogenic origin, while the arcuate and linear features described would be pseudofossils. To test this hypothesis, we have undertaken 2-D micro-Raman imaging of the Eoleptonema apex holotype and associated features using instrumentation with a high spatial and spectral resolution. In addition to this, we utilized the ratio of two Raman active quartz mode intensities (I129/I461) to assess quartz grain orientation and grain-splitting artifacts. These data lead us to conclude that the holotype of Eoleptonema apex is a sheet-shaped pseudofossil that appears to be a carbon infilled intragranular crack; therefore other holotypes should be carefully reexamined for syngenicity.

Pigment production and isotopic fractionations in continuous culture: okenone producing purple sulfur bacteria Part II

Okenone is a carotenoid pigment unique to certain members of Chromatiaceae, the dominant family of purple sulfur bacteria (PSB) found in euxinic photic zones. Diagenetic alteration of okenone produces okenane, the only recognized molecular fossil unique to PSB. The in vivo concentrations of okenone and bacteriochlorophyll a (Bchl a) on a per cell basis were monitored and quantified as a function of light intensity in continuous cultures of the purple sulfur bacterium Marichromatium purpuratum (Mpurp1591). We show that okenone-producing PSB have constant bacteriochlorophyll to carotenoid ratios in light-harvesting antenna complexes. The in vivo concentrations of Bchl a, 0.151 ± 0.012 fmol cell(-1), and okenone, 0.103 ± 0.012 fmol cell(-1), were not dependent on average light intensity (10-225 Lux) at both steady and non-steady states. This observation revealed that in autotrophic continuous cultures of Mpurp1591, there was a constant ratio for okenone to Bchl a of 1:1.5. Okenone was therefore constitutively produced in planktonic cultures of PSB, regardless of light intensity. This confirms the legitimacy of okenone as a signature for autotrophic planktonic PSB and by extrapolation water column euxinia. We measured the δ(13)C, δ(15)N, and δ(34)S bulk biomass values from cells collected daily and determined the isotopic fractionations of Mpurp1591. There was no statistical relationship in the bulk isotope measurements or stable isotope fractionations to light intensity or cell density under steady and non-steady-state conditions. The carbon isotope fractionation between okenone and Bchl a with respect to overall bulk biomass ((13)ε pigment - biomass) was 2.2 ± 0.4‰ and -4.1 ± 0.9‰, respectively. The carbon isotopic fractionation (13ε pigment-CO2) for the production of pigments in PSB is more variable than previously thought with our reported values for okenone at -15.5 ± 1.2‰ and -21.8 ± 1.7‰ for Bchl a.

Ecologically and geologically relevant isotope signatures of C, N, and S: okenone producing purple sulfur bacteria Part I

Purple sulfur bacteria (PSB) are known to couple the carbon, nitrogen, and sulfur cycling in euxinic environments. This is the first study with multiple strains and species of okenone-producing PSB to examine the carbon (C), nitrogen (N), and sulfur (S) metabolisms and isotopic signatures in controlled laboratory conditions, investigating what isotopic fractionations might be recorded in modern environments and the geologic record. PSB play an integral role in the ecology of euxinic environments and produce the unique molecular fossil okenane, derived from the diagenetic alteration of the carotenoid pigment okenone. Cultures of Marichromatium purpuratum 1591 (Mpurp1591) were observed to have carbon isotope fractionations ((13)ε biomass - CO2), via RuBisCO, ranging from -16.1 to -23.2‰ during exponential and stationary phases of growth. Cultures of Thiocapsa marina 5653 (Tmar5653) and Mpurp1591 had a nitrogen isotope fractionation ((15)ε biomass - NH 4) of -15‰, via glutamate dehydrogenase, measured and recorded for the first time in PSB. The δ(34) SVCDT values and amount of stored elemental sulfur for Mpurp1591 cells grown autotrophically and photoheterotrophically were dependent upon their carbon metabolic pathways. We show that PSB may contribute to the isotopic enrichments observed in modern and ancient anoxic basins. In a photoheterotrophic culture of Mpurp1591 that switched to autotrophy once the organic substrate was consumed, there were bulk biomass δ(13)C values that span a broader range than recorded across the Late Devonian, Permian-Triassic, Triassic-Jurassic, and OAE2 mass extinction boundaries. This finding stresses the complexities in interpreting and assigning δ(13)C values to bulk organic matter preserved in the geologic record.

Organic molecules in the Sheepbed Mudstone, Gale Crater, Mars

The Sample Analysis at Mars (SAM) instrument on board the Mars Science Laboratory Curiosity rover is designed to conduct inorganic and organic chemical analyses of the atmosphere and the surface regolith and rocks to help evaluate the past and present habitability potential of Mars at Gale Crater. Central to this task is the development of an inventory of any organic molecules present to elucidate processes associated with their origin, diagenesis, concentration, and long-term preservation. This will guide the future search for biosignatures. Here we report the definitive identification of chlorobenzene (150-300 parts per billion by weight (ppbw)) and C₂ to C₄ dichloroalkanes (up to 70 ppbw) with the SAM gas chromatograph mass spectrometer (GCMS) and detection of chlorobenzene in the direct evolved gas analysis (EGA) mode, in multiple portions of the fines from the Cumberland drill hole in the Sheepbed mudstone at Yellowknife Bay. When combined with GCMS and EGA data from multiple scooped and drilled samples, blank runs, and supporting laboratory analog studies, the elevated levels of chlorobenzene and the dichloroalkanes cannot be solely explained by instrument background sources known to be present in SAM. We conclude that these chlorinated hydrocarbons are the reaction products of Martian chlorine and organic carbon derived from Martian sources (e.g., igneous, hydrothermal, atmospheric, or biological) or exogenous sources such as meteorites, comets, or interplanetary dust particles.

KEY POINTS

First in situ evidence of nonterrestrial organics in Martian surface sediments Chlorinated hydrocarbons identified in the Sheepbed mudstone by SAM Organics preserved in sample exposed to ionizing radiation and oxidative condition.

Organic molecules in the Sheepbed Mudstone, Gale Crater, Mars

The Sample Analysis at Mars (SAM) instrument on board the Mars Science Laboratory Curiosity rover is designed to conduct inorganic and organic chemical analyses of the atmosphere and the surface regolith and rocks to help evaluate the past and present habitability potential of Mars at Gale Crater. Central to this task is the development of an inventory of any organic molecules present to elucidate processes associated with their origin, diagenesis, concentration, and long-term preservation. This will guide the future search for biosignatures. Here we report the definitive identification of chlorobenzene (150-300 parts per billion by weight (ppbw)) and C₂ to C₄ dichloroalkanes (up to 70 ppbw) with the SAM gas chromatograph mass spectrometer (GCMS) and detection of chlorobenzene in the direct evolved gas analysis (EGA) mode, in multiple portions of the fines from the Cumberland drill hole in the Sheepbed mudstone at Yellowknife Bay. When combined with GCMS and EGA data from multiple scooped and drilled samples, blank runs, and supporting laboratory analog studies, the elevated levels of chlorobenzene and the dichloroalkanes cannot be solely explained by instrument background sources known to be present in SAM. We conclude that these chlorinated hydrocarbons are the reaction products of Martian chlorine and organic carbon derived from Martian sources (e.g., igneous, hydrothermal, atmospheric, or biological) or exogenous sources such as meteorites, comets, or interplanetary dust particles.

KEY POINTS

First in situ evidence of nonterrestrial organics in Martian surface sediments Chlorinated hydrocarbons identified in the Sheepbed mudstone by SAM Organics preserved in sample exposed to ionizing radiation and oxidative condition.

Volatile and organic compositions of sedimentary rocks in Yellowknife Bay, Gale crater, Mars

H2O, CO2, SO2, O2, H2, H2S, HCl, chlorinated hydrocarbons, NO, and other trace gases were evolved during pyrolysis of two mudstone samples acquired by the Curiosity rover at Yellowknife Bay within Gale crater, Mars. H2O/OH-bearing phases included 2:1 phyllosilicate(s), bassanite, akaganeite, and amorphous materials. Thermal decomposition of carbonates and combustion of organic materials are candidate sources for the CO2. Concurrent evolution of O2 and chlorinated hydrocarbons suggests the presence of oxychlorine phase(s). Sulfides are likely sources for sulfur-bearing species. Higher abundances of chlorinated hydrocarbons in the mudstone compared with Rocknest windblown materials previously analyzed by Curiosity suggest that indigenous martian or meteoritic organic carbon sources may be preserved in the mudstone; however, the carbon source for the chlorinated hydrocarbons is not definitively of martian origin.

In situ radiometric and exposure age dating of the martian surface

We determined radiogenic and cosmogenic noble gases in a mudstone on the floor of Gale Crater. A K-Ar age of 4.21 ± 0.35 billion years represents a mixture of detrital and authigenic components and confirms the expected antiquity of rocks comprising the crater rim. Cosmic-ray-produced (3)He, (21)Ne, and (36)Ar yield concordant surface exposure ages of 78 ± 30 million years. Surface exposure occurred mainly in the present geomorphic setting rather than during primary erosion and transport. Our observations are consistent with mudstone deposition shortly after the Gale impact or possibly in a later event of rapid erosion and deposition. The mudstone remained buried until recent exposure by wind-driven scarp retreat. Sedimentary rocks exposed by this mechanism may thus offer the best potential for organic biomarker preservation against destruction by cosmic radiation.

Curiosity at Gale crater, Mars: characterization and analysis of the Rocknest sand shadow

The Rocknest aeolian deposit is similar to aeolian features analyzed by the Mars Exploration Rovers (MERs) Spirit and Opportunity. The fraction of sand <150 micrometers in size contains ~55% crystalline material consistent with a basaltic heritage and ~45% x-ray amorphous material. The amorphous component of Rocknest is iron-rich and silicon-poor and is the host of the volatiles (water, oxygen, sulfur dioxide, carbon dioxide, and chlorine) detected by the Sample Analysis at Mars instrument and of the fine-grained nanophase oxide component first described from basaltic soils analyzed by MERs. The similarity between soils and aeolian materials analyzed at Gusev Crater, Meridiani Planum, and Gale Crater implies locally sourced, globally similar basaltic materials or globally and regionally sourced basaltic components deposited locally at all three locations.

Micro Raman spectroscopy of carbonaceous material in microfossils and meteorites: improving a method for life detection

The identification of biosignatures in Earth's ancient rock record and detection of extraplanetary life is one of the primary goals in astrobiology. Intrinsic to this goal is the improvement of analytical techniques and protocols used to identify an unambiguous signal of life. Micro Raman spectroscopy is a nondestructive method that allows for in situ identification of a wide range of minerals and compounds. The use of D (∼1350 cm(-1)) and G (∼1580 cm(-1)) band parameters to infer the biogenicity of carbonaceous materials in fossils has become a commonly used analytical tool, but carbonaceous compounds from different sources often share the same spectroscopic characteristics. Microfossil studies do not always take into consideration a nonbiological source for the carbon in their samples and therefore still rely on morphology as the primary mode of identification. Comprehensive studies that consider all carbon sources are typically done on metasediments, coals, or meteorites, and the results are not clearly applicable to microfossil identification. In this study, microfossils from a suite of sedimentary rock samples of various ages were analyzed with micro Raman spectroscopy to investigate the nature and provenance of carbonaceous material. To further constrain D- and G-band carbon characteristics, micro Raman analyses were also performed on well-characterized meteorite samples as abiological controls. The results appear to show a correlation of precursor carbonaceous material with D-band parameters and thermal history with G-band parameters. This systematic study lays the groundwork for improving the use of the G- and D-band trends as useful indicators of the origin of carbon in microfossils. Before unambiguous biosignatures can be established, further work characterizing the carbonaceous material in microfossils of different ages, thermal histories, and host rock compositions is needed.

Attention deficits predict phenotypic outcomes in syndrome-specific and domain-specific ways

Attentional difficulties, both at home and in the classroom, are reported across a number of neurodevelopmental disorders. However, exactly how attention influences early socio-cognitive learning remains unclear. We addressed this question both concurrently and longitudinally in a cross-syndrome design, with respect to the communicative domain of vocabulary and to the cognitive domain of early literacy, and then extended the analysis to social behavior. Participants were young children (aged 4-9 years at Time 1) with either Williams syndrome (WS, N = 26) or Down syndrome (DS, N = 26) and typically developing controls (N = 103). Children with WS displayed significantly greater attentional deficits (as indexed by teacher report of behavior typical of attention deficit hyperactivity disorder (ADHD) than children with DS, but both groups had greater attentional problems than the controls. Despite their attention differences, children with DS and those with WS were equivalent in their cognitive abilities of reading single words, both at Time 1 and 12 months later, at Time 2, although they differed in their early communicative abilities in terms of vocabulary. Greater ADHD-like behaviors predicted poorer subsequent literacy for children with DS, but not for children with WS, pointing to syndrome-specific attentional constraints on specific aspects of early development. Overall, our findings highlight the need to investigate more precisely whether and, if so, how, syndrome-specific profiles of behavioral difficulties constrain learning and socio-cognitive outcomes across different domains.

Deep mantle cycling of oceanic crust: evidence from diamonds and their mineral inclusions

A primary consequence of plate tectonics is that basaltic oceanic crust subducts with lithospheric slabs into the mantle. Seismological studies extend this process to the lower mantle, and geochemical observations indicate return of oceanic crust to the upper mantle in plumes. There has been no direct petrologic evidence, however, of the return of subducted oceanic crustal components from the lower mantle. We analyzed superdeep diamonds from Juina-5 kimberlite, Brazil, which host inclusions with compositions comprising the entire phase assemblage expected to crystallize from basalt under lower-mantle conditions. The inclusion mineralogies require exhumation from the lower to upper mantle. Because the diamond hosts have carbon isotope signatures consistent with surface-derived carbon, we conclude that the deep carbon cycle extends into the lower mantle.

Engagement of the B cell receptor for antigen differentially affects B cell responses to Toll-like receptor-7 agonists and antagonists in BXSB mice

Nucleic acid sensors of the Toll-like receptor (TLR) family play a well-established role in the pathogenesis of lupus. This is particularly true for a single-stranded RNA-sensing TLR-7 receptor, as lupus mice lacking TLR-7 show ameliorated disease. Cytosine-guanosine dinucleotide (CpG)-DNA-sensing TLR-9, conversely, has a complex regulatory role in systemic lupus erythematosus (SLE). Much less is known about whether signals through the B cell receptor for antigen (BCR) may affect the ability of B cells to respond to suboptimal TLR-7 agonists and antagonists. We studied this question in prediseased BXSB male and female B cells. We found that male B cells responded more vigorously to numerous TLR-7 ligands and this responsiveness was enhanced further upon co-engagement of the BCR. This synergy was seen primarily with the interleukin (IL)-6 secretion. A number of 32-mer inhibitory oligonucleotides (INH-ODNs) with a nuclease-resistant phosphorothioate backbone were capable of blocking TLR-7, but not BCR-induced B cell activation, with an inhibitory concentration (IC)(50) of approximately 100 nm. Surprisingly, while the presence of a single TGC motif at the 5' end of an ODN did not increase its inhibitory capacity, INH-ODNs containing multiple TGC motifs had greater inhibitory potency. When BCR and TLR-7 were co-engaged, INH-ODNs showed a differential effect on B cell activation. Whereas apoptosis protection and G1-M entry completely escaped suppression, IL-6 secretion remained sensitive to inhibition, although with a 10-fold lower potency. Our results suggest that while TLR-7 antagonists may be considered as lupus therapeutics, simultaneous co-engagement of the TLR-7 and BCR might favour autoreactive B cell survival. This hypothesis needs further experimental validation.

Two-Functional Direct Current Sputtered Silver-Containing Titanium Dioxide Thin Films

The article reports on structure, mechanical, optical, photocatalytic and biocidal properties of Ti-Ag-O films. The Ti-Ag-O films were reactively sputter-deposited from a composed Ti/Ag target at different partial pressures of oxygen pO(2) on unheated glass substrate held on floating potential U(fl). It was found that addition of ~2 at.% of Ag into TiO(2) film has no negative influence on UV-induced hydrophilicity of TiO(2) film. Thick (~1,500 nm) TiO(2)/Ag films containing (200) anatase phase exhibit the best hydrophilicity with water droplet contact angle (WDCA) lower than 10° after UV irradiation for 20 min. Thick (~1,500 nm) TiO(2)/Ag films exhibited a better UV-induced hydrophilicity compared to that of thinner (~700 nm) TiO2/Ag films. Further it was found that hydrophilic TiO(2)/Ag films exhibit a strong biocidal effect under both the visible light and the UV irradiation with 100% killing efficiency of Escherichia coli ATCC 10536 after UV irradiation for 20 min. Reported results show that single layer of TiO(2) with Ag distributed in its whole volume exhibits, after UV irradiation, simultaneously two functions: (1) excellent hydrophilicity with WDCA < 10° and (2) strong power to kill E. coli even under visible light due to direct toxicity of Ag.

The impact and recovery of asteroid 2008 TC(3)

In the absence of a firm link between individual meteorites and their asteroidal parent bodies, asteroids are typically characterized only by their light reflection properties, and grouped accordingly into classes. On 6 October 2008, a small asteroid was discovered with a flat reflectance spectrum in the 554-995 nm wavelength range, and designated 2008 TC(3) (refs 4-6). It subsequently hit the Earth. Because it exploded at 37 km altitude, no macroscopic fragments were expected to survive. Here we report that a dedicated search along the approach trajectory recovered 47 meteorites, fragments of a single body named Almahata Sitta, with a total mass of 3.95 kg. Analysis of one of these meteorites shows it to be an achondrite, a polymict ureilite, anomalous in its class: ultra-fine-grained and porous, with large carbonaceous grains. The combined asteroid and meteorite reflectance spectra identify the asteroid as F class, now firmly linked to dark carbon-rich anomalous ureilites, a material so fragile it was not previously represented in meteorite collections.

DNA perseverance of microorganisms exposed to silica: an experimental study

The persistence of DNA from microorganisms exposed to various concentrations of SiO2 (ranging from 0 to 3000 p.p.m.) was monitored over time. The impact of silica mineralization or silicification on the longevity of 16S rRNA and 16 s rDNA genes from whole cells of Bacillus subtilis and Escherichia coli K12 was quantified using real-time polymerase chain reaction (RT-PCR), and cells were visualized using optical microscopy. For B. subtilis, DNA longevity decreased in experiments with higher levels of SiO2 (1000 and 3000 p.p.m.), in comparison to zero or low (100 p.p.m.) levels. For B. subtilis, cell viability was greatest in the absence of silica, and markedly decreased in the presence of any concentration of silica. Survival of Escherichia coli cells, on the other hand, was not sensitive to silica in the solution. All cells died at similar rates over the 180 days they were monitored, decreasing to about 1% survival. DNA longevity for E. coli did appear to be enhanced to some degree by the presence of 1000 p.p.m. silica, but higher or lower concentrations showed no increased longevity in comparison to the no-silica control. Overall, findings of this study do not support the hypothesis that siliceous environments provide enhanced protection and preservation of DNA over time. However, results of this study do provide guidelines on the persistence of DNA that might be expected in modern silica-rich environments, which may be an important factor for proper characterization of present-day microbial communities.

Short- and long-term olivine weathering in Svalbard: implications for Mars

Liquid water is essential to life as we know it on Earth; therefore, the search for water on Mars is a critical component of the search for life. Olivine, a mineral identified as present on Mars, has been proposed as an indicator of the duration and characteristics of water because it dissolves quickly, particularly under low-pH conditions. The duration of olivine persistence relative to glass under conditions of aqueous alteration reflects the pH and temperature of the reacting fluids. In this paper, we investigate the utility of 3 methodologies to detect silicate weathering in a Mars analog environment (Sverrefjell volcano, Svalbard). CheMin, a miniature X-ray diffraction instrument developed for flight on NASA's upcoming Mars Science Laboratory, was deployed on Svalbard and was successful in detecting olivine and weathering products. The persistence of olivine and glass in Svalbard rocks was also investigated via laboratory observations of weathered hand samples as well as an in situ burial experiment. Observations of hand samples are consistent with the inference that olivine persists longer than glass at near-zero temperatures in the presence of solutions at pH approximately 7-9 on Svalbard, whereas in hydrothermally altered zones, glass has persisted longer than olivine in the presence of fluids at similar pH at approximately 50 degrees C. Analysis of the surfaces of olivine and glass samples, which were buried on Sverrefjell for 1 year and then retrieved, documented only minor incipient weathering, though these results suggest the importance of biological impacts. The 3 types of observations (CheMin, laboratory observations of hand samples, burial experiments) of weathering of olivine and glass at Svalbard show promise for interpretation of weathering on Mars. Furthermore, the weathering relationships observed on Svalbard are consistent with laboratory-measured dissolution rates, which suggests that relative mineral dissolution rates in the laboratory, in concert with field observations, can be used to yield valuable information regarding the pH and temperature of reacting martian fluids.

Multivariate permutation analysis associates multiple polymorphisms with subphenotypes of major depression

Unipolar major depressive disorder (MDD) is a prevalent, disabling condition with multiple genetic and environmental factors impacting disease risk. The diagnosis of MDD relies on a cumulative measure derived from multiple trait dimensions and alone is limited in elucidating MDD genetic determinants. We and others have proposed that MDD may be better dissected using paradigms that assess how specific genes associate with component features of MDD. This within-disease design requires both a well-phenotyped cohort and a robust statistical approach that retains power with multiple tests of genetic association. In the present study, common polymorphic variants of genes related to central monoaminergic and cholinergic pathways that previous studies align with functional change in vitro or depression associations in vivo were genotyped in 110 individuals with unipolar MDD. Subphenotypic characteristics were examined using responses to individual items assessed with the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders (DSM IV), the 17-item Hamilton Rating Scale for Depression (HAM-D) and the NEO Five Factor Inventory. Multivariate Permutation Testing (MPT) was used to infer genotype-phenotype relationships underlying dimensional findings within clinical categories. MPT analyses show significant associations of the norepinephrine transporter (NET, SLC6A2) -182 T/C (rs2242446) with recurrent depression [odds ratio, OR = 4.15 (1.91-9.02)], NET -3081 A/T (rs28386840) with increase in appetite [OR = 3.58 (1.53-8.39)] and the presynaptic choline transporter (CHT, SLC5A7) Ile89Val (rs1013940) with HAM-D-17 total score {i.e. overall depression severity [OR = 2.74 (1.05-7.18)]}. These relationships illustrate an approach to the elucidation of gene influences on trait components of MDD and with replication, may help identify MDD subpopulations that can benefit from more targeted pharmacotherapy.

The transcription factor 7-like 2 (TCF7L2) gene is associated with Type 2 diabetes in UK community-based cases, but the risk allele frequency is reduced compared with UK cases selected for genetic studies

AIMS

Common polymorphisms in the transcription factor 7-like 2 (TCF7L2) gene are strongly associated with Type 2 diabetes. Many studies include a large proportion of cases enriched for family history or young age of diagnosis and may therefore provide an overestimation of the general population risk. We aimed to compare the impact of TCF7L2 in UK community-based Type 2 diabetic subjects with that in subjects ascertained for genetic studies.

METHODS

We genotyped the TCF7L2 polymorphism rs7903146 in 1068 cases from two sources: 487 from 10 GP practices and 601 ascertained for genetic studies, and 2099 control subjects from two sources: 1099 parents from a birth cohort (population control subjects) and 300 subjects with normal fasting glucose aged > or = 45 years (community control subjects).

RESULTS

When compared with Type 2 diabetes cases ascertained for genetic studies, the risk allele frequency in community-based cases was lower (40 vs. 36%, P = 0.04), but there was no difference in risk allele frequency between community-based control and population-based control subjects (31 vs. 30%, P = 0.61). The T allele of rs7903146 increased Type 2 diabetes risk with an odds ratio (OR) of 1.32 (95% CI: 1.13-1.52; P = 0.0002) in community-based cases, but this OR was lower than the OR of cases enriched for genetic studies [1.58 (95% CI: 1.38-1.80), P = 1.4 x 10(-11)] and the combined OR of meta-analysis of 10 studies to date on rs7903146 [1.48 (95% CI: 1.41-1.54), P < 10(-20)].

CONCLUSION

Common variation in the TCF7L2 gene contributes to Type 2 diabetes risk in UK patients recruited in general practice, but the risk allele frequency may be lower than that in subjects enriched for genetic effects.

Stem-like cells traffic from heart ex vivo, expand in vitro, and can be transplanted in vivo

BACKGROUND

Cells with stem cell surface markers have been identified in heart tissue. Early indications suggest that these are cardiac progenitor cells that could contribute to cardiac repair/regeneration. Clinically relevant therapeutic strategies based on these cells will require improved methods for their isolation and characterization of determinants of their mobilization, proliferation and differentiation.

METHODS

An ex vivo culture system was developed that promotes trafficking of progenitor-like cells from mouse ventricles to a culture surface. Cells that "trafficked" from cardiac tissue were phenotyped by flow cytometry and immunohistochemistry.

RESULTS

Morphologically distinct cells spontaneously trafficked from mouse ventricular tissue, adhered in culture, and proliferated for up to 4 weeks in Dulbecco's minimal essential media supplemented with fetal calf serum. After 4 weeks in culture, cell number declined. Co-culture with unfractionated bone marrow restored the proliferation of these trafficked cells. A significant population of the trafficked cells expressed a phenotype consistent with that of a myogenic progenitor such as: c-kit+, Sca-1+, CD45-, CD34-, CD90.2-, MyoD1-, desmin-, muscle-specific actin-, and, infrequently, myogenin+. An expanded population of trafficked cells from ventricles of mice expressing green fluorescent protein (GFP+) and containing cardiac-derived progenitor cells were injected into the pericardial space of GFP- mice. GFP+ cells trafficked throughout the heart but retained a primitive undifferentiated morphology. However, when injected into the pericardial space of Apo-E-deficient mice with coronary vasculopathy, progenitor-like cells trafficked into myocardium, and GFP+ cells differentiated into vessel-lining endothelial cells and, rarely, smooth muscle and cardiomyocytes.

CONCLUSIONS

Progenitor-like cells in the heart can be mobilized by tissue injury to spontaneously traffic from cardiac tissue and can expand in culture by co-culture with bone marrow. When re-infused by pericardiocentesis, these primitive cells traffic into heart, retain immature morphology, but are capable of undergoing injury-induced differentiation. The novel method described herein permits further characterization of cardiac-derived progenitor cells, which are a candidate for cardiac regeneration strategies.