Complex organic matter degradation by secondary consumers in chemolithoautotrophy-based subsurface geothermal ecosystems.

Microbial communities in terrestrial geothermal systems often contain chemolithoautotrophs with well-characterized distributions and metabolic capabilities. However, the extent to which organic matter produced by these chemolithoautotrophs supports heterotrophs remains largely unknown. Here we compared the abundance and activity of peptidases and carbohydrate active enzymes (CAZymes) that are predicted to be extracellular identified in metagenomic assemblies from 63 springs in the Central American and the Andean convergent margin (Argentinian backarc of the Central Volcanic Zone), as well as the plume-influenced spreading center in Iceland. All assemblies contain two orders of magnitude more peptidases than CAZymes, suggesting that the microorganisms more often use proteins for their carbon and/or nitrogen acquisition instead of complex sugars. The CAZy families in highest abundance are GH23 and CBM50, and the most abundant peptidase families are M23 and C26, all four of which degrade peptidoglycan found in bacterial cells. This implies that the heterotrophic community relies on autochthonous dead cell biomass, rather than allochthonous plant matter, for organic material. Enzymes involved in the degradation of cyanobacterial- and algal-derived compounds are in lower abundance at every site, with volcanic sites having more enzymes degrading cyanobacterial compounds and non-volcanic sites having more enzymes degrading algal compounds. Activity assays showed that many of these enzyme classes are active in these samples. High temperature sites (> 80°C) had similar extracellular carbon-degrading enzymes regardless of their province, suggesting a less well-developed population of secondary consumers at these sites, possibly connected with the limited extent of the subsurface biosphere in these high temperature sites. We conclude that in < 80°C springs, chemolithoautotrophic production supports heterotrophs capable of degrading a wide range of organic compounds that do not vary by geological province, even though the taxonomic and respiratory repertoire of chemolithoautotrophs and heterotrophs differ greatly across these regions.

Ultrahigh-precision noble gas isotope analyses reveal pervasive subsurface fractionation in hydrothermal systems.

Mantle-derived noble gases in volcanic gases are powerful tracers of terrestrial volatile evolution, as they contain mixtures of both primordial (from Earth's accretion) and secondary (e.g., radiogenic) isotope signals that characterize the composition of deep Earth. However, volcanic gases emitted through subaerial hydrothermal systems also contain contributions from shallow reservoirs (groundwater, crust, atmosphere). Deconvolving deep and shallow source signals is critical for robust interpretations of mantle-derived signals. Here, we use a novel dynamic mass spectrometry technique to measure argon, krypton, and xenon isotopes in volcanic gas with ultrahigh precision. Data from Iceland, Germany, United States (Yellowstone, Salton Sea), Costa Rica, and Chile show that subsurface isotope fractionation within hydrothermal systems is a globally pervasive and previously unrecognized process causing substantial nonradiogenic Ar-Kr-Xe isotope variations. Quantitatively accounting for this process is vital for accurately interpreting mantle-derived volatile (e.g., noble gas and nitrogen) signals, with profound implications for our understanding of terrestrial volatile evolution.

Langerhans' cell histiocytosis of the retropharynx: first reported case.

Langerhans' cell histiocytosis (LCH) is a rare condition characterised by histiocyte proliferation leading to destructive granulomatous lesions. It may occur anywhere in the body but extraosseous manifestations affecting the head and neck are particularly uncommon. Here, we present the first reported case of a mass arising in the retropharyngeal space caused by LCH. The patient was a 33-year-old man with various symptoms which are presented. Although rare, LCH can affect a variety of tissues in the head and neck. Clinicians need to be cognisant of its inclusion in the differential diagnoses for similar cases in their practice, in particular because of potential difficulties in diagnosis.

Chemolithoautotroph distributions across the subsurface of a convergent margin.

Subducting oceanic crusts release fluids rich in biologically relevant compounds into the overriding plate, fueling subsurface chemolithoautotrophic ecosystems. To understand the impact of subsurface geochemistry on microbial communities, we collected fluid and sediments from 14 natural springs across a ~200 km transect across the Costa Rican convergent margin and performed shotgun metagenomics. The resulting 404 metagenome-assembled genomes (MAGs) cluster into geologically distinct regions based on MAG abundance patterns: outer forearc-only (25% of total relative abundance), forearc/arc-only (38% of total relative abundance), and delocalized (37% of total relative abundance) clusters. In the outer forearc, Thermodesulfovibrionia, Candidatus Bipolaricaulia, and Firmicutes have hydrogenotrophic sulfate reduction and Wood-Ljungdahl (WL) carbon fixation pathways. In the forearc/arc, Anaerolineae, Ca. Bipolaricaulia, and Thermodesulfovibrionia have sulfur oxidation, nitrogen cycling, microaerophilic respiration, and WL, while Aquificae have aerobic sulfur oxidation and reverse tricarboxylic acid carbon fixation pathway. Transformation-based canonical correspondence analysis shows that MAG distribution corresponds to concentrations of aluminum, iron, nickel, dissolved inorganic carbon, and phosphate. While delocalized MAGs appear surface-derived, the subsurface chemolithoautotrophic, metabolic, and taxonomic landscape varies by the availability of minerals/metals and volcanically derived inorganic carbon. However, the WL pathway persists across all samples, suggesting that this versatile, energy-efficient carbon fixation pathway helps shape convergent margin subsurface ecosystems.

Influencing health behaviour using smart building interventions for people with dementia and mild cognitive impairment: expert interviews and a systematic literature review.

PURPOSE: Behaviour can have an influence on (coping with) chronic conditions such as dementia. Assistive technology can stimulate the daily behaviour of people with dementia, but the mechanisms through which this happens are unclear. Therefore, this paper focuses on potential behaviour change mechanisms, that can be employed in smart building interventions for people with dementia or MCI. METHODS: This research uses expert interviews with medical experts (n = 9) and a systematic literature review of smart building interventions stimulating health behaviour (n = 12). RESULTS: Results show how facilitation, incentive motivation (i.e., feedback), observational learning and self-efficacy are most promising according to medical experts; if they are appropriately personalised towards needs, preferences as well as abilities. The literature review shows how most of the examined research uses facilitation and incentive motivation to stimulate behaviour. Although positive results are reported in all studies, methodological quality could be improved. CONCLUSION: For the design of smart building interventions for people with MCI or dementia, facilitation and incentive motivation seem to be promising behaviour change mechanisms. Outcome expectation, observational learning and self-efficacy could reinforcing the aforementioned mechanisms. Future research should focus on how different (environmental, digital) cues can be personalized and can adapt over time, as dementia progresses.IMPLICATIONS FOR REHABILITATIONAssistive technology for people with dementia can have an effect on (health) behaviour, which may in turn influence coping strategies or quality of life.Behaviour change mechanisms can inform the design of assistive technology such as smart building interventions.Facilitation, Incentive Motivation, Observational Learning and Self-efficacy seem promising behaviour change mechanisms for people with dementia or MCI.In any intervention for people with dementia, personalized and adaptable cues are of vital importance.

Sampling across large-scale geological gradients to study geosphere-biosphere interactions.

Despite being one of the largest microbial ecosystems on Earth, many basic open questions remain about how life exists and thrives in the deep subsurface biosphere. Much of this ambiguity is due to the fact that it is exceedingly difficult and often prohibitively expensive to directly sample the deep subsurface, requiring elaborate drilling programs or access to deep mines. We propose a sampling approach which involves collection of a large suite of geological, geochemical, and biological data from numerous deeply-sourced seeps-including lower temperature sites-over large spatial scales. This enables research into interactions between the geosphere and the biosphere, expanding the classical local approach to regional or even planetary scales. Understanding the interplay between geology, geochemistry and biology on such scales is essential for building subsurface ecosystem models and extrapolating the ecological and biogeochemical roles of subsurface microbes beyond single site interpretations. This approach has been used successfully across the Central and South American Convergent Margins, and can be applied more broadly to other types of geological regions (i.e., rifting, intraplate volcanic, and hydrothermal settings). Working across geological spatial scales inherently encompasses broad temporal scales (e.g., millions of years of volatile cycling across a convergent margin), providing access to a framework for interpreting evolution and ecosystem functions through deep time and space. We propose that tectonic interactions are fundamental to maintaining planetary habitability through feedbacks that stabilize the ecosphere, and deep biosphere studies are fundamental to understanding geo-bio feedbacks on these processes on a global scale.

Management of parapharyngeal space cavernous sinus haemangioma using transoral robotic surgery.

Cavernous haemangiomas are a very rare occurrence in the parapharyngeal space (PPS). Here, we present a case of a 58-year-old woman with an incidentally identified left PPS mass thought to be a pleomorphic adenoma that underwent excision by transoral robotic surgery (TORS). Intraoperative findings demonstrated no solid mass present and histological assessment of resected tissue confirmed a cavernous haemangioma. We discuss our experience in the management of a radiological and surgical mismatch of a PPS mass in what we believe to be the first cavernous haemangioma to be excised by TORS in this region.

High 3He/4He in central Panama reveals a distal connection to the Galápagos plume.

It is well established that mantle plumes are the main conduits for upwelling geochemically enriched material from Earth's deep interior. The fashion and extent to which lateral flow processes at shallow depths may disperse enriched mantle material far (>1,000 km) from vertical plume conduits, however, remain poorly constrained. Here, we report He and C isotope data from 65 hydrothermal fluids from the southern Central America Margin (CAM) which reveal strikingly high 3He/4He (up to 8.9RA) in low-temperature (≤50 °C) geothermal springs of central Panama that are not associated with active volcanism. Following radiogenic correction, these data imply a mantle source 3He/4He >10.3RA (and potentially up to 26RA, similar to Galápagos hotspot lavas) markedly greater than the upper mantle range (8 ± 1RA). Lava geochemistry (Pb isotopes, Nb/U, and Ce/Pb) and geophysical constraints show that high 3He/4He values in central Panama are likely derived from the infiltration of a Galápagos plume-like mantle through a slab window that opened ∼8 Mya. Two potential transport mechanisms can explain the connection between the Galápagos plume and the slab window: 1) sublithospheric transport of Galápagos plume material channeled by lithosphere thinning along the Panama Fracture Zone or 2) active upwelling of Galápagos plume material blown by a "mantle wind" toward the CAM. We present a model of global mantle flow that supports the second mechanism, whereby most of the eastward transport of Galápagos plume material occurs in the shallow asthenosphere. These findings underscore the potential for lateral mantle flow to transport mantle geochemical heterogeneities thousands of kilometers away from plume conduits.

Aerial strategies advance volcanic gas measurements at inaccessible, strongly degassing volcanoes.

Volcanic emissions are a critical pathway in Earth's carbon cycle. Here, we show that aerial measurements of volcanic gases using unoccupied aerial systems (UAS) transform our ability to measure and monitor plumes remotely and to constrain global volatile fluxes from volcanoes. Combining multi-scale measurements from ground-based remote sensing, long-range aerial sampling, and satellites, we present comprehensive gas fluxes-3760 ± [600, 310] tons day-1 CO2 and 5150 ± [730, 340] tons day-1 SO2-for a strong yet previously uncharacterized volcanic emitter: Manam, Papua New Guinea. The CO2/ST ratio of 1.07 ± 0.06 suggests a modest slab sediment contribution to the sub-arc mantle. We find that aerial strategies reduce uncertainties associated with ground-based remote sensing of SO2 flux and enable near-real-time measurements of plume chemistry and carbon isotope composition. Our data emphasize the need to account for time averaging of temporal variability in volcanic gas emissions in global flux estimates.

Helium, inorganic and organic carbon isotopes of fluids and gases across the Costa Rica convergent margin.

In 2017, fluid and gas samples were collected across the Costa Rican Arc. He and Ne isotopes, C isotopes as well as total organic and inorganic carbon concentrations were measured. The samples (n = 24) from 2017 are accompanied by (n = 17) samples collected in 2008, 2010 and 2012. He-isotopes ranged from arc-like (6.8 RA) to crustal (0.5 RA). Measured dissolved inorganic carbon (DIC) δ13CVPDB values varied from 3.55 to -21.57‰, with dissolved organic carbon (DOC) following the trends of DIC. Gas phase CO2 only occurs within ~20 km of the arc; δ13CVPDB values varied from -0.84 to -5.23‰. Onsite, pH, conductivity, temperature and dissolved oxygen (DO) were measured; pH ranged from 0.9-10.0, conductivity from 200-91,900 µS/cm, temperatures from 23-89 °C and DO from 2-84%. Data were used to develop a model which suggests that ~91 ± 4.0% of carbon released from the slab/mantle beneath the Costa Rican forearc is sequestered within the crust by calcite deposition with an additional 3.3 ± 1.3% incorporated into autotrophic biomass.

Author Correction: Forearc carbon sink reduces long-term volatile recycling into the mantle.

An Amendment to this paper has been published and can be accessed via a link at the top of the paper.

Patient classification of two-week wait referrals for suspected head and neck cancer: a machine learning approach.

BACKGROUND: Machine learning algorithms could potentially be used to classify patients referred on the two-week wait pathway for suspected head and neck cancer. Patients could be classified into 'predicted cancer' or 'predicted non-cancer' groups. METHODS: A variety of machine learning algorithms were assessed using the clinical data of 5082 patients. These patients had previously been referred via the two-week wait pathway for suspected head and neck cancer to two separate tertiary referral centres in the UK. Outcomes from machine learning classification were analysed in comparison to known clinical diagnoses. RESULTS: Variational logistic regression was the most clinically useful technique of those chosen to perform the analysis and patient classification; the proportion of patients correctly classified as having 'non-cancer' was 25.8 per cent, with a false negative rate of 1 out of 1000. CONCLUSION: Machine learning algorithms can accurately and effectively classify patients referred with suspected head and neck cancer symptoms.

Revisiting the sternocleidomastoid flap as a reconstructive option in head and neck surgery.

BACKGROUND: The sternocleidomastoid can be used as a pedicled flap in head and neck reconstruction. It has previously been associated with high complication rates, likely due in part to the variable nature of its blood supply. OBJECTIVE: To provide clinicians with an up-to-date review of clinical outcomes of sternocleidomastoid flap surgery in head and neck reconstruction, integrated with a review of vascular anatomical studies of the sternocleidomastoid. METHODS: A literature search of the Medline and Web of Science databases was conducted. Complications were analysed for each study. The trend in success rates was analysed by date of the study. RESULTS: Reported complication rates have improved over time. The preservation of two vascular pedicles rather than one may have contributed to improved outcomes. CONCLUSION: The sternocleidomastoid flap is a versatile option for patients where prolonged free flap surgery is inappropriate. Modern vascular imaging techniques could optimise pre-operative planning.

Author Correction: Forearc carbon sink reduces long-term volatile recycling into the mantle.

Change history: In this Article, the original affiliation 2 was not applicable and has been removed. In addition, in the Acknowledgements there was a statement missing and an error in a name. These errors have been corrected online.

Current thinking on the management of abnormal retropharyngeal nodes in patients with oral, oropharyngeal, and nasopharyngeal squamous cell carcinoma: a structured review.

The management of enlarged retropharyngeal lymph nodes (RLN) in patients with confirmed oral, oropharyngeal, or nasopharyngeal squamous cell carcinoma (SCC) has prognostic relevance and is a challenge for the clinical teams. There is, however, no consensus regarding their clinical management or radiographic evaluation. The aim of this review therefore was to present the current thinking on management to help improve outcomes. We searched several online databases using the key terms "retropharyngeal node", "oral cancer", "head and neck cancer", "oropharyngeal cancer", "nasopharyngeal cancer", "nasopharynx", "oral cavity", "oropharynx", "TORS", and "radiotherapy". A total of 1024 papers were screened, of which 32 were eligible. There was no consensus about the management of RLN. There is a lack of randomised studies and a lack of consistency in the presentation of results. Management should be tailored in patients with nasopharyngeal carcinoma (NPC), and prophylactic irradiation is warranted as these nodes are at high risk of metastasis. In patients with non-NPC tumours, we prefer to resect them during primary operations when there is radiological uncertainty or evidence that they are affected, as the combination of radiological and histological outcomes will further our understanding. In both NPC and non-NPC tumours, sampling may also help to standardise the radiological criteria for the diagnosis of RLN by contrast-enhanced computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) CT.

Forearc carbon sink reduces long-term volatile recycling into the mantle.

Carbon and other volatiles in the form of gases, fluids or mineral phases are transported from Earth's surface into the mantle at convergent margins, where the oceanic crust subducts beneath the continental crust. The efficiency of this transfer has profound implications for the nature and scale of geochemical heterogeneities in Earth's deep mantle and shallow crustal reservoirs, as well as Earth's oxidation state. However, the proportions of volatiles released from the forearc and backarc are not well constrained compared to fluxes from the volcanic arc front. Here we use helium and carbon isotope data from deeply sourced springs along two cross-arc transects to show that about 91 per cent of carbon released from the slab and mantle beneath the Costa Rican forearc is sequestered within the crust by calcite deposition. Around an additional three per cent is incorporated into the biomass through microbial chemolithoautotrophy, whereby microbes assimilate inorganic carbon into biomass. We estimate that between 1.2 × 108 and 1.3 × 1010 moles of carbon dioxide per year are released from the slab beneath the forearc, and thus up to about 19 per cent less carbon is being transferred into Earth's deep mantle than previously estimated.

Thermoplasmatales and sulfur-oxidizing bacteria dominate the microbial community at the surface water of a CO2-rich hydrothermal spring located in Tenorio Volcano National Park, Costa Rica.

Here we report the chemical and microbial characterization of the surface water of a CO2-rich hydrothermal vent known in Costa Rica as Borbollones, located at Tenorio Volcano National Park. The Borbollones showed a temperature surrounding 60 °C, a pH of 2.4 and the gas released has a composition of ~ 97% CO2, ~ 0.07% H2S, ~ 2.3% N2 and ~ 0.12% CH4. Other chemical species such as sulfate and iron were found at high levels with respect to typical fresh water bodies. Analysis by 16S rRNA gene metabarcoding revealed that in Borbollones predominates an archaeon from the order Thermoplasmatales and one bacterium from the genus Sulfurimonas. Other sulfur- (genera Thiomonas, Acidithiobacillus, Sulfuriferula, and Sulfuricurvum) and iron-oxidizing bacteria (genera Sideroxydans, Gallionella, and Ferrovum) were identified. Our results show that CO2-influenced surface water of Borbollones contains microorganisms that are usually found in acid rock drainage environments or sulfur-rich hydrothermal vents. To our knowledge, this is the first microbiological characterization of a CO2-dominated hydrothermal spring from Central America and expands our understanding of those extreme ecosystems.

Understanding and forecasting phreatic eruptions driven by magmatic degassing.

This paper examines phreatic eruptions which are driven by inputs of magma and magmatic gas. We synthesize data from several significant phreatic systems, including two in Costa Rica (Turrialba and Poás) which are currently highly active and hazardous. We define two endmember types of phreatic eruptions, the first (type 1) in which a deeper hydrothermal system fed by magmatic gases is sealed and produces overpressure sufficient to drive explosive eruptions, and the second (type 2) where magmatic gases are supplied via open-vent degassing to a near-surface hydrothermal system, vaporizing liquid water which drives the phreatic eruptions. The surficial source of type 2 eruptions is characteristic, while the source depth of type 1 eruptions is commonly greater. Hence, type 1 eruptions tend to be more energetic than type 2 eruptions. The first type of eruption we term "phreato-vulcanian", and the second we term "phreato-surtseyan". Some systems (e.g., Ruapehu, Poás) can produce both type 1 and type 2 eruptions, and all systems can undergo sealing at various timescales. We examine a number of precursory signals which appear to be important in understanding and forecasting phreatic eruptions; these include very long period events, banded tremor, and gas ratios, in particular H2S/SO2 and CO2/SO2. We propose that if these datasets are carefully integrated during a monitoring program, it may be possible to accurately forecast phreatic eruptions.

Nitrogen recycling at the Costa Rican subduction zone: The role of incoming plate structure.

Efficient recycling of subducted sedimentary nitrogen (N) back to the atmosphere through arc volcanism has been advocated for the Central America margin while at other locations mass balance considerations and N contents of high pressure metamorphic rocks imply massive addition of subducted N to the mantle and past the zones of arc magma generation. Here, we report new results of N isotope compositions with gas chemistry and noble gas compositions of forearc and arc front springs in Costa Rica to show that the structure of the incoming plate has a profound effect on the extent of N subduction into the mantle. N isotope compositions of emitted arc gases (9-11 N°) imply less subducted pelagic sediment contribution compared to farther north. The N isotope compositions (δ15N = -4.4 to 1.6‰) of forearc springs at 9-11 N° are consistent with previously reported values in volcanic centers (δ15N = -3.0 to 1.9‰). We advocate that subduction erosion enhanced by abundant seamount subduction at 9-11 N° introduces overlying forearc crustal materials into the Costa Rican subduction zone, releasing fluids with lighter N isotope signatures. This process supports the recycling of heavier N into the deep mantle in this section of the Central America margin.

Swallowing outcomes for patients with oropharyngeal squamous cell carcinoma treated with primary (chemo)radiation therapy receiving either prophylactic gastrostomy or reactive nasogastric tube: A prospective cohort study.

OBJECTIVES: There is currently no consensus on the optimal feeding route for an oropharyngeal squamous cell cancer (OPSCC) patient without pre-existing dysphagia undergoing chemoradiotherapy. This study aimed to compare the swallowing outcomes for OPSCC patients fed via either prophylactic RIG (pRIG) or reactive nasogastric tube (rNGT). DESIGN: A prospective cohort study. SETTING: Four head and neck cancer centres in the North of England Cancer Network. PARTICIPANTS: Fifty-three participants with OPSCC, on a normal diet pre-(chemo) radiotherapy. MAIN OUTCOME MEASURE: Swallowing outcomes for patients with rNGT and pRIG were compared using the following outcome measures administered prospectively at pre-treatment, three and 12 months post-treatment: MD Anderson Dysphagia Inventory (MDADI), Performance Status Scales (Normalcy of Diet), timed water swallow test. RESULTS: Twenty-three patients received pRIG while 30 were planned for a rNGT. No differences in demographics were found between the groups. The rNGT group had a clinically significant higher score on MDADI at 12 months post-treatment. No significant difference was found on a timed water swallow test or diet texture scale. CONCLUSIONS: There is no statistical difference for swallowing outcomes in either group. However, patients' in the rNGT group reported a clinically meaningful difference at 1 year, with a trend for them to do better across all measures. Neither group returned to their baseline swallowing function. Further research with a larger sample size is indicated.