Changes In Sedimentation Rate Research Articles

Using luminescence dating to constrain lake sediment records: A new age model for the 1.38 Ma lake Malawi drill core, Eastern Africa

The 2005 Lake Malawi deep scientific drill core is the longest and most continuous high-resolution record from the continental tropics, extending to ∼1.38 Ma. While extensive sets of paleoclimate proxy data have been generated from this core, a gap in directly dated sediment, between ∼74 ka and ∼590 ka (28–167 m below lake floor), has limited the understanding of climatic drivers in this system. Previous age models fill the gap in direct dates by tuning to the global δ18O stack and interpreting paleomagnetic excursions, but these methods and the resulting models remain disputed. We fill this gap in chronology using luminescence dating, with 31 samples collected at ∼4 m resolution in this section of the core. Luminescence dating can sometimes be limited by relatively large uncertainties (typically ∼7%) and difficulty estimating the water content history of samples. We overcome these limitations by employing a high sampling density and using the sediment record to understand changes in water content during the burial period. This yields a vastly improved and robust age model that indicates changes in sedimentation rates not discernible in prior age models.

Palaeogeographic heterogeneity of large-amplitude changes in marine sedimentation rates during the Carnian Pluvial Episode (Late Triassic)

Major environmental changes marked the Carnian (Late Triassic), including global warming and enhanced hydrological cycling linked to multiple carbon cycle perturbations. These perturbations occurred in an interval called the Carnian Pluvial Episode (CPE), between the Julian 1–Julian 2 boundary and the base of the Tuvalian 2 (late early to middle late Carnian). The CPE is linked to pronounced changes in terrestrial and marine sedimentary basins, with abrupt switches in the sedimentation style and a widespread crisis of carbonate systems. In this study, we have quantified changes in sedimentation rate and the relative variations in sedimentation rate through well age-constrained successions spanning the CPE in different marine basins. Relative to background (pre-CPE) Julian 1 values, during the CPE interval sedimentation rates rose by 142%–3400% in the Julian 2, and then decreased in the Tuvalian 1 in the marine sequences of Western Tethys and Panthalassa. By contrast, in the successions of Eastern Tethys sedimentation rates dropped by 50%–100% across the CPE interval. In the Western Tethys, the high increases in sedimentation rates were coupled with a shift from prevailing carbonate to siliciclastic sedimentation, but a similar lithological shift is associated with a decrease in sedimentation rates in Eastern Tethys. In Panthalassa, higher Julian 2 sedimentation rates can be linked to mineralogical and geochemical evidence of increased input of aeolian dust under arid environmental conditions. The heterogenous changes in sedimentation rate across different basins/regions during the CPE interval indicate that sedimentation was likely controlled by the interplay of different, sometimes local phenomena such as synsedimentary tectonism, sea-level oscillations and climate. However, they could ultimately be related to palaeogeographically different responses to the pronounced environmental changes implied by the Carnian carbon cycle perturbations.

Bayesian integration of astrochronology and radioisotope geochronology

Abstract. Relating stratigraphic position to numerical time using age–depth models plays an important role in determining the rate and timing of geologic and environmental change throughout Earth history. Astrochronology uses the geologic record of astronomically derived oscillations in the rock record to measure the passage of time and has proven to be a valuable technique for developing age–depth models with high stratigraphic and temporal resolution. However, in the absence of anchoring dates, many astrochronologies float in numerical time. Anchoring these chronologies relies on radioisotope geochronology (e.g., U–Pb, 40Ar/39Ar), which produces high-precision (<±1 %), stratigraphically distributed point estimates of age. In this study, we present a new R package, astroBayes, for a Bayesian inversion of astrochronology and radioisotopic geochronology to derive age–depth models. Integrating both data types allows reduction in uncertainties related to interpolation between dated horizons and the resolution of subtle changes in sedimentation rate, especially when compared to existing Bayesian models that use a stochastic random walk to approximate sedimentation variability. The astroBayes inversion also incorporates prior information about sedimentation rate, superposition, and the presence or absence of major hiatuses. The resulting age–depth models preserve both the spatial resolution of floating astrochronologies and the accuracy as well as precision of modern radioisotopic geochronology. We test the astroBayes method using two synthetic datasets designed to mimic real-world stratigraphic sections. Model uncertainties are predominantly controlled by the precision of the radioisotopic dates and are relatively constant with depth while being significantly reduced relative to “dates-only” random walk models. Since the resulting age–depth models leverage both astrochronology and radioisotopic geochronology in a single statistical framework they can resolve ambiguities between the two chronometers. Finally, we present a case study of the Bridge Creek Limestone Member of the Greenhorn Formation where we refine the age of the Cenomanian–Turonian boundary, showing the strength of this approach when applied to deep-time chronostratigraphic questions.

Influence of sedimentary processes and fault tectonics on the evolution of submarine canyons in the East Andaman Basin: Insights from high-resolution seismic data analysis

The Andaman Sea Basin, a well-known back-arc spreading centre and a mature petroliferous basin, presents a unique and complex scenario for understanding the interplay of sedimentary processes and fault tectonics on seafloor geomorphology evolution, particularly in the eastern shelf region. This study, using high-resolution 3D seismic data and published exploratory well-seismic interpretation results, aims to establish a comprehensive stratigraphic framework for the Tanintharyi region, spanning the Lower Miocene, Middle Miocene, Upper Miocene, Pliocene, and Quaternary. A submarine canyon system was identified and investigated along the Tanintharyi continental slope within the East Andaman Basin, comprising thirteen slope-confined canyons arranged predominantly in an east-west vertical slope orientation. By analysing seismic reflection features, five distinct seismic facies have been identified, including basal lag (BL), slump and debris-flow deposits (SDFDs), canyon confined sheets (CCSs), laterally inclined packages (LIPs), and channel-levees (CLs). The evolution of this canyon system, a vital focus of this study, can be categorised into three phases based on the morphology and sedimentary structures observed: canyon initiation, canyon extension, and erosion-sedimentation. The findings of this study highlight the critical controlling role of faults in canyon evolution, with the intensity of fault activity displaying a negative correlation with canyon size, indicating the direct impact of faults on geomorphological changes. In addition, the geomorphological changes induced by fault activity have resulted in changes in sediment supply, dispersal, and sedimentation rates, thus significantly impacting the spatial distribution and dimensions of slope-confined canyons within the East Andaman Basin, with far-reaching implications.

Bioturbation by Benthic Stingrays Alters the Biogeomorphology of Tidal Flats

AbstractFishing-down-marine-food-webs has resulted in alarming declines of various species worldwide. Benthic rays are one examples of such overexploited species. On tidal flats, these rays are highly abundant and play an ecologically important role. They use tidal flats as refuge, feeding and resting grounds, during which they bury into the sediment, which results in sediment bioturbation. Changes in bioturbation intensity, following ray removal, may affect the biogeomorphology of tidal flats with possible cascading effects on the macrozoobenthic community. However, it is poorly understood how these indirect effects could influence ecosystem function. We therefore studied the geomorphic impact of benthic rays (specifically the pearl whipray/stingray Fontitrygon margaritella) on the tropical tidal flats of the Bijagós Archipelago, Guinea-Bissau, on a landscape scale. We investigated 1) bioturbation rates by rays using drone and ground surveys, 2) the spatial distribution of ray pits on multiple tidal flats, 3) the impact of rays on sediment properties and macrozoobenthos by experimental exclusion (15 months). Benthic rays bioturbated 3.7 ± 0.35% of the tidal flat’s sediment surface per day over one single 24-h period, which equals a complete top-sediment-surface turnover every 27 days. The spatial distribution of ray pits was affected by tidal flat geomorphology since pits decayed faster at areas exposed to strong hydrodynamic forces. Predator exclusion altered sediment properties, leading to changes in sedimentation (− 17%) and erosion (− 43%) rates. In addition, macrozoobenthic species composition changed, marked by an increase in Capitellidae worms and a greater biomass of Malacostraca over time. These changes indicated substantial effects of ray bioturbation on the biotic and geomorphic landscape of tidal flats. Overall, we conclude that changing abundances of benthic rays can have clear landscape-wide geomorphological effects on intertidal ecosystems. These indirect consequences of fisheries should be incorporated in integrative management plans to preserve tidal flats and connected ecosystems.

The efficacy of tofacitinib combined with bDMARDs in the treatment of ankylosing spondylitis patients with inadequate response to bDMARDs: a retrospective study

IntroductionAnkylosing spondylitis(AS) is a chronic inflammatory rheumatic disease primarily affecting the spine and sacroiliac joints. While biologic disease-modifying antirheumatic drugs(bDMARDs) and targeted synthetic DMARDs(tsDMARDs) are popular treatments for AS, there is limited research on their combined use. This study examined a cohort of AS patients who demonstrated inadequate response to bDMARDs and subsequently initiated combination therapy with tofacitinib in conjunction with bDMARDs, assessing both the efficacy and safety profile of this therapeutic approach.MethodsIn this study, we retrospectively collected the electronic medical records (EMR) of 15 adult patients with AS who were admitted to the Fourth Affiliated Hospital Zhejiang University School of Medicine between January 2018 and June 2022. All patients had received at least one bDMARD treatment for more than three months and still exhibited moderate to high disease activity. Tofacitinib 5 mg bid was added to their original biological treatment. Treatment was continued for a minimum of 12 weeks following the initiation of combination therapy. Changes in ASDAS-CRP and BASDAI scores at week 12 were collected and analyzed from baseline, while changes in C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) at weeks 4, 8, and 12 were also collected and analyzed.ResultsAfter 12 weeks of treatment, the overall ASDAS-CRP score decreased significantly from a baseline of 3.82 ± 1.47 (2.83 ~ 4.99) to 1.47 ± 0.48 (0.75 ~ 2.44), with remission achieved by 7 patients (46.7%) and low disease activity achieved by 5 patients (33.3%). The overall BASDAI score also showed significant improvement, decreasing from a baseline of 5.11 ± 1.42 (3.25 ~ 7 0.75) to 1.28 ± 0.70(0.20 ~ 2.55). Additionally, both ESR and CRP levels decreased significantly during the course of treatment without any reported adverse events leading to discontinuation.ConclusionTo a certain extent, our findings provide some evidence supporting the efficacy and safety of the combination of bDMARD and JAK inhibitor tofacitinib in AS patients with inadequate response to bDMARD monotherapy. It effectively controls disease activity while maintaining a relatively low and manageable incidence of adverse events. Further prospective randomized controlled trials with large sample sizes are anticipated to provide evidence-based medical support.

Complete Blood Count, C-reactive Protein, and Erythrocyte Sedimentation Rate Changes in People with Brucellosis

Background: Brucellosis is a major health and economic problem in many parts of the world, including the Middle East. Blood disorders such as anemia, leukopenia, and thrombocytopenia can be seen in brucellosis. However, laboratory findings of this disease are different. Therefore, this study aimed to investigate the changes in complete blood count (CBC), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) in people with brucellosis in Gonabad community health centers.
 Methods: During the 4 years from May 2016 to May 2019, a prospective study was performed on 221 patients with brucellosis. According to the national guidelines for brucellosis, titers greater than 1/80 for Wright and more than 1/40 for 2-ME were considered positive cases of brucellosis. Using the checklist, information related to CBC, CRP, and ESR test parameters was collected.
 Results: The results showed that out of 221 patients studied, 58.4% were male and 41.6% were female. The mean age was 44.9±19.8 years for men and 49.3±17.3 years for females. High ESR was seen in 43.4% and positive CRP in 59.7% of patients. Leukopenia in 8.6%, leukocytosis in 9%, neutropenia in 6.8%, neutrophilia in 9.5%, lymphopenia in 3.6%, lymphocytosis in 10%, anemia in 17.2% and thrombocytopenia in 9.5% of patients were seen.
 Conclusion: Brucellosis in endemic areas should be considered in the differential diagnosis of patients presenting with thrombocytopenia. Also in high Wright titers, CRP is a more valuable indicator than ESR.

Investigation of the last two centuries sedimentation dynamics in high-altitude lakes of Southern Carpathians, Romania

This study investigates the last two centuries sedimentation dynamics in four high-altitude lakes located in Southern Carpathians, Romania. Furthermore, a novel approach is proposed for identifying the anthropic or natural underlying causes, by comparison of the acceleration of the change in sedimentation rate with a baseline growth rate trend provided by an isolated peat bog. The high-resolution chronologies were developed using the 210Pb dating technique and the CRS model. 137Cs alternative time-marker validated the age-depth models and reassured the quality of the results. The results indicated several short-interval high sedimentation events within the lake cores, yielding up to five times the average rate for the investigated period. The cause of the high sedimentation episodes was generally attributed to anthropic activities (primarily road construction) and extreme natural events. A first-order derivative equation was employed to plot the acceleration in the sedimentation rate of the lakes with the peat bog baseline. The discrepancies between the acceleration trends highlighted significant deviations from the natural variation tendencies and provided preliminary data regarding the underlying causes of the intense sedimentation periods.

100,000 years climatic cycles recorded on very high-resolution seismic data from the Santos Basin’s upper slope during the last 800 ka

This study proposes to combine seismic stratigraphic interpretation of very high-resolution sub-bottom chirp profiles acquired along the Santos Basin slope on the Southern Brazilian Margin during the SANBA project to recently published results from five continuous long cores acquired in the Santos Basin (sampling sediments as old as 772 ka with detailed biostratigraphic and chronostratigraphic data). The seismic-core correlation is consistent over the area and shows that 100,000 years cycles’ terminations (G/IG transitions, identified on long sediment cores) do correlate to strong seismic reflectors identified regionally on chirp profiles.In particular, the last eight 100,000 years cycles (down to MIS19) are well-identified throughout the area. Additional higher-resolution sea-level drops or cooling events (e.g., MIS4, MIS7b, MIS9b) can sometimes be distinguished on the chirp profiles but only in areas with sufficiently high sedimentation rates (around 10 cm/ka). At MIS12, we observe a change in seismic architecture with more numerous, more closely spaced seismic reflectors but with smaller amplitudes. According to the available data, this change also corresponds to a change in sedimentation rates (smaller rates before MIS12), which may be related to the mid-Brunhes Transition (at 430 ka) and/or the imprint of 400 ka Milankovitch cycles. Two cores show a specific Nanno Foram Ooze at this transition towards the following Super-interglacial MIS11. This study demonstrates the ability and the reliability of very high-resolution chirp profiles to record continuously the stacking of G/IG climatic cycles on the slope of the Santos Basin despite relatively low subsidence rates on this old passive margin and small direct input from rivers. Therefore, the study points to the continuous feeding of the margin by sediment brought up laterally by currents, most probably mainly Brazilian Current (BC) that follows the shelfbreak down to the South.

ALTERNATIVE RADIOCARBON AGE-DEPTH MODEL FROM LAKE BAIKAL SEDIMENT: IMPLICATION FOR PAST HYDROLOGICAL CHANGES FOR LAST GLACIAL TO THE HOLOCENE

ABSTRACT We present an alternative radiocarbon (14C) age-depth model using IntCal20 to calibrate new accelerator mass spectrometry (AMS) data applied to a Lake Baikal sediment core (VER99G12) in southern Siberia. 14C dating showed that the core extends to 31 ka. To take into account uncertainties in 14C age and sedimentation depth in the core, a new age-depth modeling routine, undatable, was used in this study. Undatable revealed that significant changes in sedimentation rate correspond to global climate events, either warm or cold, which periods are likely close to the timing of the occurrence of the Meltwater pulses (MWP) at 19 and 14 ka, and the Last glacial Maximum (LGM) at 21–20 ka. Since the Selenga River accounts for 50% of the total river inflow to Lake Baikal, we interpret that these changes in sedimentation rate could be signals of significant changes in Selenga River discharge to the lake, which is expected to be affected by global climate change. Based on pollen analysis, it is highly probable that the sudden influx of the Selenga River to Lake Baikal, particularly at 19 ka, was due to the thawing of permafrost water through the Selenga River, which had developed in the region. Total organic carbon content and mean grain size increases concurrent with sedimentation rate, suggesting river inflow increased available nutrients for biological activity. Our results indicate that hydrological changes corresponding to MWP events can be observed in continental areas of the Northern Hemisphere.

Redox-sensitive trace metal hyper-enrichment in Tremadocian Alum Shale (graptolite argillite) in northwestern Estonia, Baltic Palaeobasin

The Alum Shale Formation, a widespread metal-rich black shale in Baltoscandia, was deposited during the Cambrian–Ordovician transition. Given that it straddles a period of alternating extinction/recovery events following the Cambrian Explosion and prior to the Great Ordovician Biodiversification Event, the Alum Shale in Scandinavia has been extensively studied to assess the effect of oceanic redox variations on these biotic events. However, there is an on-going debate about the depositional environment and the prevailing redox state. An Early Ordovician (Tremadocian) equivalent of the Scandinavian Alum Shale, locally known as graptolite argillite, can be found in Estonia and NW Russia, in the easternmost extension of the ‘Alum Shale Sea’. In this contribution, we studied the redox-sensitive metal distribution and accumulation mechanisms in graptolite argillite successions in NW Estonia. Our aim was to provide better constraints on redox and depositional environments in the Baltic Palaeobasin. Our findings reveal that despite a consistent mineral and major elemental composition, V, Mo, Re and U contents vary systematically within the stratigraphy of the up to 7-m-thick black shale unit, with element contents reaching up to hyper-enrichment at the base (Mo > 200 mg/kg, U > 100 mg/kg and V > 1000 mg/kg) followed by a declining trend towards the upper part of the succession. This implies that temporal changes in redox conditions or sedimentation rates controlled trace element accumulation in the graptolite argillite. Although the redox-sensitive trace elements are hyper-enriched (particularly Mo), which has previously been interpreted to reflect euxinic depositional conditions, the V/Al vs. U/Al and V/Al vs. Mo/Al ratios indicate a non-euxinic anoxic depositional environment within a perennial oxygen minimum zone for the graptolite argillite. Further evidence of an unrestricted, relatively open marine depositional environment possibly influenced by upwelling is suggested by Cd/Mo and Co × Mn relationships. These results are supported by UEF and MoEF ratios that follow a seawater enrichment trend. The observed redox-sensitive element contents could be explained via diffusion-controlled uptake owing to the low sedimentation rates of the graptolite argillite (3–5 mm/kyr). These results highlight considerable redox variability within the Baltic Palaeobasin underscoring the need for a careful and critical reassessment of global redox interpretations based on Alum Shale data and emphasise the importance of using multiple independent redox and depositional environment proxies to determine palaeoredox conditions.

Formation and evolution of a loess sinkhole in the southern Chinese Loess Plateau

Sinkholes are formed by the collapse of the overlying strata or the subsidence of the ground from cracks or holes in the underlying strata, which are widely developed in the karst and loess regions over southern and northern China. These sinkholes have been explored intensively to infer their climatic and ecological significances, as well as the management of geological disasters. In this study we investigated the Sanyuan (SY) sinkhole in the southern Chinese Loess Plateau to understand how it was formed and evolved. Two 30-m cores were retrieved from the SY sinkhole and a detailed chronological framework was established by applying radionuclides dating for the top 1-m sediments as well as 14C dating for the two 30-m cores. These dating results show that SY sinkhole was formed 23.7 m below the sinkhole surface at ca. 6.0 kyr BP (before 1950 CE). Changes in lithology, sedimentation rate, magnetic susceptibility, lightness, and mean grain-size of these two cores reveal that the sinkhole has undergone two-stage evolution. The first stage was characterized by a relatively slow deposition of loess sediments during 6.0–1.9 kyr BP, and the second stage was a rapid accumulating period since 1.9 kyr BP likely affected by human activities. Our results suggest that SY sinkhole can well document the combined influence of climate change and human activities, offering an ideal archive to decipher the natural and anthropogenic imprints since the mid-Holocene.

Holocene millennial-scale variability of coastal environments on the southern coast of Korea and its controlling factors

AbstractCoastal evolution is influenced by past sea-level changes and resultant shifts from fluvial- to marine-dominant environments and the accompanying significant geochemical and isotopic changes in the water mass and sediments. We investigated the elemental and isotopic features of coastal sedimentary cores (27 m in length) from a small paleo-bay located on the southern coast of Korea to determine such geochemical variability and specify past changes in the bay environment and anoxic conditions and possible links to past climate changes. We analyzed total organic carbon (TOC), total sulfur (TS), their isotopes (δ13CTOC and δ34STS), and pyrite. The δ13CTOC values ranging from −25 to −19‰ (a proxy for terrestrial influence) were lower than average (−22.5‰) before 8300 cal yr BP and since 500 cal yr BP, while the intervening Early to Late Holocene showed higher δ13CTOC values, indicating a shallow coastal environment. The δ34STS values fluctuating between −35 and +5‰ resembled sedimentation rate change. Based on the changes in the ratios of TOC to TS (C/S ratios), sedimentation rate, and δ34STS, we found five possible periods with higher salinity and intensified anoxic conditions at millennial timescales: 8900–8200, 7950–6500, 5200–4300, 3500–2600, and 2000–1100 cal yr BP. These intensified anoxic conditions seem to have been influenced by increased air temperature and sea-surface temperature conditions, which could have intensified the intensity of thermal stratification (less ventilation and mixing) between surface and bottom waters and resultant anoxic conditions.

CREEK RESTORATION EFFECTS ON TIDAL DYNAMICS IN MANGROVES

Mangroves provide natural buffers between land and sea, protecting both coastal communities and nature as they attenuate waves and stabilize shorelines but also filter terrestrial runoff. Tropical mangroves are also biodiversity hotspots and provide other ecosystem services such as supporting fish and shellfish habitat, accommodating ecotourism and sequestering carbon. Nevertheless, mangrove coasts have become increasingly exposed to changing environmental conditions, a trend that has resulted in a declining mangrove cover on a global scale. At the protected Ramsar site of Lac Bay, Bonaire, large areas of mangroves have been subject to deterioration and tree mortality (Senger et al., 2021). Excessive sediment inputs from the land and mangrove growth have clogged existing creeks and reduced hydrodynamic circulation through the mangrove system. Resulting changes in sedimentation rates, submergence and water quality affect the survival of the inland mangroves in Lac Bay. The (re-)creation of suitable morphological and hydrodynamic conditions is key for mangrove restoration (Friess et al., 2019). This study investigates the potential of creek restoration to increase the hydrodynamic circulation in the mangroves of Lac Bay, thereby accommodating their survival.

A prospective observational cohort study of the efficacy of tofacitinib plus iguratimod on rheumatoid arthritis with usual interstitial pneumonia.

This study aims to assess the efficacy of tofacitinib (TOF) plus iguratimod (IGU) in rheumatoid arthritis (RA) with usual interstitial pneumonia (UIP) (RA-UIP). This was a prospective observational cohort, single-center study. Data from 78 RA-UIP patients treated with TOF plus IGU, IGU plus conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs), and csDMARDs were analyzed. Clinically relevant responses in RA activity assessment, pulmonary function tests (PFTs), and high-resolution computed tomography (HRCT) assessment at baseline and follow-up were compared between groups to evaluate the efficacy of TOF plus IGU. A total of 78 patients were followed up for at least 6 months after treatment. There were significant changes in sedimentation rate (ESR), C reactive protein (CRP), and disease activity score (DAS) 28-CRP during the follow-up within each treatment group, but there was no statistically significant difference between the two groups. After 6 months of TOF plus IGU treatment, forced vital capacity (FVC)% (84.7 ± 14.7 vs. 90.7 ± 15.4) and HRCT fibrosis score (7.3 ± 3.4 vs. 7.0 ± 5.6) showed a significant improvement compared to the csDMARDs group (P = 0.031, P = 0.015). The TOF plus IGU-treated patients had a significantly higher regression and lower deterioration than the csDMARDs-treated patients (P = 0.026, P = 0.026) and had a significantly higher response (regression + stability), with overall response rates of 66.7% (16/24) vs. 35.7% (10/28) (P = 0.027), respectively. Our results indicate that TOF plus IGU can simultaneously relieve RA and RA-UIP and be better than the csDMARDs with a higher response rate in RA-UIP, which may be a potential choice for "dual treat-to-target".

Clinical Implication and Prognostic Value of Artificial-Intelligence-Based Results of Chest Radiographs for Assessing Clinical Outcomes of COVID-19 Patients.

This study aimed to investigate the clinical implications and prognostic value of artificial intelligence (AI)-based results for chest radiographs (CXR) in coronavirus disease 2019 (COVID-19) patients. Patients who were admitted due to COVID-19 from September 2021 to March 2022 were retrospectively included. A commercial AI-based software was used to assess CXR data for consolidation and pleural effusion scores. Clinical data, including laboratory results, were analyzed for possible prognostic factors. Total O2 supply period, the last SpO2 result, and deterioration were evaluated as prognostic indicators of treatment outcome. Generalized linear mixed model and regression tests were used to examine the prognostic value of CXR results. Among a total of 228 patients (mean 59.9 ± 18.8 years old), consolidation scores had a significant association with erythrocyte sedimentation rate and C-reactive protein changes, and initial consolidation scores were associated with the last SpO2 result (estimate -0.018, p = 0.024). All consolidation scores during admission showed significant association with the total O2 supply period and the last SpO2 result. Early changing degree of consolidation score showed an association with deterioration (odds ratio 1.017, 95% confidence interval 1.005-1.03). In conclusion, AI-based CXR results for consolidation have potential prognostic value for predicting treatment outcomes in COVID-19 patients.

Chronostratigraphy elucidates environmental changes in lacustrine sedimentation rates and metal accumulation.

All changes taking place in a watershed have repercussions on lacustrine environments, being these, the sink of all activities occurring in the basin. Lake Titicaca, the world's highest and navigable lake, is not unfamiliar with these phenomena that can alter the sedimentation dynamics and metal accumulation. This study aimed to identify temporal trends of sedimentation rates by employing a geochronological analysis (210Pb, 137Cs) and to propose metal background values in Puno Bay, as well as to identify metal concentrations (As, Ba, Ca, Cr, Cu, K, Mg, Mo, Ni, Pb, Zn) in the projected timeline to propose, for the first time, background values in Puno Bay. Two sediment cores were collected from the outer and inner bays. Sediment rate (SR) was calculated through the excess of 210Pb (210Pbxs) applying the Constant Flux Constant Sedimentation (CFCS) model. Results show that SR in the outer bay was 0.48 ± 0.08 cm a-1 and for the inner bay was 0.64 ± 0.07 cm a-1. Sediment quality guidelines (SQGs) did not indicate toxicity was likely to occur, except for As. However, enrichment factors (EFs) indicated that all metal accumulation is geogenic. Climatic factors had a marked influence on sedimentation rates for the outer bay, and in the case of the inner bay, it was a sum of climatic and human-based factors.

The Chronology of Modern Sedimentation in the Storefjorden Strait (Svalbard Archipelago)

Periods of formation of different sedimentary lithotypes were determined using the results of the study of modern sedimentation processes in the Storefjorden Strait (West Spitsbergen). The chronology of sedimentation was established from variations in specific activity of 210Pb and 226Ra and verified by 137Cs data. Sedimentation rates have varied considerably over the last century in different parts of the sedimentation basin, ranging from 0.04 to 0.3 cm/yr. Sedimentation in the Storefjorden Strait was closely related to changing climatic conditions. Climatic factors (air temperature, atmospheric precipitation) have a different effect in morphologically different sections of the sedimentation basin. In the south of the strait, lithotypes are determined by an oceanological factor (bottom current). Despite the changes in sedimentation rate, the lithotype in the south of Storefjorden has remained stable for more than 100 years. In the north and in the central part of the strait, cooling in the period from 1970 to 1995 caused a change in the bottom sediment structure.

Can Low Intensity Strength Training Alone for Older Females Improve Cardiovascular and Functional Fitness?

BACKGROUND Maintaining muscle mass and an efficient cardiovascular system is vital for healthy aging.OBJECTIVES This study investigates if a low intensity senior strength exercise program for the older females can have an effect cardiovascular function and improve senior functional fitness.METHODS There were 22 older females, randomly divided into a strength exercise (age: 72.18 ± 4.97 yrs; height: 1.54 ± 0.06 m; weight: 58.02 ± 7.29 kg; BMI:24.43 ± 2.69 kg/m2) and control group (age: 77.63 ± 4.96 yrs; height: 1.51 ± 0.05 m; weight: 53.66 ± 6.62 kg; BMI:23.54 ± 2.22 kg/m2). The strength exercise group participated three times per week for 20 weeks, while the control group did not do any additional treatment or exercise. Participants were tested pre and post strength exercise, and the data were statistically analyzed using two-way repeated measures Analysis of Variance (ANOVA), with a significance level of p <0.05.RESULTS The results show significant differences (p<0.001) in homocysteine levels, with an interaction effect between time and group. There were no differences in changes in erythrocyte sedimentation rate between groups (p=0.050). There was an interaction effect (p<0.001) for the six components of the senior fitness test and between group and time in systolic blood pressure, diastolic blood pressure, heart rate, and pulse pressure.CONCLUSION In conclusion the results suggest that low intensity strength exercise program can improved cardiovascular fitness related variables, and homocysteine, as well as functional fitness, blood pressure, heart rate and pulse pressure.

A downcore increase in time averaging is the null expectation from the transit of death assemblages through a mixed layer

AbstractUnderstanding how time averaging changes during burial is essential for using Holocene and Anthropocene cores to analyze ecosystem change, given the many ways in which time averaging affects biodiversity measures. Here, we use transition-rate matrices to explore how the extent of time averaging changes downcore as shells transit through a taphonomically complex mixed layer into permanently buried historical layers: this is a null model, without any temporal changes in rates of sedimentation or bioturbation, to contrast with downcore patterns that might be produced by human activity. Assuming stochastic burial and exhumation movements of shells between increments within the mixed layer and stochastic disintegration within increments, we find that almost all combinations of net sedimentation, mixing, and disintegration produce a downcore increase in time averaging (interquartile range [IQR] of shell ages), this trend is typically associated with a decrease in kurtosis and skewness and by a shift from right-skewed to symmetrical age distributions. A downcore increase in time averaging is thus the null expectation wherever bioturbation generates an internally structured mixed layer (i.e., a surface, well-mixed layer is underlain by an incompletely mixed layer): under these conditions, shells are mixed throughout the entire mixed layer at a slower rate than they are buried below it by sedimentation. This downcore trend created by mixing is further amplified by the downcore decline in disintegration rate. We find that transition-rate matrices accurately reproduce the downcore changes in IQR, skewness, and kurtosis observed in bivalve assemblages from the southern California shelf. The right-skewed shell age-frequency distributions typical of surface death assemblages—the focus of most actualistic research—might be fossilized under exceptional conditions of episodic anoxia or sudden burial. However, such right-skewed assemblages will typically not survive transit through the surface mixed layer into subsurface historical layers: they are geologically transient. The deep-time fossil record will be dominated instead by the more time-averaged assemblages with weakly skewed age distributions that form in the lower parts of the mixed layer.