Late Part Research Articles

Structures and properties of the late pleistocene paleosols of the loess-soil section of Obi-Mazar (Tajikistan)

The loess-soil series of Central Asia cover the history of subaerial sedimentation of the last 2–2.5 mln years. Significant thicknesses, a large number of paleosols, and an impressive chronology place the loess-soil series of the Afghan-Tajik depression on a par with the famous sections of the Loess Plateau of China. The study of the most significant sections located within the Khovaling Loess Plateau makes it possible to develop a regional chronostratigraphic chart, to study the structure and conditions of formation of the main stratigraphic benchmarks–buried paleosols. The present study is devoted to the clarification of the structural features of loess and paleosols of the Late Pleistocene in one of the sections of the Khovaling–Obi-Mazar Plateau. Based on the results of stratigraphic dissection, description of the macro- and micromorphological structure, magnetic susceptibility analysis, study of the chemical and granulometric composition, a comprehensive description of the structure and properties was carried out and the most probable conditions for the formation of paleosols and loess were established. In the Late Pleistocene part of the section, two loess layers and a pedocomplex PC1 with three welded paleosols, consisting of a total of 7 horizons, are distinguished. The deposits are characterized by high silt content, carbon content, and the presence of signs of pedogenesis and biological activity in all layers of the studied section. Available data indicate the presence of a poorly developed MIS 3 paleosol in the upper loess layer. The developed pedocomplex PC1 of Obi-Mazar, according to its stratigraphic position, structural features, and magnetic susceptibility data, belongs to the MIS 5. According to preliminary data, its formation occurred in semi-humid and humid conditions under forest vegetation, which contributed to the biogenic segregation of Fe-Mn compounds, as well as intra- and interhorizon redistribution of carbonates due to diagenetic processes. Towards the end of the Last Interglacial, gradual aridization occurred, due to which the upper paleosol to be the least developed.

Late Paleozoic slab rollback events in the southeastern part of the Central Asian orogenic belt: Implications for Paleo-Asian Ocean subduction and continental crust growth

The Central Asian orogenic belt is considered to be the largest Phanerozoic accretive orogenic belt on Earth. The late Paleozoic magmatic rocks in central Inner Mongolia are crucial for understanding continental crust growth and the tectonic evolution of the southeastern part of the Central Asian orogenic belt. We present comprehensive geochemical, isotopic, and geochronological data from three late Paleozoic magmatic units in the Mandula area, west of the Solonker suture zone. Zircon U-Pb dating indicates that these rocks formed during the late Carboniferous (316−304 Ma). The Mandula high-Mg diorites exhibit high MgO (3.9−6.5 wt%), high Mg# (61−69), and depleted Nd-Hf isotopic compositions, generated through interaction between a metasomatized mantle and slab melts with the overlying sediments. The Mandula granodiorites display adakite geochemical characteristics with high Sr/Y mass ratios (29−52), high MgO (1.7−2.2 wt%), and high Mg# (52−54), formed by partial melting of the oceanic slab with the addition of overlying sediment. Mafic microgranular enclaves have consistent ages, Sr-Nd-Hf isotope compositions, and hornblende crystallization temperature-pressure conditions with their host granodiorite, formed from a cognate magma associated with the host granodiorites through cumulate. We propose that two phases of slab rollback took place during the late Paleozoic southward subduction-accretion of the Paleo-Asian Ocean. The first phase corresponded to the transformation of low- to medium-angle slab subduction, while the second phase led to subduction-related extension. Considering the tectonic-magmatic evolution, crustal maturity, and thickness variations in the late Paleozoic southeastern part of the Central Asian orogenic belt, we propose that prolonged subduction and slab rollback promoted continental crust growth. The Central Asian orogenic belt coincides temporally and spatially with the Phanerozoic Pangea cycle, suggesting that continuous subduction and supercontinent amalgamation significantly contributed to continental crust growth.

Electromagnetic Model of K‐Changes

AbstractK‐changes are observed as step‐like increases in the thundercloud electric fields. The K‐changes occur in the late part of intra‐cloud lightning or during negative cloud‐to‐ground lightning between return strokes. It has been shown that the processes leading to K‐changes initiate in the decayed part of a positive leader channel and propagate toward the flash origin. They are often accompanied by microsecond‐scale electric field pulses. We introduce a new model to simulate processes leading to the K‐changes in cloud‐to‐ground lightning. Our method is based on the full solution of Maxwell's equations coupled to Poisson's equation for the thundercloud charge structure. To model the K‐changes, we gradually increase the decayed channel conductivity. The modeled current wavefront propagates due to the K‐processes downward along a vertical channel and completely attenuates before reaching the ground. We derive the evolution of the linear charge densities and the scalar electric potential along the channel leading to K‐changes. We model electrostatic step‐like changes in the measured electric field together with the approximate rates and amplitudes of the microsecond scale pulses. Step‐like changes increase their amplitudes with the length of the simulated channel and with a higher conductivity of the channel. The microsecond‐scale pulse waveshapes depend mainly on the propagation velocity of the current wave, and the time scale of the conductivity increase. We show that our modeled waveforms are in a good agreement with observations conducted in Florida.

Endogenous pain modulation after sleep restriction in migraine: a blinded crossover study

BackgroundPatients with migraine are vulnerable to insufficient sleep, but the impact of sleep restriction is largely unknown. In addition, the importance of sleep may be different in patients with migraine who mostly have attack onsets during sleep, so called sleep-related migraine, compared to patients with non-sleep-related migraine. In this study we investigate the effect of sleep restriction on endogenous pain modulation in patients with migraine and healthy controls. We also compared the effect of sleep restriction in sleep-related and in non-sleep-related migraine.MethodsMeasurements were conducted in 39 patients with migraine between attacks and 31 controls, once after habitual sleep and once after two consecutive nights of partial sleep restriction. There were 29 and 10 patients with non-sleep-related and sleep-related migraine respectively. Test stimulus was 2-min tonic noxious heat to the left volar forearm. Temporal summation was calculated as the regression coefficient for rated pain in the late part of this 2-min stimulation. Conditioning stimulus was right hand-immersion in 7 °C water. Conditioned pain modulation was defined as the difference in rated pain with and without the conditioning stimulus and was calculated for temporal summation and mean rated pain for the test stimulus. The effect of sleep restriction on temporal summation and conditioned pain modulation was compared in migraine subjects and controls using two-level models with recordings nested in subjects.ResultsConditioned pain modulation for temporal summation of heat pain tended to be reduced after sleep restriction in patients with migraine compared to controls (p = 0.060) and, in an exploratory analysis, was reduced more after sleep restriction in sleep-related than in non-sleep-related migraine (p = 0.017). No other differences between groups after sleep restriction were found for temporal summation or conditioned pain modulation.ConclusionPatients with migraine may have a subtly altered endogenous pain modulation system. Sleep restriction may have an increased pronociceptive effect on this system, suggesting a mechanism for vulnerability to insufficient sleep in migraine. This effect seems to be larger in sleep-related migraine than in non-sleep-related migraine.

Stratigraphic overview of the Neogene Transylvanian Basin, Romania

Although the Transylvanian Basin is often referred as part of the Miocene Pannonian Basin System, we point out important tectonic and sedimentary differences reflected in the stratigraphy. The Neogene of the Transylvanian Basin can be split into two tectonic megasequences: Lower Miocene and Middle to Upper Miocene. The Early Miocene onset of the back arc extension in the Pannonian Basin was not observed in the Transylvanian Basin, where shallow to deep marine sediments were deposited in a flexural basin. Diverse types of facies developed in the continental (e.g., Sânmihai) and marine (e.g., Coruş, Chechiş, Hida) Lower Miocene formations. Although these are poorly constrained to the standard biostratigraphy, recent 87 Sr- 86 Sr data support their limited correlation with the Burdigalian. The Middle Miocene extension in the Transylvanian Basin is very weak compared to that the Pannonian Basin. As the high-resolution Middle Miocene regional biostratigraphy of the Badenian and Sarmatian was calibrated by magnetostratigraphy and radiometric dating of the volcanic tuffs up to the Serravallian/Tortonian boundary, the influence of the regional tectonics on the basin's evolution and stratigraphy can be better understood. The regional tectonics produced a progressive basin isolation starting with the late part of the Middle Miocene. The uplift of the Carpathians isolated the basin at the beginning of the Pannonian and initiated the fan delta, lacustrine, and fluvial sedimentation. The basin was rapidly uplifted and eroded, while post-extensional subsidence was still ongoing in the Pannonian Basin. Endemic fossil assemblages allow only regional-scale correlations for this interval. The uppermost part of the stratigraphic record is represented by the volcano-sedimentary formations generated by the late evolution of the Eastern Carpathians. The sedimentation and subsidence pattern of the Transylvanian Basin reflect the effect of retreating subduction zone in the Eastern Carpathians.

Treasury auction method and underpricing: Evidence from Iceland

AbstractThe Central Bank of Iceland replaced the discriminatory method used for auctioning treasury securities with the uniform‐price method in 2009. We analyze underpricing before and after this institutional reform with a sample of 516 auctions organized from 2000 to 2018. After controlling for auction characteristics and financial market conditions, we find that underpricing is lower under the uniform‐price method. However, this underpricing decline does not translate into a reduction in sovereign issuance cost. The emergence of overpricing, observed in the late part of our sample, coincides with the growing importance of commissions paid to primary dealers. Our results provide practical implications for governments, regulators, and market participants.

Verbal Support From a Stranger Reduces the Development of Mechanical Hypersensitivity: Behavioral and Neurophysiological Evidence

Hand-holding reduces experimentally induced acute pain and buffers against the development of mechanical secondary hypersensitivity, an indirect proxy of central sensitization. Here, we tested if verbal support from a stranger, a common occurrence in clinical contexts, exerts the same effects. In this preregistered study, 44 healthy female participants were assigned to an alone or support group whereby a supportive female stranger encouraged them through the painful procedure leading to secondary mechanical hypersensitivity. Mechanical hypersensitivity was measured via self-reports and by the size of the anteroposterior and mediolateral spread of mechanical hypersensitivity. We investigated the moderating role of attachment style on self-reports and the effects of support on skin conductance level, salivary cortisol, and pinprick-evoked potentials. We also tested whether theta/beta ratio in the resting-state electroencephalogram predicted mechanical hypersensitivity. Self-reported ratings and the late part of the pinprick-evoked potentials were reduced in the support group, but the spread of mechanical hypersensitivity was not. Attachment anxiety and avoidance moderated the self-reported intensity such that individuals with higher attachment anxiety and avoidance scores reported lower intensity ratings in the support group. No significant effect of the verbal support was observed on skin conductance level and salivary cortisol. The theta/beta ratio did not predict the extent of hypersensitivity. Our data indicate that, in women, verbal support during intense pain leading to hypersensitivity is effective on some behavioral outcomes, but altogether the lack of group differences in cortisol, self-reported stress, and skin conductance does not provide strong support for the stress-buffering hypothesis. PerspectiveVerbal support by a stranger during a painful procedure leading to secondary mechanical hypersensitivity attenuated the development of some measures of mechanical hypersensitivity and associated neural responses in healthy female participants. No evidence was found for the role of stress. Data AvailabilityThe authors will make all data available upon request.

Mazovian Interglacial sites in the Sosnowica Depression and the Parczew-Kodeń Heights (Western Polesie, SE Poland), and their stratigraphic, palaeogeographic and palaeoenvironmental significance

We describe the geological context of the Pleistocene strata in the Sosnowica Depression and the Parczew-Kodeń Heights, as well as the main geological processes taking place in that area during the Middle Pleistocene. The stratigraphy of the Pleistocene succession is based on the analysis of new sites with Mazovian Interglacial deposits (MIS 11c) with age determinations obtained from palaeobotanical and palaeofaunal proxies, at Zahajki, Wygnanka, and Sytyta in the Sosnowica Depression, and Podedwórze and Gęś 3 in the Parczew-Kodeń Heights. The interglacial deposits documented occur in the direct subsurface and are not overlain by glacial deposits, which indicates that the study area was not covered by the ice-sheet of the Middle Polish Glaciations (Saalian, MIS 6). They are overlain by Early Liviecian (Fuhne, MIS 11b) lacustrine and bog deposits, or upper Vistulian (MIS 2) clastic and bog deposits. Holocene strata lie above. Therefore, the glacial deposits building the Parczew-Kodeń Heights are considered to derive from the Sanian 2 (Elsterian, MIS 12) Glaciation and not from the Saalian (MIS 6) Glaciation as previously thought. Palaeolakes formed in the late part of the Sanian 2 (Elsterian, MIS 12) Glaciation and remained open during the Mazovian Interglacial (Holsteinian, MIS 11c), with some still existing until the Early Liviecian (Fuhne, MIS 11b) Glaciation. The palaeolakes described were part of an extensive palaeolakeland of the Mazovian Interglacial, stretching from the southern part of Podlasie to the northern part of Western Polesie. The last ice-sheet in Western Polesie represented the Sanian 2 Glaciation. Downloads pdf Published 2024-07-20 — Updated on 2024-07-23 Issue Vol. 68 No. 2 (2024) Section Articles License Authors who publish with this journal agree to the following terms: Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal. Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal. Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as this can lead to productive exchanges and earlier and more frequent citation of the published work (See The Effect of Open Access).

Seismic attenuation and stress on the San Andreas Fault at Parkfield: are we critical yet?

The Parkfield transitional segment of the San Andreas Fault (SAF) is characterized by the production of frequent quasi-periodical M6 events that break the very same asperity. The last Parkfield mainshock occurred on 28 September 2004, 38 years after the 1966 earthquake, and after the segment showed a ∼22 years average recurrence time. The main reason for the much longer interevent period between the last two earthquakes is thought to be the reduction of the Coulomb stress from the M6.5 Coalinga earthquake of 2 May 1983, and the M6 Nuñez events of June 11th and 22 July 1983. Plausibly, the transitional segment of the SAF at Parkfield is now in the late part of its seismic cycle and current observations may all be relative to a state of stress close to criticality. However, the behavior of the attenuation parameter in the last few years seems substantially different from the one that characterized the years prior to the 2004 mainshock. A few questions arise: (i) Does a detectable preparation phase for the Parkfield mainshocks exist, and is it the same for all events? (ii) How dynamically/kinematically similar are the quasi-periodic occurrences of the Parkfield mainshocks? (iii) Are some dynamic/kinematic characteristics of the next mainshock predictable from the analysis of current data? (e.g., do we expect the epicenter of the next failure to be co-located to that of 2004?) (iv) Should we expect the duration of the current interseismic period to be close to the 22-year “undisturbed” average value? We respond to the questions listed above by analyzing the non-geometric attenuation of direct S-waves along the transitional segment of the SAF at Parkfield, in the close vicinity of the fault plane, between January 2001 and November 2023. Of particular interest is the preparatory behavior of the attenuation parameter as the 2004 mainshock approached, on both sides of the SAF. We also show that the non-volcanic tremor activity modulates the seismic attenuation in the area, and possibly the seismicity along the Parkfield fault segment, including the occurrence of the mainshocks.

Condition monitoring of wind turbine faults: Modeling and savings

This paper presents a case study on condition monitoring of power generators at offshore wind turbines. Two fault detection models are proposed for detecting sudden changes in the sensed value of metallic debris at the generator. The first model uses an exponentially weighted moving average, while the second monitors first-order derivatives using a fixed threshold. This is expected to improve the maintenance activities by avoiding late or early part replacement. The economic impact of the proposed approach is also provided with a realistic depiction of the cost structure associated with the corresponding maintenance plan. While the specifics of the case study are supported by real-life data, considering the prevalence of the use of generators not only in offshore wind turbines but also in other production environments, we believe the case study covered in this paper can be used as a blueprint for similar studies in other applications.

Sideritis royoi (Lamiaceae): A New Orophilous Species from Northeastern Spain

Sideritis royoi is found in the rocky limestone habitats of the Port Massif (southern Catalonia, Spain). The species was first collected by the local botanist Lluís de Torres in the late part of the 20th century, but the specimens have remained unidentified positively in herbaria for over 40 years. Sideritis royoi likely belongs to section Sideritis subsection Hyssopifoliae and shows some morphological affinities with the relatively widespread South European species S. hyssopifolia L., but it differs from this species because it has subspinescent upper leaves, the main surfaces of its leaves are glabrous or glabrescent, the main abaxial surface of its bracts is without eglandular hairs, and due to the fact that it has shorter inflorescences. Weaker similarities have also been observed with some species belonging to S. subsection Fruticulosae Obón & D.Rivera. In this paper, a description for the new orophilous species is provided, along with a detailed illustration, field photographs, and a comparison with closely related species. We include an assessment of its conservation status and a dichotomous key for the identification of all the species of Sideritis subsection Hyssopifoliae.

Early Neolithic settlers on the border of the loess of Eastern Poland: new data from the Nałęczów Plateau

This article is an interim presentation of the colonisation of the loess upland border of the western Lublin Regionby LBK societies. The main point of reference are materials discovered in Bogucin (Nałęczów Plateau) in 2011,which are currently the only homogenous Early Neolithic collection from this region. The results of the research indicate that the LBK settlement on the loess borderland started at least at the end of the 6th millennium BC, in the classical stage of the Music-Note phase (NII). It clearly intensified during its latest part (NIII), which was linked with the adaptation of the early-Želiezovce ornamentation style. The obtained data confirms the existence of at least two settlement micro-regions in the discussed period. They dynamically developed through intense and far-reaching interregional contacts and exchange of goods (especially flints and flint artefacts). The initial territories of the LBK societies inhabiting the analysed loess borderland were most probably the areas of the northern foreland of the Sandomierz Upland.

A Review of Pollen Counting Networks: From the Nineteenth Century into the Twenty-first Century.

Pollen is enormously important to the human experience. As pollen became germane to human health in the late nineteenth century, methods for pollen collection and measurement were developed. Techniques were standardized and pollen counting networks were established in many parts of the world during the middle to late part of the twentieth century. With some notable exceptions, the technology of the 1950s and 1960s is presently employed to create the current pollen counting networks. Pollen counting networks in the past faced substantial challenges. Pollen counting networks using the same technology as the past face the same challenges. As we move into the twenty-first century, automated pollen counting technology enables pollen counting networks to be robust, available, scalable, self-perpetuating, and able to meet modern demands. Automated pollen measurement networks present a promising path towards a more informed, data-driven, and effective approach to managing allergens, improving crop yields, and minimizing human suffering caused by pollen. By empowering individuals with comprehensive pollen data, a feat not possible with manual counting, we can help people make informed decisions and take proactive measures to minimize exposure to allergens and improve their well-being.

Inducing Evapotranspiration Reduction in an Engineered Natural System to Manage Saltcedar in Riparian Areas of Arid Environments

Many management practices have been implemented to control non-native saltcedar (Tamarix spp.) in the Southwestern U.S. riparian areas. These management practices include herbicide application, mechanical and biological control. Despite these methods have had some success, they are not cost-efficient and some cases not easy to apply and can create environmental harm. In this study, we use a different approach where the mowing of saltcedar is timed according to the trend of evapotranspiration (ET) rates. The approach suppresses saltcedar growth, reduces ET loss, allows native vegetation to flourish, and eventually creates a healthy and diverse plant community in riparian areas. In an experimental study from 2010–2013, saltcedar was managed by mowing in a managed riparian area in New Mexico, USA. The timing of mowing was based on the observation of ET rates which were measured using the eddy covariance method. Normalized Difference Vegetation Index (NDVI) was calculated using Landsat imagery to observe any changes in vegetation of saltcedar before and after mowing and its correlation with ET. During the four years of measurement, it was observed that the timing of mowing led to a suppression of saltcedar, allowing the undergrowth of low water-consuming native grasses and other shrubs to thrive. Nonlinear mixed effects models of years of evapotranspiration during the season showed a significant reduction in ET in 2013 compared to the baseline year of 2010 across the growing stages, especially stage 2 (intercept of −2.0871 with p < 0.001). A reduction in ET of 32% from 1209 mm to 818 mm (difference of 391 mm) was observed between 2010 and 2013. This study showed that the best time to suppress saltcedar and allow native plants to reestablish, is to mow it before it breaks dormancy, at the peak and late parts of the growing season. Mowing can be discontinued once the native plants have been established.

Core clock gene, Bmal1, is required for optimal second-level interval production

ABSTRACT Perception and production of second-level temporal intervals are critical in several behavioral and cognitive processes, including adaptive anticipation, motor control, and social communication. These processes are impaired in several neurological and psychological disorders, such as Parkinson’s disease and attention-deficit hyperactivity disorder. Although evidence indicates that second-level interval timing exhibit circadian patterns, it remains unclear whether the core clock machinery controls the circadian pattern of interval timing. To investigate the role of core clock molecules in interval timing capacity, we devised a behavioral assay called the interval timing task to examine prospective motor interval timing ability. In this task, the mouse produces two separate nose pokes in a pretrained second-level interval to obtain a sucrose solution as a reward. We discovered that interval perception in wild-type mice displayed a circadian pattern, with the best performance observed during the late active phase. To investigate whether the core molecular clock is involved in the circadian control of interval timing, we employed Bmal1 knockout mice (BKO) in the interval timing task. The interval production of BKO did not display any difference between early and late active phase, without reaching the optimal interval production level observed in wild-type. In summary, we report that the core clock gene Bmal1 is required for the optimal performance of prospective motor timing typically observed during the late part of the active period.

Revealing hot tear formation dynamics in Al–Cu alloys with X-ray radiography

Hot tears can arise during the late part of alloy solidification because of the shrinkage of isolated liquid as it turns to solid and may have a catastrophic effect on cast tensile properties. Although there are correlations to suggest alloy hot tear sensitivity to casting conditions, they do not capture the influence of microstructure on tearing, such as second-phase particles or intermetallic compounds (IMCs) commonly present in engineering alloys. We use in situ X-ray radiography to quantify the formation and growth behaviour of hot tears in Al-5Cu and Al-5Cu-1Fe alloys during solidification. An automated hot tear detection, tracking and merging algorithm is developed and applied to reveal the role of Fe-rich IMC particles, typical of recycled alloys, on hot tear behaviour. These defects are termed hot tears here on the basis of their complex, extended inter-connected morphology, distinct from more rounded shrinkage porosity. We also visualise and quantify the velocity of interdendritic flow driven by solidification shrinkage, and estimate the pressure changes due to shrinkage. Hot tearing starts at lower solid fraction when IMCs are present due to reduced interdendritic flow, and hot tear formation is more spatially homogeneous, less clustered and more numerous. We show that the largest, most damaging hot tears form from many merging events, that is enhanced by the presence of IMCs.

OR30-03 High Resolution Daily Profiles Of Tissue Adrenal Steroids By Portable Automated Collection

Abstract Disclosure: T. Upton: None. E. Zavala: None. P. Methlie: None. M. Oksnes: None. M.A. Grytaas: None. K. Simunkova: None. S. Bensing: None. I. Botusan: None. K. Berinder: None. D.A. Vassiliadi: None. O. Kampe: None. S. Tsagarakis: None. E.S. Husebye: None. G.M. Russell: None. S.L. Lightman: None. Background: Rhythms are intrinsic to endocrine systems, and disruption of these hormone oscillations occurs at very early stages of disease. Since adrenal hormones are secreted with both circadian and ultradian periods, conventional single time point measures provide limited information about rhythmicity, and crucially do not provide information during sleep when many hormones fluctuate from nadir to peak concentrations. If blood sampling is attempted overnight this necessitates admission to a clinical research unit, can be stressful and disturbs normal sleep. Aim: To obtain automated ambulatory 24-hour profiles of adrenal steroids in healthy human subcutaneous tissue to characterize healthy variability without blood sampling. Methods: We used microdialysis, an ambulatory fraction collector and liquid-chromatography mass-spectrometry to obtain 72-point profiles of tissue free adrenal steroids over 24 hours in n=214 healthy volunteers. For validation, we compared tissue against plasma measurements in n=7 inpatient healthy volunteers. We used stationery statistics, time series analyses, and mathematical methods to characterise interindividual and intraindividual variability of these hormones at different times of the day. Results: There were no serious adverse events, and the method was well tolerated, allowing almost all normal activities to continue. In addition to cortisol, we identified daily and ultradian variation in free cortisone, corticosterone, 18-OHF, aldosterone, THF, and aTHF. Rhythmic hormones were highly correlated when measured across the day, especially cortisol with 18OHF (rs = 0.99), cortisol with cortisone (rs = 0.96) and cortisol and 18-OHF with corticosterone (rs = 0.96-0.97). There was a very strong correlation between mean values of cortisol and 18OHF with aldosterone (rs = 0.91-0.93), but aldosterone profiles were characterized by high interindividual variability. Tissue 18-OHF was the most highly correlated with plasma cortisol (rs 0.89, range 0.74—0.97, p<0.001), and 18-OHF phase was advanced with respect to tissue cortisol. The ratio of tissue cortisol:cortisone exhibited a stronger daily rhythm than in plasma, with cortisol concentrations often falling below cortisone in the late afternoon and early part of sleep.Using the data, we computed mathematically defined metrics (“dynamic biomarkers”) stratified by sex, age, and BMI to quantify individual variability of hormone rhythms. Provisional analysis suggests no evidence for an effect of sex on cortisol or 18OHF, but evidence for a small effect of BMI on total 24-hour cortisol, 18OHF, corticosterone, and aldosterone. Conclusions: These data provide, for the first time, an insight into the dynamics of adrenal steroids in tissue in real world setting and will serve normative reference data for establishing novel and improved biomarkers of endocrine disease. Presentation: Sunday, June 18, 2023

A new species of Iochroma Benth. (Solanaceae) from the eastern Andes of Colombia.

Iochromaorozcoae A.Orejuela & S.D.Sm., sp. nov. (Solanaceae) is described from the Andean forests of Cundinamarca in the eastern cordillera of Colombia. Iochromaorozcoae was first collected by the eminent Spanish priest and botanist José Celestino Mutis in the late part of the 18th century, but the specimens have lain unrecognised in herbaria for over 200 years. The species shares many features with its closest relative, Iochromabaumii S.D.Sm. & S.Leiva, but it differs from it in having small flowers with five corolla lobes and few inflorescences per branch, located near the shoot apex with 1 to 4 (-8) flowers, fruits that are greenish-yellow when ripe and its restricted geographic distribution. A description of I.orozcoae is provided, along with a detailed illustration, photographs of live plants, a comparison with closely-related species and a key to all Colombian species of Iochroma Benth. In closing, we emphasise the value of historical collections for the knowledge of biodiversity.

Improved Prediction of Aquatic Beetle Diversity in a Stagnant Pool by a One-Dimensional Convolutional Neural Network Using Variational Autoencoder Generative Adversarial Network-Generated Data

Building a reasonable model for predicting biodiversity using limited data is challenging. Expanding limited experimental data using a variational autoencoder generative adversarial network (VAEGAN) to improve biodiversity predictions for a region is a new strategy. Aquatic beetle diversity in a large >30-year-old artificial pool that had not had human interference in Nanshe Village (Dapeng Peninsula, Shenzhen City, Guangdong Province, China) was investigated. Eight ecological factors were considered. These were water temperature, salinity, pH, water depth, proportional area of aquatic plants, proportional area of submerged plants, water area, and water level. Field sampling was performed for 1 or 2 days in the middle or late part of each month for a year. A type D net was swept 10 times in the same direction in each ~1 m × ~1 m sample square, generating 132 datasets (experimental data). In total, 39 aquatic beetle species were collected, 19 of which were assigned to Hydrophilidae, 16 to Dytiscidae, 3 to Noteridae, and 1 to Gyrinidae. A one-dimensional convolutional neural network (1-D CNN) was used to assess and predict the grade of the number of individuals and the number of aquatic beetle species. The Bayesian-optimized 1-D CNN established using 112 experimental datasets as the training set and the other 20 datasets as validation and testing sets gave a 74.0% prediction accuracy for the grade of the number of individuals and a 70.0% prediction accuracy for the number of species. The impact of insufficient sample data on the model was assessed using a VAEGAN to expand the training set from 112 to 512 samples, and then the Bayesian-optimized 1-D CNN-based VAEGAN prediction model was re-established. This improved prediction accuracy for the grade of the number of individuals to 86.0% and for the number of species to 85.0%. The grade of the number of individuals’ prediction accuracy was 88.0% and the number of species’ prediction accuracy was 85.0% when the random effects of only obtaining a single individual of a species were excluded. The results indicated that the accuracy of the 1-D CNN in predicting the aquatic beetle species number and abundance from relevant environmental factors can be improved using a VAEGAN to expand the experimental data.

No Difference in the Prevalence of HIV-1 gag Cytotoxic T-Lymphocyte-Associated Escape Mutations in Viral Sequences from Early and Late Parts of the HIV-1 Subtype C Pandemic in Botswana.

HIV is known to accumulate escape mutations in the gag gene in response to the immune response from cytotoxic T lymphocytes (CTLs). These mutations can occur within an individual as well as at a population level. The population of Botswana exhibits a high prevalence of HLA*B57 and HLA*B58, which are associated with effective immune control of HIV. In this retrospective cross-sectional investigation, HIV-1 gag gene sequences were analyzed from recently infected participants across two time periods which were 10 years apart: the early time point (ETP) and late time point (LTP). The prevalence of CTL escape mutations was relatively similar between the two time points-ETP (10.6%) and LTP (9.7%). The P17 protein had the most mutations (9.4%) out of the 36 mutations that were identified. Three mutations (A83T, K18R, Y79H) in P17 and T190A in P24 were unique to the ETP sequences at a prevalence of 2.4%, 4.9%, 7.3%, and 5%, respectively. Mutations unique to the LTP sequences were all in the P24 protein, including T190V (3%), E177D (6%), R264K (3%), G248D (1%), and M228L (11%). Mutation K331R was statistically higher in the ETP (10%) compared to the LTP (1%) sequences (p < 0.01), while H219Q was higher in the LTP (21%) compared to the ETP (5%) (p < 0.01). Phylogenetically, the gag sequences clustered dependently on the time points. We observed a slower adaptation of HIV-1C to CTL immune pressure at a population level in Botswana. These insights into the genetic diversity and sequence clustering of HIV-1C can aid in the design of future vaccine strategies.