A multiproxy-based reconstruction of the mid- to late Holocene paleoenvironment in the Laptev Sea off the Lena River Delta (Siberian Arctic)

Highlights • Land-shelf interactions in vicinity to the Lena River delta since 6 cal. ka. • Arctic tundra and taiga zones drained by the Lena River form shelf pollen assemblages. • Warmer-than-present climatic conditions 6–4.5 cal. ka and subsequent gradual cooling. • Estuarine-like reversed (N to S) bottom current activity along submarine paleovalleys. • Principal diversion of the major Lena River outflows to the east since 0.5 cal. ka. Abstract Land-shelf interactions and related environmental changes were reconstructed for the past 6 cal. kyrs interpreting multiproxy records from the two AMS14C-dated sediment cores from the sites located to the north and northeast of the Lena River delta. Proxies used include terrestrial and aquatic palynomorphs, benthic/planktic foraminifers and ostracods paired with benthic δ18O and δ13C records of Haynesina orbiculare. The study focused on unravelling the relation between river runoff and the regional climate changes on the one hand, and its imprint on the shelf sea environment on timescales beyond the instrumental records on the other. The palynomorph records show that the Lena River outflow largely determined the composition of species associations and the magnitude of terrestrial matter influx from land. Pollen assemblages of the inner Laptev Sea shelf reflect complex pollen contribution of the Arctic tundra and remote taiga zones drained by the Lena River and indicate a vegetation response to warmer-than-present climatic conditions between 6.0 and 4.5 cal. ka and a subsequent gradual cooling. Fluvial influence in the records is manifested by (1) increases in sedimentation rates; (2) high influxes of pollen/spores and freshwater chlorophycean algae, wood and plant remains; (3) negative δ13C excursions due to the introduction of dissolved inorganic carbon (DIC) from river water. Episodes of enhanced freshwater influence in the surface water layers (fluvial events) correlate with positive benthic δ18O excursions and increasing representation of river-distal species among benthics. Altogether, this points to an estuarine-like reversed (north to south) bottom current activity along the submarine paleovalleys on the shelf. The most pronounced fluvial events are recognized at 5.3–5.9, 1.5 and <0.5 cal. ka. The oldest fluvial event coincides with the final stage of mid-Holocene climate warming. A fluvial event at 1.5 cal. ka is specifically strong at the northeastern site thus marking a direction change of the Lena River outflow at this time and the progressive protrusion of the delta. During the past 500 years distinct negative δ13C values at the northeastern site reflect enhanced riverine influence. It is therefore concluded that the unprecedented change in the δ13C trend corroborates the other evidence for a principal diversion of the major Lena River outflows into its present-day, easterly direction

Gelatin/carboxymethyl cellulose mucoadhesive films with lysozyme: Development and characterization

The goal of our study is to develop and characterize mucoadhesive films with entrapped lysozyme based on gelatin/sodium carboxymethyl cellulose as perspective antimicrobial preparation. Lysozyme in mucoadhesive films retains more than 95 % of its initial activity for 3 years of storage. Different physical-chemical and biochemical characteristics of entrapped enzyme were evaluated, such as film thickness, weight, time of dissolution in water, bioadhesive force, in vitro lysozyme release, pH- and thermoprofiles of hydrolytic activity, effect of γ-sterilization, etc. We have shown that gelatin/sodium carboxymethyl cellulose films have adhesive force on the level of 4380 Pa. Scanning electron microscopy images shows the relative uniformity of the gelatin surface with entrapped lysozyme. Mucoadhesive films with lysozyme have 100% bactericidal effect on the test strain, Staphylococcus aureus ATCC 25923 F - 49 and thus could be considered as a perspective antimicrobial preparation

Boreal (Eemian) Transgression in the Northeastern White Sea Region: Multiproxy Evidence from Bychye-2 Section

Reconstructing interglacial marine environments helps us understand the climate change mechanisms of the past. To contribute to this body of knowledge, we studied a high-resolution 455 cm-thick sediment sequence of the Boreal (Eemian) marine beds directly overlying Moscovian (Saalian) moraine in the Bychye-2 section on the Pyoza River. We analyzed lithological and microfossil (foraminifers, ostracods, pollen, aquatic palynomorphs) variations at the studied site. Stratigraphical zonation is based on the local and well-established regional pollen zones, correlated with the western European pollen zones. The studied marine beds accumulated from the end of the Moscovian glacial (&gt;131 ka) until ca. 119.5 ka. We distinguished three successive phases: a seasonally sea-ice-covered, relatively deep, freshened basin in the initial rapid flooding stage (&gt;131–130.5 ka); a deep basin in the maximum flooding phase with less extensive sea ice cover (130.5–130.25 ka); and a shallow basin with reduced sea ice cover (130.25–119.5 ka). According to a pollen zone comparison with other sites, the regional glacioisostatic rebound started ca. 130 ka. The diverse warm-water assemblages of benthic foraminifers and ostracods containing typical Baltic Sea species occurred during the regression, mainly 128–124 ka, thus giving evidence for a relatively long-lasting connection between the White and Baltic Seas.</jats:p

Last postglacial environmental evolution of the Laptev Sea shelf as reflected in molluscan, ostracodal and foraminiferal faunas

Temporal and spatial variations in the species composition of modern and Holocene assemblages of molluscs, ostracods, and foraminifers from the Laptev Sea shelf (Arctic Siberia) have been investigated to reconstruct palaeoenvironmental changes during the last postglacial times and associated sea-level rise. Analysis of coretop sediment samples allowed to distinguish four modern assemblages. The specific habitat preferences of these species groups, such as water depth and salinity, were then used to interpret past environmental changes on the basis of two radiocarbon-dated sediment cores from the eastern middle shelf region, i.e., obtained from the Yana (51 m water depth) and Lena (45 m water depth) palaeovalleys. Despite the water depth difference of the two core sites, all downcore data document uniform fossil evidence for a gradual transformation of the Laptev Sea shelf from a terrestrial to a marine environment due to the southward transgressing sea. Three major phases have been recognized. These reflect: (1) a nearshore brackish-water environment of the initial stage of inundation (11.3–11.1 in the Yana and 11.2–10.8 cal. ka in the Lena palaeovalley); (2) a shallow inner-shelf, fluvially affected environment (11.1–10.3 and 10.8–8.2 cal. ka); (3) a modern-like marine environment which eventually became established since 10.8 and 8.2 cal. ka, depending on the specific water depth of each core site

Forecasting of the number of air passengers in the United States in terms of the maintenance of economic security during the impact of COVID-19

The purpose of the study is to forecast the number of passengers transported by air in the United States for 2021-2022. The forecast is preceded by a multidimensional comparative analysis of the number of passengers transported by air in the United States from 1 January 2019 to 2 November 2021. To achieve this goal, the data were grouped as dependent variables: years, months-years. The observed similarities, the analysis and evaluation of the literature as well as the own experience made it possible to forecast primary data for the future. The obtained results show a growing trend in the number of passengers transported by air in the United States. The forecast for 3 November 2021 to 31 December 2022 is 837 459 877 prospective air passengers in the United States. The standard deviation of the obtained forecast was 255 680,3, the arithmetic mean was 1 975 141 passengers and the median was 1 998 478 passengers. The observed similar trends in the identical months of July-October in 2019 and 2021 as well as the analysis of the literature and the own experience allowed for the selection of a method for the forecasting of the number of passengers transported by air in the United States for the future. The detected regularities as recurring trends in the number of air passengers transported in the United States on a dynamic basis may be used to forecast them for the future

Doctor: Why Has Her Urine Turned Purple?

We present the case of an elderly woman with long-term indwelling urinary catheter use whose urine turned purple due to a urinary tract infection

Gastroesophageal reflux disease: risk factors, current possibilities of diagnosis and treatment optimisation

Gastroesophageal reflux disease (GERD) is one of the most common causes of health care seeking at the primary care level in many countries. At an epidemiological level, GERD has been shown to be associated with a number of risk factors: obesity, tobacco smoking, alcohol abuse, certain patterns of eating behaviour, and the use of several medications. GERD is now regarded as a heterogeneous disease and includes different phenotypes (erosive reflux disease, non-erosive reflux disease, hypersensitive oesophagus, functional heartburn), the proper diagnosis of which improves the effectiveness of therapy in patients with heartburn symptoms. Daily impedance–pH monitoring is known to be an integral part of the diagnostic algorithm for GERD and is a functional diagnostic method to record all types of refluxes entering the oesophagus regardless of pH, to assess their association with symptoms, and to determine whether patients with heartburn symptoms belong to a particular phenotype. Esophageal manometry plays a key role in the evaluation of patients with heartburn symptoms, as it helps to rule out other conditions that may mimic GERD: achalasia cardia and scleroderma esophagus. This technique is used to assess thoracic esophageal motility and sphincter function and in the assessment of patients prior to antireflux surgery or in the refractory course of GERD. The article describes in detail GERD risk factors (triggers of heartburn), as well as diagnostic aspects, taking into account a differentiated approach to patients with heartburn based on daily impedance–pH monitoring data in accordance with the current guidelines and recommendations

Паттерны эзофагеальной ацидификации и нарушений моторики при заболеваниях пищевода

Background. Gastroesophageal reflux disease (GERD) has a high prevalence worldwide and plays a major role in the development of Barretts esophagus (BЕ) and, as a consequence, esophageal adenocarcinoma. Aims: to evaluate the patterns of esophageal acidification and esophageal motility in patients with BЕ in comparison with various GERD phenotypes and control subjects. Methods. 100 patients were examined: 31 patients with nonerosive reflux disease (NERD), 20 patients with erosive reflux disease (ERD), 17 patients with BE, 32 healthy individuals who made up the control group. All patients underwent 24-hours pH-impedance and high-resolution esophageal manometry. Results. According to the 24-hour pH-impedanсe, the total time with pH 4 in the esophagus was 1.9% (95% CI: 1.12.7) in control patients, 11.6% (95% CI: 8.7613.4) in the NERD group, 19.35 (95% CI: 12.7026.05) in the ERD group and 28% (95% CI: 10.0440.96) in patients with BE (p 0.05). The average number of acid refluxes was 18.0 (95% CI: 10.9923.0) in the control group, 58.0 (95% CI: 42.3471.0) in the group with NERD, 78.5 (95% CI: 65.34103.93) in the group with ERD and 89.0 in patients with BE (95% CI: 67.03118.72). Significant differences in the listed indicators were noted when comparing patients with BE and control individuals, as well as the NERD group (p 0.05). The number of acidic refluxes was significantly correlated with the time on the acidification of the esophagus (r = 0.5439; p 0.05). The median time of chemical clearance was 1.55 min (95% CI: 1.192.0) in control subjects, 2.4 min (95% CI: 1.652.94), in the NERD group, 2.85 min (95% CI: 1.803.84) in the ERD group, and 3 min (95% CI: 2.14.68) in the BE group. The analysis of the mean nocturnal baseline impedance (MNBI) revealed a tendency to decrease the values in patients with GERD relative to the control subjects, and there was a decrease in the values of MNBI as the severity of GERD ― from NERD to ERD and BE (p 0.05). Manometric signs of hiatal hernia and/or hypotension of the lower esophageal sphincter were more often registered in the groups of patients with ERD (70%) and BE (65%) than in patients with NERD (32%) and in control group (12%). In addition, the frequency of such esophageal motor disorders as ineffective motility and absent contractility were significantly more often observed in patients with ERD and BE (75% and 77%, respectively) compared with patients with NERD (22.5%) and control subjects (12,5%). Conclusions. Increase in level of total time with pH 4, number of acid refluxes, slowing chemical clearance, reduced values of MNBI, as well as disorders of the structure and function of the esophagogastric junction and motility of the esophagus are associated with the severity of аcid pathology of the esophagus.Обоснование. Гастроэзофагеальная рефлюксная болезнь (ГЭРБ) имеет высокую распространенность во всем мире и играет главную роль в развитии пищевода Барретта и, как следствие, аденокарциномы пищевода. Цель ― оценить характер эзофагеальной ацидификации и моторики пищевода у пациентов с пищеводом Барретта в сравнении с различными фенотипами ГЭРБ и лицами контроля. Методы. Обследовано 100 пациентов: 31 пациент с неэрозивной рефлюксной болезнью, 20 пациентов с эрозивной рефлюксной болезнью, 17 пациентов с пищеводом Барретта, 32 здоровых человека, cоставивших контрольную группу. Всем пациентам проводились суточная рН-импедансометрия и манометрия пищевода высокого разрешения. Результаты. По данным суточной рН-импедансометрии, общее время с рН 4 в пищеводе составило 1,9% (95% доверительный интервал, ДИ, 1,12,7) у лиц контроля, 11,6% (95% ДИ 8,7613,4) в группе пациентов с неэрозивной рефлюксной болезнью, 19,35% (95% ДИ 12,7026,05) в группе эрозивной рефлюксной болезни и с наибольшими значениями у больных пищеводом Барретта ― 28% (95% ДИ 10,0440,96). Среднее количество кислых рефлюксов составило 18,0 (95% ДИ 10,9923,0); 58,0 (95% ДИ 42,3471,0); 78,5 (95% ДИ 65,34103,93) и 89,0 (95% ДИ 67,03118,72) соответственно. Статистически достоверные различия в исследуемых показателях были отмечены при сравнении пациентов с пищеводом Барретта и лицами контроля, а также группой неэрозивной рефлюксной болезни (p 0,05). Количество кислых рефлюксов достоверно коррелировало с показателем времени ацидификации пищевода (r = 0,5439; p 0,05). Медиана времени химического клиренса составила 1,55 мин (95% ДИ 1,192,0) у лиц контроля, 2,4 мин (95% ДИ 1,652,94) в группе неэрозивной рефлюксной болезни, 2,85 мин (95% ДИ 1,803,84) в группе эрозивной рефлюксной болезни и 3 мин (95% ДИ 2,14,68) у пациентов с пищеводом Барретта. При анализе среднего ночного базального импеданса выявлена тенденция к снижению значений данного показателя у пациентов с ГЭРБ относительно лиц контроля, а также отмечалось снижение значений среднего ночного базального импеданса по мере возрастания тяжести ГЭРБ ― от неэрозивной к эрозивной фазе рефлюксной болезни и пищеводу Барретта (p 0,05). Манометрические признаки грыжи пищеводного отверстия диафрагмы и/или гипотонии нижнего пищеводного сфинктера чаще регистрировались в группах пациентов с эрозивной рефлюксной болезнью (70%) и пищеводом Барретта (65%), чем у пациентов с неэрозивной рефлюксной болезнью (32%) и у здоровых лиц (12%). Помимо этого, частота таких двигательных нарушений грудного отдела пищевода, как неэффективная моторика и отсутствие сократимости, достоверно чаще наблюдалась у пациентов с эрозивной рефлюксной болезнью и пищеводом Барретта (75 и 77% соответственно) в сравнении с больными неэрозивной рефлюксной болезнью (22,5%) и лицами контроля (12,5%). Заключение. Увеличение уровня экспозиции кислоты, количества кислых рефлюксов, замедление химического клиренса, снижение значений среднего ночного базального импеданса, а также расстройства структуры и функции пищеводно-желудочного перехода и моторики грудного отдела пищевода ассоциированы с тяжестью кислотозависимой патологии пищевода