140 research outputs found
The Cyrilka Cave-the longest crevice-type cave in Czechia: structural controls, genesis, and age
The Cyrilka Cave is the second longest pseudokarst cave and the longest crevice-type cave in Czechia. Developed within the headscarp area of a deep-seated landslide, the cave became a focus of scientific research in recent years when new passages were discovered. Structural analysis provided a general tectonic plan of the cave, as well as more detailed data on geometry and kinematics of the relaxed rock massif. The primary structure of NNE- to ENE-striking bedding is broken by a system of NNE-striking fissures interconnected by two continuous ENE-striking dextral fracture zones. Abundant signs of recent sinistral strike-slips within the rock massif represent a bold structural feature of the cave. Along with DEM imaging and a detailed survey of the cave, 2-D and 3-D ERT measurements completed an image of the main predispositions and revealed the internal structure of the slope deformation. These measures also detected unknown crevices above the existing headscarp, which indicate the retrograde evolution of the landslide. Methodologically, we used the 3-D electrical resistivity tomography in the incoherent sedimentary flysch rocks for the first time. Based on radiocarbon dating of the stalactite core, the minimum age of the cave is up to 19,900 +/- 280 cal BP, which is the oldest age detected in the area of the Outer Flysch Carpathians so far; we thoroughly discuss further indirect evidence indicating a probable Late Pleistocene age of the cave.Web of Science47339237
Emissions from pre-Hispanic metallurgy in the South American atmosphere
Peer reviewedPublisher PD
Kardiomiopatia z niescalenia mięśnia lewej komory
Non-compaction cardiomyopathy is a rare genetic condition and may occur either in a familial form or in a sporadic form. It is characterized by excessive trabeculation and occurrence of deep intertrabecular recesses. Usually the diagnosis is made during an accidental echocardiography or during the screening process of the family members. Although there is no gold standard for the diagnosis, Jenni et al. criteria used during echocardiography examination are the most common. Treatment is based on suppressing the progression of heart failure, thromboembolism prevention and dealing with arrhythmias. Moreover, patients have often cardioverter-defibrillator implanted and they are enrolled on the heart transplant list.Kardiomiopatia z niescalenia jest niezwykle rzadko spotykaną odmianą kardiomiopatii uwarunkowanej genetycznie i występującej zarówno rodzinnie, jak i sporadycznie. Polega ona na nadmiernym beleczkowaniu oraz na występowaniu głębokich zachyłków pomiędzy tymi beleczkami. Najczęściej wykrywana jest zupełnie przypadkowo w trakcie echokardiografii lub podczas screeningu członków rodziny. Choć nie ma złotych standardów diagnostyki kardiomiopatii z niescalenia, to najszerzej na świecie stosowane są kryteria Jenni i wsp. podczas badania echokardiograficznego. Leczenie tej kardiomiopatii opiera się głównie na spowalnianiu progresji niewydolności serca, na profilaktyce przeciwzakrzepowej oraz na leczeniu zaburzeń rytmu serca. U niektórych grup pacjentów wskazane jest również wszczepienie kardiowertera-defibrylatora, a nawet należy rozważyć przeszczepienie serca
Variations of the anterior communicating artery complex and occurance of anterior communicating artery aneurysm : a2 segment consideration
Long-term trends in diatom diversity and palaeoproductivity: a 16 000-year multidecadal record from Lake Baikal, southern Siberia
Biological diversity is inextricably linked to community stability and
ecosystem functioning, but our understanding of these relationships in
freshwater ecosystems is largely based on short-term observational,
experimental, and modelling approaches. Using a multidecadal diatom record
for the past ca. 16 000 years from Lake Baikal, we investigate how diversity
and palaeoproductivity have responded to climate change during periods of
both rapid climate fluctuation and relative climate stability. We show
dynamic changes in diatom communities during the past 16 000 years, with
decadal shifts in species dominance punctuating millennial-scale seasonal
trends. We describe for the first time in Lake Baikal a gradual shift from
spring to autumnal diatom communities that started during the Younger Dryas
and peaked during the Late Holocene, which likely represents orbitally driven
ecosystem responses to long-term changes in seasonality. Using a
multivariate classification tree, we show that trends in planktonic and
tychoplanktonic diatoms broadly reflect both long-term climatic changes
associated with the demise of Northern Hemisphere ice sheets and abrupt
climatic changes associated with, for example, the Younger Dryas stadial.
Indeed, diatom communities are most different before and after the boundary
between the Early and Middle Holocene periods of ca. 8.2 cal kyr BP, associated
with the presence and demise of Northern Hemisphere ice sheets respectively.
Diatom richness and diversity, estimated using Hill's species numbers, are
also shown to be very responsive to periods characterized by abrupt climate
change, and using knowledge of diatom autecologies in Lake Baikal, diversity
trends are interpreted in terms of resource availability. Using diatom
biovolume accumulation rates (BVARs; µm3 cm−2 yr−1), we
show that spring diatom crops dominate palaeoproductivity for nearly all of
our record, apart from a short period during the Late Holocene, when
autumnal productivity dominated between 1.8–1.4 cal kyr BP.
Palaeoproductivity was especially unstable during the Younger Dryas,
reaching peak rates of 18.3 × 103 µm3 cm−2 yr−1 at
ca. 12.3 cal kyr BP. Generalized additive models (GAMs), which explore
productivity–diversity relationships (PDRs) during pre-defined climate
periods, reveal complex relationships. The strongest statistical evidence for
GAMs were found during the Younger Dryas, the Early Holocene, and the Late
Holocene, i.e. periods of rapid climate change. We account for these
differences in terms of climate-mediated resource availability, and the
ability of endemic diatom species in Lake Baikal to adapt to extreme forms
of living in this unique ecosystem. Our analyses offer insight into how
productivity–diversity relationships may develop in the future under a
warming climate
Not Just a Pot: Visual Episodic Memory in Cannabis Users and Polydrug Cannabis Users: ROC and ERP Preliminary Investigation
Background While research has consistently identified an association between long-term cannabis use and memory impairments, few studies have examined this relationship in a polydrug context (i.e., when combining cannabis with other substances).Aims: In this preliminary study, we used event-related potentials to examine the recognition process in a visual episodic memory task in cannabis users (CU) and cannabis polydrug users (PU). We hypothesized that CU and PU will have both–behavioral and psychophysiological–indicators of memory processes affected, compared to matched non-using controls with the PU expressing more severe changes.Methods 29 non-using controls (CG), 24 CU and 27 PU were enrolled into the study. All participants completed a visual learning recognition task while brain electrical activity was recorded. Event-related potentials were calculated for familiar (old) and new images from a signal recorded during a subsequent recognition test. We used receiver operating characteristic curves for behavioral data analysis.Results The groups did not differ in memory performance based on receiver operating characteristic method in accuracy and discriminability indicators nor mean reaction times for old/new images. The frontal old/new effect expected from prior research was observed for all participants, while a parietal old/new effect was not observed. While, the significant differences in the late parietal component (LPC) amplitude was observed between CG and PU but not between CG and CU nor CU and PU. Linear regression analysis was used to examine the mean amplitude of the LPC component as a predictor of memory performance accuracy indicator. LPC amplitude predicts recognition accuracy only in the CG.Conclusion The results showed alterations in recognition memory processing in CU and PU groups compared to CG, which were not manifested on the behavioral level, and were the most prominent in cannabis polydrug users. We interpret it as a manifestation of the cumulative effect of multiple drug usage in the PU group
Molecular profiling of the intestinal mucosa and immune cells of the colon by multi-parametric histological techniques
The impact of the post-mortem interval (PMI) on the optical molecular characteristics of the colonic mucosa and the gut-associated lymphoid tissue (GALT) were examined by multi-parametric measurements techniques. Inflammatory cells were identified by immunohistochemical staining. Molecular parameters were estimated using the Raman spectroscopy (RS) and Fourier Transform Infrared (FTIR) spectroscopic imaging. The 3D refractive index (3D-RI) distributions of samples were determined using the digital holographic tomography. The distribution of immune cells between post-mortem (PM) and normal controls did show significant differences for CD4 (P = 0.0016) or CD8 (P < 0.0001), whose expression level was decreased in PM cases. No association was found between individual PMI values and inflammatory cell distribution. However, there was a tendency for a negative correlation between CD4(+) cells and PMI (r = − 0.542, P = 0.032). The alterations ongoing in post-mortem tissue may suggest that PMI has a suppressive effect on the effector properties of the cell-mediated immunity. Moreover, it was confirmed that spectroscopic and digital holotomographic histology are also a useful technique for characterization of the differences in inflammation of varying intensity and in GALT imaging in a solid tissue. Anatomical location of immune cells and methods of tissue fixation determine the molecular and optical parameters of the examined cases
Major and trace element geochemistry in a peat core from North Poland.Preliminary results
Ductus venosus opens in high-risk pregnancies without signs of increased central venous pressure
Objectives: It has been belived that changes in diastolic blood velocities in the fetal ductus venosus were due to increased central venous pressure secondary to increased fetal heart strain during hypoxia or heart failure. There have been recent reports of changes in ductus venosus blood velocity without signs of increased fetal heart strain. The aim of this evaluation was to compare blood velocity in the right hepatic vein as a marker of increased central venous pressure in relationship to changes in ductus venosus blood velocity.
Material and methods: Fifty pregnancies suspected of fetal growth resitriction were evaluated by Doppler ultrasound. Blood velocity was recorded in the right hepatic vein, ducus venosus and in the umbilical vein. Placental blood flow was also recorded in the uterine and umbilical arteries as well as the fetal middle cerebral artery.
Results: Increased umbilical artery pulsatility index was recorded in 19 fetuses and 20 has signes of brain sparing according to recordings in the middle cerebral artery. Abnormal blood velocity in the ductus venosus was recorded in 5 fetuses, none of these fetuses had an abnormal pulsatility in the right hepatic vein.
Conclusions: Opening of the ductus venosus is not only related to fetal cardiac strain. This might indicate that the ductus venosus does not primarily open due to increased central venous pressure in moderate fetal hypoxia. Increased fetal cardiac strain might be a late event in the process of chronic fetal hypoxia
Beyond FOXP3:a 20-year journey unravelling human regulatory T-cell heterogeneity
The initial idea of a distinct group of T-cells responsible for suppressing immune responses was first postulated half a century ago. However, it is only in the last three decades that we have identified what we now term regulatory T-cells (Tregs), and subsequently elucidated and crystallized our understanding of them. Human Tregs have emerged as essential to immune tolerance and the prevention of autoimmune diseases and are typically contemporaneously characterized by their CD3+CD4+CD25high CD127lowFOXP3+ phenotype. It is important to note that FOXP3+ Tregs exhibit substantial diversity in their origin, phenotypic characteristics, and function. Identifying reliable markers is crucial to the accurate identification, quantification, and assessment of Tregs in health and disease, as well as the enrichment and expansion of viable cells for adoptive cell therapy. In our comprehensive review, we address the contributions of various markers identified in the last two decades since the master transcriptional factor FOXP3 was identified in establishing and enriching purity, lineage stability, tissue homing and suppressive proficiency in CD4+ Tregs. Additionally, our review delves into recent breakthroughs in innovative Treg-based therapies, underscoring the significance of distinct markers in their therapeutic utilization. Understanding Treg subsets holds the key to effectively harnessing human Tregs for immunotherapeutic approaches
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