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Evidence of mobiliary art and body augmentation are associated with the cultural innovations introduced by Homo sapiens at the beginning of the Upper Paleolithic. Here, we report the discovery of the oldest known human-modified punctate ornament, a decorated ivory pendant from the Paleolithic layers at Stajnia Cave in Poland. We describe the features of this unique piece, as well as the stratigraphic context and the details of its chronometric dating. The Stajnia Cave plate is a personal 'jewellery' object that was created 41,500 calendar years ago (directly radiocarbon dated). It is the oldest known of its kind in Eurasia and it establishes a new starting date for a tradition directly connected to the spread of modern Homo sapiens in Europe.

The Micoquian is the broadest and longest enduring cultural facies of the Late Middle Palaeolithic that spread across the periglacial and boreal environments of Europe between Eastern France, Poland, and Northern Caucasus. Here, we present new data from the archaeological record of Stajnia Cave (Poland) and the paleogenetic analysis of a Neanderthal molar S5000, found in a Micoquian context. Our results demonstrate that the mtDNA genome of Stajnia S5000 dates to MIS 5a making the tooth the oldest Neanderthal specimen from Central-Eastern Europe. Furthermore, S5000 mtDNA has the fewest number of differences to mtDNA of Mezmaiskaya 1 Neanderthal from Northern Caucasus, and is more distant from almost contemporaneous Neanderthals of Scladina and Hohlenstein-Stadel. This observation and the technological affinity between Poland and the Northern Caucasus could be the result of increased mobility of Neanderthals that changed their subsistence strategy for coping with the new low biomass environments and the increased foraging radius of gregarious animals. The Prut and Dniester rivers were probably used as the main corridors of dispersal. The persistence of the Micoquian techno-complex in South-Eastern Europe infers that this axis of mobility was also used at the beginning of MIS 3 when a Neanderthal population turnover occurred in the Northern Caucasus.

α-Tocopheryl succinate (α-TOS) is a very promising anticancer agent; however, the mechanism of its action and the role of the succinic moiety in biological activity still remains unclear. This paper, presents the first determination of the X-ray structure of α-TOS and 2,2,5,7,8-pentamethylchroman-6-yl succinate (PMCS). The X-ray data indicated high out of planarity deformation of the aryl ring in the chroman-6-ol system. α-TOS and PMCS differed in angle θ value (28.4° vs. 21.5°, respectively) and in their heterocyclic ring conformations: 2-endo-3-exo in PMCS, and 2-endo-3-exo and 2-exo-3-endo in α-TOS. Due to their strong intermolecular hydrogen bonds, both succinates form cyclically repeated dimeric structures in well assembled crystal supramolecular structures.A population analysis of α-tocopherol (α-TOC), 2,2,5,7,8-pentamethylchroman-6-ol (PMC) and their acyl derivatives was performed at B3LYP/6-31G(d,p)/CPCM level of theory using a natural bond orbital (NBO) analysis within the Gaussian 09 program package. For all compounds, relaxed scans were performed along torsion angle γ, and for low-energy conformers the Fukui functions were calculated: electron donor (ƒ−(r)), electron acceptor (ƒ+(r)), free radical (ƒo(r)) and dual descriptor (ƒ2(r)).In general, the differences observed between α-TOC and its acyl derivative structures result from the non-bonding lone pair of the phenolic oxygen and its interaction with aromatic system π electrons. Keywords: α-Tocopheryl succinate, X-ray, Natural Bond Orbital, DFT calculation, Fukui function

In this Article, a number of single crystal structures of piperidine hydrates are presented. While the lower hydrates, i.e., containing 1/2 or 2 water molecules per amine, present features characteristic for well-defined structures of cocrystals, the higher hydrates (8.1, 9 3/4, 11) have properties more similar to clathrate hydrates with the organic molecules enclosed in cages. However, in these systems some weak hydrogen bonds between piperidine and the water framework exist; thus they cannot be considered as pure host–guest structures. The property of piperidine to crystallize with water giving full enclathration of the amine is compared with the ability of nonionic chaotropes to generate clathrate hydrate-like structures. According to the obtained crystal structures of higher hydrates of piperidine, this amine behaves more like a chaotrope. This finding is supported by Raman spectra in the solid state.

Identification of volcanic signals preserved in paleoenvironmental records can provide key insights into the timing and consequences of explosive volcanism. Yet the eruption record is incomplete and this confounds our ability to link volcanic eruptions to their impacts on climate and environments. Studies have suggested that stalagmite records can help to address these gaps, through the identification of transient geochemical variability associated with incorporation of elements derived from erupted material. However, the utility of stalagmites for tracing volcanism is poorly constrained globally. Here, we present a high-resolution geochemical dataset for stalagmite NIED08–05 from Niedźwiedzia Cave (Poland). We do this with two primary aims: (1) to test the suitability of NIED08–05 as a record of volcanism since 3 ka BP, and (2) to ascertain whether stalagmites grown in temperate regions preserve volcanic signals with success comparable to those grown in tropical regions. We find transient enrichments of 16 trace elements and the rare-earth-elements Y, La, Nd, which coincide with the timing of some known eruption events. Using Principal Component Analysis (PCA) we find that elements atypically incorporated into calcite (e.g., Fe) co-vary. Similarly, filtering PC1 (17% of the dataset variability) for high magnitude deviations from a baseline signal yields tentative agreement between PC scores and some known large eruptions with tephra found in Poland. We use our analysis to discuss the complexities involved in associating volcanic signals with stalagmite chemistry in temperate regions far from the source of large eruptions. The transport pathway from volcanic source to stalagmite growth surfaces includes the complex Niedźwiedzia Cave hydrological system and is influenced by dense forest above the cave site. Together these factors increase the potential for attenuation of volcanic-derived chemical signals prior to reaching the stalagmite, and so make it difficult to unambiguously link trace element enrichments in NIED08–05 to volcanic eruptions. Our results provide strong evidence that in a temperate depositional environment far from active volcanoes, climate and hydrology conspire to mute the strength of volcanic geochemical signals. Therefore, this work provides important incentives for future research in this area by highlighting that stalagmites grown in a comparatively simple hydrological regime and grown in caves overlain by thin vegetation and soil cover , may preserve volcanic signatures with greater success than those grown in temperate environments.

There is a widespread belief that the abrupt warming at 14.7 ka had a profound impact on the environment. However, the direct correlation between the global climatic event and changes in local environments is not obvious. We examined faunal succession in an intra-mountain basin of the Western Carpathians to assess the potential influence of the climatic change between Greenland Stadial-2a and Greenland Interstadial-1e on the local environment. We investigated three vertebrate assemblages (total number of identified specimens = 18,745; minimum number of individuals = 7515; 138 taxa) from Obłazowa Cave (western entrance) and a Rock overhang in Cisowa Rock, radiocarbon dated to the period before and after the global warming, between ca. 17.0 and 14.0 ka. Our data revealed that the major abrupt warming that occurred 14.7 ka had little impact on the local environment, which could suggest that ecosystems in Central Europe were resilient to the abrupt global climate changes. The increase in fauna population sizes and species diversities in local biotopes was gradual and began long before the temperature increase. This was supported by the analysis of ancient DNA of Microtus arvalis, which showed a gradual increase in effective population size after 19.0 ka. The results of palaeoclimatic reconstruction pointed out that the compared sites were characterized by similar climatic conditions. According to our calculations, the differences in the annual mean temperatures did not exceed 0.5 °C and mean annual thermal amplitude changed from 22.9 to 22.4 °C. The environmental changes before 14.7 ka had no impact on the activity of Final Palaeolithic hunters in the studied area.

Reactions of the chiral alcohol rac 6,7-dihydro-5H-pyrrolo[1,2-a]imidazol-7-ol [(R,S)-LH] with R3Al (R = tBu, Et) have been studied. An influence of reaction conditions on the product structures and distributions was found. The dimeric products (Al2R4L2) [R = tBu (1), R = Et (2)] were formed in the reactions of R3Al with one equivalent of (R,S)-LH as mixtures of the heterochiral (R,S) and homochiral (R,R) and (S,S) diastereomers. The X-ray diffraction measurements of the (R,S)-1 and (R,S)-2 showed dinuclear complexes with bridging ON ligands and 10-membered C4N2O2Al2 central cycles. The molecules contain two chiral ligands demonstrating (R) and (S) configurations of CO carbon atoms. Polymerization tests showed that the complexes 1 and 2 have activity in the ROP of e-caprolactone. Kinetic studies revealed first order reaction of polymerization.

In order to explore temporal trends of morphological variation in the narrow-headed vole ( Microtus gregalis ) traditional morphometric methods were used to quantify enamel differentiation quotient (SDQ), tooth size (L) and tooth proportion (A/L) in over 800 first lower molars from two sites in Central Europe. Our results suggest that SDQ values in late Middle Pleistocene assemblages are significantly lower than those in Late Pleistocene populations. A greater chronostratigraphic variation in SDQ occurs across the Late Pleistocene compared to the late Middle Pleistocene. This probably indicates repeated extinctions and re-colonisations, most likely from Eastern Europe or Asia, during MIS 3 and MIS 2. However, it is unclear whether this pattern represents a local phenomenon or whether the SDQ changes took place across a large geographical scale. Further studies on fossil and recent populations of the species are necessary to identify the determinants of SDQ variation in Microtus gregalis and to confirm the usefulness of the index for the Pleistocene stratigraphy.

Robust chronologies are crucial for the correct interpretation of climate proxy records and for detailed reconstructions of palaeoclimate. Stalagmites have garnered strong interest as recorders of past climate in part due to their amenability to U-series dating. However, many stalagmites are not dateable using this technique due to low 238U and/or high detrital Th concentrations (e.g., many tropical cave systems (Adkins et al., 2013)), and occasionally these issues affect stalagmites across wide geographical regions (e.g., large parts of Australia (Green et al. 2013)) complicating the use of stalagmites in these areas. Radiocarbon (14C) offers an alternative method of dating stalagmites, but issues associated with the ‘dead carbon fraction’ (DCF) have historically hindered this approach. Here, a novel 14C-based method for dating stalagmites is presented and discussed. The technique calculates a best-fit growth rate between a time-series of stalagmite 14C data and known atmospheric 14C variability. The new method produces excellent results for stalagmites that satisfy four requirements: i) the absence of long-term secular variability in DCF (i.e., stalagmite DCF varies around a mean value with no long-term trend), ii) stalagmite growth rate does not vary significantly (the technique identifies stalagmites with substantial growth rate variability), iii) the stalagmite record is long enough that measurable 14C decay has occurred, and iv) one ‘anchor’ point exists where the calendar age is known. The model produces good results for a previously U–Th dated stalagmite from Heshang Cave, China, and is then applied to an undated stalagmite from southern Poland. The new method will not replace high-precision U–Th measurements, because the precision of the technique is difficult to quantify. However, it provides a means for dating certain stalagmites undateable by conventional U–Th methods and for refining coarse U–Th chronologies.

The reaction of the N-tert-butyl amide of succinic acid with tBu3M (M = Al, Ga) resulted in the formation of the new complexes [AltBu2{N(H)(tBu)C(O)CH2CH2COO}] (1), [MtBu2{N(H)(tBu)C(O)CH2CH2COO}(tBu3M)] [M = Al (2), M = Ga (3), and [GatBu2{N(H)(tBu)C(O)CH2CH2COO}]2 (4). The aluminum complexes 1 and 2 contained seven-membered C4O2Al rings with the Al atom bonded to the oxygen atom and coordinated to the nitrogen atom. The reaction of tBu3Ga with the N-tert-butyl amide of succinic acid resulted in the formation of a mixture of 3 and 4. The gallium complex 3 was isostructural to 2, whereas the gallium atoms in the dinuclear compound 4 were bonded to the carboxylate oxygens only forming a central Ga2C2O4 ring. X-ray studies showed that the crystalline solid obtained after crystallization from the post-reaction mixture was composed of crystals of compound 3 and co-crystals of 3 and 4. In all reactions, only the OH protons of the ligand reacted with tBuM groups with an alkane evolution, while NH protons remained unreactive. The reaction of tBu3Ga with the N-tert-butyl amide of succinic acid in a 2:1 M ratio of the reagents in the presence of water proceeded with the formation of the unprecedented compound [(GatBu2)2(OH){N(H)(tBu)C(O)CH2CH2COO}] (5) as the only product. Compound 5 was also obtained in the hydrolysis reaction of the mixture of compounds 3 and 4 isolated from the post-reaction mixture of tBu3Ga with the N-tert-butyl amide of succinic acid. The molecular and molecular packing in the crystal structures of 1–3 and 5 were determined by single-crystal X-ray diffraction. Crystal structure examinations showed laminar structures of 1, 3, and 5 and a packed crystal network of 2.

5-[2-(N,N-dimethylamino)ethoxy]-4,7-dimethylcoumarin (1) and 6-acetyl-5-[2-(N,N-dimethylamino)ethoxy]-4,7-dimethylcoumarin (2), structurally related, were synthesized using both conventional and microwave-assisted approach. An impact of acetyl groups on the molecular structure of coumarin derivatives has been examined. Crystals of 2 were investigated using single crystal and powder X-ray diffraction techniques. Compound 2 crystallizes forming two polymorphs (denoted as 2_1 and 2_2), both belonging to P21/c space group. Both polymorphs are comparably stable and can be formed simultaneously during crystallization process. The solid state structure was also analysed using the fully resolved 13C CP/MAS NMR. The double signals with the intensity ratio of about 1:1 which were observed in the 13C CP/MAS NMR spectrum of compound 1 must arise due to the presence of two conformers of 1. In contrast, NMR spectrum recorded for powder mixture of two polymorphs of compound 2 displays no signal splitting. This is related to structural similarities of molecules in both polymorphs.

Complexes containing aminophenolate ligands are considered as very efficient initiators of ring-opening polymerization (ROP). Our systematic studies of the reactions of two selected aminophenols, 2-[(p-tolylamino)methyl]-4-(2,4,4-trimethylpentan-2-yl)phenol (L'H2) and 2-cyclohexylaminomethyl-4-methylphenol (L″H2), with alkyl compounds of aluminium, gallium and zinc resulted in the formation of a variety of products depending on the type of metallic centre and alkyl groups bonded to metal atoms. New trinuclear aluminium complexes (Me5Al3(L′)2 (1) and Me5Al3(L″)2 (2)), monomeric aluminium (tBu2Al(L'H) (3) and tBu2Al(L″H) (5)) and gallium (tBu2Ga(L'H) (4) and tBu2Ga(L″H) (6)) compounds, and dinuclear gallium (Et2Ga(L″H)·Et3Ga (7)) and zinc (tBuZn(L″H)]2 (8)) complexes were isolated and characterized. The molecular and crystal structures of 7 and 8 were determined on the basis of an X-ray diffraction study. Polymerization tests showed that only three complexes (6–8) had activity in the ROP of e-caprolactone, whereas 1–5 were inactive in ROP.

The Stajnia Cave is one of the most important archaeological sites due to the finds of the first remains of Neanderthals in Poland, and several tens of thousands of flint artefacts from the Middle Palaeolithic. Based on geological, geochemical, palaeobotanical, palaeozoological, archaeological and isotope analyses, coupled with absolute age determinations (OSL, U-Th and C 14 ), 15 lithostratigraphic layers were distinguished and palaeoenvironmental conditions during the sedimentation of these beds were determined. The cave loams accumulated through weathering, aeolian and fluvial processes. Their age may be correlated with an interval from the Early Glacial to the Late Pleniglacial of the Visulian (Weichselian) Glaciation. Archaeological relics related to the Neanderthals have been discovered in layer D with an absolute age of about 52,000–45,000 years BP and correlated with MIS 3 – the Middle Plenivistulian (Interplenivistulian). Climate oscillations in the Vistulian are reflected by the type of the sediments and their physical-chemical features, allowing determining warmer interstadial and colder stadial periods. Generally, the climate was cold, characteristic of tundra areas with a typical vegetation and fauna, and with the mean temperature of the warmest month not exceeding 12°C. Based on multi-proxy studies it can be concluded that from layer E1 upwards, the climate conditions became progressively drier. At that time, the climate was cold with continental features enhancing tundra domination. This conclusion is confirmed by palaeontological investigations and the record of stable oxygen isotopes in the teeth of reindeer. The studies have also indicated seasonal migration of reindeer on the tundra that surrounded the cave. Probably, short-term slight climate warmings occurred during the Middle Plenivistulian (Interplenivistulian).

2-Mercapto-1,3-benzothiazole (mbztH) may act as a chelating or bridging ligand. In this study, reactions of mbztH with Me3Ga and Me3In were examined. The products were characterized by NMR spectroscopy, elemental analyses, melting point, and molecular weight determinations. Formation of mononuclear chelating complexes Me2M(mbzt) (M = Ga, In) was observed in solutions. Crystallization of Me2M(mbzt) yielded uncommon non-symmetrical dinuclear complexes Me4M2(mbzt)2, in which one metal is bonded to two sulfurs and the other to two nitrogens.

Recent palaeogenetic studies indicate a highly dynamic history in collared lemmings (Dicrostonyx spp.), with several demographical changes linked to climatic fluctuations that took place during the last glaciation. At the western range margin of D. torquatus, these changes were characterized by a series of local extinctions and recolonizations. However, it is unclear whether this pattern represents a local phenomenon, possibly driven by ecological edge effects, or a global phenomenon that took place across large geographical scales. To address this, we explored the palaeogenetic history of the collared lemming using a next‐generation sequencing approach for pooled mitochondrial DNA amplicons. Sequences were obtained from over 300 fossil remains sampled across Eurasia and two sites in North America. We identified five mitochondrial lineages of D. torquatus that succeeded each other through time across Europe and western Russia, indicating a history of repeated population extinctions and recolonizations, most likely from eastern Russia, during the last 50 000 years. The observation of repeated extinctions across such a vast geographical range indicates large‐scale changes in the steppe‐tundra environment in western Eurasia during the last glaciation. All Holocene samples, from across the species' entire range, belonged to only one of the five mitochondrial lineages. Thus, extant D. torquatus populations only harbour a small fraction of the total genetic diversity that existed across different stages of the Late Pleistocene. In North American samples, haplotypes belonging to both D. groenlandicus and D. richardsoni were recovered from a Late Pleistocene site in south‐western Canada. This suggests that D. groenlandicus had a more southern and D. richardsoni a more northern glacial distribution than previously thought. This study provides significant insights into the population dynamics of a small mammal at a large geographical scale and reveals a rather complex demographical history, which could have had bottom‐up effects in the Late Pleistocene steppe‐tundra ecosystem.