Search Results (77)

In recent years, phylogenomic approaches have significantly deepened our understanding of moss diversity. These techniques have uncovered numerous previously overlooked species and provided greater clarity in resolving complex taxonomic relationships. In this context, the genus Rehubryum is particularly outstanding, because of its close morphological similarity to both Ulota and Atlantichella. The challenges posed by its segregation are addressed in this study, which integrates morphological and molecular data to reassess the circumscription of Rehubryum and its phylogenetic placement within the subtribe Lewinskyinae. Our results support the recognition of a new species, R. kiwi, and show that its inclusion within the genus further complicates the morphological delimitation of Rehubryum from Ulota, as both genera are distinguishable by only two consistent gametophytic characteristics: a submarginal leaf band of elongated cells, and the presence of geminate denticulations in the margins of the basal half of the leaf. Moreover, R. kiwi challenges the current morphological circumscription of Rehubryum itself, as it overlaps in key characteristics with its sister genus Atlantichella, rendering their morphological separation untenable. The striking interhemispheric disjunction between Rehubryum and Atlantichella raises new questions about long-distance dispersal and historical biogeography in mosses, despite these complexities at the generic level. Nevertheless, species-level distinctions remain well defined, especially in sporophytic traits and geographic distribution. These findings highlight the pervasive cryptic diversity within Orthotrichaceae, underscoring the need for integrative taxonomic frameworks that synthesize morphology, molecular phylogenetics, and biogeography to resolve evolutionary histories. Full article

Background/Objectives: Dental anomalies can manifest as a consequence of developmental defects and/or genetic influences, which disrupt the normal functioning of the oral cavity and present in various forms. Cases of fusion, gemination and concrescence are rare dental anomalies which are seen in the area of the mandibular molars. Case report: This case report concerns a 69-year-old Greek male patient who presented in the dental office asking for comprehensive oral treatment. During the clinical examination, a morphologically atypical molar was identified in the area of #37–38 presented with a large crown in the mesio-distal dimension (‘double’ crown). Panoramic and periapical radiographs offered valuable insights on the morphology of the irregular tooth, as they revealed the crown and root morphology, including the two pulp chambers and the three parallel roots of the tooth. Discussion: A plausible hypothesis identifies the atypical tooth as a third molar exhibiting morphological variation, a common characteristic of third molars. Additional diagnostic considerations—while supposing the existence of a supernumerary fourth molar—include the developmental anomalies of gemination, concrescence and fusion, as the clinical and radiographic features of the tooth display elements associated with all three. Conclusions: Considering the patient’s history, clinical and radiographic findings and the relevant literature, fusion is determined to be the most probable diagnosis. Early identification of the atypical tooth is essential to facilitate the implementation of appropriate preventive measures and to support informed treatment planning, should invasive procedures such as endodontic or surgical intervention be required in the future. Full article

This paper examines Gorgia Toscana (GT), a phenomenon of stop lenition observed in Tuscan varieties of Italian. Traditionally, this process has been understood to occur in post-vocalic positions, which, in the native lexicon, corresponds to onset position due to the absence of stops in syllable codas in Italian, apart from geminate consonants that straddle the coda and onset of adjacent syllables. However, stops in coda positions are found in both loanwords (e.g., admin, Batman) and bookwords (e.g., ritmo, tecnica). Drawing on original acoustic data collected from 42 native speakers of Florentine Italian, we investigated the realization of stops in such lexical items through allophonic classification and quantitative analysis. Our primary aim was to test the Onset Hypothesis, which posits that Gorgia exclusively affects stops in onset positions, implying that coda stops should not undergo lenition. Our findings support this hypothesis. We provide a phonological analysis within the frameworks of Strict CV and Coda Mirror, emphasizing the importance of syllable structure in understanding the manifestation of Gorgia Toscana, which we argue cannot be adequately captured solely by considering the linear order of segments. Full article

In this article, we analyse durational variation for inherently long consonants in Italian. Productions by 40 speakers of four regional varieties were elicited via a read-aloud task containing target words with inherently long consonants in the post-consonantal vs. intervocalic position. The analysis of acoustic durations revealed variation. Overall, we found that /ts/, /dz/ and /ʎ/ were considerably longer intervocalically than post-consonantally, although by smaller ratios than those reported in the literature for contrastive geminates; the effect was smaller for /ʃ/ and barely detectable for /ɲ/. We also detected a trend to lengthen /dz/ and /ʃ/ after a morphemic boundary. In terms of regional variation, north-eastern speakers were found to diverge from the others, with shorter durations and less consistent durational patterns. Additionally, we verified the existence of lengthening induced by double letters for /ts/ (vizi—vizzi) and /dz/ (Gaza—gazza), and only found it for /dz/, particularly for north-eastern speakers. We argue that this may originally have been an orthographic effect due to the acquisition of Italian at school via the written form by past generations, which has been lost for /ts/ but preserved for /dz/ under the influence of loanwords spelled with <z> and pronounced as short intervocalically. Full article

The occurrence of triplication in the deciduous teeth is rare. However, it can cause several problems in primary dentition, alteration of development, and eruption of permanent successors. Case Presentation: A three-year-old boy presented with an exuberant acute periapical abscess in the left front teeth region of the upper jaw. Examination revealed a presence of a triple tooth involving the central and lateral left primary incisors and a supernumerary tooth. Radiographs showed that the fused teeth had separate roots, pulp chambers and root canals. The implemented treatment was extraction under local anesthesia. After 2 years of observation, surgical exposure of the crowns of the permanent maxillary central incisor was performed. After seven years, the permanent dentition was completed without any sequelae. Discussion: Triple tooth, as observed in this case report, results from the union of three tooth germs, potentially influenced by physical, hereditary, or environmental factors, leading to esthetic and functional issues and increased susceptibility to caries. Treatment is challenging, requiring preventive care, complex endodontic procedures, and, in some cases, extraction with space maintenance to avoid future orthodontic complications. Conclusion: Early diagnosis, an adequate treatment plan and clinical monitoring should be performed, aiming at preventing the possible disturbances. Full article

Introduction: Dental anomalies present a significant challenge to clinicians due to their impact on both dental function and esthetics. The correction of these anomalies plays a critical role in improving the quality of life of our patients, highlighting the importance of this restorative work. Objective: The purpose of this systematic review is to assess the techniques used to restore various dental anomalies, and their subsequent esthetic impact on the overall dentition. Methods: Inclusion criteria consisted of restorative rehabilitations of the permanent dentition in non-syndromic patients with dental anomalies of morphology, structure, size, and number in the maxillary incisors. Exclusion criteria included surgical rehabilitation techniques, endodontic treatments, and anomalies of the primary dentition. The medical literature was systematically searched (Pubmed, PMC, Embase, Cochrane Central Register of Controlled Clinical trials, Scopus and Google Scholar) to identify all relevant articles reporting data regarding the chosen anomalies. ROBINS–I was used to assess the risk of bias tool, and the results were tabulate due to data heterogeneity. Results: Of the 1821 analyzed articles, 46 articles met the inclusion criteria, and were chosen to go through the final review procedure. Of the selected articles, 3 investigated amelogenesis imperfecta and dentinogenesis imperfecta, 1 analyzed conoid teeth, 1 considered hypodontia (other than MLIA), 3 concerned microdontia (excluding peg laterals and conoid teeth), 10 evaluated peg-shaped laterals, 2 investigated talon cusps and geminated teeth, 15 were regarding maxillary lateral incisor agenesis, and 11 papers were related to the perception of anomalies. Conclusions: Pre-visualization using Digital Smile Design, a treatment plan encompassing minimally invasive restorations, and using a multidisciplinary approach among practitioners helps the anomalous patient achieve the best possible esthetic result. Full article

Italian has a length contrast in its series of voiced and voiceless obstruents while also presenting phonetic differences across regional varieties. Northern varieties of the language, including Veneto Italian (VI), are described as maintaining the voicing contrast but, in some cases, not the length contrast. In central and southern varieties, the opposite trend may occur. For instance, Roman Italian (RI) is reported to optionally pre-voice intervocalic voiceless singleton obstruents whilst also maintaining the length contrast for this consonant class. This study looks at the acoustic realization of selected obstruents in VI and RI and investigates (a) prevoicing patterns and (b) the effects and interactions of regional variety, gemination, and (phonological and phonetic) voicing on consonant (C) and preceding-vowel (V) durations, as well as the ratio between the two (C/V), with a focus on that particular measure. An acoustic phonetic analysis is conducted on 3703 tokens from six speakers from each variety, producing eight repetitions of 40 real CV́C(C)V and CVC(C)V́CV words embedded in carrier sentences, with /p, pp, t, tt, k, kk, b, bb, d, dd, ɡ, ɡɡ, f, ff, v, vv, t∫, tt∫, dʒ, ddʒ/ as the target intervocalic consonants. The results show that both VI and RI speakers produce geminates, yielding high C/V ratios in both varieties, although there are cross-regional differences in the realization of singletons. On the one hand, RI speakers tend to pre-voice voiceless singletons and produce overall shorter C durations and lower C/V ratios for these consonants. On the other hand, VI speakers produce longer C durations and higher C/V ratios for all voiceless singletons, triggering some overlap between the C length categories, which results in partial degemination through singleton lengthening, although only for voiceless obstruents. The implications of a trading relationship between phonetic voicing and duration of obstruents in Italian gemination are discussed. Full article

Background: Elite kayaking demands peak conditioning, and tracking these athletes reveals the science behind world-class performance. Physiological demands and body composition changes in elite male kayakers were tracked during the preparatory and transition periods of a kayaking competitive season. Methods: Laboratory (body composition assessment and a 4 min all-out test in a kayak ergometer) on-field tests (4 × 1500 m incremental intermittent protocol with 30 s rest intervals in a kayaking/rowing track) were applied on separate days to follow eight elite male kayakers (23.1 ± 5.6 y; 80 ± 8.8 kg; 177.0 ± 6.8 cm) at the beginning of the kayaking season (preparatory period, M1; first week of October), 22 weeks later, at the beginning of the transition period (M2; last week of February), and 5 weeks later, at the end of the transition period, i.e., beginning of the competitive period of the season (M3; first week of April). M3 corresponded to the participation in international competitions. Results: Distance at peak oxygen uptake ($\dot{\mathrm{V}}{\mathrm{O}}_{2\mathrm{peak}}$) on the kayak ergometer improved by 36.7 m from M1 to M3, the pace at V4 (aerobic capacity) was reduced (improved) by 25.2 s·km⁻¹ from M1 to M2, and 25.6 s·km⁻¹ by M3. Body weight decreased by 2.3 kg from M1 to M2, and fat mass percentage and kilograms decreased by 1.8% and 3.1%, respectively. Fat-free mass increased by 1.9% and 3.1%, respectively. Skinfold measurements showed a decrease in subscapular, suprailiac, abdominal, and geminal skinfold. Aerobic power ($\dot{\mathrm{V}}$O_2peak) in absolute values (in L·min⁻¹) improved by 0.7 L·min⁻¹ from M1 to M2, and by 1.1 L·min⁻¹ by M3, and from M2 to M3 was ~0.5 L·min⁻¹. Aerobic power in relative values improved by 15.0 from M1 to M2, and by 6.4 mL·kg⁻¹·min⁻¹ from M2 to M3. Conclusions: Elite male kayakers improved their physiological performance and body composition during the preparatory and transition phases of the competitive season. Notable gains in performance were mainly due to enhanced aerobic power, and positive body composition changes. These findings provide insights for optimizing training strategies and boosting competitive performance. Full article

This paper presents a groundbreaking numerical approach, the fractional differential quadrature method (FDQM), to simulate the complex dynamics of organic polymer solar cells. The method, which leverages polynomial-based differential quadrature and Cardinal sine functions coupled with the Caputo-type fractional derivative, offers a significant improvement in accuracy and efficiency over traditional methods. By employing a block-marching technique, we effectively address the time-dependent nature of the governing equations. The efficacy of the proposed method is validated through rigorous numerical simulations and comparisons with existing analytical and numerical solutions. Each scheme’s computational characteristics are tailored to achieve high accuracy, ensuring an error margin on the order of ${10}^{-8}$ or less. Additionally, a comprehensive parametric study is conducted to investigate the impact of key parameters on device performance. These parameters include supporting conditions, time evolution, carrier mobilities, charge carrier densities, geminate pair distances, recombination rate constants, and generation efficiency. The findings of this research offer valuable insights for optimizing and enhancing the performance of organic polymer solar cell devices. Full article

Background: The rapid development of mobile communication has caused an increase in electromagnetic field (EMF) emissions in the environment. However, there is a lack of research on the impact of EMFs on microorganisms. Thus, the aim of the study was the determine the effect of exposure to 900 and 1800 MHz electromagnetic fields on the entomopathogenic fungi (EPFs) Beauveria bassiana, Cordyceps fumosorosea, and Metarhizium anisopliae. Methods: The entomopathogenic fungi developed under exposure to an EMF for seven days. After the termination of exposure, the linear colony growth, sporulation, gemination, and pathogenicity of the EPFs were investigated. Results: The effect of EMFs on B. bassiana, C. fumosorosea, and M. anisopliae depended on the EMF frequency and the tested fungus species. Exposure to the 900 MHz frequency stimulated the growth of the mycelium and the pathogenicity of the entomopathogenic fungi, whereas the 1800 MHz electromagnetic field inhibited sporulation and spore germination. Conclusions: The exposure to the 900 MHz frequency stimulated the development of the mycelium of all tested species and the pathogenicity of C. fumosorosea. The sporulation and germ tube length of the entomopathogenic fungi were stimulated by the 900 MHz frequency. The 1800 MHz electromagnetic field inhibited the sporulation and spore germination of B. bassiana. Full article

The review summarizes the results of previous and the latest studies on aromaticity and related concepts. The electron counting rule for 3D-aromatic systems 2(n + 1)² is shown to be a generalization of the 4n + 2 rule for planar molecules, and, vice versa, the latter can be derived from the former. The relative stability of the push–pull and captodative aromatic systems is shown to depend on the nature of the groups separated by the C=C bond in geminal or vicinal positions. The fully symmetrical molecules of hexamethylbenzene and hexacyanobenzene were studied using structural, energetic, and NMR criteria, and the donor substituents were shown to increase the aromaticity. Taking into account the coincidence of the number of π-electrons in aromatic systems with the number of electrons on the filled electron subshells (s, p, d, and f) and considering electrons as objects in a space of states allowed to conclude that no g-elements can exist and that the extension of the Periodic Table is possible only by filling 6f, 7d, or 8s subshells. The dimensionality of space also affects the chirality of molecules, making planar or even linear molecules chiral on oriented surfaces, which can be used for the preparation of enantiomerically pure drugs, resolution of prochiral compounds, etc. Full article

Diesters of geminal diols (R-CH(O-CO-R′)₂, RR′C(OCOR″)₂, etc. with R = H, aryl or alkyl) are termed acylals according to IUPAC recommendations (Rule P-65.6.3.6 Acylals) if the acids involved are carboxylic acids. Similar condensation products can be obtained from various other acidic structures as well, but these related “non-classical acylals”, as one might call them, differ in various aspects from classical acylals and will not be discussed in this article. Carboxylic acid diesters of geminal diols play a prominent role in organic chemistry, not only in their application as protective groups for aldehydes and ketones but also as precursors in the total synthesis of natural compounds and in a variety of organic reactions. What is more, acylals are useful as a key structural motif in clinically validated prodrug approaches. In this review, we summarise the syntheses and chemical properties of such classical acylals and show what potentially under-explored possibilities exist in the field of drug design, especially prodrugs, and classify this functional group in medicinal chemistry. Full article

Dysregulated RNA metabolism caused by SMN deficiency leads to motor neuron disease spinal muscular atrophy (SMA). Current therapies improve patient outcomes but achieve no definite cure, prompting renewed efforts to better understand disease mechanisms. The calcium channel blocker flunarizine improves motor function in Smn-deficient mice and can help uncover neuroprotective pathways. Murine motor neuron-like NSC34 cells were used to study the molecular cell-autonomous mechanism. Following RNA and protein extraction, RT-qPCR and immunodetection experiments were performed. The relationship between flunarizine mRNA targets and RNA-binding protein GEMIN5 was explored by RNA-immunoprecipitation. Flunarizine increases demethylase Kdm6b transcripts across cell cultures and mouse models. It causes, in NSC34 cells, a temporal expression of GEMIN5 and KDM6B. GEMIN5 binds to flunarizine-modulated mRNAs, including Kdm6b transcripts. Gemin5 depletion reduces Kdm6b mRNA and protein levels and hampers responses to flunarizine, including neurite extension in NSC34 cells. Moreover, flunarizine increases the axonal extension of motor neurons derived from SMA patient-induced pluripotent stem cells. Finally, immunofluorescence studies of spinal cord motor neurons in Smn-deficient mice reveal that flunarizine modulates the expression of KDM6B and its target, the motor neuron-specific transcription factor HB9, driving motor neuron maturation. Our study reveals GEMIN5 regulates Kdm6b expression with implications for motor neuron diseases and therapy. Full article

An electron donor–acceptor complex was utilized to generate alkoxy radicals from alcohols under mild conditions using visible light. This approach was combined with a hydroxybromination process to achieve the deconstructive functionalization of alkenes, leading to the production of geminal dibromides. Mechanistic investigations indicated the intermediacy of hypervalent iodine (III) compounds. Full article

This paper examines patterns of gemination in child Egyptian Arabic, with a focus on how gemination functions as a repair strategy, using data from the Egyptian Arabic Salama Corpus. The findings show that the phonological development of Egyptian Arabic-speaking children of geminated consonants correlates with previously established developmental stages. Initial stages involve the acquisition of labial geminates, transitioning through an increased use of alveolar and velar geminates, to the acquisition of rhotic and lateral geminates in later phases. The findings also suggest that gemination is not merely a phonetic phenomenon in child phonology, but also shows the children’s awareness of the phonology of the dialect, especially the moraicity of vowels and consonants. Full article