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Stabilized Wilson fermions are a reformulation of Wilson clover fermions that incorporates several numerical stabilizing techniques, but also a local change of the fermion action - the original clover term being replaced with an exponentiated version of it. We intend to apply the stabilized Wilson fermions toolbox to the thermodynamics of QCD, starting on the Nf=3 symmetric line on the Columbia plot, and to compare the results with those obtained with other fermion discretizations.
We discuss results for the Roberge Weiss (RW) phase transition at nonzero imaginary baryon and isospin chemical potentials, in the plane of temperature and quark masses. Our study focuses on the light tricritical endpoint which has already been used as a starting point for extrapolations aiming at the chiral limit at vanishing chemical potentials. In particular, we are interested in determining how imaginary isospin chemical potential shifts the tricritical mass with respect to earlier studies at zero imaginary isospin chemical potential. A positive shift might allow one to perform the chiral extrapolations from larger quark mass values, therefore making them less computationally expensive. We also present results for the dynamics of Polyakov loop clusters across the RW phase transition.
We present first results of a recently started lattice QCD investigation of antiheavy-antiheavy-light-light tetraquark systems including scattering interpolating operators in correlation functions both at the source and at the sink. In particular, we discuss the importance of such scattering interpolating operators for a precise computation of the low-lying energy levels. We focus on the b¯b¯ud four-quark system with quantum numbers I(JP)=0(1+), which has a ground state below the lowest meson-meson threshold. We carry out a scattering analysis using Lüscher's method to extrapolate the binding energy of the corresponding QCD-stable tetraquark to infinite spatial volume. Our calculation uses clover u, d valence quarks and NRQCD b valence quarks on gauge-link ensembles with HISQ sea quarks that were generated by the MILC collaboration.
In this work, the phase diagram of the 2+1-dimensional Gross-Neveu model is investigated with baryon chemical potential as well as chiral chemical potential in the mean-field approximation. We study the theory using two lattice discretizations, which are both based on naive fermions. An inhomogeneous chiral phase is observed only for one of the two discretizations. Our results suggest that this phase disappears in the continuum limit.
Nitrogen pollution is a major constituent of global change, threatening local biodiversity, ecosystem services, and causing serious environmental damage. Specifically, in areas with heavy agricultural soil-use, excessive use of nitrogen fertilizer pollutes the groundwaters with nitrates, but also with ammonia and nitrites. Freshwater fish and other aquatic fauna are especially vulnerable to nitrites, which can cause massive mortalities at even low concentrations < 0.1 mg/l NO2- - N. Adaptation of fish to environments with relatively high concentrations of chemicals has occurred throughout the history of life, although contemporary evolution acts at a much more rapid pace. The growing use of land for mass agriculture and livestock industries in the last 50 years in Florida has dramatically increased the nutrient loading into the groundwaters that feed the springs. Nitrite poses a serious threat for freshwater fauna as it is rapidly up taken and disturbs ion homeostasis and blood gas transport in fish. In this study, we evaluated, by means of a common-garden experiment, the tolerance of fish to nitrite using three different populations of eastern mosquitofish (Gambusia holbrooki) with different background nitrogen pollution histories. Mosquitofish females were exposed to nitrite in the lab, to either < 0.005 mg/l NO2- (control) or 0.3 mg/l NO2- for ten days and we assessed at the end of the exposure period their blood O2 transport capacity by measuring the concentration of four different types of hemoglobin, their total hematocrit, and their respiratory rates. Preliminary results show slight but significant varying patterns in the response of the exposed fish, depending on the population source, as evidenced by their respiratory rates and the blood erythrocyte counts. Mortality was very low, and hemoglobin profiles indicate high tolerance of G. holbrooki to nitrite contamination – a factor supporting their invasion success in agriculturally dominated regions around the world.
Sulfur in the slab: a sulfur-isotopes and thermodynamic-modeling perspective from exhumed terranes
(2022)
Sulfur is a key element in the subduction zone-volcanic arc system; however, the mechanism(s) that recycle sulfur from the slab into the overlying volcanic arc are debated. Here we summarize recent advances in quantifying this component of the deep sulfur cycle. First, primary metamorphic or inherited sulfides in oceanic-type eclogites are only rarely observed as inclusions and are typically absent from the rock matrix. Additionally, sulfides are relatively common in rocks metasomatized at the slab-mantle interface by slab-derived fluids during exhumation. Combined, these two observations suggest that sulfur loss from subducted mafic crust is relatively efficient. Thermodynamic modeling in Perple_X using the Holland and Powell (2011) database combined with the Deep Earth Water model suggests that the efficiency and speciation of sulfur loss varies depending on the degree of seafloor alteration prior to subduction and the geothermal gradient of the slab. In relatively cold subduction zones, such as Honshu, slab-fluids derived from subducted mafic crust are predicted to exhibit elevated concentrations of HSO4-, SO42-, HSO3-, and CaSO4(aq), whereas hot subduction zones, such as Cascadia, are predicted to produce slab fluids enriched in HS- and H2S at lower pressures. The oxidation of sulfur expelled from subducted pyrite is balanced by the reduction of Fe3+ to Fe2+, consistent with the low Fe3+/SFe of exhumed eclogites relative to blueschists and altered oceanic crust. Where oxidized S-bearing fluids are produced, they are anticipated to interact with more reduced rocks at the slab-mantle interface and within the mantle wedge, resulting in sulfide precipitation and significant isotopic fractionation. The δ34S values of slab fluids are estimated to fall between -11 and +8 ‰. Rayleigh fractionation during progressive fluid-rock interaction results in fractionations of tens of per mil as oxidized species are depleted and sulfides are precipitated, resulting in δ34S values of sulfides that easily span the -21.7 to +13.9 ‰ range observed in metasomatic sulfides in exhumed high-pressure rocks. However, in subduction zones where reduced species prevail, the S isotopic signature of slab fluids is expected to reflect their source and will exhibit a narrower range in δ34S values. As a result, the δ34S values measured in arc magmas may not always be a reliable indicator of the contribution of different components of the slab, such as sediments vs. AOC. Additionally, the impact of S recycling on the oxygen fugacity of arc magmas is expected to vary both spatially and temporally throughout Earth history.
Introduction: The influence of our diet on mental health is of increasing importance in current research. Study results on the gut-brain axis suggest that the gut microbiome can influence mental processes via neuronal, hormonal and immune signaling pathways [1]. The gut microbiome is largely influenced by our diet. Some studies provide evidence that a "Western diet" rich in saturated fat and sugar may promote mental disorders [2]. There is evidence, that dietary behaviour in individuals with Attention Deficit Hyperactivity Disorder (ADHD) is characterized by an increased intake of sugar and saturated fat [3]. So far, it is unclear whether this dietary pattern contributes to ADHD symptoms such as impulsivity. The aim of this study is to investigate the influence of certain macronutrients such as fats and mono/disaccharides on impulsivity in individuals with ADHD. Using our APPetite-mobile-app [4] enabled us to study dietary behaviour and momentary impulsiveness in everyday life of our participants.
Methods: 43 participants with ADHD (mean age 36.0 ± 12.3 years, 21 females) and 186 healthy controls (mean age 28.5 ± 7.7 years, 133 females) without any psychiatric condition were included into the study. Food intake was recorded over a period of three days using the APPetite-mobile-app via a 6 step process: (1) Selection of meal type, (2) Entry of time of meal, (3) Selection of consumed foods and drinks, (4) Specification of consumed amounts, (5) Presentation of reminder for commonly forgotten foods, and (6) Indication of predominant reason for eating. In addition to entering consumed foods in the APPetite-mobile-app, subjects completed an online food log for the last 24 hours (myfood 24) at the beginning of the study. After the data collection period, a detailed analysis of the ingested nutrients was performed for each subject. Trait impulsivity was assessed using the UPPS-P, a self-assessment questionnaire. Momentary impulsiveness was assessed via the mHealth APP by means of the Momentary Impulsiveness scale (MIS). The MIS consists of 4 questions capturing different aspects of impulsivity. The participants were prompted to answer these questions at 8 semi-random times per day between 8 AM and 10 PM. The minimum time between 2 prompts was 1 hour. Thereby participants could not predict the exact time of the next prompt and the assessed situations are a better reflection of the participant’s real life.
Results: ANOVA revealed higher levels of both, trait and momentary impulsivity in individuals with ADHD compared to controls (p < 0,01). After preprocessing of data that was sampled via the mHealth APP is completed, a regression analysis with different macronutrients as predictors and impulsivity as dependent variable will be computed. To assess the association between momentary impulsiveness and dietary intake, generalized linear multilevel modelling will be used. Results of these analyses will be presented.
Oral e-Poster Presentations - Booth 1: Vascular 3, September 27, 2023, 10:00 AM - 10:40 AM
Background: Despite current clinical guidelines recommending suboccipital decompressive craniectomy (SDC) in patients with space-occupying cerebellar infarction when neurological deterioration occurs, the precise definition of such deterioration remains unclear. The current study aimed at characterizing whether clinical outcomes can be predicted by the GCS score immediately prior to SDC, and whether higher GCS scores are associated with better clinical outcomes. We aimed to characterize whether clinical outcomes can be predicted by the GCS score immediately prior to SDC, and if higher GCS scores are associated with better clinical outcomes.
Methods: In a single-center, retrospective analysis of 51 patients treated with SDC for space-occupying cerebellar infarction clinical and imaging data were evaluated at the timepoints of symptom onset, hospital admission and preoperatively. Clinical outcome was measured by mRS at the last available follow-up. Preoperative GCS scores were stratified into three groups (GCS 3-8, 9-11 and 12-15). Univariate and multivariate Cox regression analyses were performed using clinical and radiological parameters as predictors of clinical outcome.
Results: In Cox-regression analysis using mRS of 1-2 as a positive clinical outcome we found a significant increase in the proportional hazard ratio (HR) of 6.581 [CI 1.839-36.414]; p=0.031 for GCS scores of 12-15 prior to SDC. Clinical outcomes (mRS 3-6) were associated with infarct volume above 6.0 cm3 (HR 2.473 [CI 1.209-5.057]; p=0.013), tonsillar herniation (HR: 0.279 [CI 0.083-0.933]; p=0.038), brainstem compression (HR 0.304 [CI 0.123-0.749]; p=0.010) and a preoperative GCS score of 3-8 (HR 2.386 [CI 1.160-4.906]; p=0.018).
Conclusions: SDC should be considered in patients with infarct volumes above 6.0 cm3 with GCS scores higher than previously described in the literature, as these patients may show better long-term outcome than those in which surgery is delayed until a GCS score of 11 or lower.
Garnet xenocrysts from kimberlites provide unique insights into the composition, structure and evolution of the subcontinental lithospheric mantle (SCLM). For example, different metasomatic events in the SCLM are reflected in compositional differences between garnet xenocrysts. As mantle metasomatism largely controls the physical and chemical properties of the SCLM, it exerts first order control over the genesis of kimberlitic magmas and diamond formation. However, dating mantle lithologies and processes is complicated by high ambient temperatures that allow the equilibration of most isotopic systems up to the time of kimberlite eruption. As a consequence, the temporal connection between metasomatic events in the mantle and kimberlite genesis is commonly ambiguous.
In this study, we applied LA-ICPMS U-Pb dating to 43 harzburgitic, lherzolithic and megacrystic garnet xenocrysts from the ~376 Ma diamondiferous V. Grib kimberlite, Russia, in order to investigate the link between different types of mantle metasomatism and kimberlite genesis.
Our results indicate that, with two possible exceptions, only harzburgitic garnet overlaps in age with the kimberlite eruption, whereas lherzolitic and megacrystic garnet crystals are ~20 to 130 million years older. Furthermore, garnet U-Pb ages and Ni-in-garnet temperatures of ~820 to 1200 °C do not correlate. This, and the high closure temperature of U-Pb in garnet (≥900 °C) suggests that the garnet U-Pb ages indeed reflect metasomatic events in the SCLM. However, the U-Pb ages could also reflect cooling ages. In this case, the metasomatic events recorded in the garnet crystals must still have occurred up to ~130 million years prior to the eruption of the V. Grib kimberlite.
These findings have far-reaching implications for the genesis of (diamondiferous) kimberlites, as they clearly show that the time lag between metasomatic events in the SCLM, as recorded in kimberlitic garnet xenocrysts, and kimberlite eruption may extend to tens of millions of years.
Oral e-Poster Presentations - Booth 3: Spine 2 (Tumors), September 26, 2023, 4:10 PM - 4:50 PM
Background: Spinal metastasis remains a persistent and oftentimes urgent challenge in the neurosurgical operating room. We aim to understand metastatic spread to the spinal bone on a molecular level in endothelial cells and tumor cells to facilitate improved therapeutic approaches and diagnostics.
Methods: We established a murine syngeneic spinal bone metastasis model. In vivo dissemination was first evaluated using fluorescent beads, followed by murine cancer cell lines (B16, LLC1). We investigated short-term seeding and long-term growth to identify correlations between seeding and tumor formation. EphrinB2-Eph4 interaction has been described as a crucial mediator of spinal bone metastasis. Transient (pharmacological) and permanent (genetical) ephrinB2-Eph4 interventions were performed.
Results: Dissemination of microbeads to distinct spinal segments depended on segment and particle size. Disseminated tumor cells on the contrary showed less frequent arrest in the bone and equal distribution among segments. EphrinB2 intervention changed the dissemination behavior towards the lumbar segment. Interestingly, only transient intervention retained this distribution, permanent ephrinB2 depletion on endothelial cells (efnb2iΔEC) resulted in equal dispersion of metastases. Histological staining revealed a reduction of Endomucin (Emcn) positive structures in combination with a reduction of Type H (Emcn high/CD31 high) endothelial cells in naïve efnb2iΔEC animals. In tumor tissue, these Type H endothelial cells were unaffected. However, an increase in CD31-expressing endothelial cells was observed under endothelial ephrinB2 depletion. These CD31-expressing endothelial cells have been recently described as Type E (Emcn low/CD31 high) and implicated in angiogenesis and osteogenesis.
Conclusions: We here describe a subpopulation of endothelial cells in efnb2iΔEC mice that seems to resemble pro-angiogenic and possibly pro-adhesive type E endothelial cells. Based on these finding we propose a compensatory pro-angiogenic mechanism in efnb2iΔEC mice that is highjacking pre-existing developmental pathways, which is critical for late-stage spinal metastatic growth independent of the initial seeding and extravasation of metastatic cells.
Oral e-Poster Presentations - Booth 2: Neuro-Oncology C (Imaging&Monitoring), September 27, 2023, 1:00 PM - 2:30 PM
Background: Repetitive TMS (rTMS) can be used to non-invasively map cortical language areas. Commonly, frequencies of 5-10 Hz are used to induce speech errors. We could recently show that frequencies of 30 and 50 Hz are advantageous to achieve higher reliability. However, high-frequent rTMS applied over perisylvian regions still suffer from limited tolerability. Using short-train or paired-pulse TMS (pp-TMS) might offer a good alternative to rTMS to interfere with speech production. In this study, we, therefore, compared 30 Hz rTMS to pp-TMS aiming at improved language mapping.
Methods: 13 healthy, right-handed subjects (f=6, 25-41 years) were investigated using two different rTMS protocols: (i) 30 Hz rTMS and (ii) pp-TMS. TMS protocols were applied in a pseudo-randomized order during a picture naming task (picture-to-trigger interval: 0 ms) over cortical language areas. In a subsequent study, we compared pp-TMS also to short trains of three TMS pulses and repetitive paired pulse TMS. Language errors were post-hoc analysed by two independent raters and were assigned to eight different error categories. The level of pain was assessed on a subjective 0-10 numeric rating scale (NRS). Moreover, language error distribution was analysed using a cortical parcellation system.
Results: 30 Hz rTMS evoked a significantly higher number of errors than the pp-protocol, i.e., 18 ± 12 % vs. 10 ± 7 % (p<0.05). However, pp-TMS was significantly better tolerated with a mean NRS of 2.3 ± 1.6 vs. 3.4 ± 1.5 (p<0.05, FDR-corrected). Of note, pp-TMS could induce a higher number of anomias (15 ± 15 %) than repetitive TMS protocols (4 ± 7 %; p<0.1, FDR-corrected), but less dysarthria. The cortical distribution of errors differed between the two protocols. The results of train-of-three TMS were similar to the pp-TMS protocol.
Conclusions: Due to its better tolerability, pp-TMS might offer the possibility to stimulate regions which are particularly prone to direct facial / trigeminal nerve stimulation, e.g., the inferior frontal gyrus. Moreover, pp-TMS seems advantageous for mapping patients who are comparatively susceptible to rTMS side effects and with regard to safety in general.
Introduction: Lumbosacral fixation is a common procedure in primary and revision spine surgery but leads to high biomechanical stress on adjacent segments and the SIJ, resulting in implant failure such as breakage and loosening and pain. This frequently results in further surgery. For patients showing clinical and radiological signs of SIJ affection/arthrosis who fail conservative therapy, transarticular lumbopelvic fusion via the SIJ may be considered. The Bedrock™ technique has been described as a new option for reinforced lumbopelvic fixation, fusing the SIJ with additional triangular titanium implants, thereby reducing biomechanical loads off the S2AI screws. We share our experiences with 19 patients treated with this technique since January 2019.
Materials and Methods: 19 patients suffering from persisting low back pain (LBP) with indication for reinforced lumbopelvic fixation and SIJ fusion were treated with reinforced lumboplevic fixation with S2AI screw and a triangular titanium implant. 14 cases were revisions. All surgeries were carried out by a single surgeon at a orthopedic university hospital. Data was gathered retrospectively.
Results: From 1/2019 - 9/2021 19 patients (11f, 8m) were treated with reinforced lumbopelvic fixation and SIJ fusion with a mean follow up of 18,2 months. Mean age 68 years (range 62-78y). Preop. walking distance was reduced to an average <100 m. Standard treatment involved S2AI screws and triangular titanium implants (SIBone, iFuse 3D™). 14 revision cases split into 5 low grade infections with screw loosening, 3 cases with rod breakage, 5 cases of painful lumbopelvic screw prominence, 7 cases with proximal junctional kyphosis, 2 cases with misplaced implants, 8 cases of poor bone mineral density. 5 patients without prior spine surgery. All patients were treated bilaterally using freehand technique. Average implant length was 65 mm. There were no intraoperative or implant associated adverse events (AE) or serious adverse events (SAE). Postoperative imaging demonstrated good implant positioning and function. All patients regained walking ability for distances > 1000 m and were satisfied with the result. All patients reported significant reduction of SIJ pain.
Conclusion: We report results of 19 patients with a reinforced lumbopelvic fixation and fusion by S2AI screws augmented by one parallelly placed triangular titanium implant fusing the SIJ bilaterally with a mean follow-up of 18.2 months. Intra- and postoperatively we experienced no implant associated adverse event. Patients regained significant walking ability and significant reduction of SIJ pain. Radiologically no signs of implant loosening or failure were detected at the end of follow-up. Our results demonstrate a safe and efficacious surgical technique for reinforced lumbopelvic fixation with fusion of SIJ with significant improvement of the health care related quality of life. Further studies need to be conducted in order to obtain additional evidence.
This article summarizes some of the current theoretical developments and the experimental status of hypernuclei in relativistic heavy-ion collisions and elementary collisions. In particular, the most recent results of hyperhydrogen of mass A = 3 and 4 are discussed. The highlight at SQM2022 in this perspective was the discovery of the anti-hyperhydrogen-4 by the STAR Collaboration, in a large data set consisting of different collision systems. Furthermore, the production yields of hyperhydrogen-4 and hyperhelium-4 from the STAR Collaboration can be described nicely by the thermal model when the excited states of these hypernuclei are taken into account. In contrast, the production measurements in small systems (pp and p–Pb) from the ALICE Collaboration tends to favour the coalescence model over the thermal description. New measurements from STAR, ALICE and HADES Collaborations of the properties, e.g. lifetime, of A = 3 and 4 hypernuclei give similar results of these properties. Also the anti-hyperhydrogen-4 lifetime is in rather good agreement with previous measurements. Interestingly, the new STAR measurement on the R3 value, that is connected to the branching ratio, points to a Λ separation energy that is below 100 keV but definitely consistent with the value of 130 keV assumed since the 70s.
We show examples of the impact of the Maxwellian averaged capture cross sections determined at n_TOF over the past 20 years on AGB stellar nucleosynthesis models. In particular, we developed an automated procedure to derive MACSs from evaluated data libraries, which are subsequently used as input to stellar models computed by means of the FuNS code. In this contribution, we present a number of s-process abundances obtained using different data libraries as input to stellar models, with a focus on the role of n_TOF data.
Lattice QCD and functional methods are making significant progress in constraining the QCD phase diagram. As an important milestone, the chiral phase transition with massless u, d-quarks at zero density is now understood to be of second order for all strange quark masses, and a smooth crossover as soon as mu,d, ≠ 0. Together with information on fluctuations and refined reweighted simulations, this bounds a possible critical point to be at µB/T ≲3. On the other hand, an approximately chiral-spin symmetric temperature window has been discovered above the chiral crossover, Tch<T ≳3Tch, with distinct correlator multiplet patterns and a pion spectral function suggesting resonance-like degrees of freedom, which dissolve graduallly with temperature.
Prediction for hyper nuclei multiplicities from GSI to LHC energies from the Ultra-relativistic Quantum Molecular Dynamics (UrQMD) model combined with a final state coalescence approach is presented and compared to the thermal model. The influence of the coalescence radius on the collision energy and centrality dependence of the Λ3H/ΛΛ3H/Λ ratio is discussed.
Present nuclear reaction network computations for astrophysical simulations involve many different types of rates, including neutron-capture reactions of interest for the modeling of heavy-element nucleosynthesis. While for many of them we still have to rely on theoretical calculations, an increasing number of experimentally-determined cross sections have now become available. In this contribution, we present “ASTrophysical Rate and rAw data Library” (ASTRAL), a new online database for neutron-capture cross sections based on experimental results, mainly obtained through activation and timeof-flight measurements. For the evaluation process, cross sections were re-calculated starting from raw data and by considering recent changes in physical properties of the involved isotopes (e.g., half-life and γ-ray intensities). We show the current status of the database, the techniques adopted to derive the recommended Maxwellian-averaged cross sections, and future developments.
Phase transitions in a non-perturbative regime can be studied by ab initio Lattice Field Theory methods. The status and future research directions for LFT investigations of Quantum Chromo-Dynamics under extreme conditions are reviewed, including properties of hadrons and of the hypothesized QCD axion as inferred from QCD topology in different phases. We discuss phase transitions in strong interactions in an extended parameter space, and the possibility of model building for Dark Matter and Electro-Weak Symmetry Breaking. Methodological challenges are addressed as well, including new developments in Artificial Intelligence geared towards the identification of different phases and transitions.
We study threshold testing, an elementary probing model with the goal to choose a large value out of n i.i.d. random variables. An algorithm can test each variable X_i once for some threshold t_i, and the test returns binary feedback whether X_i ≥ t_i or not. Thresholds can be chosen adaptively or non-adaptively by the algorithm. Given the results for the tests of each variable, we then select the variable with highest conditional expectation. We compare the expected value obtained by the testing algorithm with expected maximum of the variables. Threshold testing is a semi-online variant of the gambler’s problem and prophet inequalities. Indeed, the optimal performance of non-adaptive algorithms for threshold testing is governed by the standard i.i.d. prophet inequality of approximately 0.745 + o(1) as n → ∞. We show how adaptive algorithms can significantly improve upon this ratio. Our adaptive testing strategy guarantees a competitive ratio of at least 0.869 - o(1). Moreover, we show that there are distributions that admit only a constant ratio c < 1, even when n → ∞. Finally, when each box can be tested multiple times (with n tests in total), we design an algorithm that achieves a ratio of 1 - o(1).
The Ethics of Waiting lists and Rationing access to care (Ethics Parallel Session), September 26, 2023, 4:50 PM - 6:20 PM
Background: There has been a fivefold increase of neurosurgeons over the last three decades in Germany, despite a lesser increase in operations. Currently, there are approximately 1000 neurosurgical residents employed at training hospitals. Little is known about the overall training experience and career opportunities for these trainees.
Methods: In our role as resident representatives, we implemented a mailing list for interested German neurosurgical trainees. Thereafter, we created a survey including 25 items to assess the trainees’ satisfaction with their training and their perceived career prospects, which we then distributed through the mailing list. The survey was open from 1st April until 31st May 2021.
Results: 90 trainees were enrolled in the mailing list and we received 81 completed responses to our survey. Overall, 47% of trainees were very dissatisfied or dissatisfied with their training. 62% of trainees reported a lack of surgical training. 58% of trainees found it difficult to attend courses or classes and only 16% had consistent mentoring. There was an expressed desire for a more structured training programme and mentoring projects. In addition, 88% of trainees were willing to relocate for fellowships outside their current hospitals.
Conclusions: Half of the responders were dissatisfied with their neurosurgical training. There are various aspects that require improvement, such as the training curriculum, the lack of structured mentoring and the amount of administrative work. We propose the implementation of a modernized structured curriculum, which addresses the mentioned aspects, in order to improve neurosurgical training and, consecutively, patient care.
In the culture history of ancient Europe questions pertaining to its diverse relationships to advanced civilisations in the Mediterranean sphere look back upon a long tradition. Varyingly different single finds and groups of finds have repeatedly provided the prospect and scope for investigating the character and extent of contacts and influences as well as the consequences for cultural developments north of the Alps. In discussions on the genesis and significance of the Bronze Age in central and northern Europe, the perceived linkages between the eastern Mediterranean and the Carpathian Basin and via the Danube River as far as areas north of the Alps have played an important role. Without question, the Danube River represented a crucial axis of communication ever since the Neolithic period and in following times. Recent interdisciplinary studies, however, have broadened the scope and shown that further important communication routes existed along the Ionian-Adriatic Sea to Upper Italy and beyond the Alps, and via the Rhône valley and the West Alps to the North. Thereby, impulses of varying economic nature could be discerned, which were consequential for many aspects of the cultural development of the Early and Middle Bronze Age in Central Europe.
In QCD at large enough isospin chemical potential Bose-Einstein Condensation (BEC) takes place, separated from the normal phase by a phase transition. From previous studies the location of the BEC line at the physical point is known. In the chiral limit the condensation happens already at infinitesimally small isospin chemical potential for zero temperature according to chiral perturbation theory. The thermal chiral transition at zero density might then be affected, depending on the shape of the BEC boundary, by its proximity. As a first step towards the chiral limit, we perform simulations of 2+1 flavors QCD at half the physical quark masses. The position of the BEC transition is then extracted and compared with the results at physical masses.
In this work we study the 3+1-dimensional Nambu-Jona-Lasinio (NJL) model in the mean field-approximation. We carry out calculations using five different regularization schemes (two continuum and three lattice regularization schemes) with particular focus on inhomogeneous phases and condensates. The regularization schemes lead to drastically different inhomogeneous regions. We provide evidence that inhomogeneous condensates appear for all regularization schemes almost exclusively at values of the chemical potential and with wave numbers, which are of the order of or even larger than the corresponding regulators. This can be interpreted as indication that inhomogeneous phases in the 3+1-dimensional NJL model are rather artifacts of the regularization and not a consequence of the NJL Lagrangian and its symmetries.
In this work, inhomogeneous chiral phases are studied in a variety of Four-Fermion and Yukawa models in 2+1 dimensions at zero and non-zero temperature and chemical potentials. Employing the mean-field approximation, we do not find indications for an inhomogeneous phase in any of the studied models. We show that the homogeneous phases are stable against inhomogeneous perturbations. At zero temperature, full analytic results are presented.
Oral e-Poster Presentations - Booth 2: Spine 1 (Trauma&Misc), September 25, 2023, 10:00 AM - 10:40 AM
Background: Spondylodiscitis is a prevalent type of spinal infection, with pyogenic spondylodiscitis being the most common subtype. While antibiotic therapy is the standard treatment, some argue that early surgery can aid in infection clearance, improve survival rates, and prevent long-term complications such as deformities. However, others view early surgery as excessively risky. Due to the high mortality rate of up to 20%, it is crucial to determine the most effective treatment.
Methods: The primary objective of this study was to compare the mortality rate, relapse rate, and length of hospital stay for conservative and early surgical treatments of pyogenic spondylodiscitis, including determinants of outcomes. The study was registered on PROSPERO with the registration number CRD42022312573. The databases MEDLINE, Embase, Scopus, PubMed, and JSTOR were searched for original studies comparing conservative and early surgical treatments of pyogenic spondylodiscitis. The included studies were assessed using the ROBINS-1 tool, and eligible studies were evaluated using meta-analyses, influence, and regression analyses.
Results: The systematic review included 31 studies. The meta-analysis, which had a pooled sample size of 10,954 patients from 21 studies, found that the pooled mortality rate among patients treated with early surgery was 8%, while the rate was 13% for patients treated conservatively. The mean proportion of relapse/failure was 15% for patients treated with early surgery and 21% for those treated conservatively. Furthermore, the analysis concluded that early surgical treatment is associated with a 40% and 39% risk reduction in relapse/failure and mortality rates, respectively, when compared to conservative management. Additionally, early surgical treatment resulted in a 7.75-day reduction in length of hospital stay per patient (p<0.01). The most highly significant predictors of treatment outcome were found to be intravenous drug use, diabetes, the presence of an epidural abscess, positive cultures, location of infection, and age (p<0.001).
Conclusions: Overall, early surgical management was found to be consistently significantly more effective than conservative management in terms of relapse/failure and mortality rates when treating pyogenic spondylodiscitis, particularly for non-spinal epidural abscess spondylodiscitis.
Introduction: Spondylodiscitis is the commonest form of infectious disease of the spine and harbours a high mortality rate of up to 20%. Recent demographic trends in Germany, such as an aging population, immunosuppression, and intravenous drug use, suggest that the incidence of spondylodiscitis may be on the rise. However, the exact epidemiological development of the disease remains uncertain. This study aims to analyse the burden on the tertiary healthcare system in Germany using data from the Federal Statistical Office of Germany (FSOG) database.
Materials and Methods: All cases of spondylodiscitis diagnosed between 2005 and 2021 were identified from the FSOG database. The study characterised the mean duration of hospital stays, total and population-adjusted number of diagnoses made, age-stratified incidence, and outcomes of hospitalised patients.
Results: A total of 131,982 diagnoses for spondylodiscitis were identified between 2005 and 2021. The number of diagnoses for spondylodiscitis has doubled during this period, from 5.4/100,000 population in 2005 to 11/100,000 population in 2021. The highest increase in admissions was recorded for those aged 90 years and above (+1307%), 80-89 (+376%) and 70-79 (+99%). Hospital discharges to rehabilitation facilities have increased by 160%, and discharges against medical advice by 91%. On the other hand, during the analysed period, the in-hospital mortality rate has decreased by 52%.
Conclusion: The population-adjusted incidence of spondylodiscitis in Germany has more than doubled between 2005 and 2021, highlighting the clinical relevance of this disease. During the same period, in-hospital mortality dropped by half. These findings suggest the need for further investigation into optimal therapy, particularly the role and timing of surgical treatment.
Nitrogen pollution is a major constituent of global change, threatening local biodiversity, ecosystem services, and causing serious environmental damage. Specifically, in areas with heavy agricultural soil-use, excessive use of nitrogen fertilizer pollutes the groundwaters with nitrates, but also with ammonia and nitrites. Freshwater fish and other aquatic fauna are especially vulnerable to nitrites, which can cause massive mortalities at even low concentrations < 0.1 mg/l NO2- - N. Adaptation of fish to environments with relatively high concentrations of chemicals has occurred throughout the history of life, although contemporary evolution acts at a much more rapid pace. The growing use of land for mass agriculture and livestock industries in the last 50 years in the US has dramatically increased the nutrient loading into the surface and groundwaters. Nitrite poses a serious threat for freshwater fauna as it is rapidly up taken and disturbs ion homeostasis and blood gas transport in fish. In this study, we evaluated, by means of a laboratory experiment, the tolerance of fish to nitrite using six different populations of wild eastern mosquitofish (Gambusia holbrooki) from two regions, North FL and NC, and with different background nitrogen pollution histories. Mosquitofish females were exposed to nitrite in the lab, to either < 0.005 mg/l NO2- (control) or 0.3 mg/l NO2- for ten days and we assessed at the end of the exposure period their blood O2 transport capacity by measuring the concentration of four different types of hemoglobin, their total hematocrit, and their respiratory rates. Preliminary results show significant varying patterns in the response of the exposed fish, depending on the population source, as evidenced by their respiratory rates and the blood erythrocyte counts. Mortality was very low, and hemoglobin profiles indicate high tolerance of G. holbrooki to nitrite contamination – a factor supporting their invasion success in agriculturally dominated regions around the world
The Heidelberg Ion-Beam Therapy Centre (HIT) provides proton, helium, and carbon-ion beams with different energies and intensities for cancer treatment and oxygen-ion beams for experiments. For several experiments and possible future applications, such as helium ion beam radiography, a low-intensity ion beam monitor integrated into the dose delivery feedback system for the accelerator control is a necessary pre-requisite. The updated 2D prototype for this purpose consists of scintillating fibres with enhanced radiation hardness, silicon photomultipliers (SiPMs) to amplify the emitted light, and a dedicated front-end readout system (FERS) to process and record the generated signals. This setup was tested successfully on monitoring ion-beam position and profile horizontally and vertically, as well as the beam intensity, for all four ion types with energies from 50 to 430 MeV/u and intensities from 1E2 to 1E7 ions/s. Additionally, time-of-arrival (ToA) measurements on single ions have been successfully performed for a limited intensity range, allowing for ion tracking in a further update. This will reduce noise, and will also improve the accuracy and usability of ion radiography.
Introduction: The optimal treatment of patients with spinal infections remains a controversial topic. Within Europe, fundamentally different therapeutic concepts are found. Therefore, the aim of this study was to compare the outcome of patients who received surgical vs. antibiotic treatment alone for primary pyogenic spondylodiscitis in an international cohort analysis.
Materials and Methods: The retrospectively compiled databases of tertiary high-volume spine centers served as the baseline for this study. All documented cases of primary spondylodiscitis treated surgically and conservatively in the period of 2017-2022 were included and grouped according to the therapeutic concept: conservative vs. surgical treatment. Independent investigators collected the relevant clinical and radiological data. The primary endpoint of this study was mortality rate; secondary endpoints were relapse rate and persisting neurological deficit.
Results: A total of 392 patients were included in the analysis (155 females with a mean age of 68 years). Of these, 95 cases were treated conservatively (CoT) and 297 cases were treated surgically (SuT). There was no significant difference (p<0.01) related to patient’s disease characteristics: Lumbar was the main location (n=240, CoT 58/ SuT 182, p=0.97) followed by thoracic (n=70, CoT 24/ SuT 46, p=0,03) and cervical (n=47, CoT 7/ SuT 40, p=0.11) region. A multilocular spinal infection was present in 32 patients (CoT 3/ SuT 29, p=0.04). 181 cases (CoT 36/ SuT 145, p=0.06) presented with an epidural abscess. Neurological deficits were recorded in 100 cases (CoT 26/ SuT 74, p=0.63), and septic conditions in 88 cases (CoT 26/ SuT 62, p=0.19). Pre-existing conditions like Diabetes (p=0.57), renal failure (p= 0.97), hepatopathy (p= 0.15), malignoma (p=0.39) or i.v. drug abuse (p=0.93) did also not differ between the groups. The mortality rate of all conservatively treated was 24.2% (23 cases) and 6.7% (20 cases) in all surgically treated patients (p<0.001). A follow-up of ≥ 6 weeks was available in 289 cases (CoT 83, SuT 206 ). In this subset of patients relapse of infection occurred in six (7.2%) and 23 (11.2%) cases in the conservative and early surgical treatment group, respectively (p=0.69). Persisting neurological deficit was recorded in 21 (25.3%) of conservatively treated and 51 (24.8%) of surgically treated cases (p=0.92).
Conclusion: Whereas relapse rates and persisting neurological deficit were not found to differ significantly, the results of this international data analyses, with their respective limitations, clearly support the growing evidence of a significantly reduced mortality rate after surgical therapy for primary pyogenic spondylodiscitis when compared to conservative treatment regimen.
Spinal Tumors / Infections (Spine Parallel Session v.3), September 27, 2023, 8:30 AM - 10:00 AM
Background: The optimal treatment of patients with spinal infections remains a controversial topic. While there is some consensus regarding the indication for surgical intervention in infections with neurologic deficit, significant deformity or progressive disease, other situations remain controversial. Within Europe, fundamentally different therapeutic concepts are found. Therefore, the aim of this study was to compare the outcome of patients who received surgical vs. antibiotic treatment alone for primary pyogenic spondylodiscitis in an international cohort analysis.
Methods: The retrospectively compiled databases of tertiary high-volume spine centers served as the baseline for this study. All documented cases of primary spondylodiscitis treated surgically and conservatively in the period of 2017-2022 were included and grouped according to the therapeutic concept: conservative vs. surgical treatment. Independent investigators collected the relevant clinical and radiological data. The primary endpoint of this study was mortality rate; secondary endpoints were relapse rate and persisting neurological deficit.
Results: A total of 392 patients were included in the analysis (155 females and 237 males with a mean age of 68 years). Of these, 95 cases were treated conservatively (CoT) and 297 cases were treated surgically (SuT). Most of conservatively treated patients were treated in the United Kingdom (CoT 81/ SuT 7), while most of the surgically treated cases were treated in Germany (CoT 14/ SuT 290). There was no significant difference (p<0.01) related to patient’s disease characteristics:
Lumbar was the main location (n=240, CoT 58/ SuT 182, p=0.97) followed by thoracic (n=70, CoT 24/ SuT 46, p=0,03) and cervical (n=47, CoT 7/ SuT 40, p=0.11) region. A multilocular spinal infection was present in 32 patients (CoT 3/ SuT 29, p=0.04). 181 cases (CoT 36/ SuT 145, p=0.06) presented with an epidural abscess. Neurological deficits were recorded in 100 cases (CoT 26/ SuT 74, p=0.63), and septic conditions in 88 cases (CoT 26/ SuT 62, p=0.19). Pre-existing conditions like Diabetes (CoT 20/, SuT 71, p=0.57), renal failure (CoT 19/ SuT 60, p= 0.97), hepatopathy (CoT 4/ SuT 26, p= 0.15), malignoma (CoT 9/ SuT 38, p=0.39) or i.v. drug abuse (CoT 5/, SuT 15, p=0.93) did also not differ between the groups.
The mortality rate of all conservatively treated was 24.2% (23 cases) and 6.7% (20 cases) in all surgically treated patients (p<0.001). A follow-up of ≥ 6 weeks was available in 289 cases (CoT 83, SuT 206 ). In this subset of patients relapse of infection occurred in six (7.2%) and 23 (11.2%) cases in the conservative and early surgical treatment group, respectively (p=0.69). Persisting neurological deficit was recorded in 21 (25.3%) of conservatively treated and 51 (24.8%) of surgically treated cases (p=0.92).
Conclusions: Whereas relapse rates and persisting neurological deficit were not found to differ significantly, the results of this international data analyses, with their respective limitations, clearly support the growing evidence of a significantly reduced mortality rate after surgical therapy for primary pyogenic spondylodiscitis when compared to conservative treatment regimen.
Asymptotic giant branch (AGB) stars are responsible for the production of the main component of the solar s-process distribution. Despite enormous progress in the theoretical modeling of these objects over the last few decades, many uncertainties remain. The still-unknown mechanism leading to the production of 13C neutron source is one example. The nucleosynthetic signature of AGB stars can be examined in a number of stellar sources, from spectroscopic observations of intrinsic and extrinsic stars to the heavy-element isotopic composition of presolar grains found in meteorites. The wealth of available observational data allows for constraining the processes occurring in AGB interiors. In this view, we discuss recent results from new AGB models including the effects of mixing triggered by magnetic fields, and show comparisons of the related s-process nucleosynthesis with available observations.
The oxidation state of sulfur in slab fluids is controversial, with both dominantly oxidized and reduced species proposed. Here we use in situ X-ray absorption spectroscopy analysis of sulfur-in-apatite to monitor changes in the oxidation state of sulfur during high-P metasomatism by slab fluids in the subduction channel. Our samples include a 73 cm continuous transect of reaction zones between a metagabbroic eclogite block and serpentinite matrix from a mélange zone on the island of Syros, Greece. The block core consists of garnet, omphacite, phengite, paragonite, epidote-clinozoisite, and rutile. In this region, apatite is only observed as elongate inclusions in omphacite cores. From the core outwards micas are increasingly replaced by epidote-clinozoisite, garnets are smaller and more frequent, pyrite + bornite is observed as inclusions in recrystallized omphacite, and apatite is increasingly abundant in the matrix and inclusions in garnet. A major transition at 48 cm separates an assemblage of Ca-Na amphibole, omphacite, chlorite, pyrite, and apatite from the inner garnet-bearing eclogite assemblages. Omphacite disappears from the assemblage at ~56 cm and amphibole compositions sharply transition to tremolite at 59 cm. Finally, the assemblage tremolite + talc + pyrite is observed after ~70 cm.Apatites in the eclogite assemblages exclusively display S6+ peaks in their absorption spectra. This includes apatite inclusions in omphacite in the least altered lithology, as well as matrix apatite and isolated apatite inclusions in garnet in the outermost metasomatized eclogite zone. In the intermediate pyrite-rich (~1-5 vol %) amphibole + omphacite + chlorite zone, apatite displays a strong S1- absorption peak in most grains, with rare analyses showing mixed S1- and S6+. Finally, apatite in the outermost tremolite-bearing assemblages only displays a S6+ peak. The pyrite-rich zone at 48 cm occurs at the initial interface between the serpentinite matrix and eclogite block, characterized by a dramatic decrease in Na content and Mg#. Our data suggest that reduction of S6+ in infiltrating fluids to S1- in pyrite became focused as Fe diffused across the steep Mg# gradient, resulting in pyrite precipitation. In contrast, S reduction in the Mg-rich tremolite-dominant portions of the transect was limited by a lack of Fe, resulting in low modes of pyrite and fluid buffered S6+ in apatite. Finally, S6+-bearing apatite is also observed in reaction zone lithologies from elsewhere on Syros, suggesting our observations are not isolated.Two important conclusions are drawn from these data and observations: (1) In the case of Syros, slab fluids at eclogite-facies conditions carried oxidized S6+, and (2) The interaction of these fluids with eclogites composed of ferrous-Fe silicates resulted in extensive sulfide precipitation.
Insulin resistance and working memory exploring the role of blood glucose levels and lifestyle
(2023)
vIntroduction: Type 2 diabetes mellitus and dementia are among the leading causes for reduced quality of life and life expectancy worldwide and often occur comorbidly. Both diseases are linked by altered insulin signaling. Lifestyle factors and blood glucose monitoring play an essential role in the prevention and treatment of type 2 diabetes. So far, a relationship between blood glucose levels, lifestyle, and cognitive performance – a main symptom of dementia - has mainly been established in laboratory settings which reduces its ecological validity.
Objectives: This study uses ambulatory assessment and continuous glucose monitoring to explore the link between blood glucose levels, lifestyle and working memory in an ecological setting. We hypothesize that glycemic variations affect working memory performance in daily life. Second, we hypothesize that a high variance in blood glucose levels has a higher impact on working memory in insulin resistant participants. With this study, we aim to expand the knowledge on the relationship of insulin resistance and cognitive performance from the laboratory setting to everyday life.
Methods: This prospective, exploratory study will include 80 subjects with insulin resistance and 80 healthy controls. At baseline, blood indicators of insulin resistance will be measured to determine group assignment. Our ambulatory assessment includes smartphone-based sampling and sensor-based assessment. Therefore, cognitive performance will be recorded over three consecutive days using a smartphone. Four times a day, a numerical working memory task is prompted by signal-based alarms on the smartphone. Blood glucose levels are recorded in parallel by continuous glucose monitoring. In addition, lifestyle factors such as diet ad physical activity are examined. Diet is assessed by 24-h dietary protocols and movement acceleration by accelerometery.
Multilevel modelling will be used to map the relationship between blood glucose levels and working memory at the within- and between-person level. Diet and exercise are included in the analyses as additional predictors.
Results: Data collection started in March 2021 and is ongoing. Up to now, 40 insulin resistant participants and 36 healthy controls have been measured. Our preliminary results indicate a positive association between blood glucose levels and working memory performance at the within-person level (estimate = .48, 95% CI [.07, .89], p =0.022). At the between-person level the analysis revealed an inverse association between blood glucose levels and working memory performance (estimate = -.45, 95 % CI [-.86 - -.05], p = 0.029).
Conclusion: Our preliminary results are in line with studies showing that an acute rise in blood glucose levels leads to short-term improvements, while stable glucose profiles are beneficial in the long term. This might expand the understanding of the impact of insulin resistance on working memory and represent a target for early interventions. Our preliminary analysis needs to be repeated in our final dataset to confirm our results.
How can older adults participate equally in digitisation processes across Europe, and what inclusive research strategies are needed? This Zine summarizes findings from a “Research Innovation Lab on Ageing in a Digital Age”, funded by the VolkswagenStiftung, aiming to bring together 29 docs and postdocs anchored in 26 different disciplines coming from 11 countries, at all stages of their work, to address cutting edge questions relating to ageing in a digital age. Five groups worked together over five days in Frankfurt, Germany, in July 2023 in a creative and interactive hackathon, specific to developing non-technical solutions to social issues of this topic. Moreover, four distinguished experts presented keynote speeches and proposals from various conceptual, methodological and empirical perspectives.