Pain mechanisms in chronic pancreatitis

The purpose of the present study is the bibliographic review of chronic pancreatitis (CP) and its underlying pain-induction mechanisms. Chronic pancreatitis is defined as a progressive inflammatory process characterized by destruc­tion or total eradication of the parenchyma and fibrosis. One of its prevailing symptoms is pain. It is severe, dull, epigastric, often radiating to the back, recurrent or permanent. Pain stands for an unpleasant, frustrating sensation evoked by stimuli like harmful agents and inflammation, as a reaction of the human body alerting it for the presence of an intrinsic or extrinsic hazard. In the case of CP pain a great number of causative mechanisms has been proposed. Formerly, it was perceived as originating from the inflammatory and fibrotic process. Pancreatic ischemia related to ductal and parenchymal tissue hyper­tension and extrapancreatic causes like bile duct and duodenal stenosis have also been proposed. Most recently, emphasis has been placed on the neuropathic component of CP as pain is provoked by peripheral nociceptive mechanisms. Pancreatic neuropathy in terms of neural damage, increased neural density and hypertrophy along with central sensitization (spinal and cerebral hyperexcitability) are also involved in this theory. The various hypotheses highlight its multifactory nature and the need for further exploration

NEARBY INTERACTING GALAXY PAIRS: DYNAMICS AND IONIZED GAS PROPERTIES

Galaxy merging is an important process in galaxy formation and evolution throughout the cosmic time. Mergers are expected to play a significant role in galaxy mass assembly and transformation of galaxy morphology. In this work, we study inter- acting pairs of galaxies in a relatively early stage of the merging process, after they first pass by each other but before they coalesce into a single galaxy. At this stage, interacting disk galaxies display peculiar morphologies, often induced by the strong gravitational tidal field experienced during the first passage. These peculiar features can be utilized to constrain the encounter parameters of the merging galaxies, such as time since first passage, and pericentric separation (Toomre & Toomre, 1972; Hi- bbard & Mihos, 1995; Barnes & Hibbard, 2009). Moreover, in the early stages of galaxy mergers the individual galaxies are still clearly separated making it possible to investigate the chain of physical processes that are caused by the interaction. This includes starbursts or active galactic nuclei (AGNs) triggered by the infall of gas into the cores (Mihos & Hernquist, 1996; Hopkins & Quataert, 2011), and the shocks that are produced by feedback from starbursts and AGNs (Cox et al., 2006b; Narayanan et al., 2008; Rich et al., 2015), or by collision of gaseous clouds in the interstellar medium (ISM) of the two disks as they pass through each other (Struck, 1997). We develop a novel automated method for modeling the dynamics of equal mass galaxy mergers that puts meaningful constraints on the system’s encounter parameters. In order to understand the systematics of the measured encounter parameters, we test our method against an independent set of galaxy merger simulations with known initial conditions. For a controllable subset of these tests, our automated method recovers parameters such as merger stage and initial disk orientations within 3σ of the correct value. We explore the effects of using different kinematic tracers on the inferred encounter parameters by applying our method to HI and Hα velocity maps of a well-studied galaxy merger system in the nearby Universe, NGC 4676 a.k.a the Mice galaxies. We show for the first time that constraints on the encounter parameters derived from HI and Hα kinematics are consistent suggesting that Hα velocity maps can also be used for dynamical modeling. In total we observe a sample of 22 galaxy mergers in this work. Nineteen of them have morphological indicators similar to the Mice galaxies (separate cores and strong tidal features), and the other three are recently coalesced systems where cores are united, but outskirts are still disturbed. We use SparsePak integral field unit (IFU) (Bershady et al., 2004) on the WIYN telescope at Kitt Peak National Observatory (KPNO) to observe the Hα emission over the entire visible regions of these galaxies, including faint tidal tails. Relatively high spectral resolution of our data allows us to investigate multiple kinematic components in the emission lines. We separate Hα emission of photo-ionized HII regions from shocked gas, measure the velocity maps of HII regions, and discuss the fraction and spatial distribution of shocks and their power source. We apply our dynamical modeling method on equal mass systems in our sample and obtain the first ever constraints on the encounter parameters of one of them. We find a trend between shocked gas fraction and the projected separation between the galaxies in pairs, similar to Rich et al. (2015). In our sample of interacting pairs, for the first time, we also find a trend between shocked gas fraction and the light ratio (mass ratio). These trends suggest that in most of the observed systems the gravitational tidal impulse at the time of the first passage is the dominant origin of shocks. Also for the first time, we investigate the correlation between shocked gas fraction and encounter parameters from dynamical modeling. We find that time until coalescence and pericentric separation are both strongly anti-correlated with the amount of shocks. However, larger statistical sample is required for understanding the physical details and timing of shock production during galaxy mergers. Clean separation of shocks from star forming regions also improves the accuracy of star formation rate measurements in merging galaxies. Large ongoing and upcoming IFU galaxy surveys such as MaNGA (Bundy et al., 2015) will provide spatially resolved spectra of large numbers of galaxies including many galaxy mergers. Tools and techniques developed for this thesis project are required steps for better utilization of these valuable datasets

HUBUNGAN KONFORMITAS TEMAN SEBAYA DAN KONSEP DIRI DENGAN KENAKALAN REMAJA DI JAKARTA SELATAN

HUBUNGAN KONFORMITAS TEMAN SEBAYA DAN KONSEP DIRI DENGAN KENAKALAN REMAJA DI JAKARTA SELATAN

Η επίδραση σακχαρώδη διαβήτη τύπου ΙΙ στις γνωστικές λειτουργίες των ασθενών: διερεύνηση κινδύνου γνωστικής έκπτωσης

The issue of the adverse impact of T2DM on cognitive skills has been predominantly investigated in older age. Still, there has been recently a growth in literature, suggesting that even middle-aged diabetic populations demonstrate cognitive deficits. The present study aims at evaluating the severity of cognitive impairment in T2DM subjects of middle age (50-60 years) in comparison to age-matched, non-diabetic controls. Possible differentiations with regards to cognitive abilities will delineate whether diabetes constitutes a risk factor for cognitive impairment. Furthermore, type of diabetes treatment followed as well as disease features will be appraised, in terms of whether they determine cognitive performance. Blood parameters (FBG, HbA1c, WBCs, and IL-1β) were analyzed, considering the contributory role of hyperglycemia and inflammation in T2DM-mediated cognitive deterioration. In addition, lipid values (TC, LDL-C, HDL-C, and TG) were measured in order to elucidate the extent to which metabolic lipid profile influences cognitive functions. Comparisons between the study groups revealed considerable differences between controls and T2DM participants. These refer to the vast majority of cognitive tasks, covering a wide range of cognitive domains. Diabetics exemplified significant impairment, in relation to attention span, executive skills (planning, problem-solving, cognitive flexibility, working memory), information processing speed, and psychomotor efficiency. Decrements in the diabetes context were further observed in the domains of verbal learning and retention, verbal memory (short-term and episodic one), delayed visual and incidental memory, as well as visuoconstructional praxis. Language skills, namely receptive vocabulary, naming capacity besides receptive and expressive syntactic abilities were found attenuated in diabetic subjects. Phonemic verbal fluency was affected to a less extent. Pertaining to emotional sphere, diabetes, as a disease appeared to have noteworthy repercussions on severity of anxiety and depression symptoms. The effect of diabetes treatment was established as a crucial factor, influencing performance on cognitive tasks. Notably, diabetics in insulin use and those in combined treatment exemplified the greatest deficits. The aforesaid T2DM subgroups displayed longer duration of diabetes, higher mean HbA1c values, and inadequate disease control when compared with per os-treated patients. Thus, severity of diabetes (apropos of disease duration and control) were deemed significant parameters as respects cognitive impairment. Yet, study results indicated that WBCs and IL-1β, as inflammatory markers, could be potential determinants of cognitive performance, since they were higher in diabetic participants relative to controls. Concerning the putative significance of metabolic lipid profile on T2DM-associated cognitive decline, further examination is required for the purpose of reaching valid and reliable conclusions. It remains to be elucidated with future research.Το θέμα της δυσμενής επίδρασης του Σ.Δ-ΙΙ στις γνωστικές ικανότητες έχει κατά κύριο λόγο διερευνηθεί στις μεγαλύτερες ηλικίες. Εντούτοις, έχουν αυξηθεί τελευταία οι βιβλιογραφικές αναφορές που υποδεικνύουν ότι ακόμη και διαβητικοί πληθυσμοί μέσης ηλικίας εμφανίζουν γνωστικά ελλείμματα. Σκοπός της παρούσας μελέτης είναι η αξιολόγηση της σοβαρότητας της γνωστικής έκπτωσης σε Σ.Δ-ΙΙ άτομα της μέσης ηλικίας (50-60 έτη) συγκριτικά με μη διαβητικούς μάρτυρες της ιδίας ηλικιακής ομάδας. Πιθανές διαφοροποιήσεις τους όσον αφορά τις γνωστικές δεξιότητες θα αποσαφηνίσουν εάν η νόσος του διαβήτη αποτελεί παράγοντα κινδύνου, που προδιαθέτει σε γνωστική έκπτωση. Επιπλέον, το είδος της φαρμακευτικής αγωγής που ακολουθείται στον Σ.Δ-ΙΙ όπως και κλινικά χαρακτηριστικά της νόσου θα αξιολογηθούν σχετικά με την πιθανή συμβολή τους στην γνωστική απόδοση. Έγινε ανάλυση των επιπέδων αιματολογικών παραμέτρων (FBG, HbA1c, WBCs και IL-1β) λαμβάνοντας υπόψιν το ρόλο που διαδραματίζει η υπεργλυκαιμία και η φλεγμονή στην διαμεσολαβούμενη από τον Σ.Δ-ΙΙ γνωστική εξασθένιση. Επίσης, προσδιορίστηκαν οι τιμών των λιπιδίων (TC, LDL-C, HDL-C και TG) προκειμένου να διερευνηθεί ο βαθμός στον οποίον το μεταβολικό λιπιδαιμικό προφίλ επηρεάζει τις γνωστικές λειτουργίες. Οι συγκρίσεις μεταξύ των ομάδων μελέτης έδειξαν αξιοσημείωτες διαφορές μεταξύ μαρτύρων και Σ.Δ-ΙΙ συμμετεχόντων. Αυτές αφορούν την συντριπτική πλειοψηφία των γνωστικών δοκιμασιών, που καλύπτουν ένα ευρύ φάσμα γνωστικών τομέων. Οι διαβητικοί παρουσίασαν σημαντική έκπτωση αναφορικά με το εύρος προσοχής, τις εκτελεστικές δεξιότητες (σχεδιασμός, επίλυση προβλημάτων, γνωστική ευελιξία, εργαζόμενη μνήμη), την ταχύτητα επεξεργασίας πληροφοριών και την ψυχοκινητική επάρκεια. Στα πλαίσια του διαβήτη παρατηρήθηκαν ακόμη ελλείμματα στους τομείς της λεκτικής μάθησης και διατήρησης αυτής, λεκτικής μνήμης (άμεση και επεισοδιακή), καθυστερημένης οπτικής και παρεμπίπτουσας μνήμης καθώς και σε οπτικοκατασκευαστική ικανότητα. Σχετικά με τις γλωσσικές δεξιότητες, πιο συγκεκριμένα προσληπτικό λεξιλόγιο, κατονομασία όπως και προσληπτικές και εκφραστικές συντακτικές ικανότητες, διαπιστώθηκε ότι ήταν μειωμένες στα διαβητικά άτομα. Η φωνολογική λεκτική ευχέρεια επηρεάσθηκε σε μικρότερο βαθμό. Όσον αφορά τη συναισθηματική σφαίρα, η νόσος του διαβήτη έδειξε να έχει σημαντικές επιπτώσεις στην σοβαρότητα των συμπτωμάτων άγχους και κατάθλιψης. Ο τύπος φαρμακευτικής αγωγής του διαβήτη ήταν καθοριστικός παράγοντας για την απόδοση στις γνωστικές δοκιμασίες. Ιδιαιτέρως οι διαβητικοί σε ινσουλίνη και εκείνοι σε συνδυαστική αντιδιαβητική αγωγή σημείωσαν την μεγαλύτερη γνωστική έκπτωση. Οι προαναφερθείσες διαβητικές υποομάδες εμφάνισαν μεγαλύτερη διάρκεια διαβήτη, υψηλότερες μέσες τιμές HbA1c και ανεπαρκή έλεγχο της νόσου συγκριτικά με τα άτομα σε αγωγή με αντιδιαβητικά δισκία. Συνεπώς, η σοβαρότητα του διαβήτη (διάρκεια και έλεγχος της νόσου) θεωρήθηκαν παράμετροι με σημαντικό αντίκτυπο στην γνωστική εξασθένιση. Παράλληλα, τα αποτελέσματα της μελέτης έδειξαν ότι τα λευκά αιμοσφαίρια (WBCs) και η ιντερλευκίνη-1β (IL-1β), ως δείκτες φλεγμονής, θα μπορούσαν να είναι δυνητικά καθοριστικοί παράγοντες για την γνωστική απόδοση, καθώς οι τιμές τους ήταν υψηλότερες στους διαβητικούς συμμετέχοντες εν συγκρίσει με τους μάρτυρες. Αναφορικά με τον πιθανό ρόλο του μεταβολικού λιπιδαιμικού προφίλ στην σχετιζόμενη με τον Σ.Δ-ΙΙ γνωστική έκπτωση, χρήζει περαιτέρω διερεύνησης με σκοπό να διεξαχθούν έγκυρα και αξιόπιστα συμπεράσματα. Το ζήτημα αυτό παραμένει προς εξέταση με μελλοντική έρευνα

NEARBY INTERACTING GALAXY PAIRS: DYNAMICS AND IONIZED GAS PROPERTIES

Galaxy merging is an important process in galaxy formation and evolution throughout the cosmic time. Mergers are expected to play a significant role in galaxy mass assembly and transformation of galaxy morphology. In this work, we study inter- acting pairs of galaxies in a relatively early stage of the merging process, after they first pass by each other but before they coalesce into a single galaxy. At this stage, interacting disk galaxies display peculiar morphologies, often induced by the strong gravitational tidal field experienced during the first passage. These peculiar features can be utilized to constrain the encounter parameters of the merging galaxies, such as time since first passage, and pericentric separation (Toomre & Toomre, 1972; Hi- bbard & Mihos, 1995; Barnes & Hibbard, 2009). Moreover, in the early stages of galaxy mergers the individual galaxies are still clearly separated making it possible to investigate the chain of physical processes that are caused by the interaction. This includes starbursts or active galactic nuclei (AGNs) triggered by the infall of gas into the cores (Mihos & Hernquist, 1996; Hopkins & Quataert, 2011), and the shocks that are produced by feedback from starbursts and AGNs (Cox et al., 2006b; Narayanan et al., 2008; Rich et al., 2015), or by collision of gaseous clouds in the interstellar medium (ISM) of the two disks as they pass through each other (Struck, 1997). We develop a novel automated method for modeling the dynamics of equal mass galaxy mergers that puts meaningful constraints on the system’s encounter parameters. In order to understand the systematics of the measured encounter parameters, we test our method against an independent set of galaxy merger simulations with known initial conditions. For a controllable subset of these tests, our automated method recovers parameters such as merger stage and initial disk orientations within 3σ of the correct value. We explore the effects of using different kinematic tracers on the inferred encounter parameters by applying our method to HI and Hα velocity maps of a well-studied galaxy merger system in the nearby Universe, NGC 4676 a.k.a the Mice galaxies. We show for the first time that constraints on the encounter parameters derived from HI and Hα kinematics are consistent suggesting that Hα velocity maps can also be used for dynamical modeling. In total we observe a sample of 22 galaxy mergers in this work. Nineteen of them have morphological indicators similar to the Mice galaxies (separate cores and strong tidal features), and the other three are recently coalesced systems where cores are united, but outskirts are still disturbed. We use SparsePak integral field unit (IFU) (Bershady et al., 2004) on the WIYN telescope at Kitt Peak National Observatory (KPNO) to observe the Hα emission over the entire visible regions of these galaxies, including faint tidal tails. Relatively high spectral resolution of our data allows us to investigate multiple kinematic components in the emission lines. We separate Hα emission of photo-ionized HII regions from shocked gas, measure the velocity maps of HII regions, and discuss the fraction and spatial distribution of shocks and their power source. We apply our dynamical modeling method on equal mass systems in our sample and obtain the first ever constraints on the encounter parameters of one of them. We find a trend between shocked gas fraction and the projected separation between the galaxies in pairs, similar to Rich et al. (2015). In our sample of interacting pairs, for the first time, we also find a trend between shocked gas fraction and the light ratio (mass ratio). These trends suggest that in most of the observed systems the gravitational tidal impulse at the time of the first passage is the dominant origin of shocks. Also for the first time, we investigate the correlation between shocked gas fraction and encounter parameters from dynamical modeling. We find that time until coalescence and pericentric separation are both strongly anti-correlated with the amount of shocks. However, larger statistical sample is required for understanding the physical details and timing of shock production during galaxy mergers. Clean separation of shocks from star forming regions also improves the accuracy of star formation rate measurements in merging galaxies. Large ongoing and upcoming IFU galaxy surveys such as MaNGA (Bundy et al., 2015) will provide spatially resolved spectra of large numbers of galaxies including many galaxy mergers. Tools and techniques developed for this thesis project are required steps for better utilization of these valuable datasets

Computational Crystal Plasticity for the Design of Material and Processes

The macroscale mechanical behaviour of crystalline materials, such as polycrystalline metals and single crystal semiconductors, is dictated by the anisotropic behaviour of individual crystals/grains and their interactions with neighboring crystals or other materials. Furthermore, the elastic-plastic response of individual crystals is associated with the underlying atomic lattice structure and phenomena of dislocation glide on the slip systems and dislocation multiplication and interactions. As a result, microstructural characteristics such as grain size, shape, and orientation, have a significant effect on the macroscale mechanical properties and performance. Moreover, these microstructural features are strongly affected by the thermal-mechanical process used to create a part. Because of this, tremendous effort has been made to develop crystal plasticity models that explicitly model the crystal (grain) scale behavior to predict the local macroscale response. In this talk, a framework for computational modelling of discretized single or polycrystal grain structures subjected to thermal-mechanical loading conditions is presented. The model is general for finite deformations with the crystal plasticity model based on dislocation motion and interactions. A parallel finite element implementation is briefly described. Then, applications including predicting microstructure evolution during large deformation processing, fatigue crack initiation, and defect formation during single crystal AlN crystal growth will be presente