The Severi inequality K2≥4χK^2\ge 4\chi for surfaces of maximal Albanese dimension

We prove the so-called Severi inequality, stating that the invariants of a minimal smooth complex projective surface of maximal Albanese dimension satisfy: K^2_S >= 4\chi(S).Comment: Final version: proof slightly simplified, a reference adde

Gastrointestinal neuromuscular apparatus: An underestimated target of gut microbiota

Over the last few years, the importance of the resident intestinal microbiota in the pathogenesis of several gastro- intestinal diseases has been largely investigated. Growing evidence suggest that microbiota can influence gastro- intestinal motility. The current working hypothesis is that dysbiosis-driven mucosal alterations induce the production of several inflammatory/immune mediators which affect gut neuro-muscular functions. Besides these indirect mucosal-mediated effects, the present review highlights that recent evidence suggests that microbiota can directly affect enteric nerves and smooth muscle cells functions through its metabolic products or bacterial molecular components translocated from the intestinal lumen. Toll- like receptors, the bacterial recognition receptors, are expressed both on enteric nerves and smooth muscle and are emerging as potential mediators between microbiota and the enteric neuromuscular apparatus. Furthermore, the ongoing studies on probiotics support the hypothesis that the neuromuscular apparatus may represent a target of intervention, thus opening new physiopathological and therapeutic scenarios

A case of Barrett's oesophagus in pernicious anaemia: acid is not the only culprit!

A 46-year-old female presented at our department with the onset of episodic dyspeptic symptoms, mainly postprandial fullness and bloating, as well as paresthesia. A blood test revealed the presence of mild macrocytic anaemia (haemoglobin 11.3 g/dl; mean corpuscular volume 119 fl), a reduced level of vitamin B12 (60 pmol/l; normal 200–750 pmol/l), hypergastrinaemia (1363 pg/ml; normal for female <100 pg/ml), a low level of pepsinogen I (<2.6 pg/ml; normal 30–100 pg/ml), and positivity for antibodies against parietal cells (>1:100). The upper endoscopy showed in oesophagus a single linear erosion (grade A according to Los Angeles Classification), with an absence of macroscopic gastric abnormalities. At histology, mucosal severe atrophy with moderate intestinal metaplasia was found in fundus and gastric corpus with spared antrum, in the absence of Helicobacter pylori infection. A diagnosis of autoimmune gastritis with pernicious anaemia was therefore made, and the patient started vitamin B12 intramuscular injections. Due to the absence of specific symptoms such as heartburn and/or regurgitation and to the presence of autoimmune gastritis, the erosive oesophagitis was not treated. After 4 weeks of treatment with vitamin B12, the haemoglobin, mean corpuscular volume and vitamin B12 values were restored, paresthesia improved, while dyspepsia remained stable, with sporadic symptoms about once a week

Väärtushinnangud majandusteaduskonna sissejuhatavate ainete õppematerjalides

http://www.ester.ee/record=b4775176*es

Recent advances in understanding and managing diverticulitis.

In the past few decades, the increasing socioeconomic burden of acute diverticulitis (AD) has become evident, and with the growth of the population age, this significant economic impact will likely continue to rise. Furthermore, recent evidence showed an increased rate of hospital admissions especially evident among women and younger individuals. The natural history and pathophysiology of this clinical condition is still to be fully defined, and efforts continue to be made in the identification of risk factors and the establishment of relative preventive strategies. The actual therapeutic strategies aimed to modulate gut microbiota, such as rifaximin or probiotics, or to reduce mucosal inflammation, such as mesalazine, present a relatively poor efficacy for both the prevention of the first AD episode (primary prevention) and its recurrence (secondary prevention). In the last few years, the main goal achieved has been in the management of AD in that uncomplicated AD can, to a larger extent, be managed in an outpatient setting with no or little supportive therapy, a strategy that will certainly impact on the health costs of this disease. The problem of AD recurrence remains a topic of debate. The aim of this review is to present updated evidence on AD epidemiology and relative open clinical questions and to analyze in detail predisposing and protective factors with an attempt to integrate their possible modes of action into the several pathogenic mechanisms that have been suggested to contribute to this multifactorial disease. A unifying hypothesis dealing with the colonic luminal and extra-luminal microenvironments separately is provided. Finally, evidence-based changes in therapeutic management will be summarized. Because of an ascertained multifactorial pathogenesis of uncomplicated and complicated AD, it is probable that a single ‘causa prima’ will not be identifiable, and a better stratification of patients could allow one to pursue tailored therapeutic algorithm strategies

Digitaalisen opetuksen kasvuyritysten kansainvälistymiseen vaikuttavat tekijät

As well as many other industries, education is currently being disrupted by new emerging digital solutions. Teachers all around the world are adopting new digital materials to their everyday teaching including digital books and educational games. This recent trend engenders opportunity for new companies to emerge with cutting-edge digital educational solutions. Furthermore, with a digital solution expansion to international markets without heavy investments is possible. However, for example in Finland only few companies have been able to successfully enter new markets with educational technology. Internationalization strategies have been widely studied during the past few decades. The early studies already identified a set of different market entry modes including export, licensing, franchising, joint ventures and wholly-owned subsidiaries. However, for small resource-limited companies, export is the most viable option. Export allows company to maintain the full control of the process and product without making heavy investments on the internationalization. The export performance framework shows that the export strategy is depending on both internal (company resources) and external factors (country and industry characteristics). More recent studies have also identified alternative entry modes such as cooperative strategies and innovative use of internet. However, the previous literature has not studied this topic purely in education industry and therefore does not provide detailed knowledge for startups planning international expansion in digital education industry. The aim of this study is to identify key determinants for market entry strategy selection for startups in digital education, and identify different strategies for addressing the major challenges in the digital education markets. To study this topic, 15 interviews were carried out to both experts of internationalization of digital education and companies that are pursuing international expansion with digital educational solutions. The data analysis followed Gioia methodology (Gioia, Corley, & Hamilton, 2012), in which 1st-order terms are identified first, and then the 2nd-order themes are established accordingly. The findings revealed several market-level factors that drive the market entry strategy selection. These factors were related to cultural and regulatory differences, trust and reliability, different customer types and customer needs. In addition, the findings showed several strategies how companies can address the challenges related to the above market-level factors. Therefore, this study provides managers of startups with insights of digital education markets as well as a toolkit for addressing the market-level challenges in digital education.Opetusala on kokemassa suuria muutoksia uusien digitaalisten ratkaisuiden myötä. Opettajat ympäri maailmaa ottavat opetuskäyttöön uusia digitaalisia ratkaisuja kuten digitaalisia oppikirjoja sekä oppimispelejä. Opetuksen digitalisaatio synnyttää uusia yrityksiä, jotka tuottavat innovatiivisia ja moderneja teknologiaratkaisuja opetuskäyttöön. Tämänlaisille digitaalisia ratkaisuja tuottaville yrityksille on mahdollista myös kasvaa kansainvälisesti ilman suuria alkuinvestointeja. Kuitenkin vain muutama suomalainen digitaalisia ratkaisuja tuottava yritys on kyennyt onnistuneesti laajentumaan uusille markkinoille. Kansainvälistymisstrategioita on tutkittu laajalti viimeisten vuosikymmenien aikana. Jo aikaiset tutkimukset määrittelivät erilaisia tapoja tunkeutua uusille markkinoille. Näitä tapoja ovat muun muassa vienti, lisensointi, franchise-periaate, yhteisyritys sekä tytäryhtiö. Useimmille pienille yrityksille suora vienti on kuitenkin parhaiten sopiva tapa kansainvälistyä. Suora vienti antaa yritykselle täyden kontrollin operaatiosta ja tuotteesta vaatimatta kuitenkaan suuria alkuinvestointeja. Viennin suorituskyky –malli osoittaa, että vientistrategia perustuu sekä sisäisiin (yrityksen resurssit) että ulkoisiin tekijöihin (markkina- ja toimiala kohtaisiin tekijöihin). Uudemmat tutkimukset ovat lisäksi esittäneet vaihtoehtoisia tapoja tunkeutua markkinoille kuten yhteistyöhön perustuvat strategiat ja internetin innovatiivinen hyödyntäminen. Kirjallisuus ei kuitenkaan ole tutkinut kansainvälistymistä pelkästään opetusalan näkökulmasta, eikä täten tarjoa yksityiskohtaista tietoa pienten digitaalisia ratkaisuja tuottavan yrityksen kansainvälistymisestä. Tämän tutkimuksen tavoitteena on tunnistaa keskeisimmät tekijät, jotka vaikuttavat pienten kasvuyritysten tapaan tunkeutua markkinoille, sekä tunnistaa erilaisia strategioita markkinoiden keskeisimpien haasteiden ylittämiseen. Tutkimuksessa suoritettiin 15 haastattelua sekä opetuksen kansainvälistämisen eksperteille että pienille kasvuyrityksille, jotka ovat kansainvälistyneet digitaalisen opetuksen alalla. Haastatteludata analysoitiin käyttämällä Gioia-metodia (Gioia et al., 2012), jossa tunnistetaan ensin ensimmäisen tason aiheet, joiden perusteella voidaan luoda laajempia toisen tason teemoja. Tutkimuksen tulokset toivat ilmi useita markkina-tason tekijöitä, jotka vaikuttavat yrityksen tapaan tunkeutua markkinoille. Nämä tekijät liittyivät kulttuuriin ja sääntelyyn, luotettavuuteen, erilaisiin asiakastyyppeihin, sekä asiakkaiden tarpeisiin. Tulokset toivat esiin myös useita tapoja, joilla yritykset voivat ylittää keskeiset haasteet liittyen edellä mainittuihin markkina-tason tekijöihin. Tutkimuksen tulokset tuovat esiin markkinoiden keskeisiä piirteitä sekä erilaisia tapoja vastata markkinoiden erityispiirteistä syntyviin haasteisiin

A Light Modality for Recursion

We investigate the interplay between a modality for controlling the behaviour of recursive functional programs on infinite structures which are completely silent in the syntax. The latter means that programs do not contain "marks" showing the application of the introduction and elimination rules for the modality. This shifts the burden of controlling recursion from the programmer to the compiler. To do this, we introduce a typed lambda calculus a la Curry with a silent modality and guarded recursive types. The typing discipline guarantees normalisation and can be transformed into an algorithm which infers the type of a program.Comment: 32 pages 1 figure in pdf forma