Koncepcje zawodności rynku: teoria a rzeczywistość

Droga do konsensusu w sprawie zakresu pożądanej ekonomicznej aktywności rządu jest cały czas daleka. Wydaje się jednak, że teoretycy osiągnęli porozumienie w dwóch kwestiach: niedoskonałości rynku są faktem; potrzeba prowadzenia przez organy państwa interwencji w ramach „mądrej i skutecznej polityki gospodarczej” jest uzasadniana koniecznością poddania korekcie niedoskonałych mechanizmów rynku. W artykule w pierwszej kolejności skoncentrowano się na powodach tego, iż pewne fakty – takie cechy rzeczywistości gospodarczej, jak choćby istnienie efektów zewnętrznych czy niedoskonałej informacji – są postrzegane i klasyfikowane jako niedoskonałości. Następnie wykazano, że nawet jeśli funkcjonowanie rynku jest obciążone błędami i to takimi, które poddają się naprawie, to samo ich istnienie nie uzasadnia w sposób automatyczny interwencji państwa

COMPARISON OF EXPLICIT AND IMPLICIT FORMS OF THE MODIFIED POINT MASS TRAJECTORY MODEL

The article compares the results of trajectory computation for a 35mm projectile using two forms (explicit and implicit) of the modified point-mass trajectory model. All necessary ammunition parameters (aerodynamic coefficients, dimensions, mass etc.) and initial conditions for differential equations are provided. The results of numerical integration (using non-stiff fourth-order Runge-Kutta solver) are presented in form of projectile trajectories projections onto vertical and horizontal planes. Data tables comparing both models in terms of projectile position and velocity in chosen time steps are also attached

Czynność lewej komory serca z uwzględnieniem efektów próby dobutaminowej u pacjentów przed i po operacji wymiany zastawki z powodu przewlekłej niedomykalności mitralnej

Wstęp: U niektórych pacjentów z przewlekłą niedomykalnością mitralną, poddawanych operacji wymiany zastawki, obserwuje się niezadowalające wyniki leczenia, spowodowane prawdopodobnie niewłaściwą oceną przedoperacyjną funkcji lewej komory serca. Celem pracy była ocena przydatności echograficznych i hemodynamicznych parametrów charakteryzujących czynność lewej komory serca oraz próby z niską dawką dobutaminy do kwalifikacji i prognozowania wyników leczenia operacyjnego. Materiał i metody: U 28 pacjentów z przewlekłą, znamienną hemodynamicznie niedomykalnością mitralną, w średnim wieku 54 lat (34-73 lat), zaliczonych do III i IV klasy według klasyfikacji NYHA, dokonano pomiarów echograficznych i hemodynamicznych cewnikiem Swana-Ganza przed podawaniem dobutaminy, a następnie podczas dożylnego wlewu tego leku w dawce 7,5 µg/kg/min. Pomiary obejmowały m.in.: frakcję wyrzutową (LVEF), wymiar końcowoskurczowy (LVESD), końcoworozkurczowy (LVEDD), objętości (LVESV, LVEDV) oraz naprężenie końcowoskurczowe (LVESWS) lewej komory serca. Za pomocą cewnika Swana- Ganza mierzono m.in. średnie ciśnienie w tętnicy płucnej (MPAP), rzut minutowy (CO), wskaźnik sercowy (CI) i naczyniowy opór płucny (PVR). Po 12 miesiącach od zabiegu wymiany zastawki mitralnej ponownie oceniono parametry echograficzne i hemodynamiczne (bez podawania dobutaminy). Wyniki: W całej grupie stwierdzono zmniejszenie LVEF z średnio 58% do 50%. Pacjentów podzielono następnie na dwie grupy w zależności od pooperacyjnej wartości LVEF. Chorzy z LVEF Ł 45% w porównaniu z pacjentami z LVEF > 45% charakteryzowali sić wyjściowo istotnie niższą LVEF (40% vs. 61%) i odnotowano u nich znamiennie niższe jej przyrosty w czasie wlewu dobutaminy. Ponadto wykazano, że wskaęniki fazy skurczowej (LVESD, LVESV i LVESWS) są lepsze w prognozowaniu wyników leczenia operacyjnego od wskaęników fazy rozkurczowej i parametrów hemodynamicznych. Wnioski: Aby ocena rezerwy kurczliwości lewej komory była odpowiednia, rutynowe badanie echokardiogarficzne powinno się uzupełnić o próbę z niską dawką dobutaminy z oceną zmian wartości frakcji wyrzutowej. (Folia Cardiol. 2003; 10: 667-674

Time and Space Optimal Exact Majority Population Protocols

In this paper we study population protocols governed by the {\em random scheduler}, which uniformly at random selects pairwise interactions between $n$ agents. The main result of this paper is the first time and space optimal {\em exact majority population protocol} which also works with high probability. The new protocol operates in the optimal {\em parallel time} $O(\log n),$ which is equivalent to $O(n\log n)$ sequential {\em pairwise interactions}, where each agent utilises the optimal number of $O(\log n)$ states. The time optimality of the new majority protocol is possible thanks to the novel concept of fixed-resolution phase clocks introduced and analysed in this paper. The new phase clock allows to count approximately constant parallel time in population protocols

Symptomatic medulla compression by vertebral artery

Objective Vertebral artery medulla compression syndrome (VAMCS) is a very rare condition manifesting as different neurological focal deficits. The case of a 36-year-old male with symptomatic brainstem compression by vertebral artery (VA) treated by means of microvascular decompression (MVD) and a review of the literature is presented. Case report On admission, a 36-year-old patient presented with hypoalgesia, hypothermesthesia and hemiparesis on the left side. Magnetic resonance imaging (MRI) of the head disclosed the right VA loop compressing the ventrolateral medulla and excluded other entities such as brain tumor, stroke and multiple sclerosis. Since displacement and significant compression of the right pyramidal tract was confirmed by diffusion tensor imaging (DTI), neurovascular compression syndrome was diagnosed. The patient underwent MVD of the medulla using a Gore-Tex implant as a separating material via the right far-lateral approach. The left hemiparesis and hemisensory loss remitted rapidly after the procedure. The post-procedural neurological improvement was maintained at one year follow-up. Based on a review of the literature, a total of 33 cases of surgically treated VAMCS has been reported so far. Conclusion VAMCS should be considered as the cause of neurological deficits when other pathological entities are ruled out. In symptomatic conflict of the VA with the medulla, microvascular decompression using a Gore-Tex implant can be an effective method of treatment. Nevertheless, a statistical analysis on all reported cases showed favorable results using the VA repositioning technique when compared with MVD (success rate 91% vs. 58%, p<0.05)

Heart failure patients from hospital settings in Poland: Population characteristics and treatment patterns, a multicenter retrospective study

Background: Despite physicians&#8217; increasing knowledge regarding heart failure (HF), a significant percentage of patients still do not receive adequate treatment. The aim of this multicentre, retrospective descriptive study was to reveal the pharmacotherapy patterns in HF patients hospitalized in cardiology (CARD) and internal medicine (INT) wards in Poland. Methods: Included into the study were 800 consecutive patients who were admitted to the hospitals: 350 patients from 7 CARD wards and 450 patients from 9 INT wards. Results: The average age in the study group was about 70 years (youngest participant under 40 and oldest at 95 years of age). Decompensation of HF or acute HF were the most frequent causes of hospitalization (in both groups > 50%). The main etiology was coronary artery disease, either alone or together with hypertension (from about 60% in INT patients to about 78% in CARD patients, p = NS). With regard to pharmacotherapy, angiotensin converting enzyme inhibitors were used in 81% of cases (77% CARD and 83% INT; p = 0.05); out of this group, doses were at optimal or larger in 39.3% of patients (38% CARD patients and 39.4% INT patients). Beta-blockers were administered in 31.4% and 19.1% of patients from the CARD and INT groups respectively (p < 0.0001), but optimal dosing was negligible. Conclusions: Compared with an assessment conducted several years ago, the past education initiatives have significantly improved the quality of standard-based HF treatment. However, suboptimal dosing and the use of drugs that do not improve prognosis remain an unresolved issue in this population. (Cardiol J 2008; 15: 169-180

Difficulties in the diagnosis of schistosomiasis in patients of the Departament of Tropical and Parasitic Diseases of the MUG

Between 2002 and 2006 in the Department of Tropical and Parasitic Diseases of the Medical University of Gdansk 40 hospitalized patients were suspected of schistosomiasis on the basis of clinical manifestations, epidemiological data and positive serology tests (ELISA IgG). In spite of multiple tests, schistosoma eggs were not identified neither in stool nor in urine of the patients. Histopathological examinations of liver and colon or bladder mucosal biopsy have not revealed schistosoma eggs in chosen patients. Diagnosis confirmation in case of negative parasitic tests requires serologic tests for schistosomiasis. ELISA serology tests for antibodies class G were performed in all 40 patients. In some cases the results were dubious &#8211; index in the upper limit or only slightly elevated. In those cases, cross reactions with Plasmodium spp. were taken into account. In 10 patients, serologic index for schistosomiasis was elevated during or a few weeks after treatment for malaria. In control tests, 4-8 weeks after the first examination, serologic indexes for schistosomiasis were significantly lower or normal without specific treatment with praziquantel (Biltricide, Cesol). Seven patients were lost from follow up. Because of diagnostic difficulties confirmation tests with Immuno-Blot IgG were introduced to verify ELISA. After final clinical and serologic analysis, human schistosomiasis was diagnosed in 23 patients who were treated with success

Clinical and demographic features of acutely hospitalised schizophrenia patients according to Toxoplasma gondii serostatus

Background: Few data exist concerning the clinical correlates of Toxoplasma gondii infection in persons with schizophrenia. The aim of this study was to investigate the correlation between toxoplasmosis and schizophrenia regarding the quality of life, symptoms and course of hospitalisation in patients with schizophrenia. Methods: Acutely hospitalised patients (n = 67) were examined twice during their hospital stay. Schizophrenia psychopathology, quality of life, extrapyramidal symptoms and T. gondii antibody titres were assessed upon admission and at discharge. Results: Toxo-IgG (+) patients (59.7%) were older, less educated, more obese and less eager to undertake psychotherapy. Female gender and higher fertility were dominant in this group with abnormal involuntary movements more commonly observed. Lower antipsychotic drug doses and monotherapy were used more frequently for Toxo-IgG (+) patients. Lower education (OR 2.41, 95% CI 1.21-4.79) was the most important factor associated with higher likelihood of IgG seropositivity. High levels of Toxo-IgM antibodies correlated with lower quality of life (r = -0.37; p = 0.02) and more severe positive (r = 0.40; p = 0.01) and focal (r = 0.32; p = 0.04) schizophrenia symptoms. Conclusions: Toxoplasmosis is more common in older, obese women with lower education. Recent infection is linked to more severe schizophrenia symptoms. Patients with toxoplasmosis history were given less medication

Analysis of the Genome and Mobilome of a Dissimilatory Arsenate Reducing Aeromonas sp. O23A Reveals Multiple Mechanisms for Heavy Metal Resistance and Metabolism

Aeromonas spp. are among the most ubiquitous microorganisms, as they have been isolated from different environmental niches including waters, soil, as well as wounds and digestive tracts of poikilothermic animals and humans. Although much attention has been paid to the pathogenicity of Aeromonads, the role of these bacteria in environmentally important processes, such as transformation of heavy metals, remains to be discovered. Therefore, the aim of this study was a detailed genomic characterization of Aeromonas sp. O23A, the first representative of this genus capable of dissimilatory arsenate reduction. The strain was isolated from microbial mats from the Zloty Stok mine (SW Poland), an environment strongly contaminated with arsenic. Previous physiological studies indicated that O23A may be involved in both mobilization and immobilization of this metalloid in the environment. To discover the molecular basis of the mechanisms behind the observed abilities, the genome of O23A (∼5.0 Mbp) was sequenced and annotated, and genes for arsenic respiration, heavy metal resistance (hmr) and other phenotypic traits, including siderophore production, were identified. The functionality of the indicated gene modules was assessed in a series of minimal inhibitory concentration analyses for various metals and metalloids, as well as mineral dissolution experiments. Interestingly, comparative analyses revealed that O23A is related to a fish pathogen Aeromonas salmonicida subsp. salmonicida A449 which, however, does not carry genes for arsenic respiration. This indicates that the dissimilatory arsenate reduction ability may have been lost during genome reduction in pathogenic strains, or acquired through horizontal gene transfer. Therefore, particular emphasis was placed upon the mobilome of O23A, consisting of four plasmids, a phage, and numerous transposable elements, which may play a role in the dissemination of hmr and arsenic metabolism genes in the environment. The obtained results indicate that Aeromonas sp. O23A is well-adapted to the extreme environmental conditions occurring in the Zloty Stok mine. The analysis of genome encoded traits allowed for a better understanding of the mechanisms of adaptation of the strain, also with respect to its presumable role in colonization and remediation of arsenic-contaminated waters, which may never have been discovered based on physiological analyses alone