Compressibility anomalies in stretched water and their interplay with density anomalies

Water keeps puzzling scientists because of its numerous properties which behave oppositely to usual liquids: for instance, water expands upon cooling, and liquid water is denser than ice. To explain this anomalous behaviour, several theories have been proposed, with different predictions for the properties of supercooled water (liquid at conditions where ice is more stable). However, discriminating between those theories with experiments has remained elusive because of spontaneous ice nucleation. Here we measure the sound velocity in liquid water stretched to negative pressure, and derive an experimental equation of state, which reveals compressibility anomalies. We show by rigorous thermodynamic relations how these anomalies are intricately linked with the density anomaly. Some features we observe are necessary conditions for the validity of two theories of water.Comment: 17 pages, 3 figures, 24 reference

USE OF TRANSMISSION CANAL OF INTEREST RATES IN MANAGING OFFER AND DEMAND OF MONEY AND INVESTMENT IN BOSNIA AND HERZEGOVINA IN CONDITIONS OF CURRENCY BOARD

Changes in interest rates impact the decisions regarding consumption, savings and investments made by both economy and population. Higher interest rates discourage the borrowing but on the other hand they encourage savings, which again discourages investments. In conditions of low interest rates, economy and population get more into debt and thereby they increase the consumption and stimulate the production. In conducting monetary policy, the transmission channel of interest rates has a special impact since it directly influences prices. Central banks with their policy of reference interest rates influence the change of nominal interest rates which in accordance with inflationary expectations impact long-term interest rates and thus the consumption, investment and saving structure. In the situation in which the monetary policy of Bosnia and Herzegovina is reduced to the role of a currency board, this work researches impact of transmission channels of interest rates on consumption, investments and savings in Bosnia and Herzegovina.Key words: Interest rates, reference interest rates, monetary policy, channels of monetary policyJEL: E42; E43; E5

NEFISKALNE EKONOMSKE FUNKCIJE BUDŽETA FEDERACIJE BIH

Državni budžeti, prilikom svog usvajanja, podrazumijevaju demokratskuraspravu usmjerenu na izbor potreba koje će se budžetom finansirati.U manje razvijenim zemljama, misleći pri tome na zemlje sa nižim nivoomBDP, normalno je da se sve potrebe ne mogu svrstati u red prioritetnih, te uzavisnosti od obima potreba koje moraju biti odložene do ''boljih vremena''ostaje ili raste broj subjekata u državi nezadovoljnih činjenicom da njihovepotrebe ne mogu biti zadovoljene aktuelnim budžetom. Stvaranje preduslova zaširi obuhvat potreba svih subjekata u društvu raspoloživim budžetimapodrazumijeva ili veće fiskalno opterećenje domaćih subjekata novim državnimnametima ili povećanje BDP kao osnovice na koju će, pri postojećem fiskalnomopterećenju, biti na raspolaganju veći javni prihodi, a time se realizuje fiskalnafunkcija budžeta. Da bi se, pak, povećao BDP, neophodan je angažman javnihsredstava u pravcu širenja ekonomske osnove društva i njegovo usmjeravanje uoblasti u kojima će BDP ostvariti najbrži rast, čime se ispoljavaju ekonomskiefekti budžeta

POKAZATELJI EFIKASNOSTI I UPRAVLJANJE EFIKASNOŠĆU JAVNOG SEKTORA U BIH

Utrošak javnih sredstava predstavlja zadovoljenje javnih potreba zemalja, a u zavisnosti od socijalne osjetljivosti podržanih politika učešće javnog sektora u zemljama je različito. Učešće javnog sektora u tranzicijskim zemljama pa tako i u BiHpokazuje karakteristike socijalne osjetljivosti, naslijeđene iz prethodnog političkogsistema, ali pokazuje i nespremnost za uključivanje privatnog sektora u zadovoljenjeodređenih javnih potreba. Analizom strukture javnih rashoda jasno se dolazi do zaključka da je javni sektor i pored zadovoljenja određenih javnih potreba, to čini uzvisok stepen neefikasnosti.Pri kreiranju institucionalnog okruženja za poslovanje privatnog sektora,javni sektor, putem fiskalne politike utječe na visinu transakcionih troškovau privredi kroz ukupno fiskalno opterećenje. Zbog toga, javni sektor je stalnoizložen pritiscima za povećanje racionalnosti u trošenju budžetskih sredstava,unapređenje efikasnosti pružanja javnih dobara, kao i podizanje kvalitetajavnih usluga.Usvajajući Reformsku agendu vlasti Bosne i Hercegovine (BiH) opredjeljujuse za pristup koji će, između ostalog, povećanjem efikasnosti javnog sektora otvoriti prostor za jačanje privatnog sektora koristeći se utroškom javnihsredstava kao akceleratora profitnom sektoru.U radu je analiziran pristup mjerenju efikasnosti javnog sektora prihvaćenu međunarodnim naučnim krugovima i međunarodnim razvojnim institucijama koje podržavaju ovu vrstu reformi zemalja u tranziciji i komparacijaefikasnosti javnog sektora u zemljama okruženja. Cilj rada je da ukaže namogućnost mjerenja učinaka javnog sektora, a sa namjerom da upravljanjemrashodima za pružanje javnih usluga unaprijedi njegovu efikasnost i timeotvori prostor za podršku privrednim subjektima i ekonomskom razvoju Bi

Inducint therapeutic changes in children by creating poems

U terapijskom radu i procesu s djecom i njihovim obiteljima vrlo je važno prekinuti obrasce koji podržavaju problem. U iznalaženju načina kako pristupiti obiteljskoj dinamici i kako čim suptilinije intervenirati, te razriješiti problem zbog kojeg je obitelj potražila pomoć, uz želju za terapijskom promjenom i istraživanjem, razvijala se metoda prezentirana u radu. Stvaranje pjesmica u svrhu terapijske promjene, kao dio cjelokupnog terapijskog procesa, omogućava da se kroz neizravan i kreativan pristup dogodi promjena u skladu sa željenim ishodom. Sjedinjujući svjesna i nesvjesna učenja, kroz dijalošku igru i dijalogoterapiju terapeut, dijete i obitelj rade na željenoj promjeni. Stvaranje pjesmica definirano je autentičnošću i jedinstvenošću svakog pojedinog klijenta, kao i terapeuta i tom smislu ne postoje dvije iste primjene metodologije, iako polazišna točka može biti ista simptomatologija. Metoda je primjenjiva za djecu od 4 do 10 ili 11 godina uz individualna odstupanja s obzirom na intelektualnu i emocionalnu zrelost djeteta. Može se koristiti kod sljedećih poteškoća i stanja: enuresis nocturnae, različitih vrsta strahova, impulzivnog ponašanja, opsesivno-kompulzivnih radnji, određenih psihosomatskih smetnji te kod postoperativnog oporavka djeteta nakon nekih medicinskih kirurških zahvata. Opisana metodologija, kao dio cjelokupnog terapijskog procesa, pokazala se učinkovitom. U raspravi su opisani mogući učinci tijekom terapijskog procesa, korisnost primjene opisane metodologije u kontekstu psihoterapijskog rada te su dani prijedlozi za otkrivanje novih dimenzija opisane metodologije.In the therapeutic work process with children and their parents, it is very important to break the patterns supporting the problem. The method presented in this paper has developed though determining the best approach to family dynamics and the least intrusive intervention for solving the problem which motivated the family to seek help, with the aim of therapeutic change and research. The process of creating poems for the purpose of inducing therapeutic change as the part of the overall therapeutic process, enables these changes through an indirect and creative approach. Combining conscious and unconscious learning, through dialogic play and dialog therapy, the therapist, child and family work toward the desired change. The process of creating poems is defined by the authenticity and uniqueness of each client as well as the therapist, and in that sense there are no two identical approaches, although the starting point could be the same symptomatology. The method can be applied in children aged 4 to 10/11 years taking into consideration individual variations due to intellectual and emotional maturity and can be used in the following difficulties and states: enuresis nocturna, different fears, impulsive behaviour, obsessive-compulsive acts, certain psychosomatic disturbances and in postoperative recovery of the child after certain surgical interventions. The described therapeutic method has proven efficient in the context of the overall therapeutic process. Effects of the therapeutic process have been described, as well as its usefulness in the context of psychotherapeutic work. Suggestions for determining new dimensions of the described method have been given

MOGUĆNOSTI KORIŠTENJA FAKTORING NA TRŽIŠTU BOSNE I HERCEGOVINE I REGIJE

Autori obrađuju mogućnosti korišćenja faktoring-a kao instrumenta finansiranja transakcija preduzeća bez posredničke uloge banaka. Značaj faktoring-a je posebno naglašen u uslovima kada se teže dolazi do kreditnih izvora za finansiranje trgovine. Radi se o ominantnom obliku finansiranja u svijetu, koje se zasniva na otkupu potraživanja prodavca po osnovu prodate robe na odgodu plaćanja ili kredit kupcu. Faktoring ima nekoliko prednosti u odnosu na druge vidove finansiranja. Prvo, faktoring može biti posebno koristan u zemljama sa slabim obezbjeđenjem zajmova, neefikasnim sistemom bankrotstva, nepotpunim registrovanjem potraživanja, nerazvijene i neefikasne sudske zaštite povjerilaca. Drugo, finansiranje kod faktoringa prvenstveno se zasniva na kvaliteti osnovnog potraživanja a ne na kvaliteti zajmoprimca. Time faktoring može biti posebno privlačan za visokorizična manja i srednja preduzeća. Osnovna aktivnost faktoringa odnosi se na naplatu na njega prenijetih, tj. od komitenta (klijenata) cediranih potraživanja. Dakle, faktor time prihvata obavezu prema komitentu da u odnosu na primljenu fakturu (ili više njih) u tačno predviđenim rokovima izvrši plaćanje u određenom procentu ili u cijelosti. U zakonodavstvima regije, tek se započinje proces aktiviranja ovog specifičnog oblika finansiranja. Imajući u vidu razvijenost i tradicionalne poslovne veze među državama bivše jugoslovenske zajednice za očekivati je da faktoring značajno može doprinjeti povećanju robne razmjene, povećanju koeficijenta obrta a time i rastu GDP zahvaljujući efikasnijem finansiranju. Svojim mehanizmima faktoring predstavlja posebnu vrstu plaćanja, skračujući lanac reprodukcije za fazi plaćanja i naplate novcem u toku reprodukcije

Functional imaging of mucociliary phenomena: High-speed digital reflection contrast microscopy

We present a technique for the investigation of mucociliary phenomena on trachea explants under conditions resembling those in the respiratory tract. Using an enhanced reflection contrast, we detect simultaneously the wave-like modulation of the mucus surface by the underlying ciliary activity and the transport of particles embedded in the mucus layer. Digital recordings taken at a speed of 500 frames per second are analyzed by a set of refined data processing algorithms. The simultaneously extracted data include not only ciliary beat frequency and its surface distribution, but also space-time structure of the mucociliary wave field, wave velocity and mucus transport velocity. Furthermore, we propose the analysis of the space and time evolution of the phase of the mucociliary oscillations to be the most direct way to visualize the coordination of the cilia. In particular, this analysis indicates that the synchronization is restricted to patches with varying directions of wave propagation, but the transport direction is strongly correlated with the mean direction of waves. The capabilities of the technique and of the data-processing algorithms are documented by characteristic data obtained from mammalian and avine trachea

Exploration of the phase diagram of liquid water in the low-temperature metastable region using synthetic fluid inclusions

We present new experimental data of the low-temperature metastable region of liquid water derived from high-density synthetic fluid inclusions (996-916 kg m-3) in quartz. Microthermometric measurements include: (i) prograde (upon heating) and retrograde (upon cooling) liquid-vapour homogenisation. We used single ultrashort laser pulses to stimulate vapour bubble nucleation in initially monophase liquid inclusions. Water densities were calculated based on prograde homogenisation temperatures using the IAPWS-95 formulation. We found retrograde liquid-vapour homogenisation temperatures in excellent agreement with IAPWS-95. (ii) Retrograde ice nucleation. Raman spectroscopy was used to determine the nucleation of ice in the absence of the vapour bubble. Our ice nucleation data in the doubly metastable region are inconsistent with the low-temperature trend of the spinodal predicted by IAPWS-95, as liquid water with a density of 921 kg m-3 remains in a homogeneous state during cooling down to a temperature of -30.5 °C, where it is transformed into ice whose density corresponds to zero pressure. (iii) Ice melting. Ice melting temperatures of up to 6.8 °C were measured in the absence of the vapour bubble, i.e. in the negative pressure region. (iv) Spontaneous retrograde and, for the first time, prograde vapour bubble nucleation. Prograde bubble nucleation occurred upon heating at temperatures above ice melting. The occurrence of prograde and retrograde vapour bubble nucleation in the same inclusions indicates a maximum of the bubble nucleation curve in the ϱ-T plane at around 40 °C. The new experimental data represent valuable benchmarks to evaluate and further improve theoretical models describing the p-V-T properties of metastable water in the low-temperature region

In situ fiber-optical monitoring of cytosolic calcium in tissue explant cultures

We present a fluorescence-lifetime based method for monitoring cell and tissue activity in situ, during cell culturing and in the presence of a strong autofluorescence background. The miniature fiber-optic probes are easily incorporated in the tight space of a cell culture chamber or in an endoscope. As a first application we monitored the cytosolic calcium levels in porcine tracheal explant cultures using the Calcium Green-5N (CG5N) indicator. Despite the simplicity of the optical setup we are able to detect changes of calcium concentration as small as 2.5 nM, with a monitoring time resolution of less than 1 s.Comment: 26 pages, 6 figures Article first published online: 11 SEP 2013. appears in J. Biophoton. (2013

A quantitative interspecies comparison of the respiratory mucociliary clearance mechanism

Collectively coordinated ciliary activity propels the airway mucus, which lines the luminal surface of the vertebrate respiratory system, in cranial direction. Our contemporary understanding on how the quantitative characteristics of the metachronal wave field determines the resulting mucociliary transport is still limited, partly due to the sparse availability of quantitative observational data. We employed high-speed video reflection microscopy to image and quantitatively characterize the metachronal wave field as well as the mucociliary transport in excised bovine, porcine, ovine, lapine, turkey and ostrich samples. Image processing techniques were used to determine the ciliary beating frequency (CBF), the velocity and wavelength of the metachronal wave and the mucociliary transport velocity. The transport direction was found to strongly correlate with the mean wave propagation direction in all six species. The CBF yielded similar values (10–15 Hz) for all six species. Birds were found to exhibit higher transport speeds (130–260 [Formula: see text] m/s) than mammals (20–80 [Formula: see text] m/s). While the average transport direction significantly deviates from the tracheal long axis in mammals, no significant deviation was found in birds. The metachronal waves were found to propagate at about 4–8 times the speed of mucociliary transport in mammals, whereas in birds they propagate at about the transport speed. The mucociliary transport in birds is fast and roughly follows the TLA, whereas the transport is slower and proceeds along a left-handed spiral in mammals. The longer wavelengths and the lower ratio between the metachronal wave speed and the mucociliary transport speed provide evidence that the mucociliary clearance mechanism operates differently in birds than in mammals. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00249-021-01584-8