Non-Linear Deformations of Liquid-Liquid Interfaces Induced by Electromagnetic Radiation Pressure

The idea of working with a near-critical phase-separated liquid mixture whereby the surface tension becomes weak, has recently made the field of laser manipulation of liquid interfaces a much more convenient tool in practice. The deformation of interfaces may become as large as several tenths of micrometers, even with the use of conventional laser power. This circumstance necessitates the use of nonlinear geometrical theory for the description of surface deformations. The present paper works out such a theory, for the surface deformation under conditions of axial symmetry and stationarity. Good agreement is found with the experimental results of Casner and Delville [A. Casner and J. P. Delville, Phys. Rev. Lett. {\bf 87}, 054503 (2001); Opt. Lett. {\bf 26}, 1418 (2001); Phys. Rev. Lett. {\bf 90}, 144503 (2003)], in the case of moderate power or a broad laser beam. In the case of large power and a narrow beam, corresponding to surface deformations of about 50 micrometers or higher, the theory is found to over-predict the deformation. Possible explanations of this discrepancy are discussed.Comment: RevTeX4, 19 pages, 4 figures. Sec. IIIB rewritten, 4 new references. To appear in Phys. Rev.

Thermodynamic Properties of the 2N-Piece Relativistic String

The thermodynamic free energy F(\beta) is calculated for a gas consisting of the transverse oscillations of a piecewise uniform bosonic string. The string consists of 2N parts of equal length, of alternating type I and type II material, and is relativistic in the sense that the velocity of sound everywhere equals the velocity of light. The present paper is a continuation of two earlier papers, one dealing with the Casimir energy of a 2N--piece string [I. Brevik and R. Sollie (1997)], and another dealing with the thermodynamic properties of a string divided into two (unequal) parts [I. Brevik, A. A. Bytsenko and H. B. Nielsen (1998)]. Making use of the Meinardus theorem we calculate the asymptotics of the level state density, and show that the critical temperatures in the individual parts are equal, for arbitrary spacetime dimension D. If D=26, we find \beta= (2/N)\sqrt{2\pi /T_{II}}, T_{II} being the tension in part II. Thermodynamic interactions of parts related to high genus g is also considered.Comment: 15 pages, LaTeX, 2 figures. Discussion in section 8 expande

Overvåking av forurensningssituasjonen i indre Oslofjord 1997

Vannkvaliteten i fjordens overflatelag sommeren 1997 var omtrent like bra som i 1996, som var et meget bra år sammenlignet med 1994 og 1995, hvor overløp og flom (1995) preget forholdene. Den milde vinteren var lite gunstig for dypvannsfornyelsen og det var meget liten vannfornyelse i Bunnefjorden. Det ble allikevel registrert oksygen i dypvannet selv om konsentrasjonene ble meget lave på høsten og klart lavere enn gjennomsnittlige forhold i perioden før det siste store anlegget med kjemisk rensing ble startet i 1982. I Vestfjorden var oksygenforholdene om høsten noe bedre. I Drøbaksundet ble det observert lave oksygenkonsentrasjoner sammenlignet med tidligere observasjoner, selv om nivået, som vanlig, var betydelig høyere enn i indre Oslofjord. Årsaken til de relativt lave oksygenkonsentrasjonene var en ekstra lang stagnasjonperiode. Observasjonene i 1997 bekrefter tidligere trender i fjordens forurensningsutvikling. Vannkvaliteten i overflatelaget har blitt bedre etter gjennomførte rensetiltak og det har vært en liten men positiv utvikling i dypvannet i Vestfjorden, men ikke i Bunnefjorden. På mellomdyp i Vestfjorden er det fortsatt ofte registrert dårligere oksygenforhold. De observerte forandringer skyldes ikke bare rensetiltak men også variasjoner i dypvannsfornyelser og andre klimaavhengige variasjoner

Development of muscle ultrasound density in healthy fetuses and infants

Muscle ultrasound density (MUD) is a non-invasive parameter to indicate neuromuscular integrity in both children and adults. In healthy fetuses and infants, physiologic MUD values during development are still lacking. We therefore aimed to determine the physiologic, age-related MUD trend of biceps, quadriceps, tibialis anterior, hamstrings, gluteal and calf muscles, from pre- to the first year of postnatal life. To avoid a bias by pregnancy-related signal disturbances, we expressed fetal MUD as a ratio against bone ultrasound density. We used the full-term prenatal MUD ratio and the newborn postnatal MUD value as reference points, so that MUD development could be quantified from early pre- into postnatal life. Results: During the prenatal period, the total muscle group revealed a developmental MUD trend concerning a fetal increase in MUD-ratio from the 2nd trimester up to the end of the 3rd trimester [median increase: 27% (range 16-45), p < .001]. After birth, MUD-values increased up to the sixth month [median increase: 11% (range -7-27), p = 0.025] and stabilized thereafter. Additionally, there were also individual MUD characteristics per muscle group and developmental stage, such as relatively low MUD values of fetal hamstrings and high values of the paediatric gluteus muscles. These MUD trends are likely to concur with analogous developmentally, maturation-related alterations in the muscle water to peptide content ratios

Nematoden als indicator voor de waterkwaliteit

Het beoordelen van de waterkwaliteit is een lastige zaak. Vaak wordt de chemische kwaliteit bepaald, maar eigenlijk willen we weten welke effecten die heeft op de biologische kwaliteit. Veld- en microscopisch onderzoek aan biologische indicatoren is bewerkelijk en bovendien zijn de resultaten niet eenduidig. Met de ontwikkeling van DNA-analysetechnieken is het mogelijk geworden nematoden in de waterbodem snel en accuraat te analyseren. Nematoden zijn kleine aaltjes (lengte 0,3 tot 1,0 mm) die in grote aantallen en met een aanzienlijke diversiteit in de waterbodem aanwezig zijn. De combinatie van hoge dichtheden en grote verscheidenheid maakt de nematodengemeenschap tot potentiële bio-indicator voor de waterkwaliteit. Een pilot liet zien dat DNA-analyse van nematoden in de waterbodem duidelijke signalen van eutrofiëring aangaf en daarmee inzicht gaf in de waterkwaliteit

Pathogenesis of cerebral malformations in human fetuses with meningomyelocele

<p>Abstract</p> <p>Background</p> <p>Fetal spina bifida aperta (SBA) is characterized by a spinal meningomyelocele (MMC) and associated with cerebral pathology, such as hydrocephalus and Chiari II malformation. In various animal models, it has been suggested that a loss of ventricular lining (neuroepithelial/ependymal denudation) may trigger cerebral pathology. In fetuses with MMC, little is known about neuroepithelial/ependymal denudation and the initiating pathological events.</p> <p>The objective of this study was to investigate whether neuroepithelial/ependymal denudation occurs in human fetuses and neonates with MMC, and if so, whether it is associated with the onset of hydrocephalus.</p> <p>Methods</p> <p>Seven fetuses and 1 neonate (16–40 week gestational age, GA) with MMC and 6 fetuses with normal cerebral development (22–41 week GA) were included in the study. Identification of fetal MMC and clinical surveillance of fetal head circumference and ventricular width was performed by ultrasound (US). After birth, MMC was confirmed by histology. We characterized hydrocephalus by increased head circumference in association with ventriculomegaly. The median time interval between fetal cerebral ultrasound and fixing tissue for histology was four days.</p> <p>Results</p> <p>At 16 weeks GA, we observed neuroepithelial/ependymal denudation in the aqueduct and telencephalon together with sub-cortical heterotopias in absence of hydrocephalus and/or Chiari II malformation. At 21–34 weeks GA, we observed concurrence of aqueductal neuroepithelial/ependymal denudation and progenitor cell loss with the Chiari II malformation, whereas hydrocephalus was absent. At 37–40 weeks GA, neuroepithelial/ependymal denudation coincided with Chiari II malformation and hydrocephalus. Sub-arachnoidal fibrosis at the convexity was absent in all fetuses but present in the neonate.</p> <p>Conclusion</p> <p>In fetal SBA, neuroepithelial/ependymal denudation in the telencephalon and the aqueduct can occur before Chiari II malformation and/or hydrocephalus. Since denuded areas cannot re-establish cell function, neuro-developmental consequences could induce permanent cerebral pathology.</p

SORTA:a system for ontology-based re-coding and technical annotation of biomedical phenotype data

There is an urgent need to standardize the semantics of biomedical data values, such as phenotypes, to enable comparative and integrative analyses. However, it is unlikely that all studies will use the same data collection protocols. As a result, retrospective standardization is often required, which involves matching of original (unstructured or locally coded) data to widely used coding or ontology systems such as SNOMED CT (clinical terms), ICD-10 (International Classification of Disease) and HPO (Human Phenotype Ontology). This data curation process is usually a time-consuming process performed by a human expert. To help mechanize this process, we have developed SORTA, a computer-aided system for rapidly encoding free text or locally coded values to a formal coding system or ontology. SORTA matches original data values (uploaded in semicolon delimited format) to a target coding system (uploaded in Excel spreadsheet, OWL ontology web language or OBO open biomedical ontologies format). It then semi-automatically shortlists candidate codes for each data value using Lucene and n-gram based matching algorithms, and can also learn from matches chosen by human experts. We evaluated SORTA's applicability in two use cases. For the LifeLines biobank, we used SORTA to recode 90 000 free text values (including 5211 unique values) about physical exercise to MET (Metabolic Equivalent of Task) codes. For the CINEAS clinical symptom coding system, we used SORTA to map to HPO, enriching HPO when necessary (315 terms matched so far). Out of the shortlists at rank 1, we found a precision/recall of 0.97/0.98 in LifeLines and of 0.58/0.45 in CINEAS. More importantly, users found the tool both a major time saver and a quality improvement because SORTA reduced the chances of human mistakes. Thus, SORTA can dramatically ease data (re) coding tasks and we believe it will prove useful for many more projects

Quantifying measures to limit wind driven resuspension of sediments for improvement of the ecological quality in some shallow Dutch lakes

Although phosphorus loadings are considered the main pressure for most shallow lakes, wind-driven resuspension can cause additional problems for these aquatic ecosystems. We quantified the potential effectiveness of measures to reduce the contribution of resuspended sediments, resulting from wind action, to the overall light attenuation for three comparable shallow peat lakes with poor ecological status in the Netherlands: Loosdrecht, Nieuwkoop, and Reeuwijk (1.8–2.7 m depth, 1.6–2.5 km fetch). These measures are: 1. wave reducing barriers, 2. water level fluctuations, 3. capping of the sediment with sand, and 4. combinations of above. Critical shear stress of the sediments for resuspension (Vcrit), size distribution, and optical properties of the suspended material were quantified in the field (June 2009) and laboratory. Water quality monitoring data (2002–2009) showed that light attenuation by organic suspended matter in all lakes is high. Spatial modeling of the impact of these measures showed that in Lake Loosdrecht limiting wave action can have significant effects (reductions from 6% exceedance to 2% exceedance of Vcrit), whereas in Lake Nieuwkoop and Lake Reeuwijk this is less effective. The depth distribution and shape of Lake Nieuwkoop and Lake Reeuwijk limit the role of wind-driven resuspension in the total suspended matter concentration. Although the lakes are similar in general appearance (origin, size, and depth range) measures suitable to improve their ecological status differ. This calls for care when defining the programme of measures to improve the ecological status of a specific lake based on experience from other lakes.

Discontinuous Galerkin method for multifluid Euler equations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106454/1/AIAA2013-2595.pd

Circulating Small Non-coding RNAs as Biomarkers for Recovery After Exhaustive or Repetitive Exercise

Circulating microRNAs have proven to be reliable biomarkers, due to their high stability, both in vivo in the circulation, and ex vivo during sample preparation and storage. Small nucleolar RNAs (snoRNAs) are a different type of small non-coding RNAs that can also be reliably measured in plasma, but have only been studied sporadically. In this study, we aimed to identify RNA-biomarkers that can distinguish between different exercise regimes and that entail clues about muscle repair and recovery after prolonged exhaustive endurance exercise. We compared plasma microRNA profiles between two cohorts of elite cyclists, subjected to two different types of exercise regimes, as well as a cohort of patients with peripheral artery disease (PAD) that were scheduled to undergo lower limb amputation, due to critical limb ischemia. In elite athletes, muscle tissue recovers quickly even after exhaustive exercise, whereas in PAD patients, recovery is completely impaired. Furthermore, we measured levels of a specific group of snoRNAs in the plasma of both elite cyclists and PAD patients. Using a multiplex qPCR screening, we detected a total of 179 microRNAs overall, of which, on average, 161 microRNAs were detected per sample. However, only 30 microRNAs were consistently expressed in all samples. Of these, two microRNAs, miR-29a-3p and miR193a-5p, that responded differently two different types of exercise, namely exhaustive exercise and non-exhaustive endurance exercise. Using individual rt/qPCR, we also identified a snoRNA, SNORD114.1, which was significantly upregulated in plasma in response to endurance exercise. Furthermore, two microRNAs, miR-29a-3p and miR-495-3p, were significantly differentially expressed in athletes compared to PAD patients, but only following exercise. We suggest that these two microRNAs could function as markers of impaired muscle repair and recovery. In conclusion, microRNAs miR-29a-3p and miR-193a-5p may help us distinguish between repeated exhaustive and non-exhaustive endurance exercise. MicroRNA miR-29a-3p, as well as miR-495-3p, may further mark impaired muscle recovery in patients with severe critical limb ischemia. Furthermore, we showed for the first time that a circulating snoRNA, SNORD114.1, is regulated in response to exercise and may be used as biomarker