Electro-hydrodynamics of binary electrolytes driven by modulated surface potentials

We study the electro-hydrodynamics of the Debye screening layer that arises in an aqueous binary solution near a planar insulating wall when applying a spatially modulated AC-voltage. Combining this with first order perturbation theory we establish the governing equations for the full non-equilibrium problem and obtain analytic solutions in the bulk for the pressure and velocity fields of the electrolyte and for the electric potential. We find good agreement between the numerics of the full problem and the analytics of the linear theory. Our work provides the theoretical foundations of circuit models discussed in the literature. The non-equilibrium approach also reveals unexpected high-frequency dynamics not predicted by circuit models.Comment: 9 pages including 4 figures. Accepted for PRE

Exploring attitudinal factors influencing modal shift:a latent class analysis of Danish commuters

Governments advocate for a modal shift from motorized transport modes to active modes. Various political approaches can be adopted to affect travel behavior and patterns. However, interventions spread across the entire population offer limited opportunities to achieve behavioral change. Furthermore, attitude has been shown to cut across demographic characteristics and strongly influence the conducted travel behavior. Therefore, a latent class analysis including significant sociodemographic variables and value-based attitudes concerning factors influencing transport, settlement, and additional priorities was performed. The study objectively identified five classes of Danish commuters with the same preconditions in terms of commuting distance but with clear differences in attitude and transport modes. Each latent class represents a unique combination of characteristics, which indicates the need to design target group-specific interventions to optimize the chances of influencing travel behavior. In particular, a group of malcontented motorists demonstrating a high intention to change exhibit negative feelings toward car travel and thus appear to act in contravention of their attitudes. In contrast, a class of immovable motorists was found, a class of beneficial commuters and finally two cycling dominated classes of passionate cyclists and environmentalist cyclists. Finally, this study has emphasized that similar attitudes can lead to dissimilar behaviors and that the same behavior can be exhibited for various reasons. We deduced how transport mode choice is influenced by various factors, with habit as one of the strongest, as those with strong habits seem disinclined to information about alternatives and call for “harder” policy interventions. The findings emphasize the importance of targeted interventions tailored to specific commuter groups to encourage modal shifts towards sustainable transportation.</p

Transport coefficients for electrolytes in arbitrarily shaped nano and micro-fluidic channels

We consider laminar flow of incompressible electrolytes in long, straight channels driven by pressure and electro-osmosis. We use a Hilbert space eigenfunction expansion to address the general problem of an arbitrary cross section and obtain general results in linear-response theory for the hydraulic and electrical transport coefficients which satisfy Onsager relations. In the limit of non-overlapping Debye layers the transport coefficients are simply expressed in terms of parameters of the electrolyte as well as the geometrical correction factor for the Hagen-Poiseuille part of the problem. In particular, we consider the limits of thin non-overlapping as well as strongly overlapping Debye layers, respectively, and calculate the corrections to the hydraulic resistance due to electro-hydrodynamic interactions.Comment: 13 pages including 4 figures and 1 table. Typos corrected. Accepted for NJ

The Role of Socioeconomic Status on Infant\u27s Expression

Most language inequality for infants begins very early in their development. For most, this disparity develops prior to 36 months (Farkus & Baron, 2000). • Significant disparities in vocabulary size between socioeconomic status (SES) were evident by 18 months. By 24 months, there was a 6 month age gap (Fernald et al, 2011). • 65% of low SES preschoolers in head start programs had clinically significant language delays (Ramey and Ramey, 2004) • Maternal education is a known indicator of SES and is correlated with language input for infants (Dollaghan et al. 1999). • At 18 months, most infants experience “word spurts” and an increase in expressive vocabulary (Reznick & Goldfield, 1992). Research Question: Are SES (maternal education) and expressive vocabulary related in Kentucky families during the COVID pandemic

Regional trends in breast cancer incidence and mortality in Denmark prior to mammographic screening.

To provide a basis for the evaluation of mammographic screening programmes in Denmark, a study was undertaken of the regional differences in breast cancer incidence and mortality. All 16 regions were followed for the 20 year period, 1970-89, before the start of the first population-based mammographic screening programme in the Copenhagen municipality in 1991. Multiplicative Poisson models were used for the analysis. In general, the incidence increased during this period from 55 to 70 [per 100,000 standardised world standard population (WSP)], and the analysis shows this to be most pronounced among women below age 60. The mortality was more stable, changing only from 24 to 28 (per 100,000 standardised WSP), but a significant increase occurred in the late 1980s. The study showed regional differences in both incidence and mortality of breast cancer in Denmark. Both the incidence and the mortality varied between the regions, with maximum differences of 22%. The analysis showed no variation in the time trends in the different regions, and thus indicates that the use of a regional comparison group would be a valid basis for evaluation of the Copenhagen programme. Our study, however, underlies the difficulties inherent in the evaluation of screening programmes without internal control groups

Nucleation of quark matter bubbles in neutron stars

The thermal nucleation of quark matter bubbles inside neutron stars is examined for various temperatures which the star may realistically encounter during its lifetime. It is found that for a bag constant less than a critical value, a very large part of the star will be converted into the quark phase within a fraction of a second. Depending on the equation of state for neutron star matter and strange quark matter, all or some of the outer parts of the star may subsequently be converted by a slower burning or a detonation.Comment: 13 pages, REVTeX, Phys.Rev.D (in press), IFA 93-32. 5 figures (not included) available upon request from [email protected]

Naupliar and Metanaupliar development of Thysanoessa raschii (Malacostraca, Euphausiacea) from Godthåbsfjord, Greenland, with a reinstatement of the ancestral status of the free-living Nauplius in Malacostracan evolution

The presence of a characteristic crustacean larval type, the nauplius, in many crustacean taxa has often been considered one of the few uniting characters of the Crustacea. Within Malacostraca, the largest crustacean group, nauplii are only present in two taxa, Euphauciacea (krill) and Decapoda Dendrobranchiata. The presence of nauplii in these two taxa has traditionally been considered a retained primitive characteristic, but free-living nauplii have also been suggested to have reappeared a couple of times from direct developing ancestors during malacostracan evolution. Based on a re-study of Thysanoessa raschii (Euphausiacea) using preserved material collected in Greenland, we readdress this important controversy in crustacean evolution, and, in the process, redescribe the naupliar and metanaupliar development of T. raschii. In contrast to most previous studies of euphausiid development, we recognize three (not two) naupliar (= ortho-naupliar) stages (N1-N3) followed by a metanauplius (MN). While there are many morphological changes between nauplius 1 and 2 (e.g., appearance of long caudal setae), the changes between nauplius 2 and 3 are few but distinct. They involve the size of some caudal spines (largest in N3) and the setation of the antennal endopod (an extra seta in N3). A wider comparison between free-living nauplii of both Malacostraca and non-Malacostraca revealed similarities between nauplii in many taxa both at the general level (e.g., the gradual development and number of appendages) and at the more detailed level (e.g., unclear segmentation of naupliar appendages, caudal setation, presence of frontal filaments). We recognize these similarities as homologies and therefore suggest that free-living nauplii were part of the ancestral malacostracan type of development. The derived morphology (e.g., lack of feeding structures, no fully formed gut, high content of yolk) of both euphausiid and dendrobranchiate nauplii is evidently related to their non-feeding (lecithotrophic) status

Competition between Diffusion and Fragmentation: An Important Evolutionary Process of Nature

We investigate systems of nature where the common physical processes diffusion and fragmentation compete. We derive a rate equation for the size distribution of fragments. The equation leads to a third order differential equation which we solve exactly in terms of Bessel functions. The stationary state is a universal Bessel distribution described by one parameter, which fits perfectly experimental data from two very different system of nature, namely, the distribution of ice crystal sizes from the Greenland ice sheet and the length distribution of alpha-helices in proteins.Comment: 4 pages, 3 figures, (minor changes

Salovum Egg Yolk Containing Antisecretory Factor As an Adjunct Therapy in Severe Cholera in Adult Males: A Pilot Study

Cholera involves stimulation of intestinal secretory process in response to cholera toxin leading to profuse watery diarrhoea that might cause death due to dehydration unless timely rehydration therapy is initiated. Efforts to identify and test potential antisecretory agents are ongoing. Antisecretory factor (AF) is a naturally-occurring protein produced in the human secretory organs, including the intestine, with antisectory properties demonstrated in animal and human models of secretory diarrhoea. Salovum egg yolk powder contains proteins with antisecretory properties in a much higher (500 times) concentration than that of normal hen eggs. This is achieved by feeding hens with specially-processed cereals, capable of inducing proteins with antisecretory properties in the yolk. The aim of the study was to examine the effect of Salovum egg yolk powder containing AF in the treatment of adult cholera patients. In an open, randomized controlled trial (pilot study), 40 adult male patients with severe cholera were studied: 20 received standard treatment (oral rehydration solution, antibiotic, and usual hospital diet) plus Salovum egg yolk powder (study group) and 20 received standard treatment alone (control group). All the patients received tablet doxycycline (300 mg) once immediately after randomization. Written informed consent was obtained from each subject before enrollment. The main outcome measures were stool weight and duration of diarrhoea. The demographic and baseline clinical characteristics of the study patients were comparable between the groups. No significant differences were found in the mean stool weight, g/kg of body-weight during the first 24 hours [study vs control group, mean±standard deviation (SD), 218±119 vs 195±136], second 24 hours (mean±SD, 23±39 vs 22±34), and cumulative up to 72 hours (mean±SD, 245±152 vs 218±169). The duration (hours) of diarrhoea after admission in the hospital was also similar in both the groups (mean±SD, 33±14 vs 32±10). No adverse effect was observed. Salovum egg powder containing AF as an adjunct therapy in the treatment of severe cholera could not demonstrate any beneficial effect. Further studies with higher doses of Salovum egg yolk powder might be considered in future to establish its antisecretory effect