Bond Orientational Order, Molecular Motion and Free Energy of High Density DNA Mesophases

By equilibrating condensed DNA arrays against reservoirs of known osmotic stress and examining them with several structural probes, it has been possible to achieve a detailed thermodynamic and structural characterization of the change between two distinct regions on the liquid crystalline phase digram: a higher-density hexagonally packed region with long-range bond orientational order in the plane perpendicular to the average molecular direction; and a lower-density cholesteric region with fluid-like positional order. X-rays scattering on highly ordered DNA arrays at high density and with the helical axis oriented parallel to the incoming beam showed a six-fold azimuthal modulation of the first order diffraction peak that reflects the macroscopic bond-orientational order. Transition to the less-dense cholesteric phase through osmotically controlled swelling shows the loss of this bond orientational order that had been expected from the change in optical birefringence patterns and that is consistent with a rapid onset of molecular positional disorder. This change in motion was previously inferred from intermolecular force measurements and is now confirmed by $\rm ^{31}P$ NMR. Controlled reversible swelling and compaction under osmotic stress, spanning a range of densities between $\sim 120$ mg/ml to $\sim 600$ mg/ml, allows measurement of the free energy changes throughout each phase and at the phase transition, essential information for theories of liquid-crystalline states.Comment: 14 pages, 3 figures in gif format available at http://abulafia.mgsl.dcrt.nih.gov/pics.html E-mail: [email protected]

Transmission dynamics and prospects for the elimination of canine rabies

Rabies has been eliminated from domestic dog populations in Western Europe and North America, but continues to kill many thousands of people throughout Africa and Asia every year. A quantitative understanding of transmission dynamics in domestic dog populations provides critical information to assess whether global elimination of canine rabies is possible. We report extensive observations of individual rabid animals in Tanzania and generate a uniquely detailed analysis of transmission biology, which explains important epidemiological features, including the level of variation in epidemic trajectories. We found that the basic reproductive number for rabies, R<sub>0</sub>, is very low in our study area in rural Africa (∼1.2) and throughout its historic global range (<2). This finding provides strong support for the feasibility of controlling endemic canine rabies by vaccination, even near wildlife areas with large wild carnivore populations. However, we show that rapid turnover of domestic dog populations has been a major obstacle to successful control in developing countries, thus regular pulse vaccinations will be required to maintain population-level immunity between campaigns. Nonetheless our analyses suggest that with sustained, international commitment, global elimination of rabies from domestic dog populations, the most dangerous vector to humans, is a realistic goal

Biophysical properties of salt marsh canopies - Quantifying plant stem flexibility and above ground biomass

The three-dimensional structure of salt marsh plant canopies, amongst other marsh surface characteristics, is of critical importance to the functioning and persistence of coastal salt marshes. Together with plant flexibility it controls the contribution of vegetation to the tidal flow and wave energy dissipation potential of marshes. However detailed information on these two key biophysical properties of salt marsh canopies is scarce. In this paper we present biophysical properties of four plants commonly occurring in NW European salt marshes. We measured stem flexibility, diameter and height of the grasses Spartina anglica, Puccinellia maritima and Elymus athericus and above ground biomass and canopy height in stands of Elymus athericus and the dwarf shrub Atriplex portulacoides. Further we compared the performance of two methods for the non-destructive assessment of above ground biomass, such that they may be used during field assessments of marsh surface vegetation structure (i) measurement of light availability within the canopy and (ii) side-on photography of vegetation. All data were collected on a salt marsh on the Dengie Peninsula, eastern England, UK, in summer (July). We found significant differences in stem flexibility both between species and between the different parts of their stems. P. maritima was found to be the species with the most flexible stems, and, as a result of their relatively large stem diameter, S. anglica the species with the stiffest stems. Above ground biomass and hence potential canopy resistance to water flow could be estimated more accurately by side-on photography of vegetation than from measurement of light availability within the canopy. Our results extend the existing knowledge base on plant properties with relevance to studies of habitat structure and ecosystem functioning as well as wave energy dissipation in salt marsh environments and can be used for the development of a more realistic representation of vegetation in numerical models and laboratory flume studies of plant–flow interactions.This study was carried out with the financial support of the German Academic Exchange Service (DAAD; grant number D/12/44810), while the first author was a visitor at the Cambridge Coastal Research Unit, University of Cambridge.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.coastaleng.2015.03.00

Nachweis erniedrigter Flußgeschwindigkeiten in der Arteria cerebri anterior bei Früh- und Neugeborenen sowie älteren Säuglingen mit Hirnblutungen mit Hilfe der gepulsten Dopplersonographie = Detection of reduced flow velocities in the anterior cerebral artery in premature and newborn infants and in older infants with cerebral hemorrhages using pulsed Doppler sonography

34 infants with intracerebral haemorrhage (intraventricular haemorrhage 26; subdural haemorrhage 2; epidural haemorrhage 2; subarachnoidal haemorrhage 4) were investigated by pulsed Doppler-sonography. Absolute flow velocities were measured in the anterior cerebral arteries in infants with intracranial haemorrhage and compared with the flow velocities of a healthy control group of identical gestational age, actual age and weight. All flow velocities were significantly reduced in premature and full-term infants with intracranial haemorrhage, whereas the pulsatility-index was significantly increased. 10 infants with severe intracranial haemorrhage developed a shunt-depending posthaemorrhagic hydrocephalus. These children showed a significant reduction of all flow velocities in the anterior cerebral arteries in comparison to the healthy control group. The diastolic forward flow was more reduced than the maximal systolic velocity resulting in a significant increase of the pulsatility index. In rapidly progressive hydrocephalus, often no diastolic flow or even a retrograde diastolic flow could be found. After shunt-implantation normalisation of the flow velocities could be observed. Reduced flow velocities could be observed. Reduced flow velocities in the anterior cerebral arteries in infants with subdural, epidural and subarachnoidal haemorrhage were associated with a bad outcome: 1 infant died, 1 infant developed severe leucomalacia, and 1 infant showed atrophy of one cerebral hemisphere. Normal flow velocities in the intracranial arteries in subdural, epidural and subarachnoidal were associated with a favourable prognosis. Absent or even retrograde diastolic flow indicates a dramatic decrease of cerebral perfusion. The longer the pathologic flow patterns were demonstrable the worse was prognosis

Physikalische Parameter extrakorporaler Stoßwellen

Prerequisites for the successful investigation of the mechanism of action of ESWT (extracorporeal shockwave therapy) and the establishment of treatment standards, are the ability to measure, and a knowledge of, the physical parameters involved. The most accurate measurements are obtained with laser hydrophones. Various parameters (amplitude, rise time, pulse width, pressure pulse decay, rarification phase) of a typical shock wave can thus be determined. These can then be used to calculate energy flux density, focal extent, focal volume and as well as focal energy, effective energy in a defined area, and effective biological energy. These parameters can be utilized to work out a theoretical treatment protocol

Terrestrial Rabies and Human Postexposure Prophylaxis, New York, USA

During 1993–2002, cats accounted for 2.7% of rabid terrestrial animals in New York but for one third of human exposure incidents and treatments. Nonbite exposures and animals of undetermined rabies status accounted for 54% and 56%, respectively, of persons receiving rabies treatments

Neuroactive steroids in depression and anxiety disorders: Clinical studies

Certain neuroactive steroids modulate ligand-gated ion channels via non-genomic mechanisms. Especially 3 alpha-reduced pregnane steroids are potent positive allosteric modulators of the gamma-aminobutyric acid type A (GABA(A)) receptor. During major depression, there is a disequilibrium of 3 alpha-reduced neuroactive steroids, which is corrected by clinically effective pharmacological treatment. To investigate whether these alterations are a general principle of successful antidepressant treatment, we studied the impact of nonpharmacological treatment options on neuroactive steroid concentrations during major depression. Neither partial sleep deprivation, transcranial magnetic stimulation, nor electroconvulsive therapy affected neuroactive steroid levels irrespectively of the response to these treatments. These studies suggest that the changes in neuroactive steroid concentrations observed after antidepressant pharmacotherapy more likely reflect distinct pharmacological properties of antidepressants rather than the clinical response. In patients with panic disorder, changes in neuroactive steroid composition have been observed opposite to those seen in depression. However, during experimentally induced panic induction either with cholecystokinine-tetrapeptide or sodium lactate, there was a pronounced decline in the concentrations of 3 alpha-reduced neuroactive steroids in patients with panic disorder, which might result in a decreased GABAergic tone. In contrast, no changes in neuroactive steroid concentrations could be observed in healthy controls with the exception of 3 alpha,5 alpha-tetrahydrodeoxycorticosterone. The modulation of GABA(A) receptors by neuroactive steroids might contribute to the pathophysiology of depression and anxiety disorders and might offer new targets for the development of novel anxiolytic compounds. Copyright (c) 2006 S. Karger AG, Basel

National surveillance for human and pet contact with oral rabies vaccine baits, 2001–2009

Objective—To determine the rate and absolute number of human and pet exposures to oral rabies vaccine (ORV) bait containing liquid vaccinia rabies glycoprotein recombinant vaccine and to evaluate factors that might affect human contact with bait to modify the program and reduce human exposure to the vaccine. Design—Retrospective analysis of surveillance data (2001 to 2009). Sample—Reports on human and pet contact with ORV baits in states with ORV surveillance programs. Procedures—Data were collected from passive, multistate ORV surveillance systems in Alabama, Arizona, Florida, Georgia, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Tennessee, Texas, Vermont, Virginia, and West Virginia. Data collected included the nature of human or pet contact with bait and vaccine, the caller’s knowledge of the ORV bait program, local human population density, and other relevant demographic data. Results—All 18 states participated in the surveillance program for at least 1 year, for a combined 68 years of observation. One thousand four hundred thirty-six calls were reported, representing 3,076 found baits (6.89/100,000 baits dropped); 296 (20%) calls were related to human contact with ruptured bait, and 550 (38%) involved pet contact with the bait. Six adverse events in humans were reported, one of which required hospitalization. Fifty-nine adverse events in pets were noted, all of which were nonserious. Conclusions and Clinical Relevance—Findings from surveillance activities have been used to improve baiting strategies and minimize human and pet contact with ORV baits. Overall, human and pet contact with ORV baits was infrequent. Surveillance has led to early identification of persons exposed to ORV and rapid intervention