RNA conformational changes in the life cycles of RNA viruses, viroids, and virus-associated RNAs

The rugged nature of the RNA structural free energy landscape allows cellular RNAs to respond to environmental conditions or fluctuating levels of effector molecules by undergoing dynamic conformational changes that switch on or off activities such as catalysis, transcription or translation. Infectious RNAs must also temporally control incompatible activities and rapidly complete their life cycle before being targeted by cellular defenses. Viral genomic RNAs must switch between translation and replication, and untranslated subviral RNAs must control other activities such as RNA editing or self-cleavage. Unlike well characterized riboswitches in cellular RNAs, the control of infectious RNA activities by altering the configuration of functional RNA domains has only recently been recognized. In this review, we will present some of these molecular rearrangements found in RNA viruses, viroids and virus-associated RNAs, relating how these dynamic regions were discovered, the activities that might be regulated, and what factors or conditions might cause a switch between conformations

Liquid Feed Injection in a High Density Riser

First investigations on liquid feed injection in a high density circulating fluidized bed of FCC particles were done by means of fast responding thermocouples, capacitance and conductivity probes. The results imply very limited radial mixing between dry solids, wet solids and liquid for the injection parallel to the hot up-streaming gas-solid flow

A direct disodium dihydrogen ethylenediaminetetraacetate titration procedure for magnesium in limestone

Digitized 2007 AES.Includes bibliographical references (page 10)

A flame photometric method for potash in fertilizers : ion exchange separation of interfering anions

Digitized 2007 AES.Includes bibliographical references (page 12)

Direct ethylenediaminetetraacetate titration procedure for calcium in biological substances : anion exchange separation of phosphate

Digitized 2007 AES.Includes bibliographical references (page 10)

A manned exobiology laboratory based on the Moon

Establishment of an exobiology laboratory on the Moon would provide a unique opportunity for exploration of extraterrestrial materials on a long-term, ongoing basis, for elucidation of exobiological processes and chemical evolution. A major function of the lunar exobiology laboratory would be to examine samples collected from other planets (e.g., Mars) for the presence of extant or extinct life. By establishing a laboratory on the Moon, preliminary analyses could be conducted away from Earth, thus establishing that extraterrestrial materials are benign before their return to Earth for more extensive investigations. The Moon-based exobiology laboratory would have three major components for study of samples returned from other planets: (1) the search for extant life - this component would focus on the detection and identification of life forms using biological, physical, and chemical methods; (2) the search for extinct life - this component would concentrate on identification of extinct life using micropaleontological physical and chemical means; and (3) the search and evidence of chemical evolution - this component would be devoted to the detection and identification of molecules revealing prebiotic chemical evolution

Can the palatability of healthy, satiety-promoting foods increase with repeated exposure during weight loss?

Repeated exposure to sugary, fatty, and salty foods often enhances their appeal. However, it is unknown if exposure influences learned palatability of foods typically promoted as part of a healthy diet. We tested whether the palatability of pulse containing foods provided during a weight loss intervention which were particularly high in fiber and low in energy density would increase with repeated exposure. At weeks 0, 3, and 6, participants (n = 42; body mass index (BMI) 31.2 ± 4.3 kg/m²) were given a test battery of 28 foods, approximately half which had been provided as part of the intervention, while the remaining half were not foods provided as part of the intervention. In addition, about half of each of the foods (provided as part or not provided as part of the intervention) contained pulses. Participants rated the taste, appearance, odor, and texture pleasantness of each food, and an overall flavor pleasantness score was calculated as the mean of these four scores. Linear mixed model analyses showed an exposure type by week interaction effect for taste, texture and overall flavor pleasantness indicating statistically significant increases in ratings of provided foods in taste and texture from weeks 0 to 3 and 0 to 6, and overall flavor from weeks 0 to 6. Repeated exposure to these foods, whether they contained pulses or not, resulted in a ~4% increase in pleasantness ratings. The long-term clinical relevance of this small increase requires further study.T32 AT000815 - NCCIH NIH HH

A PTAS for Scheduling Unrelated Machines of Few Different Types

Scheduling on Unrelated Machines is a classical optimization problem where $n$ jobs have to be distributed to $m$ machines. Each of the jobs $j \in \{1, \ldots, n\}$ has on machine $i \in \{1, \ldots, m\}$ a processing time $p_{ij} \geq 0$. The goal is to minimize the makespan, i.e.\ the maximum completion time of the longest-running machine. Unless $P = NP$, this problem does not allow for a polynomial-time approximation algorithm with a ratio better than $\frac{3}{2}$. A natural scenario is however that many machines are of the same type, like a CPU and GPU cluster: for each of the $K$ machine types, the machines $i \neq i'$ of the same type $k$ satisfy $p_{ij} = p_{i'j}$ for all jobs $j$. For the case where the number $K$ of machine types is constant, this paper presents an approximation scheme, i.e.\ an algorithm of approximation ratio $1+\varepsilon$ for $\varepsilon > 0$, with an improved running time only single exponential in $\frac{1}{\varepsilon}$