840 research outputs found
Vortex reconnections between coreless vortices in binary condensates
Vortex reconnections plays an important role in the turbulent flows
associated with the superfluids. To understand the dynamics, we examine the
reconnections of vortex rings in the superfluids of dilute atomic gases
confined in trapping potentials using Gross-Petaevskii equation. Furthermore we
study the reconnection dynamics of coreless vortex rings, where one of the
species can act as a tracer.Comment: 9 pages, Proceeding from International Conference On Complex
Processes in Plasmas and Nonlinear Dynamical Systems, Gandhinagar, India
(November 2012
Systems biology: A tool for charting the antiviral landscape
The host antiviral programs that are initiated following viral infection form a dynamic and complex web of responses that we have collectively termed as “the antiviral landscape”. Conventional approaches to studying antiviral responses have primarily used reductionist systems to assess the function of a single or a limited subset of molecules. Systems biology is a holistic approach that considers the entire system as a whole, rather than individual components or molecules. Systems biology based approaches facilitate an unbiased and comprehensive analysis of the antiviral landscape, while allowing for the discovery of emergent properties that are missed by conventional approaches. The antiviral landscape can be viewed as a hierarchy of complexity, beginning at the whole organism level and progressing downward to isolated tissues, populations of cells, and single cells. In this review, we will discuss how systems biology has been applied to better understand the antiviral landscape at each of these layers. At the organismal level, the Collaborative Cross is an invaluable genetic resource for assessing how genetic diversity influences the antiviral responses. Whole tissue and isolated bulk cell transcriptomics serves as a critical tool for the comprehensive analysis of antiviral responses at both the tissue and cellular levels of complexity. Finally, new techniques in single cell analysis are emerging tools that will revolutionize our understanding of how individual cells within a bulk infected cell population contribute to the overall antiviral landscape
Evaluation of data loggers for measuring lying behavior in dairy calves
Lying behavior might indicate how the animal interacts with its environment
and is an important indicator of cow and calf comfort. Measuring behavior can
be time consuming; therefore, behavioral recording with the help of loggers
has become common. Recently, the Hobo Pendant G data logger (Onset Computer
Corp., Bourne, MA) was validated for measuring lying behavior in cows but no
work to date has validated this logger for measuring lying behavior in calves.
The objective of this study was to test the accuracy of the Hobo Pendant G
data logger for measuring total lying time and frequency of lying bouts in
dairy calves. In 2 experiments (experiment 1: thirty-seven 2-h observation
periods; experiment 2: nineteen 24-h observation periods), we tested the
effect of 2 different recording intervals, the effect of attachment to
different legs, and the effect of removing short, potentially erroneous
readings. We found an excellent relationship when comparing the 30-s and 60-s
recording intervals. For total lying time and bout frequency, the highest
correlation was found when the logger was attached to the hind legs and
recording was conducted with a 60-s sampling interval. In experiment 2,
average total lying time was 1,077 ± 54 min/24 h (18.0 ± 0.9h/24h), with an
average frequency of 19.4 ± 4.5 bouts per day. Predictability, sensitivity,
and specificity for experiment 2 were >97% using the 60-s recording interval
and removing single readings of lying or standing from the data set compared
with direct observation as reference. The data logger accurately measured
total lying time and bout frequency when the sampling interval was ≤ 60 s and
short readings of lying and standing up to 1 min were converted into the
preceding behavior. The best results were achieved by attaching the logger to
the right hind leg
Endogenous and exogenous progesterone influence body temperature in dairy cows
Three experiments were conducted to determine the effect of endogenous
progesterone (P4) on body temperature comparing lactating, pregnant with
lactating, nonpregnant cows, and to study the effect of exogenous P4
administered via a controlled internal drug release (CIDR) insert on body
temperature in lactating dairy cows. Body temperature was measured vaginally
and rectally using temperature loggers and a digital thermometer,
respectively. In experiment 1, 10 cyclic lactating cows (3 primiparous, 7
multiparous) and 10 lactating, pregnant cows (3 primiparous, 7 multiparous)
were included. Vaginal temperatures and serum P4 concentrations were greater
in pregnant cows (vaginal: 0.3±0.01°C; P4: 5.5±0.4 ng/mL) compared with
nonpregnant cows. In experiment 2, estrous cycles of 14 postpartum healthy,
cyclic, lactating cows (10 primiparous, 4 multiparous) were synchronized, and
cows were assigned randomly to 1 of 2 treatments (CIDR-P4 or CIDR-blank). A
temperature logger was inserted 1 d after ovulation using a P4-free CIDR
(CIDR-blank) and a CIDR containing 1.38g of P4 (CIDR-P4) in the control (n=7)
and the P4-treated group (n=7), respectively. On d 3 after P4 treatment,
vaginal temperature was 0.3±0.03°C greater compared with that on d 1 and d 5.
In experiment 3, 9 cyclic multiparous lactating cows were enrolled 1±1 d after
confirmed ovulation and a temperature logger inserted. Two days later, a
CIDR-P4 was inserted on top of the CIDR-blank. On d 5±1 and d 7±1,
respectively, the CIDR-P4 and CIDR-blank with the temperature logger were
removed. During the CIDR-P4 treatment (48h), vaginal temperature was
0.2±0.05°C and 0.1±0.05°C greater than during the pre- and post-treatment
periods (48h), respectively. Serum P4 concentration peaked during CIDR-P4
treatment (2.2±0.8 ng/mL) and was greater than during the pre-treatment period
(0.2±0.2 ng/mL) for 48h. An increase in vaginal temperature could be due to
endogenous and exogenous P4. However, a correlation between serum P4
concentrations and body temperature did not exist. Further investigations are
warranted to better understand the pathways of the thermogenic effect of P4 on
body temperature
Acoustic Immunosensing of Exosomes Using a Quartz Crystal Microbalance with Dissipation Monitoring
Exosomes are endocytic lipid-membrane bound bodies with the potential to be used as biomarkers in cancer and neurodegenerative disease. The limitations and scarcity of current exosome characterization approaches have led to a growing demand for translational techniques, capable of determining their molecular composition and physical properties in physiological fluids. Here, we investigate label-free immunosensing, using a quartz crystal microbalance with dissipation monitoring (QCM-D), to detect exosomes by exploiting their surface protein profile. Exosomes expressing the transmembrane protein CD63 were isolated by size-exclusion chromatography from cell culture media. QCM-D sensors functionalized with anti-CD63 antibodies formed a direct immunoassay toward CD63-positive exosomes in 75% v/v serum, exhibiting a limit-of-detection of 2.9 × 108 and 1.4 × 108 exosome sized particles (ESPs)/mL for frequency and dissipation response, respectively, i.e., clinically relevant concentrations. Our proof-of-concept findings support the adoption of dual-mode acoustic analysis of exosomes, leveraging both frequency and dissipation monitoring for use in bioanalytical characterization
Cosmogenic effects in Mbale chondrite
This article does not have an abstract
- …