The Production of HI in Photodissociation Regions and A Comparison with CO(1-0) Emission

The gas at the surfaces of molecular clouds in galaxies is heated and dissociated by photons from young stars both near and far. HI resulting from the dissociation of molecular hydrogen H2 emits hyperfine line emission at 21 cm, and warmed CO emits dipole rotational lines such as the 2.6 mm line of CO(1-0). We use previously developed models for photodissociation regions (PDRs) to compute the intensities of these HI and CO(1-0) lines as a function of the total volume density n in the cloud and the far ultraviolet flux G0 incident upon it and present the results in units familiar to observers. The intensities of these two lines behave differently with changing physical conditions in the PDR, and, taken together, the two lines can provide a ground-based radio astronomy diagnostic for determining n and G0 separately in distant molecular clouds. This diagnostic is particularly useful in the range Gzero <~ 100, 10 cm^{-3} <~ n <~ 10^5 cm^{-3}, which applies to a large fraction of the volume of the interstellar medium in galaxies. If the molecular cloud is located near discrete sources of far-UV (FUV) emission, the PDR-generated HI and CO(1-0) emission on the cloud surface can be more easily identified, appearing as layered ``blankets'' or ``blisters'' on the side of the cloud nearest to the FUV source. As an illustration, we consider the Galactic object G216 -2.5, i.e. ``Maddalena's Cloud'', which has been previously identified as a large PDR in the Galaxy. We determine that this cloud has n ~ 200 cm^{-3}, G0 ~ 0.8, consistent with other data.Comment: 13 Pages, 3 Figures. Accepted for publication in the Astrophysical Journa

Effect of progestin treatment on formation of persistent follicles in beef heifers [abstract]

Abstract only availableEffective estrous synchronization protocols frequently utilize progestins (melengestrol acetate [MGA] and Controlled Internal Drug Release [CIDR] inserts) to synchronize estrus. Previous research demonstrated that long-term treatment with MGA, in the absence of a corpus luteum, caused formation of persistent follicles and resulted in low fertility. The specific aims of this project were to determine if the presence of a new or used CIDR, in heifers without a corpus luteum, would induce the formation of persistent follicles and to compare the pattern of serum concentrations of progesterone in heifers treated with a new or used CIDR to luteal phase concentrations of progesterone (P4) in non-treated heifers. Normally cycling heifers were allocated by age, weight, and breed into four treatment groups: Control (n=8), MGA (n=4; 0.5 lbs-1hd-1day), new CIDR (n=7; 1.38 g P4), and used CIDR (n=8; new CIDR's previously inserted into cows for 7 d). Progestin treatment (MGA or CIDR) began on d 4 post-estrus and PG was injected on d 6 to induce luteolysis (d 0 = estrus). MGA or CIDR treatment continued for 14 d and length of a follicular wave was defined as the interval from follicular recruitment to ovulation or initiation of a new wave. Length of the first follicular wave (d) was 10.9a, 18.0b, 17.1b, and 16.9b (abP.05) throughout the 14 d treatment period but lower than in the control group. In summary, treatment with a new or used CIDR induced formation of persistent follicles in beef heifers and there was no difference in serum concentrations of progesterone between the two CIDR groups.CAFNR On Campus Research Internshi

Real-time Performance of the Virtual Seismologist Earthquake Early Warning Algorithm in Southern California

The Virtual Seismologist (VS) method is a Bayesian approach to regional network-based earthquake early warning (EEW) that estimates earthquake magnitude, location, and the distribution of peak ground motion using observed ground motion amplitudes, predefined prior information, and appropriate attenuation relationships (Cua 2005; Cua and Heaton 2007). The application of Bayes's theorem in earthquake early warning (Cua 2005) states that the most probable source estimate at any given time is a combination of contributions from prior information (possibilities include network topology or station health status, regional hazard maps, earthquake forecasts, the Gutenberg-Richter magnitude-frequency relationship) and a likelihood function, which takes into account observations from the ongoing earthquake. Prior information can be considered relatively static over the timescale of a given earthquake rupture. The changes in the source estimates and predicted peak ground motion distribution, which are updated each second, are due to changes in the likelihood function as additional arrival and amplitude data become available. The potential use of prior information differentiates the VS approach from other regional, network-based EEW algorithms, such as ElarmS (Allen and Kanamori 2003)

First Complete Genome Sequence of a Genotype A2, Subgroup 4 Small Ruminant Lentivirus

Genetic variation in the ovine TMEM154 gene associates with susceptibility to small ruminant lentivirus (SRLV) infection. We report here the first complete genome sequence for a genotype A2, subgroup 4 SRLV isolated from a Hampshire ewe with two copies of a TMEM154 frameshift mutation predicted to abolish protein function

First Complete Genome Sequence of a Genotype A2, Subgroup 4 Small Ruminant Lentivirus

Genetic variation in the ovine TMEM154 gene associates with susceptibility to small ruminant lentivirus (SRLV) infection. We report here the first complete genome sequence for a genotype A2, subgroup 4 SRLV isolated from a Hampshire ewe with two copies of a TMEM154 frameshift mutation predicted to abolish protein function

Stem-Boring Caterpillars of Switchgrass in the Midwestern United States

Lepidopteran stem borers were collected from switchgrass, Panicum virgatum L., tillers showing symptoms of infestation at seven locations in Illinois and Iowa, with additional observations made on larval and adult activity. Blastobasis repartella (Dietz) (Coleophoridae), whose only known host is switchgrass, was common in plots grown for \u3e5 yr, whereas the polyphagous stalk borer, Papaipema nebris (Guenée) (Noctuidae), was abundant in newly established (i.e., first- and second year) switchgrass. Haimbachia albescens Capps (Crambidae) was collected from two locations in Illinois, making switchgrass the first known host for this species. Entry holes made by B. repartella and H. albescens were usually 1-2 cm above the soil surface, precluding discrimination between these species based on external appearance of damage. Although P. nebris often entered stems within 5 cm of the soil surface, they also seemed to move between stems and were the only species entering stems at heights \u3e15 cm. Adults of B. repartella were active on and above the switchgrass canopy by 2130 hours, with peak activity at ≈0230 hours. Activity of B. repartella adults seemed greatly reduced on one night with relatively cool temperatures and low wind speeds. Data from switchgrass and giant ragweed, Ambrosia trifida L., suggest P. nebris larvae move out of switchgrass during July in search of hosts with larger diameter stems, although by then hosts such as corn, Zea mays L., or Miscanthus spp. may have outgrown the potential for serious damage. However, switchgrass could contribute to greater adult populations of P. nebris if thick-stemmed hosts such as giant ragweed are not managed

Community Seismic Network

The article describes the design of the Community Seismic Network, which is a dense open seismic network based on low cost sensors. The inputs are from sensors hosted by volunteers from the community by direct connection to their personal computers, or through sensors built into mobile devices. The server is cloud-based for robustness and to dynamically handle the load of impulsive earthquake events. The main product of the network is a map of peak acceleration, delivered within seconds of the ground shaking. The lateral variations in the level of shaking will be valuable to first responders, and the waveform information from a dense network will allow detailed mapping of the rupture process. Sensors in buildings may be useful for monitoring the state-of-health of the structure after major shaking