Salmonella serotypes from 1997-2003 NARMS swine diagnostic, on-farm, and slaughter samples

The veterinary component of the National Antimicorbial Resistance Monitoring System (NARMS) identified 8527 Salmonella isolates from swine samples in the years 1997-2003. Fifty-one Salmonella serotypes were identified from 3147 diagnostic, 2138 on-farm, and 3246 slaughter samples

The Effects on Milk Yield and Composition, and Animal Nitrogen and Phosphorus Status, of Offering Early-Lactation Dairy Cows Concentrate Feeds of Differing Crude Protein and Phosphorus Concentrations

Milk composition is affected by the dietary concentration of crude protein (CP) (Kung Jr and Huber 1983) and minerals such as phosphorus (P) (Wu and Satter 2000). Milk composition has consequent effects on the processing properties of milk (Dillon et al. 1997). The objective of this study was to determine the effects of offering supplementary concentrate feeds differing in CP and P concentration to lactating dairy cows in the early lactation period (Feb-May) on milk yield and composition, and on animal nitrogen (N) and P status

An experimental investigation of the relative strength of the silica polymorphs quartz, coesite and stishovite

In this study, quartz, coesite and stishovite were deformed concurrently with an olivine reference sample at high pressure and 850±50°C. Olivine deformed with an effective stress exponent (n) of 6.0_{+3.1}^{-2.2}, which we interpret to indicate that the Peierls creep deformation mechanism was active in the olivine. Quartz and coesite had very similar strengths and deformed by a mechanism with n = 2.8_{+1.2}^{-0.9} and 2.9_{+1.3}^{-0.9} respectively, which are consistent with previous measurements of power‐law creep in these phases. Stishovite deformed with n = 8.1_{+3.7}^{-2.7} and was stronger than both olivine and the other silica polymorphs. The high stress exponent of stishovite is greater than that typically observed for power‐law creep, indicating it is probably (but not certainly) deforming by Peierls creep. The rheology of SiO₂ minerals appears therefore to be strongly affected by the change in silicon‐coordination and density from 4‐fold in quartz and coesite to 6‐fold in stishovite. If the effect of Si‐coordination can be generalised, the increase in Si‐coordination (and density) associated with bridgmanite formation may explain the 10‐100 fold viscosity increase around 660km depth in the Earth

Early post-restoration recovery of tidal wetland structure and function at the Southern Flow Corridor project, Tillamook Bay, Oregon

A substantial fraction of estuarine tidal wetlands have been lost to development or other human uses in the Pacific Northwest since the 1800s. Wetland restoration, typically through tidal re-connection, can restore normal tidal hydrology to these areas and improve estuarine capacity to support ecosystem functions and services. Restoration may initiate a cascade of ecosystem-level impacts to channel and groundwater hydrology, soils, vegetation and fauna, and carbon cycling. Construction of the large Southern Flow Corridor (SFC) restoration project (179 ha) was implemented in southern Tillamook Bay in 2016 to reduce urban flooding and to enhance other wetland ecosystem services such as fisheries production and carbon sequestration. The project occurred on former tidal wetlands (originally emergent tidal marshes and forested tidal swamp) that had been diked for over 60 years prior to restoration. During the diked period, the site was used for crop agriculture, cattle grazing, and non-tidal freshwater marsh mitigation. Much of the site had been abandoned from active agricultural use for several years prior to restoration. We conducted pre-restoration (2013-2015) and early post-restoration (2017-2020) measurements of a wide range of hydrologic, soil, and biological parameters at SFC and least-disturbed reference tidal wetlands to assess early post-restoration change in ecosystem structure. Within the SFC site, we evaluated how pre-restoration differences in elevation and land-use/land-cover zones influenced early restoration trajectories. We compared conditions at SFC with two types of reference wetlands in Tillamook Bay: low and high reference marshes. Before restoration, SFC wetlands were more comparable to low reference marsh than high marsh in elevation and had fresh and slightly acidic soils with relatively low dry season-groundwater levels. SFC tidal channels were also fresh with maximum water levels much lower than fully-tidal reference channels. SFC vegetation was a mix of freshwater-adapted native and non-native species including reed canarygrass. Pre-restoration conditions differed to some extent by land-cover/land-use zone, with the northern zone being higher in elevation while the cropped zone at the southern part of the site was relatively low in elevation. Within two years of dike removal, hydrology, soils, and vegetation changed markedly at SFC, moving towards reference wetland conditions. Soil pH, salinity, and dry-season groundwater level tended to increase and existing vegetation began to die back, creating bare ground. Reed canarygrass in particular declined considerably in the middle and cropped zones in the site. Within 2-4 years of dike removal, many brackish-tolerant estuarine species began to colonize and spread across the southern and middle regions of SFC. Early soil accretion rates at SFC were high, especially in the cropped zone which was low in elevation both before and after restoration. Changes in channel morphology were observed in some locations, including channel widening and bottom scour. Restoration at SFC also led to changes in fish and benthic invertebrate communities in tidal channels. Juvenile chinook and chum salmon increased in abundance at SFC following restoration. Other finfish species such as juvenile coho salmon, staghorn sculpin, three-spined stickleback, and juvenile surfperch were found utilizing channels within the restored site, although not necessarily increasing substantially in abundance due to the restoration. Benthic invertebrate communities shifted to include more amphipods and less insects after restoration activities. Larval and adult mosquitos were captured at sites inside and near the SFC project both before and after restoration, but mosquito numbers were very low. In one of the first studies of greenhouse gas emissions from tidal wetlands in the Pacific Northwest, we found that fluxes of methane and carbon dioxide were driven by complex interactions of groundwater table, salinity, and temperature at SFC and in reference and disturbed (diked former) tidal wetlands. Methane emissions were highly variable in reference wetlands and at SFC, but high when groundwater levels were high and salinity was low. Nitrous oxide emissions were generally very low across all the wetland types measured. Monitoring and developing mitigation strategies for methane in tidal wetland restoration projects may be desirable for restoration practitioners since it is a powerful greenhouse gas. Our data provide an early snapshot of ecosystem change across an array of physical and biological parameters at the SFC site shortly after restoration of tidal flows at the site. Our findings suggest that several parameters, processes and functions at the SFC site are well on their way towards becoming similar to reference tidal wetland conditions. Processes and parameters that were already similar to (or exceeded) reference conditions two years after restoration included groundwater level, channel maximum water level, soil salinity and pH, soil accretion rate, and abundance of some finfish species. Other parameters and processes may take more time to become similar to reference marshes. In terms of support for native plant, invertebrate, and finfish species, our monitoring data suggest the project is enhancing tidal wetland functions in Tillamook Bay. The heterogenous nature of SFC prior to restoration allowed us to examine the role of land use/land cover in post-restoration change. We found that early rates of recovery in soils and vegetation at SFC were linked to pre-restoration gradients of elevation and land-use/land-cover differences. As development of the site proceeds, we anticipate on-going changes such as widening of channels, sediment accretion that raises wetland elevations, succession of plant composition, and potentially establishment (or persistence) of tidal forested or scrub-shrub wetlands in portions of the SFC site that have sufficiently high elevation and low salinities. To further characterize rates of change, and to collect data necessary for possible adaptive management in the future, we recommend continued periodic measurement of key ecosystem parameters at the SFC site and in reference wetlands in the coming decades. We suggest that additional data on wetland processes (such as carbon dynamics, soil accretion, fish use, and food web structure) would be a powerful complement to the parameters that have ben monitored to date. Finally, in terms of monitoring design we note that this project highlighted the value of including a variety of reference wetlands (at both low and high elevation), since their inclusion allows a more robust picture of restoration site development in comparison to the diversity of least-disturbed wetlands within an estuary

The past and future roles of competition and habitat in the range-wide occupancy dynamics of Northern Spotted Owls

Slow ecological processes challenge conservation. Short-term variability can obscure the importance of slower processes that may ultimately determine the state of a system. Furthermore, management actions with slow responses can be hard to justify. One response to slow processes is to explicitly concentrate analysis on state dynamics. Here, we focus on identifying drivers of Northern Spotted Owl (Strix occidentalis caurina) territorial occupancy dynamics across 11 study areas spanning their geographic range and forecasting response to potential management actions. Competition with Barred Owls (Strix varia) has increased Spotted Owl territory extinction probabilities across all study areas and driven recent declines in Spotted Owl populations. Without management intervention, the Northern Spotted Owl subspecies will be extirpated from parts of its current range within decades. In the short term, Barred Owl removal can be effective. Over longer time spans, however, maintaining or improving habitat conditions can help promote the persistence of northern spotted owl populations. In most study areas, habitat effects on expected Northern Spotted Owl territorial occupancy are actually greater than the effects of competition from Barred Owls. This study suggests how intensive management actions (removal of a competitor) with rapid results can complement a slower management action (i.e., promoting forest succession)

Adolescent Alcohol Exposure Reduces Behavioral Flexibility, Promotes Disinhibition and Increases Resistance to Extinction of Ethanol Self-Administration in Adulthood

The prefrontal cortex (PFC) is a brain region that is critically involved in cognitive function and inhibitory control of behavior, and adolescence represents an important period of continued PFC development that parallels the maturation of these functions. Evidence suggests that this period of continued development of the PFC may render it especially vulnerable to environmental insults that impact PFC function in adulthood. Experimentation with alcohol typically begins during adolescence when binge-like consumption of large quantities is common. In the present study, we investigated the effects of repeated cycles of adolescent intermittent ethanol (AIE) exposure (postnatal days 28–42) by vapor inhalation on different aspects of executive functioning in the adult rat. In an operant set-shifting task, AIE-exposed rats exhibited deficits in their ability to shift their response strategy when the rules of the task changed, indicating reduced behavioral flexibility. There were no differences in progressive ratio response for the reinforcer suggesting that AIE did not alter reinforcer motivation. Examination of performance on the elevated plus maze under conditions designed to minimize stress revealed that AIE exposure enhanced the number of entries into the open arms, which may reflect either reduced anxiety and/or disinhibition of exploratory-like behavior. In rats that trained to self-administer ethanol in an operant paradigm, AIE increased resistance to extinction of ethanol-seeking behavior. This resistance to extinction was reversed by positive allosteric modulation of mGluR5 during extinction training, an effect that is thought to reflect promotion of extinction learning mechanisms within the medial PFC. Consistent with this, CDPPB was also observed to reverse the deficits in behavioral flexibility. Finally, diffusion tensor imaging with multivariate analysis of 32 brain areas revealed that while there were no differences in the total brain volume, the volume of a subgroup of regions (hippocampus, thalamus, dorsal striatum, neocortex, and hypothalamus) were significantly different in AIE-exposed adults compared with litter-matched Control rats. Taken together, these findings demonstrate that binge-like exposure to alcohol during early to middle adolescence results in deficits in PFC-mediated behavioral control in adulthood

Testing the Interaction Between a Substellar Companion and a Debris Disk in the Hr 2562 System

The HR 2562 system is a rare case where a brown dwarf companion resides in a cleared inner hole of a debris disk, offering invaluable opportunities to study the dynamical interaction between a substellar companion and a dusty disk. We present the first ALMA observation of the system as well as the continued Gemini Planet Imager monitoring of the companion\u27s orbit with six new epochs from 2016 to 2018. We update the orbital fit, and in combination with absolute astrometry from GAIA, place a 3σ upper limit of 18.5 M J on the companion\u27s mass. To interpret the ALMA observations, we used radiative transfer modeling to determine the disk properties. We find that the disk is well resolved and nearly edge-on. While the misalignment angle between the disk and the orbit is weakly constrained, due to the short orbital arc available, the data strongly support a (near) coplanar geometry for the system. Furthermore, we find that the models that describe the ALMA data best have inner radii that are close to the companion\u27s semimajor axis. Including a posteriori knowledge of the system\u27s SED further narrows the constraints on the disk\u27s inner radius and places it at a location that is in reasonable agreement with (possibly interior to) predictions from existing dynamical models of disk truncation by an interior substellar companion. HR 2562 has the potential over the next few years to become a new test bed for dynamical interaction between a debris disk and a substellar companion

Range-wide sources of variation in reproductive rates of northern spotted owls

We conducted a range-wide investigation of the dynamics of site-level reproductive rate of northern spotted owls using survey data from 11 study areas across the subspecies geographic range collected during 1993–2018. Our analytical approach accounted for imperfect detection of owl pairs and misclassification of successful reproduction (i.e., at least one young fledged) and contributed further insights into northern spotted owl population ecology and dynamics. Both nondetection and state misclassification were important, especially because factors affecting these sources of error also affected focal ecological parameters. Annual probabilities of site occupancy were greatest at sites with successful reproduction in the previous year and lowest for sites not occupied by a pair in the previous year. Site-specific occupancy transition probabilities declined over time and were negatively affected by barred owl presence. Overall, the site-specific probability of successful reproduction showed substantial year-to-year fluctuations and was similar for occupied sites that did or did not experience successful reproduction the previous year. Site-specific probabilities for successful reproduction were very small for sites that were unoccupied the previous year. Barred owl presence negatively affected the probability of successful reproduction by northern spotted owls in Washington and California, as predicted, but the effect in Oregon was mixed. The proportions of sites occupied by northern spotted owl pairs showed steep, near-monotonic declines over the study period, with all study areas showing the lowest observed levels of occupancy to date. If trends continue it is likely that northern spotted owls will become extirpated throughout large portions of their range in the coming decades