Joint Report of Peer Review Panel for Numeric Nutrient Criteria for the Great Bay Estuary New Hampshire Department of Environmental Services June, 2009

This peer review was authorized through a collaborative agreement sponsored by the New Hampshire Department of Environmental Services (DES) and the Cities of Dover, Rochester and Portsmouth, New Hampshire. The purpose was to conduct an independent scientific peer review of the document entitled, “Numeric Nutrient Criteria for the Great Bay Estuary,” dated June, 2009 (DES 2009 Report)

Effect of Feed Delivery Management on Yearling Steer Performance

Gain efficiency by cattle fed high grain diets can be affected by feed delivery management (FDM). Restricted or limit feeding improves feed efficiency but can reduce ADG. This experiment was designed to evaluate if feeding near ad libitum intake while reducing the amount of variation between daily feed deliveries could provide feed efficiency advantages over unrestricted access to feed without restricting ADG. The FDM strategies for the 121-day feeding period included prescription intakes (PI) where variability between day to day feed deliveries were minimized or ad libitum intake (ALI) where feed was always available. Crossbred yearling steers (n = 76, initial BW 866 Ib ± 6.72) of mixed origin were stratified by BW and randomly assigned to one of two treatments then to one of five pens within a treatment. The 92% concentrate, 63 Mcal NE,/cwt diet, was fed to the PI group throughout the 121 –day study. Four step-up diets were fed over 12 days to adapt the ALI group to the 92% concentrate diet. Feed was delivered daily at 0730 and 1630. The bunks were slick for the PI treatment at 0700 69% of the days on feed and 40% for the ALI treatment (P\u3c .01). The PI fed steers consumed less DM (P\u3c .001) during interim periods days 1 to 29 and 58 to 85 (P\u3c.05). The PI steers were more efficient days 1 to 29 (P\u3c .03) and overall (P\u3c.10). Carcass variables associated with yield grade were not affected (P\u3e.10) by FDM and PI caused higher marbling scores (5.67 vs 5.31; P\u3c .085), while percent choice did not differ, 74 vs 79% for the PI and ALI treatments, respectively. The PI treatment lowered (P\u3c .05) feed cost $5.30/cwt gain. This experiment indicated that FDM can influence DM1 and feed efficiency without compromising ADG

A persistent and dynamic East Greenland Ice Sheet over the past 7.5 million years

Climate models show that ice-sheet melt will dominate sea-level rise over the coming centuries, but our understanding of ice-sheet variations before the last interglacial 125,000 years ago remains fragmentary. This is because terrestrial deposits of ancient glacial and interglacial periods1,2,3 are overrun and eroded by more recent glacial advances, and are therefore usually rare, isolated and poorly dated4. In contrast, material shed almost continuously from continents is preserved as marine sediment that can be analysed to infer the time-varying state of major ice sheets. Here we show that the East Greenland Ice Sheet existed over the past 7.5 million years, as indicated by beryllium and aluminium isotopes (10Be and 26Al) in quartz sand removed by deep, ongoing glacial erosion on land and deposited offshore in the marine sedimentary record5,6. During the early Pleistocene epoch, ice cover in East Greenland was dynamic; in contrast, East Greenland was mostly ice-covered during the mid-to-late Pleistocene. The isotope record we present is consistent with distinct signatures of changes in ice sheet behaviour coincident with major climate transitions. Although our data are continuous, they are from low-deposition-rate sites and sourced only from East Greenland. Consequently, the signal of extensive deglaciation during short, intense interglacials could be missed or blurred, and we cannot distinguish between a remnant ice sheet in the East Greenland highlands and a diminished continent-wide ice sheet. A clearer constraint on the behaviour of the ice sheet during past and, ultimately, future interglacial warmth could be produced by 10Be and 26Al records from a coring site with a higher deposition rate. Nonetheless, our analysis challenges the possibility of complete and extended deglaciation over the past several million years

Associations of a Leptin Gene Polymorphism with Beef Carcass Traits

The objective was to evaluate associations of leptin genotype with fat and muscle traits in cattle. A single nucleotide polymorphism located in exon 2 of the leptin gene in cattle codes for an amino acid change from arginine (R) to cysteine (C). Genotypes for the polymorphism were determined on 492 crossbred calves by AciI digestion of amplified PCR product (C allele: 130bp; R allele: 73bp and 57bp). Data were analyzed by least-squares, accounting for effects of genotype, sex, year, location, breed-type, and calf sire. Genotype was not significantly associated with carcass weight or ribeye area in any of the analyses. Associations of genotype with external fat thickness, KPH fat, and overall cutability were small and generally not statistically significant. Subjective marbling scores (assigned by USDA grader; 350 = slight 50, 400 = small 0, 450 = small 50) were higher (P = .02) for CC (411 units) than for RR (388 units) genotype when adjusted to a constant slaughter age of 433 days. Similar differences between genotypes in marbling scores were observed when adjusting to a constant carcass weight or external fat thickness. Given the relatively modest association between genotype and marbling, potential application of the marker in the industry as a selection tool would be most relevant in herds with a large proportion of market animals possessing marbling scores that are near a price threshold level (e.g., select/choice quality grade)

Human and natural controls on erosion in the Lower Jinsha River, China

The lower Jinsha River has the highest sediment yield rates of the entire Yangtze watershed; these high yields have previously been attributed to a mix of the local geologic setting as well as intensive human land use, particularly agriculture. Prior studies have not quantified long-term background rates of sediment generation, making it difficult to know if modern sediment yield is elevated relative to the long-term rate of sediment generation. Using in situ 10Be in detrital river sediments, we measured sediment generation rates for tributaries to the lower Jinsha River. We find that the ratio of modern sediment yield to long-term sediment generation rate is 5.9 ± 2.8 (mean, 1 SD, n = 5), which is significantly higher than that elsewhere in western China and implies contemporary rates of sediment export far exceed long-term rates of sediment generation by weathering on hillslopes (1.9 ± 1.6 [median, 1 SD, n = 20]; [Schmidt et al., 2017]). Long-term (thousand year) rates of sediment generation correlate best with the steepness of the upstream watershed, a result found around the world. In contrast, modern sediment yield and the ratio of sediment yield to sediment generation rates correlate best with agricultural land use and distance to the nearest dam. Modern (1950s–1980s) sediment yield and the ratio of sediment yield to sediment generation rate also correlate well with percent of the watershed containing landslides observable today. The significantly higher modern sediment yield, lack of correlation between percent of the basin with landslides and long-term rates of sediment generation, and widespread deforestation and agriculture in the region suggest that landslide scars observable today are at least in part a result of human-induced land use change. Thus, we conclude that a mix of geologic setting and human activity control high contemporary sediment yield rates in the region

Influence of topography and human activity on apparent in situ 10Be-derived erosion rates in Yunnan, SW China

In order to understand better if and where erosion rates calculated using in situ 10Be are affected by contemporary changes in land use and attendant deep regolith erosion, we calculated erosion rates using measurements of in situ 10Be in quartz from 52 samples of river sediment collected from three tributaries of the Mekong River (median basin areaD46.5 km2). Erosion rates range from 12 to 209mm kyr-1 with an area-weighted mean of 117±49mm kyr-1 (1 standard deviation) and median of 74mm kyr-1.We observed a decrease in the relative influence of human activity from our steepest and least altered watershed in the north to the most heavily altered landscapes in the south. In the areas of the landscape least disturbed by humans, erosion rates correlate best with measures of topographic steepness. In the most heavily altered landscapes, measures of modern land use correlate with 10Be-estimated erosion rates but topographic steepness parameters cease to correlate with erosion rates. We conclude that, in some small watersheds with high rates and intensity of agricultural land use that we sampled, tillage and resultant erosion has excavated deeply enough into the regolith to deliver subsurface sediment to streams and thus raise apparent in situ 10Be-derived erosion rates by as much as 2.5 times over background rates had the watersheds not been disturbed

Characterizing landscape-scale erosion using 10Be in detrital fluvial sediment: Slope-based sampling strategy detects the effect of widespread dams

Concentrations of in situ 10Be measured in detrital fluvial sediment are frequently used to estimate long-term erosion rates of drainage basins. In many regions, basin-averaged erosion rates are positively correlated with basin average slope. The slope dependence of erosion allows model-based erosion rate estimation for unsampled basins and basins where human disturbance may have biased cosmogenic nuclide concentrations in sediment. Using samples collected from southeastern North America, we demonstrate an approach that explicitly considers the relationship between average basin slope and erosion rate. Because dams and reservoirs are ubiquitous on larger channels in the field area, we selected 36 undammed headwater subbasins (average area 10.6 km2) from which we collected river sand samples and measured 10Be concentrations. We used these data to train a predictive model that relates average basin slope and 10Be-inferred erosion rate. Applying our model to 28 basins in the same region previously studied with 10Be, we find that the model successfully predicts erosion rates for basins of different sizes if they are undammed or if samples were collected \u3e25 km downstream of dams. For samples collected closer to dams, measured erosion rates exceed modeled erosion rates for two-thirds of the samples. In three of four cases where paired samples were collected upstream of reservoirs and downstream of the impounding dam, 10Be concentrations were lower downstream. This finding has implications for detrital cosmogenic studies, whether or not samples were collected directly downstream of dams, because dams obstruct most major rivers around the world, effectively trapping sediment that originated upstream

A cosmogenic view of erosion, relief generation, and the age of faulting in southern Africa

Southernmost Africa, with extensive upland geomorphic surfaces, deep canyons, and numerous faults, has long interested geoscientists. A paucity of dates and low rates of background seismicity make it challenging to quantify the pace of landscape change and determine the likelihood and timing of fault movement that could raise and lower parts of the landscape and create associated geohazards. To infer regional rates of denudation, we measured 10Be in river sediment samples and found that south-central South Africa is eroding ∼5 m m.y.-1, a slow erosion rate consistent with those measured in other non-tectonically active areas, including much of southern Africa. To estimate the rate at which extensive, fossil, upland, silcrete-mantled pediment surfaces erode, we measured 10Be and 26Al in exposed quartzite samples. Undeformed upland surfaces are little changed since the Pliocene; some have minimum exposure ages exceeding 2.5 m.y. (median, 1.3 m.y.) and maximum erosion rates of \u3c0.2 m m.y.-1 (median, 0.34 m m.y.-1), consistent with no Quaternary movement on faults that displace the underlying quartzite but not the silcrete cover. We directly dated a recent displacement event on the only recognized Quaternary-active fault in South Africa, a fault that displaces both silcrete and the underlying quartzite. The concentrations of 10Be in exposed fault scarp samples are consistent with a 1.5 m displacement occurring ca. 25 ka. Samples from this offset upland surface have lower minimum limiting exposure ages and higher maximum erosion rates than those from undeformed pediment surfaces, consistent with Pleistocene earthquakes and deformation reducing overall landscape stability proximal to the fault zone. Rates of landscape change on the extensive, stable, silcretized, upland pediment surfaces are an order of magnitude lower than basin-average erosion rates. As isostatic response to regional denudation uplifts the entire landscape at several meters per million years, valleys deepen, isolating stable upland surfaces and creating the spectacular relief for which the region is known

A Millimeter-wave Galactic Plane Survey with the BICEP Polarimeter

In order to study inflationary cosmology and the Milky Way Galaxy's composition and magnetic field structure, Stokes I, Q, and U maps of the Galactic plane covering the Galactic longitude range 260° < ℓ < 340° in three atmospheric transmission windows centered on 100, 150, and 220 GHz are presented. The maps sample an optical depth 1 ≾ AV ≾ 30, and are consistent with previous characterizations of the Galactic millimeter-wave frequency spectrum and the large-scale magnetic field structure permeating the interstellar medium. The polarization angles in all three bands are generally perpendicular to those measured by starlight polarimetry as expected and show changes in the structure of the Galactic magnetic field on the scale of 60°. The frequency spectrum of degree-scale Galactic emission is plotted between 23 and 220 GHz (including WMAP data) and is fit to a two-component (synchrotron and dust) model showing that the higher frequency BICEP data are necessary to tightly constrain the amplitude and spectral index of Galactic dust. Polarized emission is detected over the entire region within two degrees of the Galactic plane, indicating the large-scale magnetic field is oriented parallel to the plane of the Galaxy. A trend of decreasing polarization fraction with increasing total intensity is observed, ruling out the simplest model of a constant Galactic magnetic field orientation along the line of sight in the Galactic plane. A generally increasing trend of polarization fraction with electromagnetic frequency is found, varying from 0.5%-1.5% at frequencies below 50 GHz to 2.5%-3.5% above 90 GHz. The effort to extend the capabilities of BICEP by installing 220 GHz band hardware is described along with analysis of the new band