Over the last 25 years, whole-plant corn silage has become an important and popular feedstuff for dairy production. Copious research has been dedicated to the development and evaluation of ...alternatives to enhance the nutritive value of whole-plant corn silage. These efforts have been aimed at manipulating the physical and chemical characteristics of whole-plant corn silage in an effort to maximize dairy profitability. Results from this review indicate that optimization of harvest maturity, kernel processing, theoretical length of cut, and cutting height improve or maintain the nutritive value and milk production of lactating dairy cows. Technological advancements have been developed and made available to dairy producers and corn growers desiring to enhance fiber and starch digestibility of whole-plant corn silage. Future research should be directed toward further assessment of new processors available in the market and the development of assessment methods for optimization of crop processor settings, harvest efficiency, and nutritional modeling.
This paper is a brief overview of some of the key issues which have emerged from the preceding set of papers on ecological thresholds. These include:
•
Whether threshold relationships are common and ...widespread.
•
The potential for large variations in the use and application of the threshold concept to lead to adverse conservation outcomes, particularly when overly simplistic levels of vegetation cover are specified by policy makers and land managers.
•
The inherent multi-variate nature of landscape processes and responses of individual species and assemblages that creates variability in datasets. This may lead to a limited ability to make accurate predictions from threshold relationships, even when those relationships are highly statistically significant.
We believe that although the threshold concept is an appealing one and there is some empirical evidence to support it in some landscapes, it is not free of problems and a concerted research effort on the topic is needed. This is particularly important if it is to have value for robustly underpinning applied landscape management practices without unintentionally having negative impacts on rates of species loss or the loss of particular species.
Air velocity is a critical design parameter for modern commercial broiler houses, owing to the beneficial effects of increased cooling on live performance and thermal comfort in broiler chickens. As ...a result, design velocities have increased over the last 15 years and broiler growers have installed additional fan capacity or air deflectors in the ceiling peak to reduce building cross-sectional area. While deflectors have traditionally been recommended only for buildings with open ceilings, an increasing number of growers have installed deflectors in dropped ceiling houses to provide local increases in air velocity without additional fan capacity and improve air velocity uniformity across the house. However, adding additional restriction can increase static pressure and reduce fan performance. Fan flow rates were measured in three tunnel-ventilated commercial broiler houses equipped with air deflectors with the deflectors in the deployed (down) and retracted (up) positions. The broiler houses measured 15.2 x 144.8 m and were equipped with 12 tunnel exhaust fans (137.2 cm diameter) and nine air deflectors at 12.2 m intervals, beginning after the tunnel inlet area and ending 15.2 m before the fans. Flow rate and static pressure data were collected concurrently for each fan for each deflector position with all fans operating to simulate tunnel ventilation during warm weather. Data were analyzed using ANOVA and least square means were separated using Fisher’s LSD. The results show that deploying air deflectors significantly reduced mean fan flow rate by 11% (p < 0.0001) and increased static pressure by 11.2 Pa (p < 0.0001). The results of the current study suggest that adding air deflectors is likely not appropriate in existing broiler houses with dropped ceilings when fan performance and energy use are taken into consideration.
We present possible observing scenarios for the Advanced LIGO, Advanced Virgo and KAGRA gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy ...community to facilitate planning for multi-messenger astronomy with gravitational waves. We estimate the sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron star systems, which are the most promising targets for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and
90
%
credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5–
20
deg
2
requires at least three detectors of sensitivity within a factor of
∼
2
of each other and with a broad frequency bandwidth. When all detectors, including KAGRA and the third LIGO detector in India, reach design sensitivity, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.
High-precision Zn isotopic variations are reported for carbonaceous chondrites (CC), equilibrated (EOC) and unequilibrated (UOC) ordinary chondrites, iron meteorites from the IAB-IIICD (nonmagmatic) ...and IIIA (magmatic) groups, and metal from the Brenham pallasite. For irons, δ
65Cu values are also reported. Data have also been obtained on a coarse-grained type-B calcium-, aluminum-rich refractory inclusion (CAI) from Allende and on acid leaches of Allende (CV3), Krymka (LL3), and Charsonville (H6). Variations expressed as δ
66Zn (deviation in parts per thousand of
66Zn/
64Zn in samples relative to a standard) spread over a range of 0.3‰ for carbonaceous chondrites, 2‰ for ordinary chondrites, and 4‰ for irons.
The measured
66Zn/
64Zn,
67Zn/
64Zn, and
68Zn/
64Zn ratios vary linearly with mass difference and define a common isotope fractionation line with terrestrial samples, which demonstrates that Zn was derived from an initially single homogeneous reservoir. The δ
66Zn values are correlated with meteorite compositions and slightly decrease in the order CI, CM, CV-CO, and to UOC. The isotopically light Zn of Allende CAI and the acid-resistant residues of Allende and Krymka show that the light component is associated with refractory material, presumably minerals from the spinel-group. This, together with the reverse correlation between relative abundances of light Zn isotopes and volatile element abundances, suggests that Zn depletion in planetary bodies with respect to CI cannot be ascribed to devolatilization of CI-like material. These observations rather suggest that refractory material reacted with a gas phase enriched in the lighter Zn isotopes. Alternatively, chondrules with their associated rims should carry a light Zn isotopic signature. The δ
66Zn values of unequilibrated chondrites are rather uniform, whereas equilibrated chondrites show distinctly more isotopic variability.
The values of δ
65Cu-δ
66Zn in irons define two trends. The moderate and positively correlated Cu and Zn isotope variations in IIIA and pallasite samples probably reflect crystallization of silicate, sulfide, and solid metal from the liquid metal. The range of δ
66Zn values of the IAB-IIICD group is large (>3‰) and contrasts with the moderate fractionation of Cu isotopes. We interpret this feature and the negative δ
66Zn-δ
65Cu correlation as reflecting mixing, possibly achieved by percolation, between metals from a regolith devolatilized at low temperature (enriched in heavy zinc) and metallic liquids formed within the parent body.
In the acidic stream (pH 2.2–4) of the Carnoulès Pb-(Zn) mine, Gard, France, very high As contents (from 9 to 20%) can be accumulated as ferric arsenate and arsenate-sulphate precipitates in rapidly ...growing bacteria-made structures. The main bacterial forms are rod-shaped and sheathed, their sheath is made of Fe-As-rich material and is coated with ferric arsenate colloidal particles or may be partially included in authigenic crystals. Living forms of
Thiobacillus-type bacteria have been recognized in the precipitates. The cyclic development of bacterial colonies alternating with sand deposition and erosive episodes results in the formation of As-rich ferruginous accretions. These laminated and dome-shaped bacterial constructions are similar to those of stromatolites. The extremely high contents of solute As in upstream flow (250 mg/1) are lowered by 2–3 order of magnitude downstream. Lead is also precipitated and concentrated in this Fe
As-rich bacterial stromatolite (2500 ppm Pb). This accumulation and concentration of As and heavy metals via direct or induced microbial action limits pollution downflow. But seasonal storms could erode these Fe
As
Pb-rich deposits and drastically increase pollution.
The accumulation of ferric arsenate by bacterial stromatolites suggests that possible microbial remediation strategies may be used in acid mine drainage environments.
Increasing attention has been focussed on the massive iceberg discharges in the North Atlantic, Heinrich events, during the Last Glaciation, and their worldwide terrestrial counterparts. However, ...these events are particular episodes among more regular cyclic events named Dansgaard–Oeschger events in ice cores or Bond cycles in marine cores. Here we examine grain size, δ
13C, and magnetic susceptibility data from Nussloch, one of the most complete west European eolian sequence examined so far. These indices indicate that, during the 31–19
kyr interval (using chronology provided by radiocarbon, OSL and TL dates), millennial scale variations occurred affecting both precipitation and vegetation. Furthermore, these are associated with oscillations in the wind strength matching the dust deposition rate in Greenland, as recorded in the GRIP ice core. Our study shows that the abrupt climatic changes, the Dansgaard–Oeschger events, are also recorded in the west European loess sequences. This implies an atmospheric mechanism linking dust deposition over Greenland and Europe, which is probably connected to global climatic events during the Last Glaciation.
Abstract
The measurement of fluctuating pressures in gasses is relevant to a wide range of fluid flow applications. The frequency response of pressure measurement systems using remote transducers is ...usually limited by the response of the connecting tubing. For small fluctuation levels it is well established that the signal distortion can be corrected using a transfer function technique. This work extends the approach to include the more challenging issue of large amplitude fluctuations where the transfer function is strongly dependent on the fluctuation amplitude as well as frequency.
The tubing transfer function was found to closely depend on the ratio of the standard deviation of the pressure fluctuation and the absolute pressure (P
STD/P
ABS). An algorithm for correction is described and demonstrated. Levels of P
STD/P
ABS of up to 0.6 have been tested and distortions of up to 250 per cent have been corrected to within 5 per cent.
The high morbidity and mortality associated with cervical spine injuries makes identification and classification essential. It is important to have a systematic approach to evaluation, especially in ...the trauma setting with other distracting injuries. Understanding the anatomy and biomechanics enables rapid and accurate interpretation of images. In severe trauma and in patients with rigid spinal disease, the classic patterns of injury may be difficult or impossible to recognize. This article provides an approach to acquiring and interpreting cervical spine images in the setting of acute trauma and reviews the classic patterns of injury.
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