Most farms in the United States-98 percent in 2003-are family farms. They are organized as proprietorships, partnerships, or family corporations. Even the largest farms tend to be family farms, although they are more likely to have more than one operator. Very large family farms and nonfamily farms account for a small share of farms but a large-and growing-share of farm sales. Small family farms account for most of the farms in the United States but produce a modest share of farm output. Median income for farm households is 10 percent greater than the median for all U.S. households, and small-farm households receive substantial off-farm income. Many farm households have a large net worth, reflecting the land-intensive nature of farming.

Whiteness arises from the random scattering of incident light from disordered structures. [1] Opaque white materials have to contain a sufficiently large number of scatterers and therefore usually require thicker, material-rich nanostructures than structural color arising from the coherent interference of light. [2,3] In nature, bright white appearance arises from the dense arrays of pterin pigments in pierid butterflies, [4] guanine crystals in spiders, [5] or leucophore cells in the flexible skin of cuttlefish. [6] A striking example of such whiteness is found in the chitinous networks of white beetles, e.g., Lepidiota stigma and Cyphochilus sp. [7][8][9] Previous research investigating these beetle structures has shown that the chitinous network is one of the most strongly scattering materials in nature, and therefore the question arises whether this structure is evolutionary optimized for strong scattering while minimizing the Most studies of structural color in nature concern periodic arrays, which through the interference of light create color. The "color" white however relies on the multiple scattering of light within a randomly structured medium, which randomizes the direction and phase of incident light. Opaque white materials therefore must be much thicker than periodic structures. It is known that flying insects create "white" in extremely thin layers. This raises the question, whether evolution has optimized the wing scale morphology for white reflection at a minimum material use. This hypothesis is difficult to prove, since this requires the detailed knowledge of the scattering morphology combined with a suitable theoretical model. Here, a cryoptychographic X-ray tomography method is employed to obtain a full 3D structural dataset of the network morphology within a white beetle wing scale. By digitally manipulating this 3D representation, this study demonstrates that this morphology indeed provides the highest white retroreflection at the minimum use of material, and hence weight for the organism. Changing any of the network parameters (within the parameter space accessible by biological materials) either increases the weight, increases the thickness, or reduces reflectivity, providing clear evidence for the evolutionary optimization of this morphology. amount of employed material, thus reducing the weight of the organism. The brilliant white reflection from Cyphochilus beetles is assumed to be important for camouflage among white fungi and in a shady environment.In contrast to periodic photonic materials, for which the optical response is straightforward to calculate, the reflection of light from such disordered network morphologies requires a detailed knowledge of local geometry. [2,3,9,10] For these complex cases, the validity of the diffusion approximation is limited, since single scattering elements are difficult to be identified. [7] To fully understand the correlation between the structure and (optical) properties of complex materials, the detailed real-space structure in combination with a s...

We have carried out a ptychographic scanning coherent diffraction imaging experiment on a test object in order to characterize the hard x-ray nanobeam in a scanning x-ray microscope. In addition to a high resolution image of the test object, a detailed quantitative picture of the complex wave field in the nanofocus is obtained with high spatial resolution and dynamic range. Both are the result of high statistics due to the large number of diffraction patterns. The method yields a complete description of the focus, is robust against inaccuracies in sample positioning, and requires no particular shape or prior knowledge of the test object.

The emergence of hard X-ray free electron lasers (XFELs) enables new insights into many fields of science. These new sources provide short, highly intense, and coherent X-ray pulses. In a variety of scientific applications these pulses need to be strongly focused. In this article, we demonstrate focusing of hard X-ray FEL pulses to 125 nm using refractive x-ray optics. For a quantitative analysis of most experiments, the wave field or at least the intensity distribution illuminating the sample is needed. We report on the full characterization of a nanofocused XFEL beam by ptychographic imaging, giving access to the complex wave field in the nanofocus. From these data, we obtain the full caustic of the beam, identify the aberrations of the optic, and determine the wave field for individual pulses. This information is for example crucial for high-resolution imaging, creating matter in extreme conditions, and nonlinear x-ray optics.

We demonstrate x-ray scanning coherent diffraction microscopy (ptychography) with 10 nm spatial resolution, clearly exceeding the resolution limits of conventional hard x-ray microscopy. The spatial resolution in a ptychogram is shown to depend on the shape (structure factor) of a feature and can vary for different features in the object. In addition, the resolution and contrast are shown to increase with increasing coherent fluence. For an optimal ptychographic x-ray microscope, this implies a source with highest possible brilliance and an x-ray optic with a large numerical aperture to generate the optimal probe beam.

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and, where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.

The advent of hard x-ray free-electron lasers (XFELs) has opened up a variety of scientific opportunities in areas as diverse as atomic physics, plasma physics, nonlinear optics in the x-ray range, and protein crystallography. In this article, we access a new field of science by measuring quantitatively the local bulk properties and dynamics of matter under extreme conditions, in this case by using the short XFEL pulse to image an elastic compression wave in diamond. The elastic wave was initiated by an intense optical laser pulse and was imaged at different delay times after the optical pump pulse using magnified x-ray phase-contrast imaging. The temporal evolution of the shock wave can be monitored, yielding detailed information on shock dynamics, such as the shock velocity, the shock front width, and the local compression of the material. The method provides a quantitative perspective on the state of matter in extreme conditions.

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and, where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.