4,310 research outputs found
Coordinated egg production and marketing in the north central states V. Least-cost egg marketing organization under alternative production patterns
Important changes are taking place in the mid-western egg industry. Changes in Iowa are broadly representative of the transformations taking place in this industry throughout the region. One of the most significant changes has been the decline in the number of farms producing eggs. In 1940, 198,000 Iowa farms -or 93 percent of all farms-reported chickens on hand. In 1950, the number was 174,000, or 86 percent. By 1959, there had been a further decline to 68 percent.
Along with the changing number of farms producing eggs, there has been a change in the sizes of flocks on farms. In Iowa, the proportion of very small flocks has remained nearly constant. In 1940 and 1950, roughly 13 percent of all Iowa flocks had fewer than 50 hens. This rose to about 15 percent in 1959. A sharp decline in medium-sized flocks of 50 to 400 hens occurred in the same period, from 86 percent in 1940 to 71 percent in 1959. Numbers of flocks larger than 400 hens have shown substantial increases, as shown in table 1 (1, 8, 14).
Small flocks (less than 50 hens) are of little commercial importance. They are maintained mainly to supply the farm household with eggs for consumption. Farm flocks of 50 to 400 hens are most numerous; they have served as a means of acquiring a steady flow of cash for the household and an outlet for family labor on the family farm. For our study, flocks of this size take on great importance; they are the main component of the existing production pattern. Flocks larger than 400 hens are increasing rapidly and will probably continue to increase because of economies of scale in egg production and possible economies in marketing operations. This study emphasizes these larger flocks to ascertain their relationship to assembly and processing costs
HERUS: the far-IR/submm spectral energy distributions of local ULIRGs and photometric atlas
We present the Herschel-SPIRE photometric atlas for a complete flux limited sample of 43 local ultraluminous infrared galaxies (ULIRGs), selected at 60 μm by IRAS, as part of the HERschel ULIRG Survey (HERUS). Photometry observations were obtained using the SPIRE instrument at 250, 350, and 500 μm. We describe these observations, present the results, and combine the new observations with data from IRAS to examine the far-infrared spectral energy distributions (SEDs) of these sources. We fit the observed SEDs of HERUS objects with a simple parametrized modified blackbody model, where temperature and emissivity β are free parameters. We compare the fitted values to those of non-ULIRG local galaxies, and find, in agreement with earlier results, that HERUS ULIRGs have warmer dust (median temperature T = 37.9 ± 4.7 K compared to 21.3 ± 3.4 K) but a similar β distribution (median β = 1.7 compared to 1.8) to the Herschel reference sample (HRS, Cortese et al. 2014) galaxies. Dust masses are found to be in the range of 107.5–109 M⊙, significantly higher than that of HRS sources. We compare our results for local ULIRGs with higher redshift samples selected at 250 and 850 μm. These latter sources generally have cooler dust and/or redder 100-to-250  μm colours than our 60 μm-selected ULIRGs. We show that this difference may in part be the result of the sources being selected at different wavelengths rather than being a simple indication of rapid evolution in the properties of the population
Experiencing stigma as sex work researchers in professional and personal lives
Researchers have demonstrated the challenges associated with sex work research; negotiating the stigma attached to its subject matter, the perceived dangerousness of participants, and the barriers faced in reaching hidden populations. By reflecting upon our separate research experiences and drawing upon a body of reflexive sex work research, this article explores how, as sex work researchers, we experienced stigma not only in our professional roles as researchers, but also in our personal lives. We apply Goffman's (1968) notion of stigma by association; and consider how stigma often associated with prostitution became transposed onto us. In particular, we compare and contrast our separate experiences of conducting sex work research to demonstrate our similar experiences of stigma by association
Mid-Infrared Spectroscopy of Two Lensed Star-forming Galaxies
We present low-resolution, rest-frame ~ 5 - 12 micron Spitzer/IRS spectra of
two lensed z ~ 2 UV-bright star-forming galaxies, SDSS J120602.09+514229.5 and
SDSS J090122.37+181432.3. Using the magnification boost from lensing, we are
able to study the physical properties of these objects in greater detail than
is possible for unlensed systems. In both targets, we detect strong PAH
emission at 6.2, 7.7, and 11.3 microns, indicating the presence of vigorous
star formation. For J1206, we find a steeply rising continuum and significant
[S IV] emission, suggesting that a moderately hard radiation field is powering
continuum emission from small dust grains. The strength of the [S IV] emission
also implies a sub-solar metallicity of ~ 0.5 Z_{Sun}, confirming published
rest-frame optical measurements. In J0901, the PAH lines have large rest-frame
equivalent widths (> 1 micron) and the continuum rises slowly with wavelength,
suggesting that any AGN contribution to L_{IR} is insignificant, in contrast to
the implications of optical emission-line diagnostics. Using [O III] line flux
as a proxy for AGN strength, we estimate that the AGN in J0901 provides only a
small fraction of its mid-infrared continuum flux. By combining the detection
of [Ar II] with an upper limit on [Ar III] emission, we infer a metallicity of
> 1.3 Z_{Sun}. This work highlights the importance of combining rest-frame
optical and mid-IR spectroscopy in order to understand the detailed properties
of star-forming galaxies at high redshift.Comment: 20 pages, 3 figures, 2 tables. ApJ accepte
Reflecting on loss in Papua New Guinea
This article takes up the conundrum of conducting anthropological fieldwork with people who claim that they have 'lost their culture,' as is the case with Suau people in the Massim region of Papua New Guinea. But rather than claiming culture loss as a process of dispossession, Suau claim it as a consequence of their own attempts to engage with colonial interests. Suau appear to have responded to missionization and their close proximity to the colonial-era capital by jettisoning many of the practices characteristic of Massim societies, now identified as 'kastom.' The rejection of kastom in order to facilitate their relations with Europeans during colonialism, followed by the mourning for kastom after independence, both invite consideration of a kind of reflexivity that requires action based on the presumed perspective of another
The starburst-AGN connection in the merger galaxy Mrk 938: an infrared and X-ray view
Mrk938 is a luminous infrared galaxy in the local Universe believed to be the
remnant of a galaxy merger. It shows a Seyfert 2 nucleus and intense star
formation according to optical spectroscopic observations. We have studied this
galaxy using new Herschel far-IR imaging data in addition to archival X-ray,
UV, optical, near-IR and mid-IR data. Mid- and far-IR data are crucial to
characterise the starburst contribution, allowing us to shed new light on its
nature and to study the coexistence of AGN and starburst activity in the local
Universe. The decomposition of the mid-IR Spitzer spectrum shows that the AGN
bolometric contribution to the mid-IR and total infrared luminosity is small
(Lbol(AGN)/LIR~0.02), which agrees with previous estimations. We have
characterised the physical nature of its strong infrared emission and
constrained it to a relatively compact emitting region of <2kpc. It is in this
obscured region where most of the current star formation activity is taking
place as expected for LIRGs. We have used Herschel imaging data for the first
time to constrain the cold dust emission with unprecedented accuracy. We have
fitted the integrated far-IR spectral energy distribution and derived the
properties of the dust, obtaining a dust mass of 3x10^7Msun. The far-IR is
dominated by emission at 35K, consistent with dust heated by the on-going star
formation activity.Comment: 12 pages, 6 figures, 4 tables, accepted for publication in MNRA
How parents perceive and feel about participation in community activities: The comparison between parents of preschoolers with and without autism spectrum disorders
The present study compared how parents of preschoolers with and without Autism Spectrum Disorders (ASD) perceived and felt about participation in community activities. A questionnaire survey was conducted with 380 Hong Kong parents of preschoolers with ASD and 214 Hong Kong parents of preschoolers without ASD. The two groups were not different in their willingness and frequency of participation in community activities. However, the psychological processes underneath their willingness were very different. Among the parents of preschoolers with ASD, their willingness was associated with how they perceived the difficulty and importance of the participation and what emotions they experienced during the activities. This pattern of association was not evident among the parents of preschoolers without ASD. Copyright © The Author(s), 2010.published_or_final_versio
Spitzer IRS Spectral Mapping of the Toomre Sequence: Spatial Variations of PAH, Gas, and Dust Properties in Nearby Major Mergers
We have mapped the key mid-IR diagnostics in eight major merger systems of
the Toomre Sequence (NGC4676, NGC7592, NGC6621, NGC2623, NGC6240, NGC520,
NGC3921, and NGC7252) using the Spitzer Infrared Spectrograph (IRS). With these
maps, we explore the variation of the ionized-gas, PAH, and warm-gas (H_2)
properties across the sequence and within the galaxies. While the global PAH
interband strength and ionized gas flux ratios ([Ne III]/[Ne II]) are similar
to those of normal star forming galaxies, the distribution of the spatially
resolved PAH and fine structure line flux ratios is significant different from
one system to the other. Rather than a constant H_2/PAH flux ratio, we find
that the relation between the H_2 and PAH fluxes is characterized by a power
law with a roughly constant exponent (0.61+/-0.05) over all merger components
and spatial scales. While following the same power law on local scales, three
galaxies have a factor of ten larger integrated (i.e. global) H_2/PAH flux
ratio than the rest of the sample, even larger than what it is in most nearby
AGNs. These findings suggest a common dominant excitation mechanism for H_2
emission over a large range of global H_2/PAH flux ratios in major mergers.
Early merger systems show a different distribution between the cold (CO J=1-0)
and warm (H_2) molecular gas component, which is likely due to the merger
interaction. Strong evidence for buried star formation in the overlap region of
the merging galaxies is found in two merger systems (NGC6621 and NGC7592) as
seen in the PAH, [Ne II], [Ne III], and warm gas line emission, but with no
apparent corresponding CO (J=1-0) emission. Our findings also demonstrate that
the variations of the physical conditions within a merger are much larger than
any systematic trends along the Toomre Sequence.Comment: 35 pages, accepted for publication in ApJ
The Spitzer Local Volume Legacy: Survey Description and Infrared Photometry
The survey description and the near-, mid-, and far-infrared flux properties
are presented for the 258 galaxies in the Local Volume Legacy (LVL). LVL is a
Spitzer Space Telescope legacy program that surveys the local universe out to
11 Mpc, built upon a foundation of ultraviolet, H-alpha, and HST imaging from
11HUGS (11 Mpc H-alpha and Ultraviolet Galaxy Survey) and ANGST (ACS Nearby
Galaxy Survey Treasury). LVL covers an unbiased, representative, and
statistically robust sample of nearby star-forming galaxies, exploiting the
highest extragalactic spatial resolution achievable with Spitzer. As a result
of its approximately volume-limited nature, LVL augments previous Spitzer
observations of present-day galaxies with improved sampling of the
low-luminosity galaxy population. The collection of LVL galaxies shows a large
spread in mid-infrared colors, likely due to the conspicuous deficiency of 8um
PAH emission from low-metallicity, low-luminosity galaxies. Conversely, the
far-infrared emission tightly tracks the total infrared emission, with a
dispersion in their flux ratio of only 0.1 dex. In terms of the relation
between infrared-to-ultraviolet ratio and ultraviolet spectral slope, the LVL
sample shows redder colors and/or lower infrared-to-ultraviolet ratios than
starburst galaxies, suggesting that reprocessing by dust is less important in
the lower mass systems that dominate the LVL sample. Comparisons with
theoretical models suggest that the amplitude of deviations from the relation
found for starburst galaxies correlates with the age of the stellar populations
that dominate the ultraviolet/optical luminosities.Comment: Accepted for publication in ApJ; Figures 1,8,9 provided as jpeg
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