245 research outputs found
Performance of Meat Goats Grazing Winter Annual Grasses in the Piedmont of the Southeastern USA
In the Southeastern United States, meat goats (Capra hircus hircus) are becoming increasingly important contributors to the income of many small producers. Meat goats perform well in grazing situations if grazing management practices match their grazing behavior. Nevertheless, little research data are available from the region specifically directed toward forage feeding programs for goats reared for meat production. Hart et al. (1993) reported that growing Alpine, Angora and Nubian kids grazed on high quality Triticum aestivum forage gained 50 g/d, whereas Kiesling et al. (1994) reported gains ranging from 65 to 141 g/d in growing Angora goats grazing Secale cereale. This 3-year (YR) grazing study was designed to evaluate the performance of replacement does and wethers grazed on Secale cereale (SC, var. Elbon), Lolium multiflorum (LM, var. Marshall) and Triticum secale (TS, var. Resource Seeds 102)
Intake and Digestibility of Black Locust Foliage Fed to Growing Goat Wethers
Leaves of Black locust (BL, Robinia pseudoacacia), a native southeastern United States tree species known to contain substantial levels of condensed tannins, were fed to 16, four month old (20.4 kg body weight [BW]) Boer wether goats (Capra hircus hircus) to determine their effects on intake and digestibility. Four diets were stall fed in a randomized complete block design (RCBD) with four replications. Diets included: (1) 100% eastern gamagrass (EGH; Tripsacum dactyloides) hay; (2) 70% EGH and 30% mixture of ground corn (GC; Zea mays) and soybean (Glycine max) meal (SBM); (3) 75% EGH and 25% fresh BL leaves; (4) 50% EGH and 50% fresh BL leaves. Diet apparent digestibilities of dry matter (DM) [62.4, 68.2, 57.6 and 60.6%] and crude protein (CP) [62.8, 72.7, 55.5, 60.6%] were respectively different (P\u3c .03). Goats that consumed diet 1 and diet 2 had higher digestibilities (P\u3c .01) of neutral detergent fiber (NDF) and acid detergent fiber (ADF) than goats consuming diet 3 and 4. Lignin digestibilities for diet 3 (-56.7%) and diet 4 (-49.3%) were negative due to the probable complexing of tannins with the CP fraction. Intake of DM was similar across diets. The overall differences in the diets may be related to the chemical nature of tannins present in BL leaves
Mineral Concentration of Herbage from Three Paulownia Species Used for Goat Browse
Goats naturally prefer a high proportion of browse in their diets. Therefore, research was initiated to investigate various silvo-pastoral production systems. In May 1997, six Paulownia treatments were planted in a randomized complete block experiment with six replications. Trees were between 6 and 12 cm in height at planting. Treatments included: P. fortunei seedlings, P. tomentosa seedlings, P. elongata seedlings, and three P. elongata clones. Each 4-m wide plot contained a single row of 12 trees with an intra-row spacing of 1 m. Leaf samples were analyzed from all six replications to determine mineral concentration in October 1997, and June and August 1998. Ca and P concentrations varied widely, and the Ca:P ratio exceeded the desired 2:1 with a range from 2.7:1 to 10.1:1. In October 1997, concentrations of Ca were similar in leaf laminae and petioles (1.26%), whereas P concentrations were twice as high in laminae (0.19%) as in petioles (0.09%). In October 1997, laminae from seedlings contained greater concentrations of Ca, Fe, and Zn than did laminae from clones, whereas the opposite was true for every element, with the exception of Fe, in June 1998. By August 1998, these differences had disappeared. Regardless of sampling date and leaf part, concentrations of Ca, Mg, K, Fe, Mn and Zn were sufficient to fulfill goat nutritional requirements, whereas P concentrations were too low. Goats readily browsed Paulownia laminae and no clear preference trends were observed between treatments
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Virtual Surgical Planning in Subscapular System Free Flap Reconstruction of Midface Defects.
OBJECTIVES: Reconstruction of the midface has many inherent challenges, including orbital support, skull base reconstruction, optimizing midface projection, separation of the nasal cavity and dental rehabilitation. Subscapular system free flaps (SF) have sufficient bone stock to support complex reconstruction and the option of separate soft tissue components. This study analyzes the effect of virtual surgical planning (VSP) in SF for midface on subsite reconstruction, bone segment contact and anatomic position.
MATERIALS AND METHODS: Retrospective cohort of patients with midface defects that underwent SF reconstruction at a single tertiary care institution.
RESULTS: Nine cases with VSP were compared to fourteen cases without VSP. VSP was associated with a higher number of successfully reconstructed subunits (5.9 vs 4.2, 95% CI of mean difference 0.31-3.04, p = 0.018), a higher number of successful bony contact between segments (2.2 vs 1.4, 95% CI of mean difference 0.0-1.6, p = 0.050), and a higher percent of segments in anatomic position (100% vs 71%, 95% CI of mean difference 2-55%, p = 0.035). When postoperative bone position after VSP reconstruction was compared to preoperative scans, the difference in anteroposterior, vertical and lateral projection compared to the preoperative \u27ideal\u27 bone position was82% of measurements. There were no flap losses.
CONCLUSION: VSP may augment SF reconstruction of the midface by allowing for improved subunit reconstruction, bony segment contact and anatomically correct bone segment positioning. VSP can be a useful adjunct for complex midface reconstruction and the benefits should be weighed against cost
Mutation signature analysis identifies increased mutation caused by tobacco smoke associated DNA adducts in larynx squamous cell carcinoma compared with oral cavity and oropharynx.
Squamous cell carcinomas of the head and neck (HNSCC) arise from mucosal keratinocytes of the upper aero-digestive tract. Despite a common cell of origin and similar driver-gene mutations which divert cell fate from differentiation to proliferation, HNSCC are considered a heterogeneous group of tumors categorized by site of origin within the aero-digestive mucosa, and the presence or absence of HPV infection. Tobacco use is a major driver of carcinogenesis in HNSCC and is a poor prognosticator that has previously been associated with poor immune cell infiltration and higher mutation numbers. Here, we study patterns of mutations in HNSCC that are derived from the specific nucleotide changes and their surrounding nucleotide context (also known as mutation signatures). We identify that mutations linked to DNA adducts associated with tobacco smoke exposure are predominantly found in the larynx. Presence of this class of mutation, termed COSMIC signature 4, is responsible for the increased burden of mutation in this anatomical sub-site. In addition, we show that another mutation pattern, COSMIC signature 5, is positively associated with age in HNSCC from non-smokers and that larynx SCC from non-smokers have a greater number of signature 5 mutations compared with other HNSCC sub-sites. Immunohistochemistry demonstrates a significantly lower Ki-67 proliferation index in size matched larynx SCC compared with oral cavity SCC and oropharynx SCC. Collectively, these observations support a model where larynx SCC are characterized by slower growth and increased susceptibility to mutations from tobacco carcinogen DNA adducts
Preliminary Parallaxes of 40 L and T Dwarfs from the U.S. Naval Observatory Infrared Astrometry Program
We present preliminary trigonometric parallaxes and proper motions for 22 L
dwarfs and 18 T dwarfs measured using the ASTROCAM infrared imager. Relative to
absolute parallax corrections are made by employing 2MASS and/or SDSS
photometry for reference frame stars. We combine USNO infrared and optical
parallaxes with the best available CIT system photometry to determine M_J, M_H,
and M_K values for 37 L dwarfs between spectral types L0 to L8 and 19 T dwarfs
between spectral types T0.5 and T8 and present selected absolute magnitude
versus spectral type and color diagrams, based on these results. Luminosities
and temperatures are estimated for these objects. Of special interest are the
distances of several objects which are at or near the L-T dwarf boundary so
that this important transition can be better understood. The previously
reported early-mid T dwarf luminosity excess is clearly confirmed and found to
be present at J, H, and K. The large number of objects that populate this
luminosity excess region indicates that it cannot be due entirely to selection
effects. The T dwarf sequence is extended to M_J~16.9 by 2MASS J041519-0935
which, at d = 5.74 pc, is found to be the least luminous [log(L/L_sun)=-5.58]
and coldest (T_eff~760 K) brown dwarf known. Combining results from this paper
with earlier USNO CCD results we find that, in contrast to the L dwarfs, there
are no examples of low velocity (V_tan < 20 km/s) T dwarfs. We briefly discuss
future directions for the USNO infrared astrometry program.Comment: 73 pages, 9 figures, 9 tables, accepted for publication in The
Astronomical Journa
ASCA Discovery of an X-ray Pulsar in the Error Box of SGR1900+14
We present a 2 - 10 keV ASCA observation of the field around the soft gamma
repeater SGR1900+14. One quiescent X-ray source was detected in this
observation, and it was in the SGR error box. In 2 - 10 keV X-rays, its
spectrum may be fit by a power law with index -2.2, and its unabsorbed flux is
9.6 x 10^-12 erg cm^-2 s^-1. We also find a clear 5.16 s period. The properties
of the three well-studied soft gamma repeaters are remarkably similar to one
another, and provide evidence that all of them are associated with young,
strongly magnetized neutron stars in supernova remnants.Comment: Accepted for publication in the Astrophysical Journal Letter
Exosome-mediated transfer from the tumor microenvironment increases TGFβ signaling in squamous cell carcinoma
Transforming growth factor-beta (TGFβ) signaling in cancer is context dependent and acts either as a tumor suppressor or a tumor promoter. Loss of function mutation in TGFβ type II receptor (TβRII) is a frequent event in oral cavity squamous cell carcinoma (SCC). Recently, heterogeneity of TGFβ response has been described at the leading edge of SCC and this heterogeneity has been shown to influence stem cell renewal and drug resistance. Because exosome transfer from stromal to breast cancer cells regulates therapy resistance pathways we investigated whether exosomes contain components of the TGFβ signaling pathway and whether exosome transfer between stromal fibroblasts and tumor cells can influence TGFβ signaling in SCC. We demonstrate that exosomes purified from stromal fibroblasts isolated from patients with oral SCC contains TβRII. We also demonstrate that transfer of fibroblast exosomes increases TGFβ signaling in SCC keratinocytes devoid of TβRII which remain non-responsive to TGFβ ligand in the absence of exosome transfer. Overall our data show that stromal communication with tumor cells can direct TGFβ signaling in SCC
A ROSAT Deep Survey of Four Small Gamma-Ray Burst Error Boxes
We have used the ROSAT High Resolution Imager to search for quiescent X-ray
counterparts to four gamma-ray bursts which were localized to small (< 10 sq.
arcmin.) error boxes with the Interplanetary Network. The observations took
place years after the bursts, and the effective exposure times for each target
varied from ~16 - 23 ks. We have not found any X-ray sources inside any of the
error boxes. The 0.1 - 2.4 keV 3 sigma flux upper limits range from around 5 x
10^-14 erg cm^-2 s^-1 to 6 x 10^-13 erg cm^-2 s^-1 depending on the burst and
the assumed shape of the quiescent spectrum. We consider four types of X-ray
emitting galaxies (normal, AGN, faint, and star-forming) and use the flux upper
limits to constrain their redshifts. We then use the GRB fluences to constrain
the total energies of the bursts.Comment: 16 pages, 4 figures; submitted to the Astrophysical Journa
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