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Homogeneous and inhomogeneous ignition of real and surrogate fuels were imaged in two Stanford shock tubes, revealing the influence of small particle fragmentation. n-Heptane, iso-octane, and Jet A were studied, each mixed in an oxidizer containing 21% oxygen and ignited at low temperatures (900-1000 K), low pressures (1-2 atm), with an equivalence ratio of 0.5. Visible images (350-1050 nm) were captured through the shock tube endwall using a high-speed camera. Particles were found to arrive near the endwalls of the shock tubes approximately 5 ms after reflection of the incident shock wave. Reflected shock wave experiments using diaphragm materials of Lexan and steel were investigated. Particles collected from the shock tubes after each experiment were found to match the material of the diaphragm burst during the experiment. Following each experiment, the shock tubes were cleaned by scrubbing with cotton cloths soaked with acetone. Particles were observed to fragment after arrival near the endwall, often leading to inhomogeneous ignition of the fuel. Distinctly more particles were observed during experiments using steel diaphragms. In experiments exhibiting inhomogeneous ignition, flames were observed to grow radially until all the fuel within the cross section of the shock tube had been consumed. The influence of diluent gas (argon or helium) was also investigated. The use of He diluent gas was found to suppress the number of particles capable of causing inhomogeneous flames. The use of He thus allowed time history studies of ignition to extend past the test times that would have been limited by inhomogeneous ignition. [ABSTRACT FROM AUTHOR]

Untrained Thoroughbred horses (6 mares and 6 geldings; 11 yr [SE 1] and 565 kg [SE 11]) were used to evaluate antioxidant gene expression and enzyme activity in blood and skeletal muscle in response to prolonged exercise after receiving 2 levels of dietary selenium for 36 d: 0.1 (CON; n = 6) or 0.3 mg/kg DM (SEL; n = 6). Horses were individually fed 1.6% BW coastal bermudagrass hay, 0.4% BW whole oats, and a mineral/vitamin premix containing no Se. Sodium selenite was added to achieve either 0.1 or 0.3 mg Se/kg DM in the total diet. On d 35, horses underwent 2 h of submaximal exercise in a free-stall exerciser. Blood samples were obtained before (d 0) and after 34 d of Se supplementation and on d 35 to 36 immediately after exercise and at 6 and 24 h after exercise. Biopsies of the middle gluteal muscle were obtained on d 0, before exercise on d 34, and at 6 and 24 h after exercise. Supplementation with Se above the NRC requirement (SEL) increased serum Se (P = 0.011) and muscle thioredoxin reductase (TrxR) activity (P = 0.051) but had no effect on glutathione peroxidase (GPx) activity in plasma, red blood cell (RBC) lysate, or muscle in horses at rest. Serum creatine kinase activity increased (P < 0.0001) in response to prolonged exercise but was not affected by dietary treatment. Serum lipid hydroperoxides were affected by treatment (P = 0.052) and were higher (P = 0.012) in horses receiving CON than SEL immediately following exercise. Muscle expression of TrxR1 was unchanged at 6 h but increased (P = 0.005) 2.8-fold 24 h after exercise, whereas muscle TrxR activity remained unchanged. Glutathione peroxidase activity increased in plasma (P < 0.0001) and decreased in RBC lysate (P = 0.010) after prolonged exercise. A Se treatment ? time interaction was observed for RBC GPx activity (P = 0.048). Muscle GPx1 and GPx3 expression and GPx activity did not change during the 24-h period after exercise. Level of dietary Se had no overall effect on expression of MT1B, MT3, TrxR1, GPx1, GPx3, SOD1, or SOD2 in muscle following exercise. The impact of prolonged exercise on the activities of antioxidant enzymes varied. Furthermore, changes in enzyme activity did not necessarily align with enzyme gene expression following exercise. A higher level of Se intake elevated Se status of untrained horses, increased GPx activity, and lessened lipid peroxidation following exercise, suggesting that Se may be beneficial for mitigating oxidative muscle damage and aiding in postexercise recovery. [ABSTRACT FROM AUTHOR]

Brahman x British crossbred steers (n = 40 and 38 in yr 1 and 2, respectively) were used to evaluate the effects of calf management systems following early weaning (EW) on growth performance, muscle gene expression, and carcass characteristics. On the day of EW (d 0), steers were stratified by BW and age (95 ± 14 kg; 74 ± 14 d) and randomly assigned to a control treatment that was normally weaned (NW) on d 180 (n = 10 steers/yr) or to 1 of 3 EW treatments: 1) EW and limit fed a high-concentrate diet at 3.5% of BW (as-fed basis) in drylot until d 180 (EW180; n = 10 steers/yr), 2) EW and limit fed a high-concentrate diet at 3.5% of BW (as-fed basis) in drylot until d 90 and then grazed on bahiagrass pastures until d 180 (EW90; n = 10 steers/yr), or 3) EW and grazed on annual ryegrass pastures until d 60 (yr 1; n = 10 steers) or 90 (yr 2; n = 8 steers) and then on bahiagrass pastures until d 180 (EWRG). Early-weaned steers on ryegrass and bahiagrass pastures were supplemented with high-concentrate diet at 1.0% of BW (as-fed basis) until d 180. From d 180 to 270 (yr 1), all EW steers remained in their respective treatments, whereas NW steers were provided high-concentrate diet at 1.0% of BW (as-fed basis) on bahiagrass pastures. In yr 1, feedlot finishing period began on d 270. In yr 2, the study was terminated on d 180. In both years, EW 180 steers were heaviest (P < 0.0001) on d 180. On d 180 of yr 1, EWRG steers were lightest (P < 0.0001) and EW90 steers were heavier (P = 0.05) than NW steers, whereas EW90, EWRG, and NW steers had similar BW on d 180 of yr 2 (P ≥ 0.14). On d 90, muscle PPARγ mRNA expression tended (P = 0.07) to be greater for EW180 steers and was greater (P = 0.008) for EW90 vs. EWRG steers but similar (P = 0.25) between EW180 and NW steers. On d 180, PPARγ mRNA was greater (P ≤ 0.06) for EW180 vs. NW, EW90, and EWRG steers. From d 274 to 302, EW180 steers had the least ADG (P ≤ 0.09), whereas EW90 steers had similar (P = 0.19) ADG compared with EWRG steers but greater (P = 0.03) ADG than NW steers. At slaughter, carcass characteristics did not differ (P ≥ 0.22) among treatments. In summary, EW steers provided a high-concentrate diet in drylot for at least 90 d were heavier at the time of normal weaning than NW steers and EW steers grazed on ryegrass pastures for 60 to 90 d and supplemented with concentrate at 1.0% of BW. Feeding a high-concentrate diet immediately after EW enhanced the muscle PPARγ expression but did not enhance marbling at slaughter. [ABSTRACT FROM AUTHOR]

Brahman × British crossbred heifers (n = 40 and 38 heifers in yr 1 and 2, respectively) were used to evaluate the effects of calf weaning age and subsequent management system on growth and reproductive performance. On d 0, heifers were ranked by BW (89 ± 16 kg) and age (72 ± 13 d) and randomly assigned to a conventional management group that was normally weaned on d 180 (NW; n = 10 heifers annually) or early weaned (EW) on d 0 and 1) limit fed a highconcentrate diet at 3.5% of BW (as fed) in drylot until d 180 (EW180; n = 10 heifers annually), 2) limit fed a high-concentrate diet at 3.5% of BW (as fed) in drylot until d 90, then grazed on Bahiagrass pastures until d 180 (EW90; n = 10 heifers annually), or 3) grazed on annual ryegrass pastures until d 60 (yr 1; « = 10 heifers) or 90 (yr 2; n = 8 heifers), then on Bahiagrass pastures until d 180 (EWRG). On d 180, all heifers were grouped by treatment and rotated on Bahiagrass pastures until d 390. Grazing heifers were supplemented at 1.0% BW until d 180 and at 1.5% BW from d 180 to 390. From d 0 to 90, EW180 and EW90 heifers were heavier (P ≤ 0.02) than NW and EWRG heifers, whereas NW heifers tended [P = 0.09) to be heavier on d 90 than EWRG heifers. In yr 1 and 2, EW180 heifers were heaviest (P < 0.0001) on d 180. In yr 1, EWRG heifers were lightest (P < 0.0001), whereas EW90 and NW heifers had similar BW (P = 0.58). Conversely, EW90, EWRG, and NW heifers achieved similar BW on d 180 of yr 2 (P ≥ 0.18). Positive correlations were detected (P ≤ 0.05) between liver IGF-1 mRNA abundance on d 90 and ADG from d 0 to 90 and between liver IGF-1 mRNA abundance on d 180 and ADG from d 90 to 180. The EW180 heifers were youngest (P ≤ 0.01) at puberty. From d 260 to 340, the percentage of pubertal heifers was greater (P ≤ 0.03) for EW90 vs. NW heifers but did not differ (P ≥ 0.15) between EWRG and NW heifers. The ADG from d 0 to 90 and the plasma IGF-1 on d 90 and 180 explained approximately 34% of the variability in age at puberty. In summary, the EW90 and EW 180 heifer management systems evaluated in this study altered the BW at the time of NW and were good alternatives for anticipating puberty achievement compared to NW heifers. [ABSTRACT FROM AUTHOR]

As we strive toward a more accurate understanding and quantification of carbon pools in forested ecosystems, the development of regional-scale maps of forest characteristics is essential in order to establish baselines and monitor change. Light Detection and Ranging (LiDAR) is increasingly being used to improve our understanding of forested ecosystems on a broad spatial scale, although obtaining data can be expensive and time consuming. We evaluated the effectiveness of using freely available low point density, leaf-off LiDAR collected for the entire state of Pennsylvania, in the United States, to create an accurate regionalscale dominant/codominant canopy height model for state forests in Pennsylvania. We evaluated several methodologies using an inventory dataset with over 1400 sample plots. The developed canopy height model was accurate to about 10% of the fieldmeasured dominant/codominant tree heights for each plot, although it underestimated the field values. Root mean square error relative to the mean field height ranged between 3.5% and 12.5% across all site and forest variables such as forest community type, age, and height class. Factors that affected the accuracy of the canopy height model included tree density, slope, and percent evergreen cover. [ABSTRACT FROM AUTHOR]

Satellite cells are the resident stem cell population of adult skeletal muscle tissue that is respon-sible for growth and regeneration. The cells typically congregate near the tips of the muscle fibers and in close proximity to the neural muscular junction (NMJ). Ephrin-A5 is a chemotactic molecule that participates in the correct positioning and formation of the NMJ. The objective of the experiment was to examine the effects of ephrin-A5 signaling on bovine satellite cell (BSC) biol-ogy. Primary cultures of BSC demonstrate changes in velocity with time in culture that is unique to the Paired box protein 7 (Pax7):Myogenic factor 5 (Myf5) subpop-ulation. Treatment of the BSC with ephrin-A5 causes a reduction (P < 0.05) in velocity with a concomitant increase (P < 0.05) in directed migration. The chemoat-tractant properties of ephrin-A5 occur before myogenic differentiation 1 (MyoD) expression in the myogenic precursors and are abrogated after their differentiation to committed myoblasts. Ephrin-A5 induced migration appears to require components of the Ras homolog gene family member A (RhoA) and Rho-associated protein kinase (ROCK) signaling machinery. Supplementa-tion of culture media with a chemical ROCK inhibitor suppressed (P < 0.05) ephrin-A5 initiated BSC migra-tion. These results contrast with treatment of BSC with hepatocyte growth factor (HGF), a key modulator of myogenic and motogenic activity. Treatment of BSC with HGF had no effect on cell motility or migration immediately after culture establishment. Twenty-four hours after culture establishment, BSC demonstrated an increase (P < 0.05) in transwell migration toward HGF. These results document that temporal and spatial gradi-ents of chemokines and growth factors participate in the localization of BSC within the niche. [ABSTRACT FROM AUTHOR]

The article reports on the development of a crenulation cleavage in a Mooselookmeguntic igneous complex roof due to intrusion resulting to mechanical thinning by complex thermal, chemical and mechanical interaction. This deformation gradient may reportedly mirror the steeply dipping of the pre-emplacement foliation that might be expected for nonlinear creep mechanisms. The article states that the cleavage may be important in the spatial distribution of localized strain in evolving orogens.

A well preserved strain and reaction gradient records the progressive transformation of a megacrystic Kfs+Cpx+Opx+Bt1±Qtz syenitic pluton to a strongly sheared Kfs+Act+Bt2+Ab+Qtz tectonite within the exhumed Norumbega Fault System, Maine, USA. Detailed microstructural analysis indicates that fracturing and localized fluid infiltration initiated the deconstruction of the existing K-feldspar and two-pyroxene load-bearing framework, and that feedback among metamorphic reactions, fabric development and enhanced permeability during progressive shearing led to the development of an interconnected, biotite- and actinolite-rich foliation. The activation of dislocation creep in biotite and quartz, and dissolution–precipitation creep in actinolite and feldspar, with increasing strain ultimately resulted in a transition from dominantly frictional to dominantly viscous deformation processes. Petrological data show that various scales of geochemical disequilibrium exist across the strain and reaction gradient, and that reaction progress was limited by slow chemical diffusion during the early stages of deformation. Petrological modelling results indicate that the existing plutonic assemblage was metastable at mid-crustal conditions, and that fluid infiltration and deformation allowed the product assemblage to advance towards chemical equilibration. Comparison of the observed microstructures and deformation mechanisms with experimental and numerical modelling results suggest that the development of an interconnected biotite-dominated fabric probably caused a major (up to three fold) reduction in bulk rock strength and localization of strain into the foliated margin. [ABSTRACT FROM AUTHOR]

ABSTRACT: The goal of this study was to evaluate the effects of ractopamine-hydrochioride (RAC) supplementation on the myosin heavy chain isoform distribution and shelf-life properties of muscles from beef top round, knuckle, and loin. Thirty-four steer carcasses were selected from 4 separate slaughter groups. Within each slaughter group (3 groups, n = 8; 1 group, n = 10), steers were separated into pens (n = 8) and fed 0 or 200 mg.animaL*d1 of RAC for the final 28 d of feeding. Seventy-two hours postmortem, the longissimus lumborum, semimembranosus (SM), adductor, gracilis, vastus lateralis (VL), and rectus femoris were removed from each carcass. A subsample of each muscle was collected for immunohistochemical analysis. Whole muscles were vacuum packaged and wet aged at 1 + 2°C for 13 d before processing into steaks for a 5-d simulated retail display study. Daily, steaks were analyzed for reduction of nitric oxide metmyoglobin, lean color, fat color, and surface discoloration. Objective measures of metmyoglobin, oxymyoglobin, L*, aK, and b* values were recorded çlaily. Ractopamirie significantly (P < 0.05) changed the fiber type isoform distribution in all muscles except the SM. The VL and gracilis presented the greatest fiber type switch with approximately 21% of type I fibers switching to type hA fibers. However, the fiber type shifts induced by RAG supplementation had little to no effect on subjective and objective color measurements during the 5-d retail display period. Metmyoglobin and oxymyoglobin accumulation, L*, a*, and b* values were not affected (P > 0.05) by RAG supplementation. Percent nitric oxide metmyoglobin reduction data indicate that reducing ability of RAGtreated steaks from the adductor and longissimus lumborum were significantly affected (P < 0.05). Visual panel data suggest that RAG tended (P < 0.10) to have the most detrimental effect on the lean color and surface discoloration scores of steaks from the VL during the last 3 d of display. Ractopamine significantly (P < 0.05) increased the surface discoloration of the rectus femoris and SM on d 5. Although RAG supplementation had no effect on objective color measurements, subjective measurements indicate that it may have some effect on surface discoloration of some muscles. [ABSTRACT FROM AUTHOR]

Exercise places an increased demand on the body's systems, both to provide fuel for working musculature and to neutralize and dispose of toxic build-up. By-products of demanding performance are reactive free radicals. Dietary consumption of vitamin E, an antioxidant, may be a plausible way to reduce free radical damage. The present study examined the effects of supplemental dietary vitamin E on the presence of oxidation products and antioxidant capacity in blood and tissue of exercising horses. Eight Thoroughbred horses were used in a crossover design study, with one group consuming a diet containing vitamin E at the 1989 National Research Council (NRC) level recommended for horses in moderate to intense work (80 IU kgDM-1 [National Research Council (1989). Nutrient Requirements of Horses. 5th revised edn.; Washingto, DC: National Academy Press, pp. 48]), and the second group being fed the control diet plus 3000 IU day-1 DL-a-tocopheryl acetate. The horses underwent an adaptation phase, an 8-week training programme and a final standard exercise test (SET) during which the horses ran on a 68 incline to exhaustion, and then a washout phase. Horses were then crossed over to opposite treatment groups and these phases repeated. Blood samples were collected at specific points before and after exercise during the training period and before and after performing the SET. Neither plasma vitamin E nor thiobarbituric acid-reactive substance concentrations were influenced by supplemental vitamin E. Blood Troloxequivalent antioxidant capacity values increased (P < 0.05) following 5 weeks of training in both groups, indicating improved antioxidant capacity as horses became fitter. Vitamin E supplementation did not alter plasma reduced, oxidized or total glutathione levels, nor the percentage of glutathione in the reduced form during the training period. However, vitamin E did cause an elevation in the percentage of glutathione existing in the reduced form following a SET as compared with the control diet (P < 0.006). This is possibly due to lower plasma oxidized glutathione levels in vitamin E-treated horses (P < 0.03). This study indicates that vitamin E supplementation above NRC levels can influence certain measures of oxidative stress in intensely exercising horses, and training has the ability to improve the antioxidant status of the animal. [ABSTRACT FROM AUTHOR]

Intense exercise has been associated with free radical damage that forms potentially measurable by-products in the blood and muscle of exercising subjects. The extent of damage to the exercising animal has yet to be conclusively determined, and studies often focus on by-products in the blood rather than muscle. The current study examined the presence of oxidative products in the muscle of exercising horses as well as the effects of excess vitamin E on the presence of these products. Eight Thoroughbred horses were used in a crossover design, with one group being fed vitamin E at the 1989 NRC [National Research Council (1989) Nutrient Requirements of Horses. 5th revised edn.; Washington DC: National Academy Press, pp. 48] level recommended for horses in moderate to intense work (80 IU kgDM-1), and the second group being fed the control diet plus 3000 IU day-1 DL-atocopheryl acetate. The horses underwent an 8-week training programme and a final standard exercise test (SET). During the SET, the horses ran on a 68 incline to exhaustion. Muscle samples were biopsied before and after performing the SET and analysed for the presence of carbonyl groups and ubiquitin. Blood was collected prior to the SET and analysed for vitamin E. No significant differences in plasma vitamin E were found between treatment groups. However, myofibril carbonylation, a product of free radical damage to muscle tissue, was found to be lower in vitamin E-supplemented horses post-SET exercise (P < 0.05), suggesting that vitamin E influences some measures of oxidative stress in exercising horses, particularly following a strenuous bout of exercise. Ubiquitin was not detected in myofibrils, indicating clearance of carbonyl groups by a different mechanism. [ABSTRACT FROM AUTHOR]

Numerical models are used to examine the effects of porphyroblast growth on the rheology of compositionally layered rocks (metapelites and metapsammites) and by extension the middle crust during prograde metamorphism. As porphyroblast abundance increases during prograde metamorphism, metapelitic layers will strengthen relative to porphyroblast-free metapelitic units, and potentially relative to quartzofeldspathic metapsammitic units. As metapelitic layers become stronger, the integrated strength of compositionally layered successions increases, potentially causing large volumes of mid-crustal rock to strengthen, altering the strain-rate distribution in the middle crust and affecting the geodynamic evolution of an orogenic belt. The growth of effectively rigid porphyroblasts creates strength heterogeneities in the layer undergoing porphyroblast growth, which leads to complex strain-rate distributions within the layer. At the orogen scale, the strengthening of large crustal volumes (on the order of thousands of cubic kilometres) changes the strain-rate distribution, which may change exhumation rates of high-grade metamorphic rocks, the geothermal structure and the topography of the orogen. The presence of a strong zone in the middle crust causes strain-rate partitioning around the zone, suppressed uplift rates within and above the zone and leads to the development of a basin on the surface. [ABSTRACT FROM AUTHOR]

The Chain Lakes massif has long been an enigmatic component of the Appalachian orogen, but new structural, microstructural, and geochronological information provides the basis for the following new interpretation of the massif and its history. In the early Paleozoic, sediments and volcanic rocks from Laurentia or a Laurentian-derived microcontinent were deposited in a fore-arc basin on the western margin of the Iapetus ocean. Following intrusion of arc-related magmas, the sedimentary–volcanic sequence was heated sufficiently to melt in place, resulting in stratigraphic disaggregation and diatexite formation. We dated monazite growth from this metamorphic event at 469 ± 4 Ma. Although some melt may have left the system, much remained, including water dissolved in the melt. Upon crystallization, this water drove thorough retrogression of the massif, causing pervasive pseudomorphism of porphyroblasts. With cooling and crystallization, the Chain Lakes massif became sufficiently rigid that it was not significantly deformed during the Middle Ordovician through Devonian stages of Appalachian orogenesis involving the arrival of several peri-Gondwanan microcontinents. [ABSTRACT FROM AUTHOR]

Pre-Silurian bedrock units played key roles in the early Paleozoic history of the Maine–Quebec Appalachians. These units represent peri-Laurentian material whose collision with the craton deformed the Neoproteozoic passive margin and initiated the Appalachian mountain-building cycle. We present new field, petrological, geochronological, and geochemical data to support the following interpretations related to these units. (1) The Boil Mountain Complex and Jim Pond Formation do not represent part of a coherent ophiolite. (2) Gabbro and tonalite of the Boil Mountain Complex intruded the Chain Lakes massif at ca. 477 Ma. (3) The Skinner pluton, an arc-related granodiorite, intruded the Chain Lakes massif at ca. 472 Ma. (4) The Attean pluton, with a reconfirmed age of ca. 443 Ma, is unrelated to Early Ordovician orogenesis. (5) The most likely timing for the juxtaposition of the Jim Pond Formation and the Boil Mountain Complex was during regional Devonian deformation. These interpretations suggest that the Boundary Mountains were once part of a series of arcs extending at least from central New England through Newfoundland. [ABSTRACT FROM AUTHOR]

Low-pressure anatexis, whereby rocks melt in place after passing through the andalusite stability field, develops under more restricted conditions than does low-pressure metamorphism. Our thermal modelling and review of published work indicate that the following mechanisms, operating alone, may induce anatexis in typical pelitic rocks without inducing wholesale melting in the lower crust: (i) magmatic advection by pervasive flow; (ii) crustal-scale detachment faulting; and (iii) the presence of a high heat-producing layer. Of these, only magmatic advection by pervasive flow and crustal-scale detachment faulting have been shown quantitatively to provide sufficient heat to cause widespread melting. Combinations of the above mechanisms with pluton-scale magmatic advection, shear heating, removal of the lithospheric mantle, or with each other provide additional means of developing suitable high temperatures at shallow crustal levels to generate low-pressure anatexis. [ABSTRACT FROM AUTHOR]

In the low-pressure, high-temperature metamorphic rocks of western Maine, USA, staurolite porphyroblasts grew at c. 400 Ma, very late during the regional orogenesis. These porphyroblasts, which preserve straight inclusion trails with small thin-section-scale variation in pitch, were subsequently involved in the strain and metamorphic aureole of the c. 370 Ma Mooselookmeguntic pluton. The aureole shows a progressive fabric intensity gradient from effectively zero emplacement-related deformation at the outer edge of the aureole ∼2900 m (map distance) from the pluton margin to the development of a pervasive emplacement-related foliation adjacent to the pluton. The development of this pervasive foliation spanned all stages of crenulation cleavage development, which are preserved at different distances from the pluton. The spread of inclusion-trail pitches in the staurolite porphyroblasts, as measured in two-dimensional (2-D) thin sections, increases nonlinearly from ∼16° to 75° with increasing strain in the aureole. These data provide clear evidence for rotation of the staurolite porphyroblasts relative to one another and to the developing crenulation cleavage. The data spread is qualitatively modelled for both pure and simple shear, and both solutions match the data reasonably well. The spread of inclusion-trail orientations (40–75°) in the moderately to highly strained rocks is similar to the spread reported in several previous studies. We consider it likely that the sample-scale spread in these previous studies is also the result of porphyroblast rotation relative to one another. However, the average inclusion-trail orientation for a single sample may, in at least some instances, reflect the original orientation of the overgrown foliation. [ABSTRACT FROM AUTHOR]

Presents a study which investigated the health behavior factors of the Swedish adult population which use dietary supplements and natural remedies. Classification of dietary supplements, natural remedies and covariates; Statistical methods; Sociodemographic factors; Health behavior factors.

This article describes a case of plicae palmatae, a normal anatomical variant, that was initially misinterpreted as a possible malignancy on ultrasound. Further investigation using magnetic resonance imaging (MRI) and specialized gynecological ultrasound confirmed the finding as plicae palmatae. Plicae palmatae are folds of the endocervix that can be mistaken for pathological findings, leading to unnecessary additional imaging and stress for patients. The article emphasizes the importance of recognizing plicae palmatae on different imaging modalities and highlights the utility of specialized gynecological ultrasound performed by experienced sonologists for accurate diagnosis. [Extracted from the article]

Information about several papers discussed at the symposium "Participation of adult tissue-restricted stem cells in livestock growth and development" held July 15-19, 2012, in Phoenix, Arizona, is presented. Topics include the movement of myogenic cells within the tissue, bovine spermatagonial stem cell propagation, and novel stem cell line capable of forming hepatocytes and bile duct cells. The symposium featured several scientists including Ronald Allen, Jon Oatley, and Anthony Capuco.

The article presents the abstract of the paper "Variation in Social Structure, Ranging, and Intergroup Interactions Among Red Fronted Brown Lemur (Eulemur Fulvus Rufus), White-Collared Lemur (E. Albocollaris), and Hybrid Populations in Southeastern Madagascar," by S. E. Johnson and D. J. Overdorff, to be presented at the 21st Congress of the International Primatological Society in Entebbe, Uganda from June 25-30, 2006.

The article presents an abstract of the paper "Chimpanzees' response to a novel environment: factors affecting the survival rates of chimpanzees in an island release program in the Gambia," presented at the 21st Congress of the International Primatological Society held June 25-30, 2006 at Entebbe, Uganda.

The article presents an abstract of the symposium "Distribution and patchiness of endangered lemurs in the Ranomafana rainforest of Madgascar: the crisis of the greater bamboo lemur," presented at the 21st Congress of the International Primatological Society held June 25-30, 2006 at Entebbe, Uganda.

The present work describes a multi-physics model to investigate subcritical propagation of initially oil-filled, sub-horizontal collinear microcracks driven by the excess pressure induced by the conversion of oil to gas in a petroleum source rock under continuous burial. The crack propagation distance, propagation duration, crack coalescence and excess pressure in the crack are determined using a finite difference scheme that couples linear elastic fracture mechanics, oil-gas transformation kinetics and an equation of state for the gas. The numerical results for a shale source rock with typical properties show that when the crack spacing parameter b/a 0 is greater than 3, where a 0 is the half crack length and b the half distance between the crack centers, the cracks do not coalesce, and the duration of gas-driven crack propagation is governed by the transformation kinetics because the oil-gas conversion rate is much slower than the subcritical crack propagation rate. The collinear cracks coalesce for smaller crack spacing and the crack propagation duration may reduce significantly due to crack interactions. The multi-physics model presented in this work together with our previous model for crack propagation during the conversion of solid kerogen to oil indicates that self-propagating microcracks resulting from the buildup of excess fluid pressure during hydrocarbon generation may serve as effective pathways for primary migration of hydrocarbons. [ABSTRACT FROM AUTHOR]

SUMMARY To investigate primary petroleum migration through microfracturing of source rocks, we develop a theoretical multiphysics model incorporating simultaneous generation of oil and gas from kerogen, elastic anisotropy of the source rock and propagation of microcracks filled with oil and gas. The variations of excess fluid pressure in the crack and crack propagation distance with time are determined. A detailed parametric analysis is performed to study the sensitivity of petroleum migration behaviour to changes in the input parameters including kerogen type (chemistry of kerogen to oil/gas conversion), elastic anisotropy of source rocks, geothermal gradient and burial rate. Numerical results show that a microcrack in type III kerogen-bearing source rocks can attain greater length than in rocks containing type I and II kerogen which have higher oil potentials and transform to oil/gas much faster than type III kerogen. Elastic anisotropy of source rocks has a profound influence on the crack propagation distance, but only a marginal effect on the duration of crack propagation and the excess fluid pressure. The simulation also shows that higher geothermal gradients and fast burial reduce the crack propagation duration significantly, but excess pressure and final crack length are not sensitive to the variations of geothermal gradient and burial rate. [ABSTRACT FROM AUTHOR]

We conduct a parametric study on the subcritical propagation of an oil-filled, penny-shaped microcrack induced by the pressure increase caused by transformation of kerogen to oil. The excess oil pressure on the crack surfaces, and the subcritical crack propagation distance and duration, are obtained using a coupled model of fracture mechanics and kerogen–oil transformation kinetics. The numerical results show that the excess oil pressure and crack propagation distance/duration are significantly influenced by the temperature and elastic/fracture properties of the source rock, and the initial kerogen particle size. The subcritical propagation behaviour is relatively insensitive to the volume expansion rate associated with the conversion of kerogen to oil. Because the subcritical crack propagation rate is much faster than the kerogen–oil conversion rate, the crack propagation duration is primarily determined by the transformation kinetics. [ABSTRACT FROM AUTHOR]

We present a perturbation method to investigate the steady-state propagation of a dyke from an over pressured source (e.g. a magma chamber) into a semi-infinite elastic solid with graded mass density. The non-linear dyke propagation/magma transport problem is reduced to a series of linear problems using a perturbation technique with the small non-dimensional parameter , where η is the magma viscosity, V the propagation velocity, the difference between the densities of the host rock and magma at the dyke tail, g the gravitational acceleration and H a parameter on the order of maximum dyke thickness. In general, the perturbation method is applicable to mafic dyke propagation at a relatively low propagation velocity wherein ℇ remains small (e.g. less than 0.1). We describe an integral equation approach to obtain the stress intensity factor at the dyke tip and the separation displacement of the two dyke surfaces. Numerical examples are presented to examine the effects of various physical parameters, for example, buoyancy, density gradation, propagation velocity and overpressure on the dyke propagation behaviour. It is found that dyke propagation could reach a steady-state in some specific ranges of growth for a given density gradient of the host rock. The propagation tends to decelerate when the dyke tip approaches the level of neutral buoyancy. [ABSTRACT FROM AUTHOR]

The pseudoautosomal region (PAR) of bovine chromosome X (BTA X) has a particularly low representation of genes and markers, making comparative gene mapping in this region difficult. We describe the localization of three genes, colony-stimulating factor 2 receptor alpha (CSF2RA), ADP/ATP translocase 3 (ANT3) and steroid sulphatase (STS) on PAR of BTA X using a 5000 rad whole-genome radiation hybrid panel. The relationship of these genes to a number of previously mapped simple sequence repeat (microsatellite) markers is determined by physical and radiation hybrid mapping methods. The resulting radiation hybrid map resolves a discrepancy between the two major bovine linkage maps in the PAR of BTA X. [ABSTRACT FROM AUTHOR]

Adaptation of skeletal muscle to exercise is partially mediated by satellite cells (SCs) residing near the myofiber. Exercise stimulates production of growth factors (GF) that induce SCs to enter the cell cycle, differentiate, and fuse to the nearby myofiber. Growth factors responsible for entry of equine SCs (eqSCs) into the cell cycle are unknown. The objective of the study was to examine the effects of GFs expressed by skeletal muscle on eqSCs time to S-phase entry in vitro. Biopsies were obtained from the gluteal muscle of mature thoroughbred geldings (n=8), eqSCs isolated, and myogenicity confirmed. Following 24 h attachment to an entactin-collagen-laminin matrix, eqSCs were washed exhaustively and incubated with Dulbecco's Modified Medium containing 1% fetal bovine serum, 1% penicillin-streptomycin, and 0.2% gentamicin supplemented with either 10 ng/mL Epidermal GF (EGF), 10 ng/mL Fibroblast GF-2 (FGF-2), 25 ng/ mL Hepatocyte GF (HGF), 100 ng/mL IGF-1, 10 ng/ mL IGF-2, 10 ng/mL IL-6, or an equivalent amount of 0.1% BSA. Parallel plates were maintained and cells co-incubated with 5-ethynyl-2'-deoxyuridine (EdU), a thymidine analog, for 2 h prior to fixation at either 0, 24, 48 or 72 h post-treatment. Incorporation of EdU was detected by click chemistry (AlexaFluor 488 EdU Detection kit; ThermoFisher) and total nuclei detected by Hoechst 33342. Epifluorescent micrographs were obtained and the percentage of cells in S-phase calculated as (number of EdU positive)/(number of nuclei) x 100. Results were analyzed by ANOVA with Tukey's posthoc adjustment using the GLM procedure of SAS. As time in culture progressed, the percentage of EdU positive eqSC increased from 0 ± 0.85 % at 0 h post-treatment to 11.65 ± 0.85 and 34.71 ± 0.85% at 48 and 72 h post-treatment, respectively (P < 0.0001). At 48 h in treatment, only IGF-2 (14.42 ± 0.89) increased (P = 0.05) the percentage of cells in S-phase compared to control (10.54 ± 0.89). After 72 h in treatment, FGF-2 (40.34 ± 1.65) and HGF (41.73 ± 1.65) increased (P < 0.0004) the percentage of cells in S-phase relative to control (29.19 ± 1.65). Control and IGF-2 treated cells were not different 72 h post-treatment. These results indicate that following isolation, adult eqSCs require 72 to 96 h to enter S-phase of the cell cycle irrespective of treatment. Of the GF tested, only IGF-2 accelerated entry into S-phase while FGF-2 and HGF served as mitogens at 72 h. [ABSTRACT FROM AUTHOR]

Equine muscle stem cells, or equine satellite cells (eqSCs), play a key role in the maintenance of skeletal muscle. Normally quiescent, eqSCs are activated in response to exercise-induced muscle microdamage after which they proliferate and differentiate to repair the fiber. Insulinlike growth factor 1 (IGF1) is an anabolic growth factor for skeletal muscle that may contribute to post-exercise repair. The objective of this study was to determine if IGF1 alters eqSC myogenesis in vitro. Isolates (n=6) were examined for proliferation, differentiation and protein synthesis capacity. Subconfluent eqSCs were treated with 0 or 100 ng/mL human IGF1 for 48 h with an EdU pulse during the final 2 h. Incorporation of EdU, a thymidine analog, was detected by click chemistry. Total nuclei were detected by Hoechst 33342 dye. Confluent eqSCs were treated in an analogous manner followed by fixation and immunocytochemical detection of myosin heavy chain (MyHC). A mitotic index was calculated as EdU(+)/Hoechst(+) X 100 and a fusion index was calculated as number nuclei in MyHC fibers/Hoechst(+) X 100. The metabolic effect of IGF1 on muscle fibers was examined by Western blot for key kinases. Serum-starved myofibers were treated with 0 or 100 ng/mL IGF1 for 20 min, lysed and protein content measured. Equal amounts of protein were separated electrophoretically and transferred to nitrocellulose. Blots were incubated with antibodies directed against AKT1, phospho-AKT1-S473, mTORC1, phospho- mTORC1-S2448, and tubulin. Immune complexes were detected by chemiluminescence and quantified. Myofiber protein synthesis was measured by SuNSET assay following 48 h with 0 or 100 ng/mL IGF1 treatment with a 2 h pulse of puromycin (10 ug/mL) included immediately prior to cell lysis. Equal amounts of cell lysates (20 ug) were analyzed for label content by Western blot using anti-puromycin and chemiluminescent detection, as described above. Data was analyzed by ANOVA with Tukey's posthoc test in the GLM function of SAS. Results demonstrate that IGF1 did not affect either proliferation (P=0.31) or fusion (P=0.45). IGF1 increased AKT1 phosphorylation compared to the control as seen visually on western blot. Phosphorylation of mTORC1 was unaffected by IGF1 treatment. Protein synthesis was increased in the IGF1 treatment group compared to control as seen visually on western blot. In summary, these results provide evidence that IGF1 does not affect eqSC proliferation and differentiation but does affect fiber metabolism as indicated by an increase in protein synthesis. [ABSTRACT FROM AUTHOR]

Plane of nutrition effects on body, tissue and cellular growth in the neonatal calf are poorly understood. The hypothesis that a low plane of nutrition ( LPN) would limit skeletal muscle size by reducing fibre growth and muscle progenitor cell activity was tested. At birth, calves were randomly assigned to either a LPN (20% CP, 20% fat; GE=1.9 Mcal/days) or a high plane of nutrition ( HPN; 27% CP, 10% fat, GE = 3.8 Mcal/days) in a 2 × 3 factorial design to test the impact of diet on neonatal calf growth, organ weight and skeletal muscle morphometry with time. Groups of calves ( n = 4 or 5) were euthanised at 2, 4 and 8 week of age and organ and empty carcass weights were recorded. Body composition was measured by DXA. Longissimus muscle ( LM) fibre cross-sectional area ( CSA), fibre/mm2 and Pax7 were measured by immunohistology. Satellite cells were isolated at each time point and proliferation rates were measured by EdU incorporation. Calves fed a HPN had greater (p < 0.05) BW, ADG and hip height than those fed a LPN for 2, 4 or 8 weeks. HPN calves contained a greater (p < 0.05) percentage of fat tissue than LPN calves. Liver, spleen and thymus weights were less (p < 0.05) in LPN calves than HPN animals. Calves fed HPN had larger (p < 0.05) LM CSA at 8 weeks than LPN fed animals with no differences between the groups in numbers of satellite cells per fibre. Proliferation rates of satellite cells isolated from HPN fed calves were greater (p < 0.05) at 2 weeks than LPN fed animals, which exhibited greater (p < 0.05) proliferation rates at 4 weeks than HPN fed calves. We conclude a LPN diet reduces body growth and organ size and metabolically reprograms satellite cell activity. [ABSTRACT FROM AUTHOR]

The article discusses preventing the extinction of Madagascar's lemur populations. Topics include the interdependence of habitat and lemur conservation, the impact of habitat destruction, such as the illegal logging of rosewood, on lemur populations, and the challenges of in situ lemur conservation. Also discussed is the interrelationship of ecotourism, long-term lemur research at critical lemur sites, and local management of protected areas.

The effects of administration of recombinant bovine ST (bST) on plasma hormone concentrations of cows, conceptus development, and postnatal calf performance were examined. Lactating beef cows (n = 190) were exposed to a fixed-time AI (TAI) protocol from d -10 to 0 (TAI on d 0). Cows were blocked by breed and stratified by days postpartum and then randomly assigned to receive, subcutaneously 1) 2 injections of saline (1 mL of 0.9% saline), 1 on d 0 at TAI and a second injection on d 14 (CTRL; n = 53); 2) an injection of 325 mg of bST on d 0 and a saline injection on d 14 (bST0; n = 48); 3) a saline injection on d 0 and an injection of 325 mg of bST on d 14 (bST14; n = 49); or 4) 2 injections of 325 mg of bST, 1 on d 0 and a second injection on d 14 (bST0+14; n = 40). Pregnancy status, crown-to-rump length (CRL) on Day 35, and crown-to-nose length (CNL) on Day 65 were determined via transrectal ultrasonography. Blood samples were collected on d 0, 7, 14, 21, 35, and 65, relative to TAI, to determine plasma concentrations of progesterone (P4), IGF-1, and pregnancy-specific protein B (PSPB) and also on d 18 and 21 for isolation of peripheral blood leukocytes for RNA extraction and measurement of interferon-stimulated genes transcript abundance. Individual calf BW was determined at birth and every 30 d until weaning. A subset of 24 calves was randomly selected for liver biopsies at birth to determine mRNA expression of target genes. Administration of bST to cows increased (P < 0.0001) concentrations of plasma IGF-1 for 14 d after injection compared with CTRL but did not affect fetal CRL and CNL (P = 0.23). Cows receiving bST only on d 0 had a greater (P = 0.05) transcript abundance in myxovirus resistance 2 on d 21 compared with 2bST cows (2.0- and 0.8-fold for bST0 and 2bST, respectively), whereas cows receiving bST14 and CTRL were intermediate (1.2- and 0.9-fold, respectively). Calf BW did not differ (P ≥ 0.100) among treatments on d 0, 30, 60, 90, 120, and 150 relative to birth. Injection of bST only on d 0 tended (P = 0.062) to increase calf liver mRNA expression of IGF-1 receptor at birth compared with the calves born to cows in other treatments. Therefore, during a TAI protocol, the administration of 1 or 2 injections of 325 mg of bST to lactating beef cows enhanced their plasma concentrations of IGF-1 but failed to improve fetal size and plasma concentrations of maternal PSPB and P4 and had no effect on postnatal calf growth performance. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine the effects of alternative finishing strategies on beef steak color and cooked meat characteristics. Beef steers (n = 64 pens; 8 steers/pen) were allocated to a randomized complete block design with a 2 x 2 factorial treatment arrangement and initial body weight serving as the blocking factor. Factor 1 consisted of dietary treatment with cattle either being fed a conventional feedlot diet (CON) or a diet that included Programmed Nutrition Beef Program supplements. Cattle in the Programmed Nutrition (PN) treatments were fed in two-stages: 1) the basal diet with Programmed Nutrition Beef Receiver from d 1 to 20 and the basal diet with Programmed Nutrition Beef Finisher from d 21 to harvest. Factor 2 consisted of the inclusion (EGP+) or absence (EGP-) of an exogenous growth promoting program. Steers in the EGP+ treatments were implanted initially with Component E-S, reimplanted with Component TE-IS, and fed 400 mg.d-1.steer-1 of ractopamine hydrochloride for the final 28 d before harvest. Steers were harvested on d 175 of feeding and 1 strip loin was removed from 2 car-casses selected at random from each pen for transport to Kansas State University. After 14 d of aging, loins were fabricated into 2.54-cm thick steaks for objective and trained sensory panel measurement of cooked meat characteristics and objective color measurements during 7 d retail display. There were no interactions (P >0.10) between feeding strategy and exogenous growth promotants for all objective measures of color and cooked meat characteristics. Throughout the display period, PN steaks were darker (P = 0.02) than CON steaks, but surface percentages of oxymyoglobin and metmyoglobin and metmyoglobin reducing ability were unaffected by feeding strategy (P > 0.10). Loins and steaks from PN cattle possessed decreased moisture loss during aging and cooking (P < 0.01). Trained sensory panel evaluation of cooked meat revealed a dietary program x growth promotant interaction for myofibrillar tenderness, connective tissue amount, and overall tenderness (P = 0.01). Compared to the CON/EGP- and PN/EGP-treatments, steaks from the CON/EGP+ and PN/EGP+ treatments were evaluated by panelists as being less myofibrillar and overall tender (P < 0.05). The alternative feeding strategies presented in this study can favorably impact water-holding capacity without negatively compromising retail display discoloration. [ABSTRACT FROM AUTHOR]

Drought and other weather-related disasters impact the amount and quality of grains and forages available to beef cattle. The impact of nutrient restriction at specific gestational timeframes on fetal skeletal muscle growth was examined. Crossbred beef cows were fed to NRC recommendations (CCC) or restricted to 60% of said levels for the first 85 or 140 d of pregnancy followed by realimentation to rec-ommended protein and energy levels (RCC and RRC, respectively). Fetal infraspinatus (INF) morphomet-ries and gene expression analyses were performed at d 85, 140, and 254 of gestation. Results demonstrate that fetal primary myofibers are larger (P < 0.05) after 85 d of maternal caloric restriction by comparison to controls. Realimentation of pregnant dams at d 85 causes an increase (P < 0.05) in RCC INF cross-sec-tional area (CSA) by comparison to RRC at d 140 but the fibers remain smaller (P < 0.05) than CCC muscle cells. Returning nutrient load to recommended levels at d 140 of pregnancy increases RRC CSA equivalent to CCC fibers at d 254 (343.4 ± 5.2 and 345.2 ± 5.3 μm², respectively). Fetal RRC and CCC muscle fibers are smaller {P < 0.05) than RCC fibers at d 254 suggesting the later experienced compensatory growth. Numbers of Paired box 7 (Pax7) immunopositive cells were few-er (P < 0.05) in the nutrient restricted fetuses at d 85 suggesting a loss of muscle progenitor cells. Moreover, mRNA content for the collagen crosslinking enzymes, lysyl oxidase and bone morphogenetic protein 1, were greater (P < 0.05) in the d 85 nutrient restricted fetal INF than CCC suggesting increased connective tissue cell numbers and/or activity. Because myogenesis is acutely regulated by the IGF, mRNA content of these growth factors and their receptors was examined. Fetal 1GFI mRNA content was lower in the d 85 nutrient restriction fetuses (P < 0.05) by comparison to CCC. Levels of INF IGF2 mRNA were greater (P < 0.05) in d 85 NR fetuses than CCC. Continued nutrient restric-tion through d 140 resulted in a reduction (P < 0.05) in IGF2 expression by comparison to CCC. No treatment effect on IGF1R or IGF2R mRNA content was noted. In summary, NR for 85 d causes an increase in primary INF fiber size that may be a result of increased IGF2 transcription and Pax7-immunopositive cell fusion. Realimentation of NR beef cows supports compensa-tory growth of the fetal musculature such that normal muscle fiber size and muscle progenitor numbers are achieved before birth. [ABSTRACT FROM AUTHOR]

Studies of hybrid zones can inform our understanding of reproductive isolation and speciation. Two species of brown lemur ( Eulemur rufifrons and E. cinereiceps) form an apparently stable hybrid zone in the Andringitra region of south-eastern Madagascar. The aim of this study was to identify factors that contribute to this stability. We sampled animals at 11 sites along a 90-km transect through the hybrid zone and examined variation in 26 microsatellites, the D-loop region of mitochondrial DNA, six pelage and nine morphological traits; we also included samples collected in more distant allopatric sites. Clines in these traits were noncoincident, and there was no increase in either inbreeding coefficients or linkage disequilibrium at the centre of the zone. These results could suggest that the hybrid zone is maintained by weak selection against hybrids, conforming to either the tension zone or geographical selection-gradient model. However, a closer examination of clines in pelage and microsatellites indicates that these clines are not sigmoid or stepped in shape but instead plateau at their centre. Sites within the hybrid zone also occur in a distinct habitat, characterized by greater seasonality in precipitation and lower seasonality in temperature. Together, these findings suggest that the hybrid zone may follow the bounded superiority model, with exogenous selection favouring hybrids within the transitional zone. These findings are noteworthy, as examples supporting the bounded superiority model are rare and may indicate a process of ecologically driven speciation without geographical isolation. [ABSTRACT FROM AUTHOR]

Heat stress during the dry period negatively affects hepatic metabolism and cellular immune function during the transition period, and milk production in the subsequent lactation. However, the cellular mechanisms involved in the depressed mammary gland function remain unknown. The objective of the present study was to determine the effect of heat stress during the dry period on various indices of mammary gland development of multiparous cows. Cows were dried off approximately 46 d before expected calving and randomly assigned to 2 treatments, heat stress (HT, n = 15) or cooling (CL, n = 14), based on mature equivalent milk production. Cows in the CL treatment were provided with sprinklers and fans that came on when ambient temperatures reached 21.1°C, whereas HT cows were housed in the same barn without fans and sprinklers. After parturition, all cows were housed in a freestall barn with cooling. Rectal temperatures were measured twice daily (0730 and 1430 h) and respiration rates recorded at 1500 h on a Monday-Wednesday-Friday schedule from dry off to calving. Milk yield and composition were recorded daily up to 280 d in milk. Daily dry matter intake was measured from dry off to 42 d relative to calving. Mammary biopsies were collected at dry off, -20, 2, and 20 d relative to calving from a subset of cows (HT, n = 7; CL, n = 7). Labeling with Ki67 antigen and terminal deoxynucleotidyl transferase deoxyuridine triphosphate nick-end labeling were used to evaluate mammary cell proliferation and apoptosis, respectively. The average temperature-humidity index during the dry period was 76.6 and not different between treatments. Heat-stressed cows had higher rectal temperatures in the morning (38.8 vs. 38.6°C) and afternoon (39.4 vs. 39.0°C), greater respiration rates (78.4 vs. 45.6 breath/min), and decreased dry matter intake (8.9 vs. 10.6 kg/d) when dry compared with CL cows. Relative to HT cows, CL cows had greater milk production (28.9 vs. 33.9 kg/d), lower milk protein concentration (3.01 vs. 2.87%), and tended to have lower somatic cell score (3.35 vs. 2.94) through 280 d in milk. Heat stress during the dry period decreased mammary cell proliferation rate (1.0 vs. 3.3%) at -20 d relative to calving compared with CL cows. Mammary cell apoptosis was not affected by prepartum heat stress. We conclude that heat stress during the dry period compromises mammary gland development before parturition, which decreases milk yield in the next lactation. [ABSTRACT FROM AUTHOR]

Satellite cells are a heterogeneous population of myogenic precursors responsible for muscle growth and repair in mammals. The objectives of the experiment were to examine the growth rates and degree of heterogeneity within bovine satellite cells (BSC) isolated from young and adult animals. The BSC were harvested from the semimembranosus of young (4.3 ± 0.5 d) and adult (estimated 24 to 27 mo) cattle and cultured en masse. Young animal BSC re-enter the cell cycle sooner and reach maximal 5-ethynyl-2′-deoxyuridine (EdU) incorporation earlier (P < 0.05) than adult contemporaries. Adult BSC contain fewer (P < 0.05) MyoD and myogenin immunopositive nuclei than BSC isolated from young animals after 3, 4, and 5 d in culture. These results indicate that BSC from young animals activate, proliferate, and differentiate sooner than isolates from adult animals. Lineage heterogeneity within BSC was examined using anti-bodies specific for Pax7 and Myf5, lineage markers of satellite cells, and myoblasts. Immunocytochemistry revealed the majority of Pax7-expressing BSC also express Myf5; a minor population (~5%) fails to exhibit Myf5 immunoreactivity. The percentage of Pax7:Myf5 BSC from young animals decreases sooner (P < 0.05) in culture than adult BSC, indicating a more rapid rate of muscle fiber formation. A subpopulation immunopositive for Myf5 only was identified in both ages of BSC isolates. The growth kinetics and heterogeneity of young BSC was further evaluated by clonal analysis. Single cell clones were established and analyzed after 10 d. Colonies segregated into 2 groups based upon population doubling time. Immunostaining of the slow-growing colonies (population doubling time ≥ 3 d) revealed that a portion exhibited asymmetric distribution of the lineage markers Pax7 and Myf5, similar to self-renewable mouse muscle stem cells. In summary, these results offer insight into the heterogeneity of BSC and provide evidence for subtle differences between rodent and bovine myogenic precursors. [ABSTRACT FROM AUTHOR]

Structural, microstructural and petrological data have enabled determination of the mechanical and geochemical processes involved in dynamic weakening and fabric transposition along the margins of a granulite nappe [the Parry Sound domain (PSD)] during transport to mid-crustal levels of the Grenville Orogen. The data establish a genetic link between outcrop-scale structures in the southern PSD and the development of the underlying Twelve Mile Bay shear zone (TMBSZ). Following granulite facies metamorphism (∼11 kbar/∼850 °C) in the southern PSD, the emplacement of pegmatite dykes resulted in hydration reactions within adjacent wall rocks and the development of thin (<1 m) amphibolite facies (∼6.5 kbar/∼700 °C) shear zones. The shear zones exhibit bulk HO and KO enrichment and oxygen isotope values similar to the adjacent pegmatites, suggesting metasomatic alteration by pegmatite-derived fluids. Phase-equilibrium models indicate that the destabilization of the pre-existing pyroxene and garnet-bearing assemblages, as observed within discrete shear zones in the southern PSD and the TMBSZ, requires HO-saturated conditions at these (amphibolite facies) P-T conditions. The spacing between discrete shear zones and the depth of hydration into the adjacent wall rock are of comparable length-scales (∼metres), suggesting that this type of reworking process can be an effective means of hydrating kilometre-scale areas of crust relatively rapidly. Furthermore, considering the well-established effects of hydrous fluids on the creep strength of anhydrous minerals, a fracture-initiated, localized hydration-and-shearing process may be an efficient mechanism for weakening strong, dry rocks (e.g. granulites) in the middle to lower orogenic crust. [ABSTRACT FROM AUTHOR]

Skeletal muscle growth is accomplished chiefly through the actions of satellite cells, a heterogeneous population that includes the adult muscle stem cell. Located adjacent to a mature muscle fiber, satellite cells typically reside in a quiescent state. Little information exists detailing satellite cell regulation of reversible G0. One member of the mitosin family of centromere proteins, LEK 1 (leucine/glutamic acid/ lysine protein 1), is present in the nucleus of nondividing mouse satellite cells. The objective of this study was to evaluate LEK1 as a marker of quiescent bovine satellite cells (BSC) in vitro and in vivo. The BSC were isolated from young bull calves (≤7 d) and cultured in vitro for up to 9 d before fixation and immunostaining for LEK1. Results demonstrated that all myogenic cells contain the protein, with immunostaining primarily within the nucleus and immediate perinuclear region. Immunocytochemical detection of LEK1 in cryosections of mature cows revealed that the protein was present in a fraction of satellite cells and muscle fiber nuclei. Approximately 20% of Pax7-expressing satellite cells contained LEK1. An equivalent percentage of myonuclei, as defined by nuclei within a dystrophin boundary, contained nuclear LEK1. To gain insight into the functional role of LEK1, BSC were transiently transfected with plasmids coding for putative dominant inhibitory LEK1 proteins [ΔLEK1(991) and ΔLEK1(911)] and evaluated for cell proliferation. Both forms of ΔLEK1 inhibited (P < 0.05) BSC proliferation, as indicated by a decrease in Ki67 immunopositive cells. In C2C12 myoblasts, ΔLEK1(911) inhibited (P < 0.05) myoblast determination protein 1 (MyoD)-directed muscle gene transcriptional activity; ΔLEK1(991) had no effect on TnI-Luc transcription. By contrast, both ΔLEK1 fusion proteins inhibited myogenin expression in BSC without disrupting myoblast fusion. These results provide evidence that LEK1 serves to coordinate proliferation and differentiation in myogenic cells. Coupling the immunostaining pattern and functional data, we propose that LEK1 may serve as a useful marker for satellite cells that are preparing to fuse into adjacent fibers as well as an indicator of recently added myonuclei. [ABSTRACT FROM AUTHOR]

Ractopamine-HC1 (RAC) is a 3-adrenergic agonist with variable effects on cattle performance and carcass variables. Cull cows fed RAC (200 mg·head[sup-1]·d[sup-1]) demonstrate an increased size of type I and II muscle fibers that does not translate into a larger ribeye area. The objective of this study was to examine the dose-dependent effects of RAC on cull cow muscle morphometrics. Eighty-eight cull beef cows representing 2 breed types (n = 44 each) were fed 0, 100, 200, and 300 mg·head[sup-1]·d[sup-1] of RAC for the last 28 d of a 54-d feeding period. On d 54, cows were slaughtered, and samples of the LM and semimembranosus muscle (SM) from 16 randomly selected carcasses (n = 4 per treatment) were taken for measurement of 32- adrenergic receptors and type I, IIA, and IIX myosin heavy chain (MyHC) gene expression. Twenty-four hours postmortem, LM, SM, infraspinatus (INF), and vastus lateralis samples from 40 randomly selected carcasses (n = 10 per treatment) were obtained and frozen for immunohistochemical analysis. Muscle fiber cross-sectional area and diameter, MyHC isoform expression, and fiber-associated, nuclei numbers were measured. Ractopamine dosage exhibited differential effects on muscle morphometrics and MyHC gene expression. Muscle fiber cross-sectional area and diameter were increased (P < 0.05) by RAG in INF type I and IIA fibers and SM type IIA fibers. Ractopamine increased (P < 0.05) MyHC type IIX mRNA and tended to increase (P < 0.10) β[sub2]-adrenergic receptors in the SM; a change in mRNA abundance was not detected for either gene in the LM. Treatment with RAG decreased (P < 0.05) fiber-associated nuclei numbers in the INF, vastus lateralis, and LM but did not affect (P> 0.05) MyHG or β-adrenergic receptor expression. These results indicate that cull cow feeding programs may consider supplementing RAG as a means of adding value to cuts within the chuck, such as the INF. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effects of coadministration of ractopamine-HCl (RAC) and trenbolone acetate plus estradiol (TBA) on LM fiber cross-sectional area (CSA), diameter, fiber-associated myonuclei, and satellite cell number. Culled crossbred beef cows (n = 98; 11 ± 1.8 yr old; BCS 4.3 ± 0.03) from a single ranch in south Florida were fed a concentrate diet for 92 d in a 2 x 2, randomized block design. Cows were blocked by BW on arrival into light (initial BW = 369.75 ± 2.68 kg and end BW = 501.96 ± 6.90 kg) and heavy (initial BW = 418.31 ± 2.75 kg and end BW = 522.15 ± 7.09 kg) groups before assignment to treatment. Factors included dietary treatment (0 or 15 ppm) and implant status (0 or 80 mg of trenbolone acetate + 16 mg of estradiol). Ractopamine was provided in the diet to 2 pens or half the treatments during the final 35 d of feeding. Cows were slaughtered on d 92. Forty-eight hours postmortem, the 6th-rib portions of the LM were obtained from 10 randomly selected carcasses from each treatment group (n = 40). Cryosections (12 μm) were immunostained for dystrophin and myosin heavy chain I or II for the measurement of fiber CSA and type, respectively. Fiber-associated nuclei and satellite cell numbers were measured in serial cryosections. There was a RAC x TBA interaction (P < 0.05). Type I fiber CSA and diameter were increased (P < 0.05) by TBA and RAC. Type I CSA and diameter were larger (P < 0.05) in TBA + RAC than RAC only. Type II fiber CSA and diameter were not affected by TBA (P = 0.48), RAC (P = 0.15), or TBA + RAC (P = 0.60). Satellite cell numbers and fiber-associated nuclei were not affected (P > 0.05) by implant status or ractopamine supplementation. These results indicate that TBA and RAC preferentially increase the size of type I fibers in cull cows. [ABSTRACT FROM AUTHOR]

The article presents the abstract of the paper "Geographic Distribution, Population Densities and Population Viability Analysis for Propithecus Edwardsi," by F. Ratelolahy, A.E. Dunham, S.E. Johnson and P.C. Wright, to be presented at the 21st Congress of the International Primatological Society in Entebbe, Uganda from June 25-30, 2006.

Establishment and maintenance of a successful pregnancy requires signaling from the embryo to the mare, a process known as maternal recognition. Six days after fertilization the trophectoderm (TE), the placental precursor, forms. Signals emanating from the TE to the uterine environment are critical to maternal recognition of pregnancy. The identity of factors necessary for this process remain unknown. A novel equine induced trophoblast cell line (iTr) was created that closely mimics the genotype and phenotype of native equine TE. Transcriptome analysis of iTr revealed expression of growth factor (GF) receptors for Epidermal GF (EGF),Hepatocyte GF (HGF), Fibroblast GF-2 (FGF-2), IGF-1, and IGF-2, suggesting these GF may be important targets during TE development in the early embryo. We hypothesized that treatment of iTr cells with these GF would induce changes in cell proliferation and expression of genes likely involved in maternal recognition. The objectives of this experiment were to evaluate the effect of these GFs on iTr mitotic response and regulation of genes involved in steroidogenesis. Equine iTr cells (n = 3) were cultured with 10 ng/mL EGF, HGF, FGF-2, IGF-1 or IGF-2 for 24 hr with 5-ethynyl-2'-deoxyuridine (EdU) supplementation during the final 2 hr. Subsequently, cells were fixed and EdU positive and total nuclei were enumerated. A parallel plate of iTr cells was treated in a similar manner and lysed for total RNA isolation. Quantitative PCR using gene-specific primers for CYP11A1, PTGS2, PTGES2, and PTGES3 was performed. Data were analyzed by ANOVA with Tukey's post hoc adjustment using the GLM procedure of SAS. Treatment with EGF, FGF-2, HGF, and IGF-1 increased (P < 0.05) iTr proliferation from control levels of 25.33 ± 1.029% to 38.58 ± 1.605, 45.50 ± 2.937, 38.23 ± 2.007, and 35.38 ± 2.753, respectively. The 2-ΔΔCT method was used to calculate the fold change (FC) using GAPDH as the reference gene for normalization. Expression of CYP11A2, PTGES2, and PTGES3 was not affected by GF, as measured by qPCR. By contrast, PTGS2 transcript abundance increased (P < 0.05) following FGF-2 (FC = 3.327 ± 0.8291) and HGF (FC = 11.88 ± 4.572) treatment. These results indicate that FGF-2 and HGF may simultaneously induce proliferation and prostaglandin production by TE cells. The combined results of these experiments will improve our understanding of TE morphogenesis and its response to uterine-derived growth factors. [ABSTRACT FROM AUTHOR]

To evaluate the impact of energy restriction on embryonic survival in Bos taurus and Bos indicus genotypes, a reciprocal embryo transfer approach was used in a completely randomized design with a 2 × 2 × 2 factorial arrangement of treatments. Recipient cows were assigned randomly to 1) a diet to meet daily maintenance requirements (MAINT), or 2) restricted intake of nutrients to 70% of energy maintenance requirements (RESTR). Angus (AN) and Brangus (BN) embryo donors were superovulated and artificially inseminated with female sexed-sorted semen from the same breed. Embryos were then randomly transferred 7 d post-insemination (d 7) to either AN or BN recipients fed the respective diets for 20 d to create 8 treatment combinations (AN × AN × RESTR, n =14; AN × AN × MAINT, n = 19; AN × BN × RESTR, n = 16; AN × BN × MAINT, n = 17; BN × BN × RESTR, n = 15; BN × BN × MAINT, n = 19; BN × AN × RESTR, n = 14, BN × AN × MAINT, n = 19). Recipients remained on the dietary scheme until d 91. All cows were then submitted to the same feeding regime until calving. Pregnancy diagnosis was performed at d 28 and 91. Embryo loss was defined as a cow that received an embryo but was diagnosed as nonpregnant. There was an effect of diet (P < 0.001) and day (P < 0.001) on recipient BW. Similarly, diet altered recipient BCS (diet × day, P = 0.005). There was a recipient breed × diet interaction on embryo loss at d 28 (P < 0.001), where AN × RESTR recipients had greater embryo loss than AN × MAINT (69.0 vs 28.2%, respectively), and BN × RESTR (69.0 vs 27.9%, respectively). There was also an embryo breed × diet interaction (P < 0.021) on embryo loss by d 28, with RESTR recipients that received an AN embryo experiencing greater embryo loss than RESTR recipients receiving BN embryos (64.3 vs 31.9%, respectively). At d 91, AN × RESTR recipients had greater (recipient breed × diet, P < 0.001) embryo loss than AN × MAINT (78.4 vs 41.9%, respectively) and BR × RESTR (78.4 vs 41.0%, respectively). These results indicate that Bos taurus cattle may be more susceptible to embryonic loss than Bos indicus when submitted to a feed restriction scheme during the first trimester of gestation. [ABSTRACT FROM AUTHOR]

To evaluate maternal and fetal system influence on early embryonic and fetal development in Bos indicus and Bos taurus cattle, a reciprocal embryo transfer approach was used in a completely randomized design with a 2 × 2 × 2 factorial arrangement of treatments in order to generate 55 pregnancies over 2 consecutive years (n = 55). Recipient cows were placed into the University of Florida Feed Efficiency Facility, containing a GrowSafe feed intake monitoring system, and were randomly assigned to 1) a diet to meet daily maintenance requirements (MAINT) or 2) a diet that restricts intake of nutrients to 70% of energy maintenance requirements (RESTR). Angus (AN) and Brangus (BN) embryo donors were superovulated and artificially inseminated with female sexed-sorted semen from the same breed. Embryos were then randomly transferred 7 d after insemination (d 7) to either AN or BN recipients fed the respective diets for 20 d. Recipients remained on the dietary scheme until d 91, at which time cows were commingled and fed a common diet that met their energy and protein requirements to the same feeding regime until calving. Transrectal ultrasonography was performed to assess fetal crown to rump length (CRL) weekly from d 42 to 91. Blood samples were collected weekly from d 28 to 91 to determine plasma concentrations of pregnancy-specific protein B (PSPB). All analyses were performed using the MIXED procedure of SAS. There was an effect of diet (P < 0.001) and day (P < 0.001) on recipient BW, with RESTR recipients having lower BW than MAINT. Similarly, diet altered recipient BCS from d 70 to 91 (diet × day, P = 0.005). Embryos from BN donors transferred to recipients fed the RESTR diet resulted in a greater (embryo breed × diet, P < 0.001) plasma concentrations of PSPB. Although no effects of embryo breed (P > 0.05) or diet (P > 0.05) were observed on fetal morphometries, fetuses from AN recipients had greater CRL on d 91 (breed × day, P = 0.021) when compared with BN recipients (167.7 ± 1.8 vs. 160.7 ± 1.6 mm, respectively). No effect of recipient breed, embryo breed, or diet was detected on gestation length (P > 0.05) or birth weight of the offspring (P > 0.05). In conclusion, Bos indicus genotype was a significant factor altering concentrations of PSPB during early gestation, whereas Bos taurus recipient genotype positively impacted early fetal growth. [ABSTRACT FROM AUTHOR]

Information about the Growth and Development Symposium titled "Understanding and Mitigating the Impacts of Inflammation on Animal Growth and Development" held July 10-14, 2011 at the Joint Annual Meeting of the American Society of Animal Science and the American Dairy Science Association in New Orleans, Louisiana is presented. Topics include inflammation process, loss prevention, and animal survival. It featured several animal scientists including Theo Niewold, Clint Krehbiel, and Kirk Klasing.

Following hatching, bovine and ovine conceptuses undergo a phase of massive development and remodelling that causes elongation and filamentation. Proper trophoblast cell development and interaction with the uterus is critical for the establishment and maintenance of pregnancy. Various growth factors, including several fibroblast growth factors (FGFs), are produced by the uterus, and at least two of these, FGF2 and FGF10, are released into uterus lumen during early pregnancy. Microarray analysis found that gene products associated with migration and invasion were altered in bovine blastocysts exposed to FGF2 or 10. The objective of this work was to determine if FGF2 and FGF10 impact bovine and ovine trophoblast cell migration. The ability of FGF2 and FGF10 to influence migratory ability of trophoblast cells was examined by using an in vitrotranswell migration assay. The bovine trophoblast line, CT1, was used in the first study. After serum starvation, CT1 cells were seeded on the top of each transwell membrane (50000/transwell) in the presence of vehicle, 0.5, 5, or 50ngmL-1bovine recombinant FGF2 or human recombinant FGF10. After 12h, the transwell was fixed and stained with Hoechst 33342 (0.5μgmL-1). Migrated cells were counted on five non-overlapping areas of each filter using epifluorescence microscopy. Supplementation with 0.5ngmL-1FGF2 increased the number of migrated CT1 cells when compared with controls (268.3±58.3 v.167.3±47.7; P<0.01). Supplementation with 5 or 50ngmL-1FGF2 further increased the number of migrated CT1 cells (297.0±51.4 and 429.4±98.3, respectively; P<0.001). Adding 0.5ngmL-1FGF10 did not affect CT1 migration but providing 5 or 50ngmL-1FGF10 increased CT1 migration (399.8±29.7 and 392.7±58.6 v.194.2±40.3 for controls; P<0.005). A subsequent study utilised the ovine trophoblast line, oTR1 in the migration assay (30000 cells/transwell; 8h migration assay). Adding 0.5ngmL-1FGF2 or FGF10 did not affect oTR1 migration number but exposure to holdout 5 or 50ngmL-1FGF2 or FGF10 increased oTR1 migrated cell numbers v.controls (P<0.05). In a subsequent study, p38 mitogen-activated protein kinase (MAPK), ERK1/2 and JNK signalling cascades utilised by FGF2 and FGF10 in oTR1 cells were investigated. Western blot analysis indicated that both FGF2 and FGF10 induced ERK1/2 and p38 MAPK phosphorylation status. Interestingly FGF10 activated JNK but not p38 MAPK. Taken together, FGF2 and FGF10 stimulate trophoblast cell migration. This response could be mediated by an ERK1/2- or p38 MAPK-dependent system. This project was supported by NRICGP number 2008-35203-19106 from the USDA-NIFA. [ABSTRACT FROM AUTHOR]

The bioavailability and desorption characteristics of nonextractablesoil-aged atrazine were investigated to examine the significance of this potentially large contaminant fraction in agricultural soils. Radiolabeled atrazine-applied soil was aged for 3 months and then extracted by one of three methods-methanol-water (4:1) at 75 deg. C, acetone, and artificial soil water-representing a range of extraction efficiencies. Viable microcosms were constructed with the dried, extracted soil to compare rates and extents of microbially facilitated release and mineralization with desorption rates in sterile microcosms. Themost rigorously extracted soil exhibited slow desorption over a 90-dperiod, but the other soil treatments showed continued slow sorptionafter reaching an initial maximum desorption concentration within 1 to 5 d. No microbially facilitated release of the nonextractable atrazine was detected for any of the treatments. Rates of ring-and chain-labeled atrazine mineralization declined with decreasing extractability of the soil-associated atrazine fraction. However, the extent of biodegradation (less than 2% of the total atrazine for all extracted soil treatments) was less than the extent of abiotic desorption. Mass-balance calculations suggest that all biodegradation occurred in the dissolved phase. [ABSTRACT FROM AUTHOR]