Greater Average Diameter Research Articles

A Comparison of the Physical Properties Between Merino Wool and Camel Hair Through Discriminant Analysis

ABSTRACT The applicability of camel hair is still conditioned by a gap in the knowledge about this raw material, which in turn hinders its supply chain, commercial possibilities, and the value that the product reaches in the market. The present research compares the physical-mechanical properties of Canarian camel hair versus Merino sheep wool, the world’s most popular proteinic fabric material, using a discriminant canonical analysis. The attributes that maximized differences between both types of animal-origin fibers were related to average fiber diameter, fineness, length staple, and residual dirt. Although slightly shorter than sheep wool, camel hair can reach a prominent fabric quality and spinning performance given its greater average diameter and its lower variation within small fragments along the snippet, as well as the higher distance from the tip to the finest point in the staple, which is an indicator for the breaking point. Such characteristics are known to increase bending rigidity during the manufacturing process. Residual dirt may be associated with the low-input, extensive exploitation of camels. The present paper provides a reference for maturing pre-process and manufacture techniques for the further valorization of camel hair in the present-day textile industry and, thus, engages income opportunities for this livestock production.

Reproductive and lactational responses of multiparous dairy cattle to short-term postpartum chromium supplementation during the summer months

The objective of this work was to evaluate the potential benefits of short-duration, high-dose chromium (Cr) supplementation in early postpartum dairy cows during the summer months. Multiparous, early-lactation cows (20.95 ± 0.21 d in milk) were assigned to 1 of 2 treatment groups: (1) control diet (Con; n = 10) or (2) control diet + Cr propionate (CrPro; 12 mg/head per day Cr; n = 12). Measurements of ovarian structures, respiration rates (RR), rectal temperatures (RT), and blood glucose concentrations were recorded every 3 d. Blood was also collected for analysis of plasma progesterone concentrations. Every 6 d, in conjunction with ultrasonography, endometrial cytology samples were collected via cytobrush from each cow to determine the incidences of subclinical endometritis, as determined by polymorphonuclear leukocyte (PMNL)%. No differences were detected in RR, RT, blood glucose, feed intake, milk yield, or change in body weight. The supplementation did, however, improve some reproductive parameters. At cytology sample 6, the PMNL% increased in Con cows, and was greater than the PMNL% in the CrPro group. Chromium consumption did not affect the number or size of most follicles, with the exception being the 6 to 9 mm category where the CrPro group had a greater average diameter and tended to have greater numbers of follicles in this category. While corpus luteum numbers and size did not differ between treatments, the ratio of progesterone to average corpus luteum volume was greater in the CrPro group compared with the Con group. The results from this study indicate that, whereas the short-term, high-dose supplementation strategy did not affect feed intake or milk yield, this Cr supplementation strategy could benefit reproductive performance during periods of stress.

Comparison of the Five Different Methods in Arterial Diameter Measurement

Background/Aims: In this study, the different types of arterial diameter measurement methods were com-pared with each other on rat model. Methods: The study was planned in three phases. In phase 1, all subjects (n = 30) underwent high resolution B-mode ultrasound examination and external diameter of the right com-mon carotid artery (RCCA) was measured. In phase 2, RCCA was explored. In phase 3, rats were put into three groups. Group 1 was kept at -20oC, group 2 was embedded in 4% formaldehyde solution. In group 3, circulatory system was filled with %20 latex solution. In all groups, digital image of the RCCA was taken after the processes mentioned above. Images were assessed by Image – Pro Plus software. Results: The greatest average diameter was observed in the high resolution B-mode ultrasound (phase 1). In group 1 and 2, direct measurement of the RCCA on living animal (phase 2) gave significantly wider diameter than those obtained at phase 3 in the same groups. Direct (phase 2) and latex (phase 3) measurements were equal in group 3. Conclusion: High resolution B-mode ultrasound gives larger, probably actual diameter of the artery. Latex injection results might correspond those encountered during operation.

Sudden Oak Death-Induced Tanoak Mortality in Coast Redwood Forests: Current and Predicted Impacts to Stand Structure

Tanoak (Notholithocarpus densiflorus syn. Lithocarpus densiflorus) is one of the most widespread and abundant associates of coast redwood (Sequoia sempervirens), but little is known about the structural relationships between these two species. Knowledge of such relationships is essential for a thorough understanding of the impacts of sudden oak death (caused by the exotic pathogen Phytophthora ramorum), which is currently decimating tanoak populations throughout the redwood range. In this study, we utilized a stratified plot design and a stand reconstruction technique to assess structural impacts, at present and in the future, of this emerging disease. We found that residual trees in diseased plots were more aggregated than trees in unaffected plots, and we predicted that the loss of tanoak will lead to the following short-term changes: greater average diameter, height, height-to-live-crown, and crown length, as well as an increase in average nearest neighbor differences for diameter, height, and crown length. In addition, plots lacking tanoak (living or dead)—as compared to plots with tanoak—exhibited greater average diameter and increased nearest neighbor differences with regard to diameter, height, and crown length. We also conducted a preliminary exploration of how sudden oak death-induced structural changes compare with typical old-growth characteristics, and how this disease may affect the structure of old-growth forests.

Nine-Year Growth Responses to Planting Density Manipulation and Repeated Early Fertilization in a Loblolly Pine Stand in the Virginia Piedmont

Abstract Achieving maximum stand leaf area early in the rotation can have large positive effects on plantation productivity. Two silvicultural management strategies that can enhance leaf area development are increasing planting density and improving nutrition. A trial was established to determine how these two silvicultural management strategies affect the growth of Pinus taeda L. in the Virginia Piedmont. The study was designed as a factorial with two planting densities (363 and 726 trees ac−1) and three levels of nutrient additions. The three nutrient levels were aimed at maintaining the current site index (SI25) of the stand (55 ft) or improving the SI25 to 70 and 80 ft. None of the treatments affected survival or height during the first 9 years. At age 9, the lower stand density treatment had a greater average diameter (6.03 in.) compared with the high stand density treatment (5.10 in.) averaged across all nutrient levels. The intermediate and high nutrient treatments increased diameter by 0.21 and 0.35 in., respectively, compared with the low nutrient treatment (5.38 in.), when averaged across both stand densities. Intraspecific competition affected diameter growth from age 5, whereas nutrient additions increased growth from age 4.

Características estruturais e físico-químicas de amidos de mandioquinha-salsa (Arracacia xanthorrhiza)

Starch has very important physicochemical properties that depend on its botanical source and structural characteristics. Peruvian carrot starch displays special characteristics, which make it appropriate for industrial application in many processed foods. In this work, starch from two Peruvian carrot varieties, Amarela de Carandai (AC) and Amarela de Senador Amaral (ASA), were isolated and their physicochemical and structural properties were determined. Starch from the ASA variety exhibited granules with a greater average diameter than those from the AC variety and more than double the number of granules with size >20 µm, when compared to the other variety. Starches from both varieties, observed in a Scanning Electron Microscope, showed smooth granule surface with circular and polyhedral shapes for large and small granules, respectively. Molecular size distribution, intrinsic viscosity and degree of cristallinity of starches from both varieties were similar; however, amylose content was higher for the starch from the AC variety. Higher values of viscosity, swelling power and gelatinization temperatures were observed for the starch from the ASA variety, which could be related to the lower amylose content and the higher proportion of large granules exhibited by this starch.

Variation in needle-trace diameter in respect of needle morphology in five conifer species

Needle traces have been used for revealing historical changes in needle longevity of Pinus sylvestris L. and Picea abies (L.) H. Karst. In this paper we compared the needle-trace diameter of five conifer species [Abies sibirica Ledeb., Picea abies, Pinus sylvestris, Pseudotsuga menziesii (Mirb.) Franco and Taxus baccata L.] in respect of needle size. In case of P. sylvestris, we studied how needle-trace diameter varied among different growing sites and among different shoots within a site, and related that variation to needle morphology and structure. Pinus sylvestris had the greatest diameter of needle traces (mean±SD =233±30 μm) followed by T. baccata (141±19 μm) and P. menziesii (121±30 μm). The smallest needle-trace diameter was in A. sibirica (85±21 μm) and P. abies (80±18 μm). Among species, the needle-trace diameter was strongly correlated with needle length (r =0.93, P <0.05). Within P. sylvestris, the needle-trace diameter was significantly affected by location (P <0.001) and varied significantly among shoots within a location (P <0.001). The shoots of P. sylvestris which had greater average diameter of needle traces, tended to have longer (r =0.36, P <0.05), wider (r =0.55, P <0.05) and heavier (r =0.64, P <0.05) needles with greater stomatal density (r =0.55, P <0.05). Although our results do not allow the use of needle-trace diameter to predict properties of needle structure at the present stage, they nevertheless indicate general trends and point to a need for further studies.

The ultrastructural effects of beta-amyloid peptide on cultured PC12 cells: changes in cytoplasmic and intramembranous features.

The fine structural features of cultured PC12 cells were investigated after treatment for 1, 3, or 5 days with different concentrations of the vascular form of beta-amyloid 1-40 (beta-AP). PC12 cells treated with beta-AP showed time- and concentration-dependent lysosomal system activation and cell toxicity. We observed increases in the number and size of cytoplasmic lysosomes as indicated by increased acid phosphatase reactivity. Some lysosomes were in the form of multivesicular bodies or large residual bodies that appeared to arise by autophagia or by endocytotic uptake. Double-sided plasma membrane invaginations were observed to give rise to increasingly extensive intracytoplasmic vacuolization that was correlated with duration of beta-AP treatment. Freeze-fracture studies of the intramembranous particle (IMP) population in the plasma membrane P-face showed that both control and beta-AP treated cells had two major P-face IMP populations, small-diameter (4-8 nm) IMPs, and large-diameter (> or = 9 nm) IMPs. The larger category of IMPs was found to possess a greater average diameter in the beta-AP treated cells than in the control cells. These IMPs could represent modifications to existing transmembranous receptors, channels, or transducing molecules by the beta-AP. These results demonstrate that beta-AP can induce time- and concentration-dependent ultrastructural changes in PC12 cell membranes.

The fate of residual saphenous vein after partial removal or ligation

Duplex scanning was used to study residual greater and lesser saphenous vein segments in 14 limbs with previous partial distal greater saphenous vein removal, 19 limbs with partial proximal greater saphenous vein removal, 29 limbs with total greater saphenous vein removal, 10 limbs with high greater saphenous vein ligation, as well as 37 contralateral unoperated and 8 other normal limbs. Partial distal removal showed better preservation of residual greater saphenous vein than partial proximal removal, with greater preservation of “usable” length and greater average diameter. Compared to contralateral unoperated legs, partial distal removal, partial proximal removal, and total removal all showed a similar degree of compensatory lesser saphenous vein enlargement. High ligation showed no lesser saphenous vein enlargement but showed the best greater saphenous vein preservation, none had less than 85% preservation of potential length. Combining residual greater saphenous vein and lesser saphenous vein segments of usable caliber, 100% of high ligation, 93% of partial distal removal, and 74% of partial proximal removal had >60 cm total length, and most total removal had >40 cm usable residual lesser saphenous vein. Previous saphenous vein surgery should not categorically exclude patients as having no usable residual ipsilateral vein for bypass. Partial distal removal allows better preservation of length and caliber of residual greater saphenous vein than proximal harvest, with both showing equivalent lesser saphenous vein enlargement to those with total greater saphenous vein removal. High ligation, performed for early tributary varicosities, in patients with saphenofemoral but no perforator incompetence, gives excellent preservation of residual greater saphenous vein length and caliber. Sclerotherapy to tributary varicosities did not obliterate distal greater saphenous vein segments.

Effect of Seedling Size and Transplant Bed Density on Performance of Eastern Hemlock Planting Stock

After grading two-year-old Eastern hemlock (Tsuga canadensis (L.) Carr.) seedlings by height, performance was examined for one year under various transplant bed densities, and for 2 years in the field. In the nursery, average diameter growth and dry matter production were influenced by bed density; height growth was not. A transplant bed density of 65 plants/m2 (6/ft2) resulted in the greatest average diameter and dry weight, but densities up to 151 plants/m2 (14/ft2) yielded more usable transplants per unit of nursery bed. Although there were residual effects of transplant bed density, the major differences in growth after 2 growing seasons in the field were due to initial seedling size. Transplants originating from large seedlings outperformed those from small seedlings. Compared to small seedlings, larger plants require less time in transplant beds, are less troublesome to maintain in the field, and reach marketable size in fewer years, all of which increase their value relative to small seedlings.