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991.
Although the woodpeckers have long been recognized as a natural, monophyletic taxon, morphological analyses of their intra- and intergeneric relationships have produced conflicting results. To clarify this issue, and as part of a larger study of piciform relationships, nucleotide sequences for the 12S ribosomal RNA (12S; 1123 bp), cytochrome b (Cyt b; 1022 bp), and cytochrome oxidase c subunit 1 (COI; 1512 bp) mitochondrial genes were obtained from 34 piciform species that included 16 of the 23 currently recognized woodpecker genera (subfamily Picinae), three piculets (subfamily Picumninae), a wryneck (subfamily Jynginae), a honeyguide (family Indicatoridae), and three barbets (infraorder Ramphastides). Analyses were conducted on the individual and combined 12S, Cyt b, and COI sequences with maximum parsimony, neighbor-joining, maximum likelihood, and Bayesian algorithms. Based on the strong, congruent support among the different data partitions and models of sequence evolution, a highly resolved consensus of the relationships among woodpeckers and their allies could be formed. The monophyly of Indicatoridae + Picidae (infraorder Picides), Picidae, Picinae + Picumninae, and Picinae was strongly supported in all analyses. However, the tribes Colaptini, Picini, Campephilini, and Campetherini were shown to be paraphyletic as were the genera of Colaptes and Piculus. A revision of the tribal-level classification of woodpeckers is proposed and the importance of plumage convergence among woodpeckers is discussed.  相似文献   
992.
Olympic-style lifts (OSL) and plyometric exercises (PE) are frequently combined with traditional resistance training (TRT) to improve athletic performance. The goal of this study was to directly compare the performance effect of TRT (30 minutes) combined with either OSL or nondepth-jump PE (15 minutes) on entry level competitive collegiate athletes. Ten female and 5 male competitive soccer players, divided into 2 groups, completed 12 weeks of tri-weekly training during their off-season. Countermovement vertical jump, 4 repetition maximum squat, 25-m sprint, and figure-8 drill on a 5-dot mat were conducted pre-, mid-, and postintervention. Significant improvements were made by both groups in each performance parameter over the 12-week period (p < 0.05), with no significant differences found between the training groups. Although these training modalities may achieve their results through slightly different mechanisms, the performance-related improvements may not be significantly different for entry-level collegiate athletes with little resistance training experience.  相似文献   
993.
Early post-hatch fasting induces satellite cell self-renewal   总被引:3,自引:0,他引:3  
Early post-hatch satellite cell kinetics are an important aspect of muscle development, and understanding the interplay between fasting and muscle development will lead to improvements in muscle mass following an illness, and optimal meat production. The objective of this experiment was to test the influence of immediate post-hatch fasting on satellite cells in the poult. Male Nicholas poults (Meleagris gallopavo) were placed into two treatments: a fed treatment with immediate access to feed and water upon placement and a fasted treatment without access to feed and water for the first three days post-hatch. 5-bromo-2'-deoxyuridine (BrdU) was injected intra-abdominally in all poults to label mitotically active satellite cells. The pectoralis thoracicus muscle was harvested two hours following the BrdU injection. Immunohistochemistry for BrdU, Pax7, Bcl-2, Pax7 with BrdU, and determining myofiber cross-sectional area along with computer-based image analysis was used to study muscle development. Fed poults had higher body masses throughout the experiment (P< or =0.01), and they had higher pectoralis thoracicus muscle mass (P< or =0.01) at ten days of age than the fasted poults. Fed poults had higher satellite cell mitotic activity at three days and four days of age (P< or =0.01) compared to the fasted poults. However, Pax7 labeling index was higher in the fasted poults (P< or =0.01) at three days, four days, and five days post-hatch than the fed group. Similarly Bcl-2 labeling was higher in the fasted than in the fed group at three days post-hatch. Therefore, fasting depleted proliferating satellite cells indicated by the lower BrdU labeling in the fasted poults compared to the fed poults, and conserved the satellite cell proliferative reserve indicated by the higher level of Pax7 labeling for the fasted poults compared to the fed poults.  相似文献   
994.
He X  Moore C 《Molecular cell》2005,19(5):619-629
Recent studies have found that the phosphatase Glc7 associates with the yeast cleavage/polyadenylation factor (CPF), but the role of Glc7 in 3' end processing has not been investigated. Here, we report that depletion of Glc7 causes shortened poly(A) tails in vivo and accumulation of phosphorylated Pta1, a CPF subunit. Removal of Glc7 also gives extract defective for poly(A) addition but normal for cleavage at the poly(A) site. Polyadenylation is rescued by addition of Glc7 or Pta1, but not by phosphorylated Pta1. Moreover, Ypi1, a Glc7-specific inhibitor, or the Cka1 kinase blocks poly(A) addition in wild-type (wt) extract. Pta1 interacts physically and genetically with Glc7, suggesting that Pta1 may also regulate Glc7 or recruit it to CPF. A weakened association of Fip1 with phosphorylated CPF may explain the specific effect on polyadenylation. These results support a model in which poly(A) synthesis is controlled by cycles of phosphorylation and dephosphorylation that require the action of Glc7.  相似文献   
995.
AIM: To measure the decline rates of zoonotic agents introduced into liquid livestock wastes in on-farm storage tanks. METHODS AND RESULTS: Salmonella spp., Escherichia coli O157, Campylobacter jejuni, Listeria monocytogenes and Cryptosporidium parvum, propagated in laboratory-controlled conditions, were inoculated into 35,000-l volumes of fresh livestock wastes (pig slurries, cattle slurries and dirty waters). D-values for bacteria were six to 44 days, and for C. parvum were 133 to 345 days. Campylobacter jejuni declined significantly more rapidly than the other bacterial pathogens, while E. coli O157 declined significantly more slowly. On average, bacterial declines were not affected by the season of waste deposition and storage or by the dry matter content of the wastes, but were more rapid in dirty waters than in pig slurries. The physiciochemical composition of wastes in each category varied significantly. CONCLUSIONS: Zoonotic agents can survive for several months during storage of liquid livestock wastes. Livestock wastes should be batch-stored and not subjected to continuous additions. SIGNIFICANCE AND IMPACT OF THE STUDY: This study indicates that batches of liquid livestock waste, if contaminated with bacterial pathogens, should be stored for 6 months to reduce contamination levels. Alternative strategies for reducing C. parvum levels in liquid livestock wastes should be explored.  相似文献   
996.
Decline of zoonotic agents in livestock waste and bedding heaps   总被引:1,自引:0,他引:1  
AIMS: To measure the rates of decline of zoonotic agents introduced into heaps of spent bedding and faecal wastes generated by commercially farmed livestock and managed in a similar way to that of a working farm. METHODS AND RESULTS: Livestock isolates of Salmonella, pathogenic Listeria, Campylobacter and Escherichia coli O157 were laboratory cultured and used to inoculate 5 m3 heaps of cattle, sheep or pig wastes mixed with bedding materials. Decline of each of the infectious agents was monitored with time as was the temperature inside each heap. Temperatures of >50 degrees C were typically achieved at the core of the heaps. Pathogen decline was rapid, typically <3 days for a 1-log reduction in levels. The longest time that zoonotic agents were isolated from the heaps was 93 days. CONCLUSIONS: Movement of heaps of livestock bedding waste from animal pens to a secondary store, and storing them under conditions conducive for increased temperature is a simple and cost-effective treatment for rapidly lowering levels of zoonotic agents in solid farm wastes. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates a simple and cheap treatment that can be used to help prevent the spread of zoonotic agents through agricultural environments.  相似文献   
997.
998.
Plasmodium vivax is one of four Plasmodium species that cause human malaria. P. vivax and a related simian malaria parasite, Plasmodium knowlesi, invade erythrocytes by binding the Duffy antigen/receptor for chemokines (DARC) through their respective Duffy binding proteins. Here we show that tyrosines 30 and 41 of DARC are modified by addition of sulphate groups, and that the sulphated tyrosine 41 is essential for association of the Duffy binding proteins of P. vivax (PvDBP) and P. knowlesi (PkDaBP) with DARC-expressing cells. These sulphated tyrosines also participate in the association of DARC with each of its four known chemokine ligands. Alteration of tyrosine 41 to phenylalanine interferes with MCP-1, RANTES and MGSA association with DARC, but not with that of IL8. In contrast, alteration of tyrosine 30 to phenylalanine interferes with the association of IL8 with DARC. A soluble sulphated amino-terminal domain of DARC, but not one modified to phenylalanine at residue 41, can be used to block the association of PvDBP and PkDaBP with red blood cells, with an IC50 of approximately 5 nM. These data are consistent with a role for tyrosine sulphation in the association of many or most chemokines with their receptors, and identify a key molecular determinant of erythrocyte invasion by P. vivax.  相似文献   
999.
Interleukin-10-/- (IL-10) knockout (KO) mice develop an intestinal inflammation that closely mimics human inflammatory bowel disease (IBD) which is accompanied by inflammation-associated bone abnormalities and elevated serum proinflammatory cytokines. The objective of this study was to use the IL-10 KO mouse model to determine whether flaxseed oil (FO) diet, rich in alpha-linolenic acid (ALA), attenuates intestinal inflammation and inflammation-associated bone abnormalities, compared to a corn oil (CO) control diet. Male wild-type (WT) or IL-10 KO mice were fed a 10% CO or 10% FO diet from weaning (postnatal day 28) for 9 weeks. At necropsy, serum, intestine, femurs and lumbar vertebrae were collected and analyzed. IL-10 KO mice fed CO had lower femur bone mineral content (BMC; P<.001), bone mineral density (BMD; P<.001), peak load (P=.033) and lumbar vertebrae BMD (P=.02) compared to WT mice fed either diet. Flaxseed oil had a modest, favorable effect on IL-10 KO mice as femur BMC, BMD and peak load were similar to WT mice fed CO or FO. In addition, lumbar vertebra BMD was similar among IL-10 KO mice fed FO and WT mice fed CO or FO. The fact that FO attenuated serum tumor necrosis factor-alpha (TNF-alpha) among IL-10 KO mice suggests that the positive effects of FO on femur BMC, BMD, peak load and vertebral BMD in IL-10 KO mice may have been partly mediated by changes in serum TNF-alpha. In conclusion, these findings suggest that a dietary level of ALA attainable from a 10% flaxseed oil diet results in modest improvements in some bone outcomes but does not attenuate intestinal inflammation that is characteristic of IL-10 KO mice.  相似文献   
1000.
Increased numbers of swine producers will be removing sludge from their anaerobic waste treatment lagoons in the next few years, due to sludge exceeding designed storage capacity. Information on availability of nitrogen (N) in the sludge is needed to improve application recommendations for crops. The objective of this study was to investigate possible effects of different companies and types of swine operations on the availability of N in sludge from their associated lagoons. A laboratory incubation study was conducted to quantify the availability of N (i.e. initial inorganic N plus the potentially mineralizable organic N) in the sludge. Nine sludge sources from lagoons of sow, nursery and finishing operations of three different swine companies were mixed with a loamy sand soil (200 mg total Kjeldahl N kg(-1) soil) and incubated at a water content of 0.19 g. water g(-1) dry soil and 25+/-2 degrees C for 12 weeks. Samples were taken at eight times over the 12-week period and analyzed for inorganic N (i.e. NH(4)-N and NO(3)-N) to determine mineralization of organic N in the sludge. Company and type of swine operation had no significant effects (P < 0.05) on the pattern of inorganic N accumulation over time. Thus, inorganic N accumulation from all sludge sources was fit to a first order equation [Nt = Ni + No (1-e(-kt)]. This relationship indicated that of the 200 mg of total sludge N added per kg soil, 23.5% was in the form of potentially mineralizable organic N (No) and 17.5% was in the form of inorganic N (Ni). The sum of these two pools (41%) represents an estimate of the proportion of total N in the applied sludge in plant available form after the 12 week incubation. While plant N availability coefficients were not measured in this study, the lack of significant company or type of swine operation effects on sludge N mineralization suggests that use of the same plant N availability coefficient for sludge from different types of lagoons is justifiable. The validity of this interpretation depends on the assumption that variation in other components of different sludge sources such as Cu and Zn does not differentially alter N uptake by the receiver crops.  相似文献   
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