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71.
The Republic of Kiribati is a small, highly infertile Pacific Island nation and is one of the most challenging locations to attempt to support dense urban populations. Kiribati, like other nations in the Pacific, faces an urban future where food insecurity, unemployment, waste management and malnutrition will become increasing issues. Homegardening is suggested as one way to address many of these problems. However, the most recent study on agriculture production in urban centres in Kiribati shows that, in general, intensive cultivation of homegardens is not a common practice. This disparity between theory and practice creates an opportunity to re‐examine homegardening in Kiribati and, more broadly, in the Pacific. This paper examines the practice of homegardening in urban centres in Kiribati and explores reasons why change has or has not occurred through interviews with homegardeners and government/donor representatives. Results show that homegardening has increased significantly in the past five years, largely because of the promotion of homegardens and organic composting systems by donor organisations. While findings further endorse homegardening as an excellent theoretical solution to many of the problems that confront urban settlements in Kiribati and the Pacific, it raises additional questions regarding the continuation of homegarden schemes beyond donor support programmes.  相似文献   
72.
Log-linear methodology was used to examine relations among caprine arthritis-encephalitis virus (CAEV) seroreactivity and host/management factors in a cross-sectional study of 2,826 goats on 13 California dairies. The CAEV serologic status was associated with age and feeding method (pasteurized/unpasteurized milk), but not with breed. Data from a prevalence survey of 321 goats from 2 additional dairies demonstrated very good fit of the selected log-linear model (P = 1.00), indicating that the model was very appropriate to describe the relations. Odds of seropositivity and odds ratios were generated by use of a logit model derived from the log-linear model. Goats raised by the unpasteurized feeding method were estimated to have been 3.3 times more likely to be CAEV-seropositive than goats fed by the pasteurized method, when adjusted for the effects of age. Goats aged 2, 3, 4, and 5 or greater years were estimated to have been 1.7, 2.6, 4.5, and 5.7 times, respectively, more likely to be CAEV-seropositive than were yearling goats when ratios were adjusted for pasteurization status. Breed, gender, and herd of origin were not associated with CAEV seroreactivity when the effects of other factors were considered. Estimated odds of CAEV seroreactivity and the associated odds ratios for combinations of factor levels are reported. In this study, the magnitude and direction of the associations among CAEV serologic status, age, and pasteurized feeding methods were demonstrated.  相似文献   
73.
Extracellular polysaccharide from Tremella aurantialba (TEP) significantly inhibited H2O2-induced haemolysis of RBCs, significantly decreased the amount of malondialdehyde (MDA) produced in mice liver homogenates as a result of autoxidation, and inhibited VitC-Fe2 -induced swelling of liver mitochondria.  相似文献   
74.
Comparisons were made of dry matter production and forage quality of two coolseason grasses, Canada wildrye (Elymus canadensis L.), Virginia wildrye (Elymus virginicus L.), and two warm-season grasses, green panic (Panicum maximum var.trichoglume Eyles) and plains bristlegrass (Setaria leucopila Scribn. & Merr.), planted under and outside the canopies of mature honey mesquite (Prosopis glandulosa Torr. var.glandulosa). Green panic gave the greatest cumulative dry matter yield in both canopy (5120 kg ha–1) and open (3370 kg ha–1) locations, followed by plains bristlegrass under mesquite (1130 kg ha–1) and in the open (570 kg ha–1). One-time yields from Canada wildrye and Virginia wildrye, under and outside mesquite canopy, were 247 and 329 kg ha–1, and 272 and 268 kg ha–1, respectively. Dry matter production of green panic (p=0.001) and plains bristlegrass (p=0.026) was greater under mesquite only for the first of four harvests, although both warm-season grasses exhibited a trend for greater production under mesquite than in the open. Average nitrogen content of green panic was greater (p=0.0004) under mesquite than in the open, while plains bristlegrass exhibited a trend for greater crude protein content in the open than under mesquite. Overall, moisture content of the warm-season grasses was greater (p=0.0001) under mesquite than in the open, while Virginia wildrye was more (p=0.002) succulent under mesquite than in the open. Averagein-vitro dry matter digestibility of warm-season grasses was almost significantly greater (p=0.0501) in the open than under mesquite. Canopy soils contained significantly more organic C (p=0.0004) and total N (p=0.0001) than open soils, with differences of 8.3 Mg organic C ha–1 and 1.3 Mg total N ha–1. Correlations indicated that soil fertility was more limiting to grass production than light intensity.  相似文献   
75.
Seventeen adult and cyclic Moxoto goats were synchronized using 60 mg MPA vaginal sponge for 11 days and 50 μg cloprostenol, 48 h before sponge removal, and superovulated with 120 mg pFSH i.m. in decreasing doses at 12 h intervals for three consecutive days. In seven goats, 0.2 IU/kg BW/day of long acting insulin was subcutaneously injected at same time as pFSH, and in the other five goats, the same dose of insulin was injected for three consecutive days starting 24 h after mating. Finally, five goats were supplemented with an oral dose of 80 ml/goat/day of propylene glycol continuously during the experiment. The animals were flushed at 7 days after mating and the embryos were classified based on International Embryo Transfer Society criteria. Blood samples were collected every 3 days for insulin assay. Administration of insulin raised the insulin levels of the goats (p < 0.05), whereas in the group treated with propylene glycol, insulin rate was different only between FSH treatment and after mating (p < 0.05). Similar rates of recovery for total (80.05 ± 9.78%) or transferable structures (61.03 ± 15.13%) were obtained. Treatment was not influenced (p > 0.05) by responsiveness to superovulation, which averaged 64%. By contrast, insulin treatments were shown to increase the number of embryos considered excellent with respect to goats supplemented with propylene glycol (p < 0.05). When insulin was given before mating, a strong relationship (r = 0. 90) (p < 0.05) between number of transferable embryo and ovulations was observed in the animals. In conclusion, superovulated goats treated with low doses of exogenous insulin resulted in an enhancement in embryo quality, which was related to changes in circulating insulin concentrations.  相似文献   
76.
The objective of this study was to find out the impact of L‐carnitine (10 mM) on developmental regulation of preimplantation sheep embryos cultured in vitro when supplemented in maturation medium and post‐fertilization medium separately. Subsequent objective was to observe the L‐carnitine‐mediated alteration in expression of apoptotic genes (Bcl2, Bax, Casp3 and PCNA) in sheep oocytes and developing embryos produced in vitro. Oocytes matured with L‐carnitine showed significantly (p < .05) higher cleavage (67.23% vs 43.12%), morula (47.65% vs 28.58%) and blastocysts (32.12% vs 13.24%) percentage as compared to presumptive zygotes cultured with L‐carnitine during post‐fertilization period. So it is suggested to use L‐carnitine during maturation than post‐fertilization period. Antiapoptotic and proliferative effects of L‐carnitine were confirmed by inducing culture medium with actinomycin D (apoptotic agent) and TNFα (antiproliferative agent), respectively, with and without L‐carnitine. Oocytes and embryos cultured with actinomycin D and TNFα showed developmental arrest with significant (p < .05) decrease in morula and blastocysts percentage but s upplementation of L‐carnitine to actinomycin D and TNFα induced culture medium showed similar result as that of control . L‐carnitine supplementation during IVM significantly (p < .05) upregulated the expression of Bcl2 and PCNA genes in majority of the developmental stages. Although L‐carnitine upregulated the expression of Bax in initial developmental stages but downregulated at latter part, whereas the expression of Casp3 was upregulated upto 16‐cell stage but after that there was no difference in expression. Expression of GAPDH gene was not affected by L‐carnitine supplementation. In conclusion, L‐carnitine acted as an antiapoptotic and proliferative compound during embryo development and supplementation of L‐carnitine during IVM altered the expression of apoptotic genes in the developmental stages of embryos.  相似文献   
77.
The coupled electronic and vibrational motions governing chemical processes are best viewed from the molecule's point of view-the molecular frame. Measurements made in the laboratory frame often conceal information because of the random orientations the molecule can take. We used a combination of time-resolved photoelectron spectroscopy, multidimensional coincidence imaging spectroscopy, and ab initio computation to trace a complete reactant-to-product pathway-the photodissociation of the nitric oxide dimer-from the molecule's point of view, on the femtosecond time scale. This method revealed an elusive photochemical process involving intermediate electronic configurations.  相似文献   
78.
The effects of lactation on the fertility of dairy cows   总被引:1,自引:0,他引:1  
Lactation has been negatively associated with fertility because pregnancy rates in maiden heifers exceed those obtained after first or subsequent calvings. The extent of this difference is less in pasture-fed dairy cows (<10%) than in American Holsteins (>20%) fed grain and conserved forages. The latter cows have pregnancy rates to first insemination and oestrus detection rates of only 40 to 45%. This suggests that the subsequent fertility of inherently fertile Holstein heifers may be severely compromised by high levels of milk production. International comparisons show that pasture-fed dairy cows may experience extended periods of anovulatory anoestrum but have normal fertility (60% pregnancy rate to first insemination) once cycling. The high-producing American Holstein may ovulate within 4 weeks postpartum but is more likely to continue ovulating without being detected in oestrus. Both situations are associated with negative energy balances (NEB) during early lactation. The severity and duration of this NEB may vary with body condition at calving, age or parity, ration formulation, production level and environmental factors. Relative daily milk yield is not an absolute indicator of NEB, because some lower producing cows within a herd have lower feed intakes and more severe energy deficits. NEB is not simple to measure; nonetheless, it is correlated with genetic improvement for milk yield. A positive energy balance, greater weight gain and higher body condition score have all been shown to be positively correlated with plasma progesterone concentrations in early lactation. No studies have investigated the possibility that the rapid increase in metabolic rate at this time may also alter steroid concentrations with consequent effects on oestrous behaviour and fertility. Studies to more precisely define the effects of increasing milk yields in early lactation, especially in Holsteins, may need to be completed in Australia and New Zealand. Oestrus detection rates and pregnancy rates for American Holsteins of less than 50% are accepted widely in the USA. Such low detection rates confound studies on fertility. The objective should be to increase these 2 rates to at least 80% and 60% respectively. This may involve the use of controlled breeding, especially if oestrous behaviour is less overt in high-producing Holstein cows.  相似文献   
79.
80.
Objective To measure acute pain in sheep, based on a human pain model, and examined changes in both electroencephalogram frequency spectrum and behavioural responses to increased electrical stimulation in sheep. Design Analysis of variance (treatment and animal effects) for stimulus intensity where each animal received each electric shock treatment given in the order 0, 5,10 and 20 mA. Procedure Eight sheep with electrodes implanted over the surface of the brain were examined for escape-avoidance and electroencephalogram responses to four levels of electrical stimulation from 0–20 mA. Results With increasing stimulus intensity at the time of feeding, the sheep were more hesitant to return to the feeder or remain near the feeder following stimulation. There was little difference between the 0 and 5 mA stimuli for any of the behaviour variables (P > 0.05). However, there were marked increases in the time taken to re-approach the feeder after receiving an electric shock of 5 mA and of 20 mA (P < 0.05; mean values 3 and 119 s, respectively) and remaining near the feeder for 5 s (P < 0.001; mean values 10 and 167 s, respectively). Following the stimulus, there was an overall increase in the electroencephalogram power spectrum in the first four seconds, which then rapidly returned to normal. In particular, the 20 mA stimulus resulted in higher absolute power values than in the control (0 mA) treatment for delta 2 (P < 0.001), theta 1 (P < 0.05), theta 2 (P < 0.05), alpha 1 (P < 0.001), alpha 2 (P < 0.001) and beta 1 (P < 0.01) band-widths. Similarly, for the 10 mA stimulus, the absolute power values were greater than the control treatment for delta 2 (P < 0.05), alpha 1 (P < 0.01), alpha 2 (P < 0.001) and beta 1 (P < 0.01) bandwidths. Conclusion The experiment suggests that a human acute pain model is applicable to sheep and that these electroencephalogram changes may provide a good measure of acute pain in sheep.  相似文献   
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