970 resultados para repeated offences


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Dietary nitrate (NO3−) supplementation with beetroot juice (BR) over 4–6 days has been shown to reduce the O2 cost of submaximal exercise and to improve exercise tolerance. However, it is not known whether shorter (or longer) periods of supplementation have similar (or greater) effects. We therefore investigated the effects of acute and chronic NO3− supplementation on resting blood pressure (BP) and the physiological responses to moderate-intensity exercise and ramp incremental cycle exercise in eight healthy subjects. Following baseline tests, the subjects were assigned in a balanced crossover design to receive BR (0.5 l/day; 5.2 mmol of NO3−/day) and placebo (PL; 0.5 l/day low-calorie juice cordial) treatments. The exercise protocol (two moderate-intensity step tests followed by a ramp test) was repeated 2.5 h following first ingestion (0.5 liter) and after 5 and 15 days of BR and PL. Plasma nitrite concentration (baseline: 454 ± 81 nM) was significantly elevated (+39% at 2.5 h postingestion; +25% at 5 days; +46% at 15 days; P < 0.05) and systolic and diastolic BP (baseline: 127 ± 6 and 72 ± 5 mmHg, respectively) were reduced by ∼4% throughout the BR supplementation period (P < 0.05). Compared with PL, the steady-state V̇o2 during moderate exercise was reduced by ∼4% after 2.5 h and remained similarly reduced after 5 and 15 days of BR (P < 0.05). The ramp test peak power and the work rate at the gas exchange threshold (baseline: 322 ± 67 W and 89 ± 15 W, respectively) were elevated after 15 days of BR (331 ± 68 W and 105 ± 28 W; P < 0.05) but not PL (323 ± 68 W and 84 ± 18 W). These results indicate that dietary NO3− supplementation acutely reduces BP and the O2 cost of submaximal exercise and that these effects are maintained for at least 15 days if supplementation is continued.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

3,5-Diethoxycarbonyl-1,4-dihydrocollidine (DDC) is a porphyrinogenic agent and is a powerful inducer of δ-aminolaevulinate synthetase, the first and rate-limiting enzyme of the haem-biosynthetic pathway, in mouse liver. However, DDC strikingly inhibits mitochondrial as well as microsomal haem synthesis by depressing the activity of ferrochelatase in vivo. The drug on repeated administration to female mice has been found to elicit hypertrophic effects in the liver microsomes initially, but the effects observed at later stages denote either hyperplasia or increase in polyploidal cells. The microsomal protein concentration shows a striking decrease with repeated doses of the drug. The rate of microsomal protein synthesis in vivo as well as in vitro shows an increase with two injections of DDC but decreases considerably with repeated administration of the drug. The activities of NADPH-cytochrome creductase and ribonuclease are not affected in the liver microsomes of drug-treated animals when expressed per mg of microsomal protein. DDC has also been found to cause degradation of microsomal haem, which is primarily responsible for the decrease in cytochrome P-450 content. The drug also leads to a decrease in mitochondrial cytochrome c levels due to inhibition of haem synthesis and also due to degradation of mitochondrial haem at later stages. The biochemical effects of the drug are compared and discussed with those reported for allylisopropylacetamide and phenobarbital.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Chick embryo tRNA, prepared by a simple large-scale method, was fractionated on three different ion-exchange columns. In all cases simple chromatographic patterns for various tRNA species were observed, indicating the presence of only a few major species of tRNA for each amino acid. By repeated chromatography one species of alanine tRNA was purified to approx. 80% purity. T1 ribonuclease digest of this purified tRNA gave a simple chromatographic pattern. Because of the simplicity of the method of preparation of tRNA from this readily available source and the presence of only a few species of tRNA for each amino acid, chick embryo is suited for the study of tRNA and its various functions in higher systems.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Puccinia psidii has long been considered a significant threat to Australian plant industries and ecosystems. In April 2010, P. psidii was detected for the first time in Australia on the central coast of New South Wales (NSW). The fungus spread rapidly along the east coast and in December 2010 was found in Queensland (Qld) followed by Victoria a year later. Puccinia psidii was initially restricted to the southeastern part of Qld but spread as far north as Mossman. In Qld, 48 species of Myrtaceae are considered highly or extremely susceptible to the disease. The impact of P. psidii on individual trees and shrubs has ranged from minor leaf spots, foliage, stem and branch dieback to reduced fecundity. Tree death, as a result of repeated infection, has been recorded for Rhodomyrtus psidioides. Rust infection has also been recorded on flower buds, flowers and fruits of 28 host species. Morphological and molecular characteristics were used to confirm the identification of P. psidii from a range of Myrtaceae in Qld and compared with isolates from NSW and overseas. A reconstructed phylogeny based on the LSU and SSU regions of rDNA did not resolve the familial placement of P. psidii, but indicated that it does not belong to the Pucciniaceae. Uredo rangelii was found to be con-specific with all isolates of P. psidii in morphology, ITS and LSU sequence data, and host range.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Fire is a major driver of ecosystem change and can disproportionately affect the cycling of different nutrients. Thus, a stoichiometric approach to investigate the relationships between nutrient availability and microbial resource use during decomposition is likely to provide insight into the effects of fire on ecosystem functioning. We conducted a field litter bag experiment to investigate the long-term impact of repeated fire on the stoichiometry of leaf litter C, N and P pools, and nutrient-acquiring enzyme activities during decomposition in a wet sclerophyll eucalypt forest in Queensland, Australia. Fire frequency treatments have been maintained since 1972, including burning every two years (2yrB), burning every four years (4yrB) and no burning (NB). C:N ratios in freshly fallen litter were 29-42% higher and C:P ratios were 6-25% lower for 2yrB than NB during decomposition, with correspondingly lower 2yrB N:P ratios (27-32) than for NB (34-49). Trends in litter soluble and microbial N:P ratios were similar to the overall litter N:P ratios across fire treatments. Consistent with these, the ratio of activities for N-acquiring to P-acquiring enzymes in litter was higher for 2yrB than NB while 4yrB was generally intermediate between 2yrB and NB. Decomposition rates of freshly fallen litter were significantly lower for 2yrB (72±2% mass remaining at the end of experiment) than for 4yrB (59±3%) and NB (62±3%), a difference that may be related to effects of N limitation, lower moisture content, and/or litter C quality. Results for older mixed-age litter were similar to those for freshly fallen litter although treatment differences were less pronounced. Overall, these findings show that frequent fire (2yrB) decoupled N and P cycling, as manifested in litter C:N:P stoichiometry and in microbial biomass N:P ratio and enzymatic activities. These data indicate that fire induced a transient shift to N-limited ecosystem conditions during the post-fire recovery phase. This article is protected by copyright. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Irene Runge wrote 14 books so far. This one was written for the occasion of her 63rd birthday - instead of a speech, it was printed and delivered to 63 of her friends. The book is a memoir, and jumps back and forth in time. It consists mostly of personal memories and anecdotes, but there is also an essay-style to it, with very reflective passages and analyses. It is divided into many chapters, which also resemble diary entries. Irene Runge is a member of the "second generation". She was born in the New York exile, but her parents moved back to Germany after the war, during a climate in the USA, which made it very difficult for sympathisers with the communist party. Her memories give rich insight into the life as an emigrant in New York, but also as re-emigrant in Germany. She writes about the their disappointments with the evolving German Democratic Republic (GDR), Eastern Germany, experiences, which repeated again in 1989/1990, when the reunification with West Germany took place. The year 1989 had practical consequences for her private life--she lost her job at the university, because her past seemed not compatible. She discusses the PDS, the party which evolved from the communist party of Eastern Germany, Berlin after the "Wende" (reunification), and life in Berlin after the reunification. At one point she asks whether the current Turkish-Muslim community in Berlin could be comparable to the living conditions of the Jewish community in the 1930. This is a rare memoir documenting many recent aspects of German-speaking Jewry.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The conventional wisdom is that offenders have very high discount rates not only with respect to income and fines but also with respect to time incarcerated. These rates are difficult to measure objectively and the usual approach is to ask subjects hypothetical questions and infer time preference from their answers. In this article, we propose estimating rates at which offenders discount time incarcerated by specifying their equilibrium plea, defined as the discount rate, which equates the time and expected time spent in jail following a guilty plea and a trial. Offenders are assumed to exhibit positive time preference and discount time spent in jail at a constant rate. Our choice of sample is interesting because the offenders are not on bail, punishment is not delayed and the offences are planned therefore conforming to Becker’s model of the decision to commit a crime. Contrary to the discussion in the literature, we do not find evidence of consistently high time discount rates, and therefore cannot unequivocally infer that the prison experience always results in low levels of specific deterrence.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background People admitted to intensive care units and those with chronic health care problems often require long-term vascular access. Central venous access devices (CVADs) are used for administering intravenous medications and blood sampling. CVADs are covered with a dressing and secured with an adhesive or adhesive tape to protect them from infection and reduce movement. Dressings are changed when they become soiled with blood or start to come away from the skin. Repeated removal and application of dressings can cause damage to the skin. The skin is an important barrier that protects the body against infection. Less frequent dressing changes may reduce skin damage, but it is unclear whether this practice affects the frequency of catheter-related infections. Objectives To assess the effect of the frequency of CVAD dressing changes on the incidence of catheter-related infections and other outcomes including pain and skin damage. Search methods In June 2015 we searched: The Cochrane Wounds Specialised Register; The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid EMBASE and EBSCO CINAHL. We also searched clinical trials registries for registered trials. There were no restrictions with respect to language, date of publication or study setting. Selection criteria All randomised controlled trials (RCTs) evaluating the effect of the frequency of CVAD dressing changes on the incidence of catheter-related infections on all patients in any healthcare setting. Data collection and analysis We used standard Cochrane review methodology. Two review authors independently assessed studies for inclusion, performed risk of bias assessment and data extraction. We undertook meta-analysis where appropriate or otherwise synthesised data descriptively when heterogeneous. Main results We included five RCTs (2277 participants) that compared different frequencies of CVAD dressing changes. The studies were all conducted in Europe and published between 1995 and 2009. Participants were recruited from the intensive care and cancer care departments of one children's and four adult hospitals. The studies used a variety of transparent dressings and compared a longer interval between dressing changes (5 to15 days; intervention) with a shorter interval between changes (2 to 5 days; control). In each study participants were followed up until the CVAD was removed or until discharge from ICU or hospital. - Confirmed catheter-related bloodstream infection (CRBSI) One trial randomised 995 people receiving central venous catheters to a longer or shorter interval between dressing changes and measured CRBSI. It is unclear whether there is a difference in the risk of CRBSI between people having long or short intervals between dressing changes (RR 1.42, 95% confidence interval (CI) 0.40 to 4.98) (low quality evidence). - Suspected catheter-related bloodstream infection Two trials randomised a total of 151 participants to longer or shorter dressing intervals and measured suspected CRBSI. It is unclear whether there is a difference in the risk of suspected CRBSI between people having long or short intervals between dressing changes (RR 0.70, 95% CI 0.23 to 2.10) (low quality evidence). - All cause mortality Three trials randomised a total of 896 participants to longer or shorter dressing intervals and measured all cause mortality. It is unclear whether there is a difference in the risk of death from any cause between people having long or short intervals between dressing changes (RR 1.06, 95% CI 0.90 to 1.25) (low quality evidence). - Catheter-site infection Two trials randomised a total of 371 participants to longer or shorter dressing intervals and measured catheter-site infection. It is unclear whether there is a difference in risk of catheter-site infection between people having long or short intervals between dressing changes (RR 1.07, 95% CI 0.71 to 1.63) (low quality evidence). - Skin damage One small trial (112 children) and three trials (1475 adults) measured skin damage. There was very low quality evidence for the effect of long intervals between dressing changes on skin damage compared with short intervals (children: RR of scoring ≥ 2 on the skin damage scale 0.33, 95% CI 0.16 to 0.68; data for adults not pooled). - Pain Two studies involving 193 participants measured pain. It is unclear if there is a difference between long and short interval dressing changes on pain during dressing removal (RR 0.80, 95% CI 0.46 to 1.38) (low quality evidence). Authors' conclusions The best available evidence is currently inconclusive regarding whether longer intervals between CVAD dressing changes are associated with more or less catheter-related infection, mortality or pain than shorter intervals.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Top-predators contribute to ecosystem resilience, yet individuals or populations are often subject to lethal control to protect livestock, managed game or humans from predation. Such management actions sometimes attract concern that lethal control might affect top-predator function in ways ultimately detrimental to biodiversity conservation. The primary function of a predator is predation, which is often investigated by assessing their diet. We therefore use data on prey remains found in 4,298 Australian dingo scats systematically collected from three arid sites over a four year period to experimentally assess the effects of repeated broad-scale poison-baiting programs on dingo diet. Indices of dingo dietary diversity and similarity were either identical or near-identical in baited and adjacent unbaited treatment areas in each case, demonstrating no control-induced change to dingo diets. Associated studies on dingoes' movement behaviour and interactions with sympatric mesopredators were similarly unaffected by poison-baiting. These results indicate that mid-sized top-predators with flexible and generalist diets (such as dingoes) may be resilient to ongoing and moderate levels of population control without substantial alteration of their diets and other related aspects of their ecological function.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND The emergence of high levels of resistance in Cryptolestes ferrugineus (Stephens) in recent years threatens the sustainability of phosphine, a key fumigant used worldwide to disinfest stored grain. We aimed at developing robust fumigation protocols that could be used in a range of practical situations to control this resistant pest. RESULTS Values of the lethal time to kill 99.9% (LT99.9, in days) of mixed-age populations, containing all life stages, of a susceptible and a strongly resistant C. ferrugineus population were established at three phosphine concentrations (1.0, 1.5 and 2.0 mg L−1) and three temperatures (25, 30 and 35 °C). Multiple linear regression analysis revealed that phosphine concentration and temperature both contributed significantly to the LT99.9 of a population (P < 0.003, R2 = 0.92), with concentration being the dominant variable, accounting for 75.9% of the variation. Across all concentrations, LT99.9 of the strongly resistant C. ferrugineus population was longest at the lowest temperature and shortest at the highest temperature. For example, 1.0 mg L−1 of phosphine is required for 20, 15 and 15 days, 1.5 mg L−1 for 12, 11 and 9 days and 2.0 mg L−1 for 10, 7 and 6 days at 25, 30 and 35 °C, respectively, to achieve 99.9% mortality of the strongly resistant C. ferrugineus population. We also observed that phosphine concentration is inversely proportional to fumigation period in regard to the population extinction of this pest. CONCLUSION The fumigation protocols developed in this study will be used in recommending changes to the currently registered rates of phosphine in Australia towards management of strongly resistant C. ferrugineus populations, and can be repeated in any country where this type of resistance appears.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background In 2000, the Mater Child and Youth Mental Health Service Indigenous consultant saw that Indigenous families were isolated from kinship networks following the assimilation policy and clinicians were largely unaware of these socio-cultural histories. Experiences of marginalisation by mainstream society and services were exacerbated by assumptions clinicians made about this population. To enhance Mater’s care the consultant undertook research with Indigenous Elders. The project, “Bringing up Children Gran’s Way”, on which the presenter is the research advisor, was funded by AIATSIS. Aims Increase service quality Improve staff confidence, skills and satisfaction working with this population Promote the wellbeing of Indigenous families Acknowledge the significance of Elders and extended family networks. Methods Over 2006/07 the team used narrative and Indigenous methodologies, (e.g. yarning circles and the use of Indigenous research staff) to arrange and audio-record structured interviews with 19 Aboriginal Elders, on growing up and parenting. The participants were recruited by the Indigenous consultant and gave written consent, following ethical approval and information giving. The team immersed themselves in the material by repeated reading of the transcripts to note recurring themes in Elders’ narratives. Findings The recurring themes included the importance of cultural protocols and extended family; impacts of being ‘under the Act and stories of surviving change; culture, spiritualty and religion; trans-generational impacts; childrearing and the need to reconcile with Elders. Discussion The narratives show Elders resilience in the face of enduring impact of policies of genocide and assimilation. Clinicians need to approach their work with a deeper understanding of the diversity of clients’ social experience and cultural identity. Clinicians need to examine their own cultural assumptions about this population. Conclusion The dissemination of the knowledge and experience of Elders is a matter of social justice and crucial for the well-being of future generations and for improved service access.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background Forward head postures (FHP) are proposed to adversely load cervical spine structures. Neck muscles provide support for the neck, and thus an imbalance in neck muscle performance could potentially contribute to the development of FHP. Previous studies have not considered the interaction of multiple muscle groups with regard to postural orientation. Given the interdependence of muscles along the cervical spine for optimal orientation and physical support of the vertebral column, the performance of a single muscle group may not accurately reflect the coordinated ability of the muscles to maintain a neutral neck posture. Purpose The purpose of this study was to investigate the relationship between FHP and the balance between the cervical extensor and flexor muscle groups in healthy individuals. We hypothesised that the magnitude of FHP would be associated with the strength and endurance performance ratios between the cervical extensor and flexor muscle groups. Methods Twenty male and 24 female volunteers were photographed in the sagittal plane wearing surface markers. The FHP of each participant was measured via the tragus-sternum marker distance over two conditions: (1)in relaxed standing and (2)during a sustained sitting task. Maximal strength (Nm) and endurance (s) performance of the extensor and flexor muscle groups were recorded at the upper (craniocervical flexion/extension (CCF/CCE)) and lower (cervicothoracic flexion/extension (CTF/CTE)) cervical regions. Muscle performance measures were expressed as extension:flexion ratios and their relation to FHP evaluated. A stepwise multiple regression analysis using backward elimination was utilised to examine the relationship between the postural measures and the muscle performance ratio measures. Separate models were used for the two different postural conditions (standing, sustained sitting). Gender was included as a constant correction factor in all regression models. Where gender was a significant variable in the model, analyses were repeated separately for males and females. Results Greater FHP in standing was significantly associated with reduced proportional CTE to CCF strength in females (R2 = 0.21, P = 0.03) and greater proportional CTE to CTF strength in males (R2 = 0.23, P = 0.03). A greater drift into FHP during sustained sitting was associated with a relative reduction in CCE endurance proportional to CTF endurance in females only (R2 = 0.27, P = 0.017). Conclusion(s) This initial study indicates that the balance in performance between the cervical flexor and extensor muscle groups may impact FHP in healthy individuals. However, the findings were inconsistent across different muscle performance ratios and gender. Larger scale studies are therefore now needed to further clarify the relationship between FHP and muscle performance. Implications The findings suggest that relative performance of the various cervical muscle groups needs to be accounted for when considering postural correction strategies in the clinical setting, as is often recommended.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Olkiluoto Island is situated in the northern Baltic Sea, near the southwestern coast of Finland, and is the proposed location of a spent nuclear fuel repository. This study examined Holocene palaeoseismicity in the Olkiluoto area and in the surrounding sea areas by computer simulations together with acoustic-seismic, sedimentological and dating methods. The most abundant rock type on the island is migmatic mica gneiss, intruded by tonalites, granodiorites and granites. The surrounding Baltic Sea seabed consists of Palaeoproterozoic crystalline bedrock, which is to a great extent covered by younger Mesoproterozoic sedimentary rocks. The area contains several ancient deep-seated fracture zones that divide it into bedrock blocks. The response of bedrock at the Olkiluoto site was modelled considering four future ice-age scenarios. Each scenario produced shear displacements of fractures with different times of occurrence and varying recovery rates. Generally, the larger the maximum ice load, the larger were the permanent shear displacements. For a basic case, the maximum shear displacements were a few centimetres at the proposed nuclear waste repository level, at proximately 500 m b.s.l. High-resolution, low-frequency echo-sounding was used to examine the Holocene submarine sedimentary structures and possible direct and indirect indicators of palaeoseismic activity in the northern Baltic Sea. Echo-sounding profiles of Holocene submarine sediments revealed slides and slumps, normal faults, debris flows and turbidite-type structures. The profiles also showed pockmarks and other structures related to gas or groundwater seepages, which might be related to fracture zone activation. Evidence of postglacial reactivation in the study area was derived from the spatial occurrence of some of the structures, especial the faults and the seepages, in the vicinity of some old bedrock fracture zones. Palaeoseismic event(s) (a single or several events) in the Olkiluoto area were dated and the palaeoenvironment was characterized using palaeomagnetic, biostratigraphical and lithostratigraphical methods, enhancing the reliability of the chronology. Combined lithostratigraphy, biostratigraphy and palaeomagnetic stratigraphy revealed an age estimation of 10 650 to 10 200 cal. years BP for the palaeoseismic event(s). All Holocene sediment faults in the northern Baltic Sea occur at the same stratigraphical level, the age of which is estimated at 10 700 cal. years BP (9500 radiocarbon years BP). Their movement is suggested to have been triggered by palaeoseismic event(s) when the Late Weichselian ice sheet was retreating from the site and bedrock stresses were released along the bedrock fracture zones. Since no younger or repeated traces of seismic events were found, it corroborates the suggestion that the major seismic activity occurred within a short time during and after the last deglaciation. The origin of the gas/groundwater seepages remains unclear. Their reflections in the echo-sounding profiles imply that part of the gas is derived from the organic-bearing Litorina and modern gyttja clays. However, at least some of the gas is derived from the bedrock. Additional information could be gained by pore water analysis from the pockmarks. Information on postglacial fault activation and possible gas and/or fluid discharges under high hydraulic heads has relevance in evaluating the safety assessment of a planned spent nuclear fuel repository in the region.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Probiotic supplements are single or mixed strain cultures of live microorganisms that benefit the host by improving the properties of the indigenous microflora (Seo et al 2010). In a pilot study at the University of Queensland, Norton et al (2008) found that Bacillus amyloliquefaciens Strain H57 (H57), primarily investigated as an inoculum to make high-quality hay, improved feed intake and nitrogen utilisation over several weeks in pregnant ewes. The purpose of the following study was to further challenge the potential of H57 -to show it survives the steam-pelleting process, and that it improves the performance of ewes fed pellets based on an agro-industrial by-product with a reputation for poor palatability, palm kernel meal (PKM), (McNeill 2013). Thirty-two first-parity White Dorper ewes (day 37 of pregnancy, mean liveweight = 47.3 kg, mean age = 15 months) were inducted into individual pens in the animal house at the University of Queensland, Gatton. They were adjusted onto PKM-based pellets (g/kg drymatter (DM): PKM, 408; sorghum, 430; chick pea hulls, 103; minerals and vitamins; Crude protein, 128; ME: 11.1MJ/kg DM) until day 89 of pregnancy and thereafter fed a predominately pelleted diet incorporating with or without H57 spores (10 9 colony forming units (cfu)/kg pellet, as fed), plus 100g/ewe/day oaten chaff, until day 7 of lactation. From day 7 to 20 of lactation the pelleted component of the diet was steadily reduced to be replaced by a 50:50 mix of lucerne: oaten chaff, fed ad libitum, plus 100g/ewe/day of ground sorghum grain with or without H57 (10 9 cfu/ewe/day). The period of adjustment in pregnancy (day 37-89) extended beyond expectations due to some evidence of mild ruminal acidosis after some initially high intakes that were followed by low intakes. During that time the diet was modified, in an attempt to improve palatability, by the addition of oaten chaff and the removal of an acidifying agent (NH4Cl) that was added initially to reduce the risk of urinary calculi. Eight ewes were removed due to inappetence, leaving 24 ewes to start the trial at day 90 of pregnancy. From day 90 of pregnancy until day 63 of lactation, liveweights of the ewes and their lambs were determined weekly and at parturition. Feed intakes of the ewes were determined weekly. Once lambing began, 1 ewe was removed as it gave birth to twin lambs (whereas the rest gave birth to a single lamb), 4 due to the loss of their lambs (2 to dystocia), and 1 due to copper toxicity. The PKM pellets were suspected to be the cause of the copper toxicity and so were removed in early lactation. Hence, the final statistical analysis using STATISTICA 8 (Repeated measures ANOVA for feed intake, One-way ANOVA for liveweight change and birth weight) was completed on 23 ewes for the pregnancy period (n = 11 fed H57; n = 12 control), and 18 ewes or lambs for the lactation period (n = 8 fed H57; n = 10 control). From day 90 of pregnancy until parturition the H57 supplemented ewes ate 17 more DM (g/day: 1041 vs 889, sed = 42.4, P = 0.04) and gained more liveweight (g/day: 193 vs 24.0, sed = 25.4, P = 0.0002), but produced lambs with a similar birthweight (kg: 4.18 vs 3.99, sed = 0.19, P = 0.54). Over the 63 days of lactation the H57 ewes ate similar amounts of DM but grew slower than the control ewes (g/day: 1.5 vs 97.0, sed = 21.7, P = 0.012). The lambs of the H57 ewes grew faster than those of the control ewes for the first 21 days of lactation (g/day: 356 vs 265, sed = 16.5, P = 0.006). These data support the findings of Norton et al (2008) and Kritas et al (2006) that certain Bacillus spp. supplements can improve the performance of pregnant and lactating ewes. In the current study we particularly highlighted the capacity of H57 to stimulate immature ewes to continue to grow maternal tissue through pregnancy, possibly through an enhanced appetite, which appeared then to stimulate a greater capacity to partition nutrients to their lambs through milk, at least for the first few weeks of lactation, a critical time for optimising lamb survival. To conclude, H57 can survive the steam pelleting process to improve feed intake and maternal liveweight gain in late pregnancy, and performance in early lactation, of first-parity ewes fed a diet based on PKM.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

BACKGROUND The emergence of high levels of resistance in Cryptolestes ferrugineus (Stephens) in recent years threatens the sustainability of phosphine, a key fumigant used worldwide to disinfest stored grain. We aimed at developing robust fumigation protocols that could be used in a range of practical situations to control this resistant pest. RESULTS Values of the lethal time to kill 99.9% (LT99.9, in days) of mixed-age populations, containing all life stages, of a susceptible and a strongly resistant C. ferrugineus population were established at three phosphine concentrations (1.0, 1.5 and 2.0 mg L−1) and three temperatures (25, 30 and 35 °C). Multiple linear regression analysis revealed that phosphine concentration and temperature both contributed significantly to the LT99.9 of a population (P < 0.003, R2 = 0.92), with concentration being the dominant variable, accounting for 75.9% of the variation. Across all concentrations, LT99.9 of the strongly resistant C. ferrugineus population was longest at the lowest temperature and shortest at the highest temperature. For example, 1.0 mg L−1 of phosphine is required for 20, 15 and 15 days, 1.5 mg L−1 for 12, 11 and 9 days and 2.0 mg L−1 for 10, 7 and 6 days at 25, 30 and 35 °C, respectively, to achieve 99.9% mortality of the strongly resistant C. ferrugineus population. We also observed that phosphine concentration is inversely proportional to fumigation period in regard to the population extinction of this pest. CONCLUSION The fumigation protocols developed in this study will be used in recommending changes to the currently registered rates of phosphine in Australia towards management of strongly resistant C. ferrugineus populations, and can be repeated in any country where this type of resistance appears. © 2014 Commonwealth of Australia. Pest Management Science © 2014 Society of Chemical Industry