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OBJECTIVE: Near-infrared spectroscopy (NIRS) allows assessment of regional tissue oxygen delivery and extraction. There are doubts regarding reliability of gut NIRS measurements. This study assesses reliability of NIRS for monitoring gut oxygenation. STUDY DESIGN: Splanchnic tissue haemoglobin index (sTHI), tissue oxygenation index (sTOI) and fractional tissue oxygen extraction (sFTOE) changes during blood transfusion were measured using NIRS and compared to stable control infants. Infants were grouped into 3 chronological age groups: 1-7, 8-28 and ≥29 days of life. RESULTS: sTHI, sTOI significantly increased, and sFTOE reduced following blood transfusion in all age group infants (n = 59), with no changes seen in control infants (n = 12). Baseline characteristics including gestational age and feed volumes did not differ between groups. CONCLUSION: Gut perfusion measured by NIRS improved in infants who received blood transfusion, a change not seen in the control group, thus suggesting NIRS is a reliable method to measure splanchnic tissue oxygenation.
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Recien Nacido Prematuro , Espectroscopía Infrarroja Corta , Lactante , Recién Nacido , Humanos , Reproducibilidad de los Resultados , Oxígeno , Edad Gestacional , Circulación EsplácnicaRESUMEN
Ewe wastage encompasses ewes that do not reach the end of their potential productive lives and is the combination of premature culling and on-farm mortality. Increased ewe wastage results in reduced flock productivity and profitability, primarily driven by the need for increased replacement ewe lambs to maintain flock numbers and the costs associated with these additional replacements (e.g. reduced sale lambs, reduced flock age resulting in lower lamb production, and reduced ability to utilise terminal sires). Annual ewe mortality rates are reported to range from 2.8 to 40.2% in New Zealand commercial flocks, while wastage over a ewe's productive lifespan (i.e. mortality and premature culling combined to 6-7 years-of-age) is reported to be up to 90%. To date, ewe wastage has received relatively little attention in the published literature. This article reviews published studies describing wastage in non-dairy ewes, focusing on New Zealand commercial flocks, although overseas pasture-based data is also considered. The relevance of, and challenges associated with, investigating ewe wastage are discussed. Ewe culling and mortality data is outlined, and causes are described. Known key risk factors for wastage, namely, reproductive performance, udder health, dental health, body condition score and breeding of ewe lambs, are reviewed. Finally, current knowledge gaps and future areas of research are identified and evaluated.
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Reproducción , Enfermedades de las Ovejas , Animales , Granjas , Femenino , Glándulas Mamarias Animales , Nueva Zelanda/epidemiología , Ovinos , Enfermedades de las Ovejas/epidemiologíaRESUMEN
OBJECTIVE: An experiment was designed to determine if behaviour traits expressed by twinand triplet-bearing lambs and their dams at 3 to 18 hours of age (after the immediate ewelamb bonding had occurred) were associated with lamb survival to weaning. METHODS: The behaviour of twin and triplet lambs and their dams was assessed in the paddock at 3 to 18 hours after birth. Observations were made of the number of high- and low-pitched bleats, time to stand, make contact with dam, suck from dam and follow dam were recorded for each lamb. The maternal behaviour score of each dam was assessed. A random sub-sample of lambs were assessed during a maternal-recognition test at 12 or 24 hours of age. Traits included time spent standing, sitting, walking, time taken to reach the ewes and time spent with the ewes as well as the number of high- and low-pitched bleats emitted by the lamb. RESULTS: In the paddock, for each additional second required for twin-born lambs to follow their dam, lambs were 1.004 (95% confidence interval [CI] 1.000 to 1.008) times more likely to survive to weaning (p<0.05). The opposite relationship, however, was seen in triplet lambs. For each additional second required for triplet-born lambs to follow their dam, lambs were 0.996 (95% CI 0.993 to 0.999) times as likely to survive to weaning (p<0.05). During the maternal recognition test, twin-born lambs were 0.989 (95% CI 0.979 to 1.000) times as likely to survive to weaning for every additional second they took to reach the contact zone (p<0.05). Similarly, triplet-born lambs were 0.994 (95% CI 0.989 to 0.999) as likely to survive for every additional second they took to reach their dam (p<0.05). CONCLUSION: All ewe behaviours and the majority of lamb paddock and test behaviours were not associated with the survival of twin- or triplet-born lambs and, therefore, are of little use as indicators of lamb survival to weaning.
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Aims: To examine a range of udder and teat traits in Romney ewes and to describe the frequency with which different scores occur, and to investigate associations between lamb survival to weaning and ewe udder and teat scores. Methods: Mixed-age, mature Romney ewes (n = 1,009) were enrolled from a commercial sheep flock located in the Wellington region of New Zealand in January 2017. A range of udder and teat traits were scored in all ewes, using visual assessment and palpation, at pre-mating (February), pre-lambing (October), docking (November) and weaning (January 2018). During the lambing period each newborn lamb was matched to its dam, with lamb mortalities recorded until weaning. Associations between udder and teat scores and lamb survival to weaning were examined using multivariable models for each udder-scoring time. Results: Records from 981 ewes and 1,822 live-born lambs were included in analyses, with 252 (13.8%) lambs recorded dead between birth and weaning. Lambs born to ewes with pre-mating udder scores of lump or hard had 4.9 (95% CI = 2.6-9.6, p = 0.003) and 3.0 (95% CI = 1.5-6.1, p < 0.001) increased odds of failure to survive to weaning, respectively, compared with lambs whose dams had normal udder scores. Lambs born to ewes with mastitis at docking or weaning had 3.0 (95% CI = 1.5-5.9, p = 0.001) and 3.9 (95% CI = 1.3-11.6, p = 0.013) increased odds of failure to survive to weaning, respectively, compared with lambs whose dams did not have mastitis. Offspring of dams with asymmetrical udders at docking or weaning had 3.3 (95% CI = 2.2-4.9, p < 0.001) and 2.5 (95% CI = 1.5-4.0, p < 0.001) increased odds of failure to survive, respectively, compared with lambs whose dams had symmetrical udders. Conclusion and Clinical Relevance: Pre-mating udder palpation scores of hard or lump were associated with increased odds of lambs not surviving to weaning compared with normal scores, and could be used to identify ewes that are likely to be unsuitable for retaining in the breeding flock. Farmers could also use clinical mastitis scores and udder symmetry scores at docking or weaning to identify ewes whose lambs had greater odds of failure to survive to weaning. However these scores do not provide an indication of future performance, therefore further investigation into the impact of the present season's score on future seasons' lamb survival is required.
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Glándulas Mamarias Animales/fisiopatología , Mastitis/veterinaria , Enfermedades de las Ovejas/epidemiología , Enfermedades de las Ovejas/fisiopatología , Crianza de Animales Domésticos , Animales , Animales Recién Nacidos , Animales Lactantes , Femenino , Masculino , Mastitis/epidemiología , Mortalidad , Análisis Multivariante , Nueva Zelanda/epidemiología , Factores de Riesgo , Ovinos , Sobrevida , DesteteRESUMEN
Aims: To investigate associations between lamb growth to weaning and dam udder and teat scores measured at pre-mating, pre-lambing, docking and weaning. Methods: Mature Romney ewes (n = 1,009) were enrolled from a commercial sheep flock located near Masterton, in the Wellington region of New Zealand in 2017. A range of udder and teat traits were scored in all ewes, using visual assessment and palpation, at pre-mating, pre-lambing, docking and weaning. During the lambing period, each newborn lamb was matched to its dam and lamb sex, birthweight and birth-rank were recorded. A rearing rank was allocated to each live-lamb at weaning, when all lambs were weighed (n = 1,570), allowing calculation of daily growth rates (g/day). Associations between udder and teat scores and lamb growth rates to weaning were examined using multivariable models for each udder-scoring time. Results: Growth rates of lambs whose dams had udder palpation scores of hard, or both teats recorded as abnormal, pre-mating were lower than lambs whose dams had normal scores (229.9 (95% CI = 213.2-246.6) vs. 254.5 (95% CI = 245.6-263.5) g/day; p = 0.011) and (227.4 (95% CI = 208.3-246.6) vs. 247.9 (95% CI = 235.7-260.2) g/day; p = 0.024), respectively. Growth rates of lambs whose dams had clinical mastitis at docking or weaning were lower than those without mastitis (215.8 (95% CI = 199.9-231.7) vs. 235.4 (95% CI = 225.4-255.0) g/day; p = 0.007) and (220.0 (95% CI = 205.2-234.8) vs. 254.7 (95% CI = 248.9-260.5) g/day; p < 0.001), respectively. Growth rates of lambs whose dams had asymmetrical udders at docking or weaning were lower than lambs whose dams had symmetrical udders (204.6 (95% CI = 189.7-219.5) vs. 240.2 (95% CI = 225.4-255.0) g/day; p < 0.001) and (223.3 (95% CI = 213.9-232.7) vs. 242.2 (95% CI = 229.4-255.0) g/day; p = 0.014), respectively. Conclusions and Clinical Relevance: Pre-mating udder palpation and teat palpation scores can be used to identify ewes whose lambs are predicted to have lower growth to weaning. Assuming a mean lamb age at weaning of 84.4 days, lambs born to ewes with a pre-mating score of hard would be expected to have a mean weaning weight that was 2.1â kg less than those whose dams had normal scores. Udder palpation, udder symmetry and clinical mastitis scores during lactation were also associated with lamb growth rates. Abbreviation: CALW: Conceptus-adjusted liveweight.
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Glándulas Mamarias Animales/fisiopatología , Mastitis/complicaciones , Mastitis/epidemiología , Enfermedades de las Ovejas/epidemiología , Enfermedades de las Ovejas/fisiopatología , Crianza de Animales Domésticos , Animales , Animales Lactantes , Peso Corporal , Femenino , Análisis Multivariante , Nueva Zelanda/epidemiología , Ovinos/crecimiento & desarrollo , Destete , Aumento de PesoRESUMEN
Some authors have suggested that in the fetus, neonate and infant, intradural hemorrhage (IDH) is relatively common and often presents alongside subdural hemorrhage (SDH). These authors have theorized that pediatric SDH may result from an IDH due to blood leakage from a dural vascular plexus. In this study, we report the inter-observer variation for detection of IDH from a retrospectively collected series of pediatric autopsy photographs, with and without SDH. Autopsy photographs of the falx and tentorium from 27 neonatal, infant and early childhood autopsies were assessed by two independent consultant forensic pathologists blinded to all case histories for the presence and extent (focal or diffuse) of IDH. Inter-observer agreement between the pathologists was calculated using Cohen's kappa coefficient. The occurrence of subdural hemorrhage was also recorded at autopsy. A kappa coefficient value of 0.669 (p = 0.001), indicated a substantial level of agreement for the presence/absence of IDH between the pathologists. For the extent of IDH a kappa coefficient value of 0.6 (p = 0.038) indicated a moderate level of agreement. The pathologists agreed on the presence of IDH in 10 of the 27 cases. Subdural hemorrhage was recorded for 8 out of 27 cases. Of these 8 cases, it was agreed that 4 had IDH. Using standardized methods of image capture and assessment, inter-observer agreement for the presence/absence of IDH was substantial. In this paper, we report a much lower frequency of macroscopic IDH occurring alongside SDH than previous studies, which included both gross observation of IDH and histological examination.
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Duramadre/patología , Hematoma Subdural/patología , Hemorragias Intracraneales/patología , Variaciones Dependientes del Observador , Fotograbar , Preescolar , Femenino , Patologia Forense , Humanos , Lactante , Recién Nacido , Masculino , Estudios RetrospectivosRESUMEN
OBJECTIVE: The aim of the present study was to identify the impact of early weaning of lambs at approximately seven weeks of age onto a herb-clover mix on the liveweight gain of lambs and their dams. METHODS: In 2015, twin-born lambs that weighed a minimum of 16 kg (n = 134) were randomly allocated to one of three treatments: i) Early-weaned (58 days after the midpoint of lambing) onto an unrestricted allowance (>1,200 kg dry matter/ha) of herb-clover mix (HerbEW); ii) Lambs+dams unweaned onto an unrestricted allowance of herb-clover mix until conventional weaning (95 days after the midpoint of lambing) (HerbCW); iii) Lambs+ dams unweaned onto an unrestricted allowance of grass-clover pasture until conventional weaning (GrassCW). In 2016, twin-born lambs that weighed a minimum of 16 kg (n = 170) were randomly allocated to one of four treatments: i), ii), iii) (similar to 2015) and iv) Lambs+ dams unweaned onto a restricted allowance (<1,200 kg dry matter/ha) of grass-clover pasture until conventional weaning (93 days after the midpoint of lambing) (Restricted-GrassCW). RESULTS: In 2015, liveweight gain from L58 to L95 of HerbCW and GrassCW lambs did not differ (p>0.05), but were greater than HerbEW lambs. In 2016, HerbCW lambs had greater (p<0.05) liveweight gains from L51 to L93 than GrassCW followed by HerbEW and Restricted-GrassCW lambs. In 2015, liveweight gain from L58 to L95 of HerbEW ewes were greater than both GrassCW and HerbCW ewes while in 2016, liveweight gain of from L51 to L93 GrassCW and HerbCW ewes did not differ (p>0.05) but were greater (p<0.05) than those of HerbEW and Restricted-GrassCW ewes. CONCLUSION: These results indicate that when grass-clover pasture supply can be maintained at unrestricted intake level, there may be no benefit of weaning lambs early. However, at restricted pasture conditions lambs can achieve greater liveweight gains when weaned early onto a herb-clover mix.
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AIMS Firstly, to investigate associations between liveweight and body condition score (BCS) of two-tooth ewes (18-months-old at breeding) at breeding, pregnancy diagnosis (PD) and pre-lambing and the risk of being dry at docking, on commercial New Zealand sheep farms. Secondly, to investigate the association between previous reproductive outcomes as ewe lambs, and risk of being dry at docking as two-tooth ewes. METHODS Two-tooth ewes (n=9,006) were enrolled in four cohorts from three commercial sheep farms between 2010-14. Ewes were weighed and BCS assessed immediately pre-breeding, at PD (mid-pregnancy) and pre-lambing. At PD, ewes were identified as either non-pregnant, or having single or multiple fetuses. Palpation and examination of udders at docking was used to classify each ewe as either lactating or dry at docking. RESULTS Overall, 437/8,025 (5.4%) of ewes that were diagnosed pregnant at PD were dry at docking. The risk of being dry at docking decreased with increasing pre-lambing conceptus adjusted liveweight (CALW) on all farms (p≤0.002); for 2010-born ewes from Farm A the OR=0.87 (95% CI=0.81-0.92); for Farm B the OR=0.88 (95% CI=0.83-0.92) and for Farm C the OR=0.86 (95% CI=0.79-0.95). The risk of being dry at docking also decreased with increasing CALW gain from PD to pre-lambing for all farms (p≤0.003); for 2010-born ewes from Farm A the OR=0.89 (95% CI=0.84-0.94); for Farm B the OR=0.85 (95% CI=0.81-0.89) and for Farm C the OR=0.88 (95% CI=0.80-0.96). There was no association between BCS at breeding, PD or pre-lambing and the risk of being dry at docking for 2010-born ewes from Farm A, Farm B or Farm C (p>0.05). For 2010-born ewes on Farm A, the risk of being dry at docking was greater for two-tooth ewes that were previously dry at docking as ewe lambs than those that were lactating at docking as ewe lambs (OR=1.7 (95% CI=1.1-2.8); p=0.018), but this difference was not observed for ewes on Farm B or Farm C (p>0.5). CONCLUSIONS There were negative associations between ewe CALW pre-lambing, and CALW gain between PD and pre-lambing, and risk of being dry at docking. For all cohorts, heavier ewes and those that gained CALW were less likely to be dry at docking than lighter ewes or those that lost CALW, however these relationships varied between cohorts.
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Peso Corporal/fisiología , Trastornos de la Lactancia/veterinaria , Lactancia/fisiología , Enfermedades de las Ovejas/etiología , Ovinos/fisiología , Crianza de Animales Domésticos , Animales , Cruzamiento , Femenino , Trastornos de la Lactancia/etiología , Nueva Zelanda , Parto , Embarazo , Reproducción , Factores de Riesgo , Aumento de Peso/fisiologíaRESUMEN
A UK multicentre audit to evaluate HDR and PDR brachytherapy has been performed using alanine absolute dosimetry. This is the first national UK audit performing an absolute dose measurement at a clinically relevant distance (20 mm) from the source. It was performed in both INTERLACE (a phase III multicentre trial in cervical cancer) and non-INTERLACE brachytherapy centres treating gynaecological tumours. Forty-seven UK centres (including the National Physical Laboratory) were visited. A simulated line source was generated within each centre's treatment planning system and dwell times calculated to deliver 10 Gy at 20 mm from the midpoint of the central dwell (representative of Point A of the Manchester system). The line source was delivered in a water-equivalent plastic phantom (Barts Solid Water) encased in blocks of PMMA (polymethyl methacrylate) and charge measured with an ion chamber at 3 positions (120° apart, 20 mm from the source). Absorbed dose was then measured with alanine at the same positions and averaged to reduce source positional uncertainties. Charge was also measured at 50 mm from the source (representative of Point B of the Manchester system). Source types included 46 HDR and PDR 192Ir sources, (7 Flexisource, 24 mHDR-v2, 12 GammaMed HDR Plus, 2 GammaMed PDR Plus, 1 VS2000) and 1 HDR 60Co source, (Co0.A86). Alanine measurements when compared to the centres' calculated dose showed a mean difference (±SD) of +1.1% (±1.4%) at 20 mm. Differences were also observed between source types and dose calculation algorithm. Ion chamber measurements demonstrated significant discrepancies between the three holes mainly due to positional variation of the source within the catheter (0.4%-4.9% maximum difference between two holes). This comprehensive audit of absolute dose to water from a simulated line source showed all centres could deliver the prescribed dose to within 5% maximum difference between measurement and calculation.
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Braquiterapia , Auditoría Clínica , Ensayos Clínicos Fase III como Asunto , Dosis de Radiación , Algoritmos , Catéteres , Femenino , Humanos , Radioisótopos de Iridio/uso terapéutico , Fantasmas de Imagen , Radiometría , Dosificación Radioterapéutica , Neoplasias del Cuello Uterino/radioterapiaRESUMEN
Atmospheric monitoring systems (AMS) have been widely used in underground coal mines in the United States for the detection of fire in the belt entry and the monitoring of other ventilation-related parameters such as airflow velocity and methane concentration in specific mine locations. In addition to an AMS being able to detect a mine fire, the AMS data have the potential to provide fire characteristic information such as fire growth - in terms of heat release rate - and exact fire location. Such information is critical in making decisions regarding fire-fighting strategies, underground personnel evacuation and optimal escape routes. In this study, a methodology was developed to calculate the fire heat release rate using AMS sensor data for carbon monoxide concentration, carbon dioxide concentration and airflow velocity based on the theory of heat and species transfer in ventilation airflow. Full-scale mine fire experiments were then conducted in the Pittsburgh Mining Research Division's Safety Research Coal Mine using an AMS with different fire sources. Sensor data collected from the experiments were used to calculate the heat release rates of the fires using this methodology. The calculated heat release rate was compared with the value determined from the mass loss rate of the combustible material using a digital load cell. The experimental results show that the heat release rate of a mine fire can be calculated using AMS sensor data with reasonable accuracy.
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OBJECTIVE: The present study aimed to determine the impact of ewe body condition score (BCS) (over a range of 2.0 to 3.0) and nutritional treatments (consisting of differing herbage masses) during very late pregnancy and lactation and their potential interaction on the performance of twin-bearing ewes and their lambs to weaning. METHODS: On day 142 of pregnancy, twin-bearing ewes with a BCS of 2.0, 2.5, or 3.0 were allocated to a "Moderate' or 'Unrestricted' nutritional treatment until day 95 of lactation (weaning). The nutritional treatments aimed to achieve average herbage masses of 1,200 to 1,300 kg dry matter (DM)/ha (Moderate) and 1,500 to 1,800 kg DM/ha (Unrestricted). RESULTS: There were no three-way interactions between ewe BCS group, nutritional treatment and time for any ewe or lamb parameter. The nutritional treatments had no effect (p>0.05) on lamb birth or weaning weight. Lambs born to Moderate ewes had greater survival and total litter weight at weaning (p<0.05). Regardless of BCS group, Unrestricted treatment ewes had greater body condition and back-fat depth at weaning than Moderate treatment ewes (p<0.05). Ewes of BCS 2.0 group reared lighter lambs to weaning (p<0.05) and tended to have a lower total litter weight (p = 0.06) than BCS 3.0 group ewes. CONCLUSION: This study suggests farmers should aim to have all ewes with a BCS of 2.5 or 3 in late pregnancy for optimal lamb weaning performance. Furthermore, there is no benefit to lamb production of offering ewes pasture masses >1,200 kg DM/ha during very late pregnancy and lactation.
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AIMS: To investigate associations between changes in liveweight and fetal loss in ewe lambs and to determine whether fetal loss was associated with concentrations of progesterone in early and mid-gestation. METHODS: Ewe lambs on two commercial sheep farms (Flock A; n=504 and Flock B; n=460) in the southern North Island of New Zealand were weighed, and body condition score was assessed, prior to breeding and throughout pregnancy. Pregnancy diagnosis was undertaken approximately 56 (PD1), 80 (PD2) and 110 (PD3) days after the start of breeding and fetal loss determined. Blood samples were collected from a cohort of 407 ewe lambs between 45-54 and 73-84 days of gestation. Those that subsequently were diagnosed with fetal loss (n=16) were matched with ewe lambs that maintained pregnancy (n=16), and concentrations of progesterone were measured in the plasma samples from these animals. RESULTS: Fetal loss was diagnosed in 55/472 (11.7%) pregnant ewes from Flock A and 14/378 (3.7%) from Flock B. In both flocks the change in conceptus-free liveweight (CFLW) between PD1 and PD2 differed between ewe lambs with and without fetal loss; in Flock A the mean change was -59.9 (95% CI=-80.1 to -39.7) g/day vs. -3.43 (95% CI=-9.8 to 3.0) g/day (p<0.001), and in Flock B the change was -38.5 (95% CI=-78.9 to 1.94) g/day vs. 79.5 (95% CI=72.6-86.4) g/day (p<0.001). Similarly in Flock A the mean increase in CFLW between PD2 and PD3 was lower in ewe lambs with fetal loss than in those that maintained pregnancy (25.8 (95% CI=-13.8 to 65.4) g/day vs. 181.9 (95% CI=175.1-188.7) g/day) (p<0.001). There was no difference (p>0.05) in early and mid-gestation mean concentrations of progesterone in plasma between ewe lambs that had fetal loss compared with those that maintained pregnancy. CONCLUSIONS: Ewe lambs with fetal loss had a marked reduction in CFLW in the 24-30 days leading up to the identification of the fetal loss compared with those that maintained pregnancy. Early and mid-gestation concentrations of progesterone in plasma were similar between ewe lambs who went on to have fetal loss and those that maintained pregnancy.
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Peso Corporal , Muerte Fetal/etiología , Progesterona/sangre , Ovinos , Animales , Femenino , Edad Gestacional , Nueva Zelanda , EmbarazoRESUMEN
PURPOSE: In this work, ion recombination is studied as a function of energy and depth in carbon ion beams. METHODS: Measurements were performed in three different passively scattered carbon ion beams with energies of 62 MeV/n, 135 MeV/n, and 290 MeV/n using various types of plane-parallel ionization chambers. Experimental results were compared with two analytical models for initial recombination. One model is generally used for photon beams and the other model, developed by Jaffé, takes into account the ionization density along the ion track. An investigation was carried out to ascertain the effect on the ion recombination correction with varying ionization chamber orientation with respect to the direction of the ion tracks. The variation of the ion recombination correction factors as a function of depth was studied for a Markus ionization chamber in the 62 MeV/n nonmodulated carbon ion beam. This variation can be related to the depth distribution of linear energy transfer. RESULTS: Results show that the theory for photon beams is not applicable to carbon ion beams. On the other hand, by optimizing the value of the ionization density and the initial mean-square radius, good agreement is found between Jaffé's theory and the experimental results. As predicted by Jaffé's theory, the results confirm that ion recombination corrections strongly decrease with an increasing angle between the ion tracks and the electric field lines. For the Markus ionization chamber, the variation of the ion recombination correction factor with depth was modeled adequately by a sigmoid function, which is approximately constant in the plateau and strongly increasing in the Bragg peak region to values of up to 1.06. Except in the distal edge region, all experimental results are accurately described by Jaffé's theory. CONCLUSIONS: Experimental results confirm that ion recombination in the investigated carbon ion beams is dominated by initial recombination. Ion recombination corrections are found to be significant and cannot be neglected for reference dosimetry and for the determination of depth dose curves in carbon ion beams.
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Carbono/uso terapéutico , Iones/uso terapéutico , Radioterapia/métodos , Algoritmos , Simulación por Computador , Ciclotrones , Modelos Teóricos , Método de Montecarlo , Radioterapia/instrumentación , SincrotronesRESUMEN
The objective of this study was to develop a laboratory-scale method to rank the ignition and fire hazards of commonly used underground mine materials and to eliminate the need for the expensive large-scale tests that are currently being used. A radiant-panel apparatus was used to determine the materials' relevant thermal characteristics: time to ignition, critical heat flux for ignition, heat of gasification, and mass-loss rate. Three thermal parameters, TRP, TP1 and TP4, were derived from the data, then developed and subsequently used to rank the combined ignition and fire hazards of the combustible materials from low hazard to high hazard. The results compared favorably with the thermal and ignition hazards of similar materials reported in the literature and support this approach as a simpler one for quantifying these combustible hazards.
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This review outlines the benefits of using multiple approaches to improve model design and facilitate multidisciplinary research into infectious diseases, as well as showing and proposing practical examples of effective integration. It looks particularly at the benefits of using participatory research in conjunction with traditional modelling methods to potentially improve disease research, control and management. Integrated approaches can lead to more realistic mathematical models which in turn can assist with making policy decisions that reduce disease and benefit local people. The emergence, risk, spread and control of diseases are affected by many complex bio-physical, environmental and socio-economic factors. These include climate and environmental change, land-use variation, changes in population and people's behaviour. The evidence base for this scoping review comes from the work of a consortium, with the aim of integrating modelling approaches traditionally used in epidemiological, ecological and development research. A total of five examples of the impacts of participatory research on the choice of model structure are presented. Example 1 focused on using participatory research as a tool to structure a model. Example 2 looks at identifying the most relevant parameters of the system. Example 3 concentrates on identifying the most relevant regime of the system (e.g., temporal stability or otherwise), Example 4 examines the feedbacks from mathematical models to guide participatory research and Example 5 goes beyond the so-far described two-way interplay between participatory and mathematical approaches to look at the integration of multiple methods and frameworks. This scoping review describes examples of best practice in the use of participatory methods, illustrating their potential to overcome disciplinary hurdles and promote multidisciplinary collaboration, with the aim of making models and their predictions more useful for decision-making and policy formulation.
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Enfermedades Transmisibles/epidemiología , Zoonosis/epidemiología , África/epidemiología , Animales , Enfermedades Transmisibles/transmisión , Humanos , Modelos Teóricos , Formulación de Políticas , Zoonosis/prevención & control , Zoonosis/transmisiónRESUMEN
Atmospheric monitoring systems (AMS) are required when using air from conveyor belt entries to ventilate working sections in U.S. underground coal mines. AMS technology has the potential to increase fire safety mine-wide, but research is needed to determine the detection and response times for fires of a variety of combustible materials. To evaluate the potential of an AMS for fire detection in other areas of a coal mine, a series of full-scale fire experiments were conducted to determine detection and response times from fires of different combustible materials that are found in U.S. underground coal mines, including high- and low-volatility coals, conveyor belts, brattice materials, different types of wood, diesel fuel, and a foam sealant. These experiments were conducted in the Safety Research Coal Mine (SRCM) of the U.S. National Institute for Occupational Safety and Health (NIOSH) located in Pittsburgh, PA, using a commercially available AMS that is typical of current technology. The results showed that through proper selection of sensors and their locations, a mine-wide AMS can provide sufficient early fire warning times and improve the health and safety of miners.
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In drug development, the "onus" of the low R&D efficiency has been put traditionally onto the drug discovery process (i.e., finding the right target or "binding" functionality). Here, we show that manufacturing is not only a central component of product success, but also that, by integrating manufacturing and discovery activities in a "holistic" interpretation of QbD methodologies, we could expect to increase the efficiency of the drug discovery process as a whole. In this new context, early risk assessment, using developability methodologies and computational methods in particular, can assist in reducing risks during development in a cost-effective way. We define specific areas of risk and how they can impact product quality in a broad sense, including essential aspects such as product efficacy and patient safety. Emerging industry practices around developability are introduced, including some specific examples of applications to biotherapeutics. Furthermore, we suggest some potential workflows to illustrate how developability strategies can be introduced in practical terms during early drug development in order to mitigate risks, reduce drug attrition and ultimately increase the robustness of the biopharmaceutical supply chain. Finally, we also discuss how the implementation of such methodologies could accelerate the access of new therapeutic treatments to patients in the clinic.
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Biofarmacia/métodos , Diseño de Fármacos , Industria Farmacéutica/métodos , HumanosRESUMEN
Aggregation is a common problem affecting biopharmaceutical development that can have a significant effect on the quality of the product, as well as the safety to patients, particularly because of the increased risk of immune reactions. Here, we describe a new high-throughput screening algorithm developed to classify antibody molecules based on their propensity to aggregate. The tool, constructed and validated on experimental aggregation data for over 500 antibodies, is able to discern molecules with a high aggregation propensity as defined by experimental criteria relevant to bioprocessing and manufacturing of these molecules. Furthermore, we show how this tool can be combined with other computational approaches during early drug development to select molecules with reduced risk of aggregation and optimal developability properties.
Asunto(s)
Algoritmos , Anticuerpos/química , Agregado de Proteínas , HumanosRESUMEN
The present study evaluated the effect of controlled ryegrass-white clover herbage availability from day 128 until day 142 of pregnancy in comparison to unrestricted availability, on the performance of twin-bearing ewes of varying body condition score (BCS; 2.0, 2.5, or 3.0) and their lambs. It was hypothesised that under conditions of controlled herbage availability, the performance of lambs born to ewes with a greater BCS would be greater than those born to ewes with a lower BCS. During the period that the nutritional regimens were imposed, the pre- and post-grazing herbage masses of the Control regimen (1,070±69 and 801±30 kg dry matter [DM]/ha) were lower than the ad libitum regimen (1,784±69 and 1,333±33 kg DM/ha; p<0.05). The average herbage masses during lactation were 1,410±31 kg DM/ha. Nutritional regimen had no effect on ewe live weight, BCS and back fat depth or on lamb live weight, indices of colostrum uptake, maximal heat production, total litter weight weaned or survival to weaning (p>0.05). The difference in ewe BCSs and back fats observed among body condition groups was maintained throughout pregnancy (p<0.05). At weaning, ewes from the BCS2.0 group had lower BCS and live weight (2.4±0.2, 74.3±2.6 kg) than both the BCS2.5 (2.6±0.2, 78.6±2.4 kg) and BCS3.0 ewes (2.7±0.2, 79.0±2.6 kg; p<0.05), which did not differ (p>0.05). Ewe BCS group had no effect on lamb live weight at birth or weaning or on maximal heat production (p>0.05). Serum gamma glutamyl transferase concentrations of lambs born to BCS3.0 ewes were higher within 36 hours of birth than lambs born to BCS2.0 ewes and BCS2.5 ewes (51.8±1.9 vs 46.5±1.9 and 45.6±1.9 IU/mL, respectively [p<0.05]). There was, however, no effect of ewe body condition on lamb plasma glucose concentration (p>0.05). Lamb survival was the only lamb parameter that showed an interaction between ewe nutritional regimen and ewe BCS whereby survival of lambs born to BCS2.5 and BCS3.0 ewes differed but only within the Control nutritional regimen ewes (p<0.05). These results indicate farmers can provide twin-bearing ewes with pre- and post-grazing ryegrass-white clover herbage covers of approximately 1,100 and 800 kg DM/ha in late pregnancy, provided that herbage covers are 1400 in lactation, without affecting lamb performance to weaning. The present results also indicate that under these grazing conditions, there is little difference in ewe performance within the BCS range of 2.0 to 3.0 and therefore they do not need to be managed separately.