Effect of DDGS manure on soil and plant: preliminary results of the greenhouse study

Non-Peer ReviewedThe use of dried distillers’ grains with solubles (DDGS) in feedlot cattle diets is increasing as the bio-ethanol industry expands. Manure derived from dried distiller’s grain with solubles (DDGS) fed cattle seem to have higher amounts of N and P than manure from regular grain fed cattle. This study investigates how DDGS manure affects soil fertility and nutrient uptake by barley grown in a controlled greenhouse environment. Both DDGS and regular manure were applied at 30, 60, 120 and 180 Mg ha-1 yr-1 to a sand soil. The results of the first 3 harvest cycles indicate that both types of manure resulted in similar increase in plant total P content. However, soil TP and available P concentrations in DDGS manure treatments were higher. Soil available in DDGS treatments was twice as much of that in regular manure. Increase in soil TN and available N contents was similar with both types of manure. Plant TN content did not seem to be influenced by manure application. This study indicates that the main concern with the use of DDGS manure is its high P solubility. However, no significant increase in soil available P was observed at a manure rate of 30 Mg ha-1 yr-1

Growth and production of a tropical predatory shrimp, Macrobrachium hainanense (Palaemonidae), in two Hong Kong streams

1. Macrobrachium hainanense is a predatory palaemonid shrimp (total length >7 cm) that can be abundant [density 3-5 m-2; biomass 484-606 mg ash-free dry mass (AFDM) m-2] in forest streams in Hong Kong, China. This study investigated the growth and production of M. hainanense during 2001 and 2002 in pools of two forested streams (one third- and one fourth-order). 2. The growth of tagged individuals was recorded in situ and compared with that of tagged and untagged shrimps in laboratory tanks. Field and laboratory estimates yielded similar growth rates of 0.7 mm carapace length (CL) per month, and instantaneous growth rate was 0.004 g AFDM g-1 day-1. Tagging did not affect growth in the laboratory. Cohort analysis of field populations produced similar estimates of growth to that of tagged individuals, and the growth of M. hainanense was generally slower than has been reported for other Macrobrachium species. Mass-specific growth rate of M. hainanense in the field varied with size and was two to five times higher in small individuals (<10 mm CL). In addition, growth rate varied with season and was 40% lower in the dry season when temperature was at the annual minimum. 3. Males grew bigger than females (36 versus 25 mm CL). The minimum lifespan of M. hainanense in the field, calculated from size-specific growth rates, ranged from 29.3 months (females) to 47.6 months (males). Male lifespan derived from cohort analysis was estimated as 48 and 46 months in the two streams. Females reached maturity in 17-18 months (at 15-17 mm CL) while males matured at 24-26 months (at 18-22 mm CL). Females bred twice (at 2 and 3 years of age) while males probably bred three times (at 2, 3 and 4 years) in both streams. 4. Macrobrachium hainanense production in the fourth-order stream, calculated by the size-frequency method, was 900 and 1096 mg AFDM m-2 year-1 (for 2001 and 2002, respectively) with a production/biomass (P/B) of 2.1-2.3 year-1. In the third-order stream, production was 987 and 1304 mg AFDM m-2 year-1 (for 2001 and 2002, respectively) with a P/B of 1.7-2.1 year-1. Production estimates based on the instantaneous growth method were half of those obtained by the size-frequency method. 5. Although M. hainanense production at the third-order stream exceeded that in the fourth-order, growth rates showed the opposite pattern and were 0.31-0.43 mm CL month-1 and 0.56-0.65 mm CL month-1 in the third- and fourth-order streams, respectively. Greater mortality in the latter may account for low production at a site where growth rate was high. 6. Production of M. hainanense in both streams was lower during 2001 when rainfall was higher. This may reflect the influence of spates associated with monsoonal rains, which could have reduced M. hainanense production through spate-induced mortality or by reducing the abundance of prey. This study provides the first in situ estimate of secondary production by a non-commercial Macrobrachium species in Asia or elsewhere. It involved a whole-pool approach to sampling that allowed the estimation of production and population parameters on a realistic scale.link_to_subscribed_fulltex

Hearing loss and PRPS1 mutations: Wide spectrum of phenotypes and potential therapy

Item does not contain fulltextOBJECTIVE: The purpose of this review was to evaluate the current literature on phosphoribosylpyrophosphate synthetase 1 (PRPS1)-related diseases and their consequences on hearing function. DESIGN: A literature search of peer-reviewed, published journal articles was conducted in online bibliographic databases. Study sample: Three databases for medical research were included in this review. RESULTS: Mutations in PRPS1 are associated with a spectrum of non-syndromic to syndromic hearing loss. Hearing loss in male patients with PRPS1 mutations is bilateral, moderate to profound, and can be prelingual or postlingual, progressive or non-progressive. Audiogram shapes associated with PRPS1 deafness are usually residual and flat. Female carriers can have unilateral or bilateral hearing impairment. Gain of function mutations in PRPS1 cause a superactivity of the PRS-I protein whereas the loss-of-function mutations result in X-linked nonsyndromic sensorineural deafness type 2 (DFN2), or in syndromic deafness including Arts syndrome and X-linked Charcot-Marie-Tooth disease-5 (CMTX5). CONCLUSIONS: Lower residual activity in PRS-I leads to a more severe clinical manifestation. Clinical and molecular findings suggest that the four PRPS1 disorders discovered to date belong to the same disease spectrum. Dietary supplementation with S-adenosylmethionine (SAM) appeared to alleviate the symptoms of Arts syndrome patients, suggesting that SAM could compensate for PRS-I deficiency