Amalthea's density is less than that of water

Radio Doppler data from the Galileo spacecraft's encounter with Amalthea, one of Jupiter's small inner moons, on 5 November 2002 yield a mass of (2.08 +/- 0.15) x 10(18) kilograms. Images of Amalthea from two Voyager spacecraft in 1979 and Galileo imaging between November 1996 and June 1997 yield a volume of (2.43 +/- 0.22) x 10(6) cubic kilometers. The satellite thus has a density of 857 +/- 99 kilograms per cubic meter. We suggest that Amalthea is porous and composed of water ice, as well as rocky material, and thus formed in a cold region of the solar system, possibly not at its present location near Jupiter.     

The Chinese grass carp, Ctenopharyngodon idella, its biology,introduction, control of aquatic macrophytes and breeding in the Sudan

The paper describes the distribution and biology of the grass carp following its introduction into Sudan. It provides aspects on the culture of the grass carp and its breeding under Sudanese conditions with emphasis on future research.     

Do some IPM concepts contribute to the development of fungicide resistance? Lessons learned from the apple scab pathosystem in the United States

One goal of integrated pest management (IPM) as it is currently practiced is an overall reduction in fungicide use in the management of plant disease. Repeated and long‐term success of the early broad‐spectrum fungicides led to optimism about the capabilities of fungicides, but to an underestimation of the risk of fungicide resistance within agriculture. In 1913, Paul Ehrlich recognized that it was best to ‘hit hard and hit early’ to prevent microbes from evolving resistance to treatment. This tenet conflicts with the fungicide reduction strategies that have been widely promoted over the past 40 years as integral to IPM. The authors hypothesize that the approaches used to implement IPM have contributed to fungicide resistance problems and may still be driving that process in apple scab management and in IPM requests for proposals. This paper also proposes that IPM as it is currently practiced for plant diseases of perennial systems has been based on the wrong model, and that conceptual shifts in thinking are needed to address the problem of fungicide resistance. © 2013 Society of Chemical Industry     

Detection of QTL for forage yield,lodging resistance and spring vigor traits in alfalfa (Medicago sativa L.)

Alfalfa (Medicago sativa L.) is an internationally significant forage crop. Forage yield, lodging resistance and spring vigor are important agronomic traits conditioned by quantitative genetic and environmental effects. The objective of this study was to identify quantitative trait loci (QTL) and molecular markers associated with increased forage yield, resistance to lodging, and spring vigor. A backcross population composed of 128 progeny was developed by crossing the breeding parents DW000577 (lodging susceptible) and NL002724 (lodging-resistant) and back-crossing an individual F₁ plant to the maternal parent (i.e. DW000577). A linkage map of NL002724 was developed based upon the segregation of 236 AFLP, SRAP, and SSR markers among the backcross progeny. The markers were distributed among 14 linkage groups, covering an estimated recombination distance of 1497.6 centiMorgans (cM). Replicated clones of both parents and backcross progeny were evaluated in the field for estimated forage yield, lodging, and spring vigor in Washington and Wisconsin during 2007 and 2008. Significant QTL were found for all three traits. In particular, two QTL for lodging resistance were identified that explained ≥14 % of trait variation, and were significant in all years and locations. Major QTL explaining over 25 % of trait variation for forage yield were detected in multiple environments at two separate locations on chromosome III. Several QTL for spring vigor were located in the same or similar positions as QTL for forage yield, possibly explaining the significant correlation between these traits. Molecular markers associated with the aforementioned QTL were also identified.     

Infrared spectroscopy of comet 81P/Wild 2 samples returned by Stardust

Infrared spectra of material captured from comet 81P/Wild 2 by the Stardust spacecraft reveal indigenous aliphatic hydrocarbons similar to those in interplanetary dust particles thought to be derived from comets, but with longer chain lengths than those observed in the diffuse interstellar medium. Similarly, the Stardust samples contain abundant amorphous silicates in addition to crystalline silicates such as olivine and pyroxene. The presence of crystalline silicates in Wild 2 is consistent with mixing of solar system and interstellar matter. No hydrous silicates or carbonate minerals were detected, which suggests a lack of aqueous processing of Wild 2 dust.     

Central Diabetes Insipidus in a Dog With a Pro-Opiomelanocortin-Producing Pituitary Tumor ot Causing Hyperadrenocorticism

Central diabetes insipidus was diagnosed by vasopressin measurements during hypertonic stimulation in a 9-year-old male giant Schnauzer with polyuria and polydipsia. The impaired release of vasopressin was believed to be caused by a large pituitary tumor, which was visualized by computed tomography. Studies of the function of the anterior lobe and the pars intermedia of the pituitary gland were conducted, and high concentrations of ACTH and α-melanotrophic hormone (α-MSH) were found without concomitant hyperadrenocorticism. Studies of the molecular size of the immunoreactive ACTH in plasma by gel filtration revealed that most of the circulating immunoreactivity was not ACTH but its precursor pro-opiomelanocortin (POMC) and low-molecular-weight POMC-derived peptides. The pituitary tumor of this dog probably originated from melanotrophic cells of the pars intermedia. The sensitivity of the pituitary-adrenocortical system for the suppressive effect of dexamethasone was unaffected.     

Atraumatic loop electrodes for electroretinography

A simple method is described for producing inexpensive, atraumatic electrodes for electroretinography. Scleral contact is obtained by a loop of ultra-lightweight stainless steel wire placed between the eye and lower lid. Recordings obtained by this method in animals are equal to those recorded with needle electrodes, and the expense and complex construction of contact lens electrodes of varying sizes is avoided. Sample recordings made with loop and needle electrodes from the same ophthalmologically normal dog are presented.