Nauclefolinine: A new alkaloid from the roots of Nauclea latifolia

A novel indole alkaloid, nauclefolinine (1) and five known triterpenic compounds, rotundic acid (2), a-L-rhamnoquinovic acid (3), 3-O-b-D-glucopyranosyl-b-sitosterol (4), squalene (5) and sitosterol-3-O-6’-stearoyl-b-D-glucopyranoside (6) have been isolated from the roots of Nauclea latifolia. KEY WORDS: Nauclea latifolia, Rubiaceae, Indole alkaloid, Triterpenic acids, Rotundic acid, Rhamnoquinovic acid  Bull. Chem. Soc. Ethiop. 2003, 17(2), 173-176

Effects of Seasonal Variation in Milk Composition on the Quality of Pizza Cheese

End of Project ReportThe main aims of this study were to investigate the effects of diet and lactation stage on the composition and cheesemaking quality of milk produced under controlled conditions. The main conclusions were as follows: These studies clearly demonstrated that the Recommended Moorepark Milk Production System in conjunction with an objectively standardised cheesemaking process provides a model for year round production of quality Mozzarella cheese. Databases have been established on the effects of diet quantity and quality, and stage of lactation on the composition, processability and cheesemaking characteristics of milk from both Spring- and Autumn-calving herds. Increasing the daily herbage allowance from 16 to 24 kgs DM/cow/day during mid-lactation, resulted in increases in the level of milk casein and cheese yield but had little influence on cheese functionality. Similarily improving diet quality in mid-lactation by reducing the stocking density from 4.3 to 3.8 cows/ha combined with concentrate supplementation (3 kgs/cow/day) had the same effect. Using milk from a Spring-calving herd, produced according to the Recommended Moorepark Milk Production System, in conjunction with an objectively-standardised Mozzarella cheesemaking process, no major problems were encountered during the lactation period 170 - 273 days from calving. Extending the lactation period of the Spring-calving herd from ~ 273 to 286 days resulted in higher cheese moisture (by ~ 2%), softer cheese, and lower chewiness in the melted cheese. A sharp decline in both total protein, casein and lactose in the milk was observed during this period. However the blending of this milk with milk of an Autumn-calving herd overcame these cheesemaking problems. The yield of low moisture Mozzarella cheese (using milks from Spring- or Autumn-calved herds) was positively correlated with milk casein level. The yield of cheese from the Spring-calved herd increased concomitantly with increasing casein level to day 273 of lactation and decreased thereafter as the casein concentration declined. In these studies it was found that easy-to-use tests such as lactose level in the milk and rennet coagulation properties as determined by Formagraph were useful indicators of the suitability of milk for cheesemaking. The Recommended Moorepark Milk Production System, as applied in the late lactation period, was characterised by a high plane of nutrition and a drying-off strategy which ensured a minimum daily milk yield per cow of 9 kg. It resulted in milk of good cheesemaking quality - lactose > 4.25%, and casein > 2.6% and satisfactory rennet coagulation properties - curd firming rate of > 0.15 min ¯¹ curd firmness at 60 min of > 45mm - at the end of lactation.Department of Agriculture, Food and the Marin

Genetic Variants of Milk Proteins - Relevance to Milk Composition and Cheese Production.

End of Project ReportObjectives: (i) to develop rapid screening procedures for the determination of milk protein polymorphism (genetic variants) (ii) to determine the frequency distribution of milk protein genetic variants in a large population of Irish Holstein-Friesians and to determine if there was an association between κ-casein variant and milk yield and composition in this group of animals, and (iii) to make Cheddar and low-moisture part-skim Mozzarella cheese from different κ-casein genetic variant milks and to assess any effect on cheese yield, composition and functional characteristics. Conclusions:Analysis of 6,007 individual Irish Holstein-Friesian milks showed that the phenotype distribution of the κ-casein BB variant was very low at 1.98% compared to 53.07% for κ-casein AA and 44.95% for κ-casein AB. While no statistically significant associations were observed between κ-casein variant and milk yield and composition, κ-casein BB variant milks had superior rennet coagulation properties to that of the AA or AB variants. Generally, κ-casein variant had little effect on compositional attributes of cheese apart from FDM (fat in dry matter) which was significantly higher in cheeses from κ-casein BB milk than in those from κ-casein AA milk. Generally, κ-casein variant had no significant effects on either primary or secondary proteolysis, or on the sensory and/or textural characteristics of Cheddar or Mozzarella cheese throughout ripening; or on the functional characteristics (e.g. flow and stretch) of baked Mozzarella on storage for 90 days at 4°C. However, κ-casein BB variant milk gave significantly higher actual, and moisture adjusted yields of Cheddar and Mozzarella cheese than either κ-casein AB or AA variant milks. For example, the moisture adjusted Cheddar yield from κ-casein BB milk was 8.2% higher than from κ-casein AA milk. In the case of Mozzarella, the moisture adjusted yield was 12% higher. Based on the results, it is estimated that the actual yield of cheese in a plant producing 20,000 tonnes per year from κ-casein AA milk would increase to approximately 21,180 tonnes of Cheddar, or 21,780 tonnes of Mozzarella if made from κ-casein BB milk. Where κ-casein AB milk is used instead of κ-casein BB milk, the estimated yield of Mozzarella would increase to 21,580 tonnes.Department of Agriculture, Food and the Marin

Local Charge Excesses in Metallic Alloys: a Local Field Coherent Potential Approximation Theory

Electronic structure calculations performed on very large supercells have shown that the local charge excesses in metallic alloys are related through simple linear relations to the local electrostatic field resulting from distribution of charges in the whole crystal. By including local external fields in the single site Coherent Potential Approximation theory, we develop a novel theoretical scheme in which the local charge excesses for random alloys can be obtained as the responses to local external fields. Our model maintains all the computational advantages of a single site theory but allows for full charge relaxation at the impurity sites. Through applications to CuPd and CuZn alloys, we find that, as a general rule, non linear charge rearrangements occur at the impurity site as a consequence of the complex phenomena related with the electronic screening of the external potential. This nothwithstanding, we observe that linear relations hold between charge excesses and external potentials, in quantitative agreement with the mentioned supercell calculations, and well beyond the limits of linearity for any other site property.Comment: 11 pages, 1 table, 7 figure

A Measurement of Time-Averaged Aerosol Optical Depth using Air-Showers Observed in Stereo by HiRes

Air fluorescence measurements of cosmic ray energy must be corrected for attenuation of the atmosphere. In this paper we show that the air-showers themselves can yield a measurement of the aerosol attenuation in terms of optical depth, time-averaged over extended periods. Although the technique lacks statistical power to make the critical hourly measurements that only specialized active instruments can achieve, we note the technique does not depend on absolute calibration of the detector hardware, and requires no additional equipment beyond the fluorescence detectors that observe the air showers. This paper describes the technique, and presents results based on analysis of 1258 air-showers observed in stereo by the High Resolution Fly's Eye over a four year span.Comment: 7 pages, 3 figures, accepted for publication by Astroparticle Physics Journa

Search for Global Dipole Enhancements in the HiRes-I Monocular Data above 10^{18.5} eV

Several proposed source models for Ultra-High Energy Cosmic Rays (UHECRs) consist of dipole distributions oriented towards major astrophysical landmarks such as the galactic center, M87, or Centaurus A. We use a comparison between real data and simulated data to show that the HiRes-I monocular data for energies above 10^{18.5} eV is, in fact, consistent with an isotropic source model. We then explore methods to quantify our sensitivity to dipole source models oriented towards the Galactic Center, M87, and Centaurus A.Comment: 17 pages, 31 figure

Observation of the Ankle and Evidence for a High-Energy Break in the Cosmic Ray Spectrum

We have measured the cosmic ray spectrum at energies above $10^{17}$ eV using the two air fluorescence detectors of the High Resolution Fly's Eye experiment operating in monocular mode. We describe the detector, PMT and atmospheric calibrations, and the analysis techniques for the two detectors. We fit the spectrum to models describing galactic and extragalactic sources. Our measured spectrum gives an observation of a feature known as the ``ankle'' near $3\times 10^{18}$ eV, and strong evidence for a suppression near $6\times 10^{19}$ eV.Comment: 14 pages, 9 figures. To appear in Physics Letters B. Accepted versio

Compound heterozygous variants in NBAS as a cause of atypical osteogenesis imperfecta

Background Osteogenesis imperfecta (OI), the commonest inherited bone fragility disorder, affects 1 in 15,000 live births resulting in frequent fractures and reduced mobility, with significant impact on quality of life. Early diagnosis is important, as therapeutic advances can lead to improved clinical outcome and patient benefit. Report Whole exome sequencing in patients with OI identified, in two patients with a multi-system phenotype, compound heterozygous variants in NBAS (neuroblastoma amplified sequence). Patient 1: NBAS c.5741G > A p.(Arg1914His); c.3010C > T p.(Arg1004*) in a 10-year old boy with significant short stature, bone fragility requiring treatment with bisphosphonates, developmental delay and immunodeficiency. Patient 2: NBAS c.5741G > A p.(Arg1914His); c.2032C > T p.(Gln678*) in a 5-year old boy with similar presenting features, bone fragility, mild developmental delay, abnormal liver function tests and immunodeficiency. Discussion Homozygous missense NBAS variants cause SOPH syndrome (short stature; optic atrophy; Pelger-Huet anomaly), the same missense variant was found in our patients on one allele and a nonsense variant in the other allele. Recent literature suggests a multi-system phenotype. In this study, patient fibroblasts have shown reduced collagen expression, compared to control cells and RNAseq studies, in bone cells show that NBAS is expressed in osteoblasts and osteocytes of rodents and primates. These findings provide proof-of-concept that NBAS mutations have mechanistic effects in bone, and that NBAS variants are a novel cause of bone fragility, which is distinguishable from ‘Classical’ OI. Conclusions Here we report on variants in NBAS, as a cause of bone fragility in humans, and expand the phenotypic spectrum associated with NBAS. We explore the mechanism underlying NBAS and the striking skeletal phenotype in our patients

Fitting the integrated Spectral Energy Distributions of Galaxies

Fitting the spectral energy distributions (SEDs) of galaxies is an almost universally used technique that has matured significantly in the last decade. Model predictions and fitting procedures have improved significantly over this time, attempting to keep up with the vastly increased volume and quality of available data. We review here the field of SED fitting, describing the modelling of ultraviolet to infrared galaxy SEDs, the creation of multiwavelength data sets, and the methods used to fit model SEDs to observed galaxy data sets. We touch upon the achievements and challenges in the major ingredients of SED fitting, with a special emphasis on describing the interplay between the quality of the available data, the quality of the available models, and the best fitting technique to use in order to obtain a realistic measurement as well as realistic uncertainties. We conclude that SED fitting can be used effectively to derive a range of physical properties of galaxies, such as redshift, stellar masses, star formation rates, dust masses, and metallicities, with care taken not to over-interpret the available data. Yet there still exist many issues such as estimating the age of the oldest stars in a galaxy, finer details ofdust properties and dust-star geometry, and the influences of poorly understood, luminous stellar types and phases. The challenge for the coming years will be to improve both the models and the observational data sets to resolve these uncertainties. The present review will be made available on an interactive, moderated web page (sedfitting.org), where the community can access and change the text. The intention is to expand the text and keep it up to date over the coming years.Comment: 54 pages, 26 figures, Accepted for publication in Astrophysics & Space Scienc