A Study to Determine the Effect of Web-based Information on Improving the Knowledge of Automotive Students at Danville Community College

The following hypothesis will guide this study: 1. Danville Community College automotive students who used the internet as part of instruction in 1999 will achieve better test and exam scores which will lead to higher final grades in electrical and computerized fuel control classes than students in the same classes in 1998 who were not taught internet search skills

Using lactation curves as a tool for breeding, nutrition and health management decisions in pasture-based dairy systems

Milk yield and reproductive efficiency are crucial to profitable dairying. Although, genetic improvement in the last few decades has led to substantial increases in milk yield/cow, fertility and reproductive health have declined (Dematawewa and Berger, 1998). In a pasture-based system, a 365 day calving interval is crucial for optimum profit. Hence the need to increase milk yield by improving persistence of lactation rather than peak lactation which puts increased stress on the cows at the time when they should be rebreeding. Peak milk yield, persistency and lactation length are the key components of the lactation profile. Dairy cows with high peak yields are more prone to metabolic and physiological disorders (Terkeli et al 1999). Although estimated breeding values (EBV) in dairy cows in Australia incorporates indices of economic value, such as survival and milking speed, the impact of the current breeding approach and management on the shape of the lactation profile is not clear. Mathematical functions such as those previously used to describe a series of milk test day records (Wood, 1967, Wilmink, 1987), have the advantage of minimizing random variation while simultaneously summarising the lactation profile into biologically interpretable parameters

Does Leaf Position within a Canopy Affect Acclimation of Photosynthesis to Elevated CO2? . Analysis of a Wheat Crop under Free-Air CO2 Enrichment

Previous studies of photosynthetic acclimation to elevated CO2 have focused on the most recently expanded, sunlit leaves in the canopy. We examined acclimation in a vertical profile of leaves through a canopy of wheat (Triticum aestivum L.). The crop was grown at an elevated CO2 partial pressure of 55 Pa within a replicated field experiment using free-air CO2 enrichment. Gas exchange was used to estimate in vivo carboxylation capacity and the maximum rate of ribulose-1,5-bisphosphate-limited photosynthesis. Net photosynthetic CO2 uptake was measured for leaves in situ within the canopy. Leaf contents of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), light-harvesting-complex (LHC) proteins, and total N were determined. Elevated CO2 did not affect carboxylation capacity in the most recently expanded leaves but led to a decrease in lower, shaded leaves during grain development. Despite this acclimation, in situ photosynthetic CO2 uptake remained higher under elevated CO2. Acclimation at elevated CO2 was accompanied by decreases in both Rubisco and total leaf N contents and an increase in LHC content. Elevated CO2 led to a larger increase in LHC/Rubisco in lower canopy leaves than in the uppermost leaf. Acclimation of leaf photosynthesis to elevated CO2 therefore depended on both vertical position within the canopy and the developmental stage

Genetic and phenotypic factors inuencing milk, protein and fat yields of dairy cows in Tasmania, Australia

The Australian State of Tasmania enjoys a cool, temperate climate that remains the backbone of its pasture-based dairy production system. In this study, 330,366 lactation records from 428 Tasmanian dairy herds collected between 2000 and 2005 were analysed. The objective was to determine the inuence of genetic and non-genetic factors on milk, protein and fat yields of pasture-based dairy cows. The data were statistically subjected to analyses of variance using general linear mixed model procedures with repeated measures. State-wide average milk yield per lactation over a standard 305-day lactation length was 5200.7 ± 1239.7 litres (ranging from 1107 to 13256 litres), while fat and protein yields averaged 205.5 ± 47.0 kg (ranging from 53 to 385 kg) and 166.2 ± 41.5 kg (ranging from 47 to 297 kg), respectively. Highly signicant (P<0.001) effects on milk, protein and fat yields attributable to variation in herd size, cow’s parity, breed, season and year of calving were detected. Milk yield increased linearly with increase in parity (means of 3482.4, 4019.5, 4615.4, 4826.1 and 5018.8 litres per lactation for parities 1, 2, 3, 4 and >4, respectively). Milk, fat and protein yields were highest in cows calving during the spring season (4769.8 litres, 215.2kg and 168 kg respectively), Holstein-Friesian genotypes produced the most milk (5211 litres), protein (171 kg) and fat (210kg) yields per lactation. Herd sizes of more than 1110 cows produced the most milk, fat and protein. Productivity per cow increased with calving year except in 2003 when total milk yield was lower than in 2002. We conclude that herd size, breed, parity, season and year of calving were among the main factors driving production of dairy cows in Tasmania and adjustments for these factors would be mandatory for any unbiased comparison of lactation performance within and between pasture-based dairy production systems

Student Housing: Trends, Preferences And Needs

To attract and retain students, universities are confronted with increased demand to provide housing options that meet the new expectations of the millennial generation.&nbsp; Recent trends and housing preferences are examined.&nbsp; The results of surveys detailing some of these new demands and how universities are attempting to address these demands are discussed.&nbsp; Additionally, universities are under pressure to efficiently use their limited resources and, as government support for higher education declines, public universities are seeking other sources of funding for major projects. Suggestions are made for unique partnering and financing options.&nbsp

Predictive characteristics of lactation models for pasture-based Holstein-Friesian dairy cows

Mathematical functions to describe a series of milk test day records have the advantage of minimizing random variation, while simultaneously summarizing the lactation profile. Five empirical functions and two mechanistic models were used to model herd and individual milk yield profiles of multiparous Holstein-Friesian cows on 113, 290 milk yield records (8438 lactations) collected from 1994-2005. The models tested were the incomplete gamma (IG), a modified gamma (MG), an exponential (EXP), a polynomial regression (PR), a mixed log (ML), the bi-compartmental (BC), and Dijkstra (DJ) functions, the latter two being mechanistic models. Each model was fitted using the non-linear (NLIN) function of SAS. Model accuracy was evaluated based on residual mean square (RMS), the magnitude and distribution of residuals, and the correlation between the observed and predicted values. All the models, except MG, did equally well in portraying the lactation profile. Parameter estimates were significant (P<0.05), with large serial correlations indicating biased predictions, especially during mid-lactation. Correlations of residuals and observed herd average lactations ranged between -0.13 (MG) to 0.19 (IG), while that between observed and predicted was between 0.76 and 0.99 for the same models. Lactation curves of individual cow milk yields were more varied, exhibited the tendency for a second peak which were not accurately modeled. Mechanistic models performed best with herd data, the PR model fitted overall best, while the MG model fitted the profile least accurately in this study

Book Reviews

Critical Thinking and Intelligence Analysis. By David T.Moore. At The Center Of The Storm: The CIA During America's Time of Crisis. By George Tenet with Bill Harlow. Female Suicide Bombers. By Rosemarie Skaine. Information Operations: Doctrine and Practice. By Christopher Paul. The Secret Sentry: The Untold History of the National Security Agency. By Matthew M. Aid. The Blood of Lambs: A Former Terrorist's Memoir of Death and Redemption. By Kamal Saleem with Lynn Vincent. Attaché Extraordinaire: Vernon A. Walters in Brazil. By Frank Márcio De Oliveira

Technical note: A comparison of editing criteria for lying-behaviour data derived from three-dimensional accelerometer devices on grazing dairy cows

fals

Design of photoactivatable metallodrugs : selective and rapid light-induced ligand dissociation from half-sandwich [Ru([9]aneS3)(N–N′)(py)]2+ complexes

The synthesis of the inert Ru(II) half-sandwich coordination compounds, [Ru([9]aneS3)(bpy)(py)][PF6]2 (1, [9]aneS3 = 1,4,7-trithiacyclononane, bpy = 2,2′-bipyridine, py = pyridine), [Ru([9]aneS3)(en)(py)][PF6]2 (2, en = 1,2-diaminoethane), and [Ru([9]aneN3)(en)(dmso-S)][PF6]2 (3, [9]aneN3 = 1,4,7-triazacyclononane), is reported along with the X-ray crystal structure of 1. We investigated whether these complexes have photochemical properties which might make them suitable for use as pro-drugs in photochemotherapy. Complexes 1 and 2 underwent rapid (minutes) aquation with dissociation of the pyridine ligand in aqueous solution when irradiated with blue light (λ = 420 or 467 nm). The photodecomposition of 3 was much slower. All complexes readily formed adducts with 9-ethylguanine (9-EtG) when this model nucleobase was present in the photolysis solution. Similarly, complex 1 formed adducts with the tripeptide glutathione (GSH), but only when photoactivated. HPLC and MS studies of 1 showed that irradiation promoted rapid formation of 1:1 (major) and 1:2 (minor) adducts of the oligonucleotide d(ATACATGCTACATA) with the fragment {Ru([9]aneS3)(bpy)}2+. Density functional theory (DFT) calculations and time-dependent DFT reproduced the major features of the absorption spectra and suggested that the lowest-lying triplet state with 3MLCT character, which is readily accessible via intersystem crossing, might be responsible for the observed dissociative behavior of the excited states. These complexes are promising for further study as potential photochemotherapeutic agents