Using pork to teach students quality variations and how they are measured. 1998 UW-AS-305 Class.

Using a total of eight pork loins representing DFD (dark, firm, and dry) and PSE (pale, soft, and exudative) conditions, 35 students conducted a series of objective and subjective measurements to demonstrate extremes in meat quality in a single 2-h laboratory. Students learned to objectively assess appearance, water-holding and water-binding capacity, ultimate pH (pHu), and shear force (cooked samples) by operating seven commonly known laboratory instruments. They also learned how to prepare and present samples for organoleptic analysis using hedonic and triangle tests. Finally, the students learned the factors related to meat quality and how extremely they can vary. Within one laboratory, they observed that DFD, when compared with PSE, averaged 1.5 units higher in pHu, 4.7% (absolute) less drip loss, bound 136% (absolute) more water, was darker in color (26 units lower L* value), was firmer with a more attractive structure requiring 1 kg/cm less force to shear, and was superior in organoleptic properties (overall 21% more desirable). Having 35 replicates to use for the data set, the results illustrated statistically significant variations in meat-quality traits and how they could be objectively measured. Nine months later, 12 of the students were surveyed. It was their perception that the laboratory was not any more effective than other laboratories in the same class, but they were able to remember 85% of the methods used to measure quality; about twice that of other methods taught in other laboratory sessions.     

Allelopathic potential of native plants against water hyacinth

Classical biocontrol of water hyacinth using insects in India is constrained by seasonal occurrence of water flow and interrupted host range. Use of fungal pathogens is also difficult due to lack of shelf-life and virulence under severe climatic fluctuations and a lack of knowledge of spray techniques. Hence, the allelopathic potential of native plants is reviewed for use as an alternative bio-control tactic. Dried powder of the leaves of Omavalli Coleus amboinicus L. at 40 g l⁻¹ as a water suspension killed water hyacinth within 24 h reducing the fresh weight by 80.72% and the dry weight by 75.63% within one week. The lowest dose required to kill the whole plant was 10 g l⁻¹. Coleus powder was injurious to cut leaves of water hyacinth even at 0.1 g l⁻¹ dose as it was absorbed directly by the cut leaf, indicating that the dose required to kill the whole plant could still be reduced, if either the natural product or the active principle is formulated for absorption through foliage.     

Monoclonal antibody probe for assessing beer foam stabilizing proteins.

A monoclonal antibody (Mab; IFRN 1625) has been produced, which is specific for the most hydrophobic polypeptides responsible for foam stabilization. The binding characteristics of the Mab suggest that it is the conformation of certain hydrophobic polypeptides which is important for foam stabilization. An enzyme-linked immunosorbent assay (ELISA) for assessing the foam-positive form of the foam-stabilizing polypeptides in beer was developed using IFRN 1625. A good correlation was obtained between ELISA determination of foam-stabilizing polypeptides and an empirical means of determining foaming, that is, the Rudin head retention values, for a collection of beers of various foam qualities. Application of the ELISA to different stages of the brewing process showed that the amounts of foam-positive polypeptides increased during barley germination. During the brewing process the proportion of foam-positive polypeptides present after fermentation increased slightly, although a large amount was lost along with other beer proteins during subsequent steps, such as filtering. The present study demonstrates that the amounts of beer polypeptide present in a foam-positive form have a direct relationship with the foaming potential of beer, that their levels are altered by processing, and that there is potential for greater quality control.     

Water Quality Trends (1970 to 2005) Along Delaware Streams in the Delaware and Chesapeake Bay Watersheds, USA

Water quality trends from 1970 to 2005 were defined along 30 Delaware streams in the Delaware and Chesapeake Bay watersheds in the USA. Water quality improved or was constant at 69% of stations since 1990 and at 80% of stations since 1970/1980. Dissolved oxygen (DO) improved or was constant at 73% of streams since 1990 and 32% of streams since 1970/1980. Total suspended sediment improved or was constant at 75% of streams since 1990 and 100% of streams since 1970/1980. Enterococcus bacteria improved or remained constant at 80% of streams since 1990 and 93% of streams since 1970/1980. Total Kjeldahl nitrogen improved or was constant at 48% of streams since 1990 and 100% of streams since 1970/1980. Total phosphorus improved or was constant at 66% of streams since 1990 and 85% of streams since 1970/1980. During 2001–2005, median levels were good or fair at 100% of the stations for DO, 78% for sediment, 50% for bacteria, 59% for nitrogen, and 56% for phosphorus. Good water quality correlates with high amounts of forest area (>25%) in Delaware watersheds. Since the Federal Clean Water Act Amendments of the 1970s, improving Delaware water quality stations (50) outnumbered degrading stations (23) by a 2:1 margin. Since 1990, degrading water quality stations (46) exceeded improving stations (38) mostly due to deteriorating nitrogen levels in half of Delaware streams, a reversal from early gains achieved since the 1970s. Over the last three and a half decades, watershed strategies have improved or preserved water quality along Delaware streams; however, greater emphasis is needed to curb recently resurging increases in nitrogen levels.     

Effects of barefoot trimming on hoof morphology

Objective To monitor changes in hoof morphology in response to barefoot trimming. Methods Seven horses were trimmed every 6 weeks according to barefoot trimming principles, which involved levelling the hoof to live sole, lowering the heels, bevelling the toe and rounding the peripheral wall, while leaving the sole, frog and bars intact. A 4‐month period was allowed to lower the heels sufficiently to achieve a hoof shape representative of the barefoot trim. This was regarded as the starting point for morphological adaptations in response to maintenance of the trim. Hoof morphology was measured from lateral, dorsal and solar view photographs and lateromedial radiographs taken at 0, 4 and 16 months. Changes from 0 to 4 months represented differences between a natural hoof shape and the trim, while changes from 4 to 16 months represented adaptive effects during hoof growth. Results Establishment of the barefoot trim involved significant shortening of the toe, heel and medial and lateral walls, with increases in angulation at the toe, medial and lateral walls, but not at the heel. Maintenance of the trim resulted in a palmar/plantar migration of the heels, with increases in support length, heel angle and solar angle of the distal phalanx (P3). Conclusions Bevelling the toe and engaging the frog and bars in the weight‐bearing function of the foot resulted in elevation of the heel angle and solar angle of P3. These changes may be beneficial in treating under‐run heels and negative solar plane angulation of P3.     

The effects of pre-anesthetic administration of xylazine on the cardiovascular responses to dobutamine in halothane anaesthetized horses

Studies evaluating the effects of dobutamine in horses do not consistently report increases in cardiac output despite increases in arterial blood pressure. The concurrent administration of the α₂ agonist clonidine, in people, inhibited the chronotropic effects of dobutamine and increased left ventricular stroke work ( Zimpfer et al. 1982 ). Our study was performed to determine if pre‐medication with an α₂ agonist affects the response to dobutamine in anaesthetized horses. Eleven horses were anaesthetized on four separate occasions for one of four randomly assigned treatments; (I) no xylazine, no dobutamine (II) xylazine, no dobutamine (III) no xylazine, dobutamine, and (IV) xylazine, dobutamine. Horses received 0.02 mg kg^?1 of butorphanol IV 10 minutes prior to anesthetic induction. Two minutes prior to induction, groups II and IV received 0.5 mg kg^?1 of IV xylazine. Anaesthesia was induced with 6–7 mg kg^?1 of thiopental and maintained with halothane. End‐tidal halothane concentrations were maintained between 1.1 and 1.2% in groups I and III, and 0.9–1.0% for groups II and IV. Heart rate, cardiac output, right atrial pressure, and systolic (SAP), diastolic (DAP) and mean (MAP) arterial pressure were recorded 30 minutes after beginning halothane anaesthesia (T10). Cardiac output was estimated using Lithium dilution ( Linton et al. 2000 ). Baseline measurements were repeated twice, at 5‐minute intervals (T5 and T0). At time 0 (T0), an IV infusion of either saline (100 mL hour^?1) or dobutamine (0.001 mg kg^?1 minute^?1) was started and data recorded at 5‐minute intervals for 30 minutes (T5 – T30). Stroke volume and systemic vascular resistance (SVR) were calculated. Data were analysed using repeated measures anova (p < 0.01 significant) and Newman–Keuls for multiple comparisons. Cardiac output and stroke volume increased over time in groups III and IV. Cardiac index was higher in groups III and IV than in groups I and II from T10 until completion of the study. Estimates of cardiac index at T30 for groups I–IV were 45 ± 9, 46 ± 11, 71 ± 11, and 78 ± 19 mL kg^?1 minute^?1, respectively (mean ± SD). Stroke index was higher in groups III and IV than in groups I and II from T15 to T30. Values for stroke index at T30 for groups I–IV were 0.98 ± 0.19, 1.11 ± 0.18, 1.46 ± 0.21, 1.74 ± 0.33 mL kg^?1. Heart rate decreased from T10–T30 in groups I and II. Heart rate was greater in groups I and III than in groups II and IV at T5 and T0. Values for heart rate at T0 for groups I–IV were 48 ± 5, 42 ± 5, 50 ± 4, 43 ± 4 beats minute^?1. Systolic arterial pressure, DAP and MAP were higher in groups III and IV than in groups I and II from T5 to T30. There were no differences in SVR between groups. Dobutamine at 0.001 mg kg^?1 minute^?1 increased cardiac output, blood pressure, and stroke volume. Premedication with xylazine at 0.5 mg kg^?1 did not appear to affect the response to dobutamine.     

High-Pressure Framework Silicates

Recent syntheses of high-pressure alkali and alkaline earth silicates reveal a class of framework structures with corner-linked 4- and 6-coordinated silicon. These compounds possess the structural formula (A4-2x1+Bx2+)SimVI(SinIVO2(m+n)+2), where x, m, and n specify the amounts of alkaline earth, 6-coordinated silicon, and 4-coordinated silicon, respectively. Appropriate values of m and n yield a range of high-pressure structures, from fully 4-coordinated to fully 6-coordinated silicate frameworks. Recognition of this class of framework silicates leads to predictions of high-pressure structures as well as room-pressure isomorphs of high-pressure silicates.