Milk fat responses to a change in diet fermentability vary by production level in dairy cattle

The effects of dietary starch fermentability on plasma metabolites and hormones, milk production, and milk fatty acid profile were evaluated in a crossover study. Thirty-two multiparous Holstein cows (121 +/- 48 d in milk, 41 +/- 9 kg/d 3.5% fat-corrected milk [FCM]; mean +/- SD) were randomly assigned to treatment sequence and were fed a diet intermediate to the treatments during an initial 21-d period. Treatments were dry ground corn grain (DG) and high moisture corn (HM) harvested from the same field. Treatment periods were 14 d, with the final 4 d used for data and sample collection. Diets included corn silage and alfalfa haylage at a 2:1 ratio and were ~26% neutral detergent fiber, 16.5% crude protein, 32% starch, and 3.5% fatty acids. High moisture corn increased plasma glucose, nonesterified fatty acid, and triglyceride concentrations, but treatment had no consistent effect on yield of milk or FCM. High moisture corn increased trans C(18:1) concentrations at an increasing rate as production level decreased across cows, and milk fat depression was evident in cows below approximately 40 kg/d FCM yield. In contrast, production level had little influence on milk trans C(18:1) concentration for DG. Milk trans C(18:1) concentration was negatively correlated with milk fat concentration, as was trans-9 C(18:1), trans-10 C(18:1), and cis-9, trans-11 C(18:2). Concentration of trans-10, cis-12 C(18:2) was not correlated with milk fat concentration. Production level may influence biohydrogenation patterns and trans C(18:1) production because of differences in rumen environment; rumen pH and dilution rate can alter metabolism and populations of rumen microbes. Diets with highly fermentable starch sources and without supplemental dietary polyunsaturated fatty acids can induce milk fat depression in lower-producing cows, likely because of increased production of trans C(18:1) fatty acids.     

Transdermal nicotine use in postmenopausal women: does the treatment efficacy differ in women using and not using hormone replacement therapy?

This study of postmenopausal female smokers (N = 94) asked: During short-term smoking abstinence, do the beneficial effects of transdermal nicotine replacement therapy (NRT) on acute symptomatology (i.e., withdrawal, cigarette craving, smoking urges, mood, depressive symptoms, motor speed, and reaction time) differ in women who use and do not use hormone replacement therapy (HRT)? Participants were recruited according to HRT and non-HRT use (self-selecting), then randomized within strata to active nicotine or placebo nicotine patch. After 1 baseline week of smoking, participants quit smoking for 2 weeks. Women received cessation counseling and were monitored for abstinence. Dependent measures were collected during five clinic visits. Two-way analysis of covariance (ANCOVA) were run on change scores for dependent variables, with nicotine patch group (active/placebo) and HRT group (HRT/non-HRT) as independent variables and age as a covariate. No interactions were found between HRT and patch condition, but both showed specific effects. During the first abstinent week, women on active nicotine patch (compared with placebo) experienced less severe withdrawal, greater reductions in cigarette cravings, and lower (more favorable) Factor 1 scores on the Questionnaire of Smoking Urges. During the second abstinent week, women using HRT (compared with the non-HRT group) exhibited better mood (Profile of Mood States scores) and less depression (Beck Depression Inventory scores). These results suggest the following: First, the efficacy of transdermal nicotine replacement is not adversely modified by women's HRT use; second, ovarian hormones might influence women's responses to smoking cessation, and thus should be considered in developing effective strategies for women to quit smoking.     

A comparison of drying operations on the rheological properties of whey protein thickening ingredients

An existing procedure for the alteration of whey proteins into a cold‐set thickening agent was modified by developing a spray‐drying operation to replace the prohibitively expensive freeze‐drying step. The original and the modified derivatization procedures were used with a commercial whey protein concentrate (WPC). The freeze‐dried and spray‐dried derivatized WPC powders, along with polysaccharide thickeners, were reconstituted in water and evaluated by using a range of rheological studies. The effects of temperature, concentration, and shear on viscosity as well as the mechanical spectra were assessed to characterize the ability of the powders to function in food systems. Rheological characterization revealed the modified derivatization procedure yielded an ingredient having the same cold‐set thickening and gelling ability as the original derivatized powder. The modified whey proteins were also able to achieve, at higher usage levels, textural properties similar to several polysaccharide thickeners. Use of a spray‐drying technique created a more economical process for the production of a whey protein ingredient that was suitable for contributing viscosity and texture to a wide range of food systems.     

Analyzing B-vitamins in Human Milk: Methodological Approaches

According to the World Health Organization (WHO), infants should be exclusively breastfed for the first six months of life. However, there is insufficient information about the concentration of nutrients in human milk. For some nutrients, including B-vitamins, maternal intake affects their concentration in human milk but the extent to which inadequate maternal diets affect milk B-vitamin content is poorly documented. Little is known about infant requirements for B-vitamins; recommendations are generally set as Adequate Intakes (AI) calculated on the basis of the mean volume of milk (0.78 L/day) consumed by infants exclusively fed with human milk from well-nourished mothers during the first six months, and the concentration of each vitamin in milk based on reported values. Methods used for analyzing B-vitamins, commonly microbiological, radioisotope dilution or more recently chromatographic, coupled with UV, fluorometric and MS detection, have rarely been validated for the complex human milk matrix. Thus the validity, accuracy, and sensitivity of analytical methods is important for understanding infant requirements for these nutrients, the maternal intakes needed to support adequate concentrations in breast milk. This review summarizes current knowledge on methods used for analyzing the B-vitamins thiamin, riboflavin, niacin, vitamin B-6 and pantothenic acid, vitamin B-12, folate, biotin, and choline in human milk, their chemical and physical properties, the different forms and changes in concentration during lactation, and the effects of deficiency on the infant.     

Fetomaternal interactions and influences during equine pregnancy

The equine embryo takes 6 days to traverse the oviduct and, when it finally enters the uterus, it remains spherical in shape and moves continually throughout the uterine lumen until day 17 after ovulation to deliver its maternal recognition of pregnancy signal to the entire endometrium. Between day 25 and day 35 after ovulation, the trophoblast cells of a discrete annulate portion of the chorion multiply rapidly and acquire an invasive phenotype and, between day 36 and day 38, migrate deeply into the maternal endometrium to form the equine-unique endometrial protuberances known as endometrial cups. These cups secrete large quantities of a gonadotrophic hormone (eCG) into the maternal circulation which, in conjunction with pituitary FSH, stimulates the development of accessory luteal structures in the maternal ovaries to supplement the supply of progesterone to maintain the pregnancy until the placenta can assume this role at about day 100. The non-invasive allantochorion extends slowly to fill the uterus by days 80-85 and its microcotyledonary architecture, which provides both haemotrophic and histotrophic nutrition for the growing fetus, is not fully established until days 120-140. The fetoplacental unit synthesizes large quantities of steroid hormones during the second half of pregnancy, using fetal C-19 precursors secreted by the enlarged fetal gonads for the production of oestrogens and maternal C-21 precursors for the synthesis of progesterone and large quantities of 5alpha-reduced progestagens. Near term, additional pregnenelone is secreted by the fetal adrenal glands so that the mare exhibits the unusual phenomenon of foaling while maternal serum progestagen concentrations are increasing and oestrogen concentrations are decreasing.     

Analyzing intention in utterances

This paper describes a model of cooperative behavior and describes how such a model can be applied in a natural language understanding system. We assume that agents attempt to recognize the plans of other agents and, then, use this plan when deciding what response to make. In particular, we show that, given a setting in which purposeful dialogues occur, this model can account for responses that provide more information that explicitly requested and for appropriate responses to both short sentence fragments and indirect speech acts.     

Factors that determine the fracture properties and microstructure of globular protein gels

Protein gel matrices are responsible for the texture of many foods. Therefore an understanding of the chemical reactions and physical processes associated with fracture properties of gels provides a fundamental understanding of select mechanical properties associated with texture. Globular proteins form thermally induced gels that are classified as fine-stranded, mixed or particulate, based on the protein network appearance. The fundamental properties of true shear stress and true shear strain at fracture, used to describe the physical properties of gels, depend on the gel network. Type and amount of mineral salt in whey protein and β-lactoglobulin protein dispersions determines the type of thermally induced gel matrix that forms, and thus its fracture properties. A fine-stranded matrix is formed when protein suspensions contain monovalent cation (Li⁺, K⁺, Rb⁺, Cs⁺) chlorides, sodium sulfate or sodium phosphate at ionic strengths ≤0.1 mol/dm³. This matrix has a well-defined network structure, and varies in stress and strain at fracture at different salt concentrations. At ionic strengths >0.1 mol/dm³ the matrix becomes mixed. This network appears as a combination of fine strands and spherical aggregates, and has high stress values and minimum strain values at fracture. Higher concentrations of monovalent cation salts cause the formation of particulate gels, which are high in stress and strain at fracture. The salt concentration required to change microstructure depends on the salt's position in the Hofmeister series. The formation of a particulate matrix also occurs when protein suspensions contain low concentrations (10–20 mol/dm³) of divalent cation (Ca²⁺, Mg²⁺, Ba²⁺) chloride salts or di-cationic 1,6-hexanediamine at pH 7.0. The divalent cation effect on β-lactoglobulin gelation is associated with minor changes in tertiary structure involving amide—amide interproton connectivities (determined by ¹H NMR) at 40–45°C, increasing hydrophobicity and intermolecular aggregation. The type of matrix formed appears to be related to the dispersed or aggregated state of proteins prior to denaturation. Mixed and particulate matrices result from conditions which favor aggregation at temperatures (25–45°C) which are much lower than the denaturation temperature (~65°C). Therefore, general (e.g. Hofmeister series) and protein-specific factors can affect the dispersibility of proteins and thereby determine the microstructure and fracture properties of globular protein gels.     

Manufacture of stainless steel edge filters: an application of electrolytic photopolishing

Electrolytic photopolishing of AISI 304 stainless steel has been used, together with conventional photochemical machining techniques, to produce an edge filter with a surface texture value of 0.065 μm (R_a)     

Surface textures and process characteristics of the electrolytic photoetching of annealed AISI 304 stainless steel in hydrochloric acid

Electrolytic photoetching of AISI 304 stainless steel surfaces in 10% (w/w) hydrochloric acid has been studied. A surface texture value of 1.35 μm ($\text{R}{}_{\mathrm{a}}$) has been measured for a commercially acceptable rate of etch (10 μm/min). Comparisons of this etching system with FeCl₃-HCl-H₂O spray systems used in conventional photochemical machining have also been made