Fatal unintentional non-fire-related carbon monoxide poisoning: England and Wales, 1979-2012.

CONTEXT: Unintentional carbon monoxide poisoning remains a significant cause of morbidity and mortality in England and Wales. METHODS. STUDY DESIGN: observational case series. Data on fatal carbon monoxide poisoning in England and Wales from 1979 to 2012 were obtained from coroner reports. Data on unintentional non-fire-related carbon monoxide poisoning were extracted and were analysed by year of registration of death, sex, age group, and whether death occurred at a private house, flat, associated garage, or residential caravan ('home'), or elsewhere. RESULTS AND DISCUSSION: There were 28,944 carbon monoxide-related deaths, of which 82% were male. Deaths increased from 965 (1979) to 1700 (1987), and then fell to 182 (2012). Of these 2208 (64% male) were recorded as unintentional non-fire-related deaths. Annual numbers of these latter deaths fell from 166 in 1979 to 25 in 2012 (i.e. from 3.37 to 0.44 per million population). Some 81 and 92% of such deaths in males and in females, respectively, occurred at 'home'. A clear preponderance of male versus female deaths was seen in the 10-19, 20-39 and 40-64 years age groups, with similar numbers of deaths in males and in females in the younger (< 1 and 1-9 year) and higher (65-79 and 80 + years) age groups. A higher proportion of these excess deaths in males occurred outside the deceased's 'home' in those aged 10-19, 20-39 and 40-64 years. CONCLUSION: Deaths from unintentional non-fire-related carbon monoxide poisoning are now much less common in England and Wales than in earlier years, but remain a cause for concern. Installation and proper maintenance of carbon monoxide alarms in dwellings and outhouses, for example, and education not only of the public, but also of health and other professionals as to the danger posed by carbon monoxide could help prevent such deaths.

Hydrologic transport of fecal bacteria attenuated by flue gas desulfurization gypsum.

Flue gas desulfurization (FGD) gypsum is a byproduct of coal-fired power plants. Its application to agricultural fields may increase water infiltration, reduce soil erosion, and decrease nutrient losses from applications of animal manures. It may also reduce fecal bacterial contamination of surface waters. We tested the hypothesis that FGD gypsum applications would decrease the load of and the fecal indicator bacterium from poultry litter applications. Two rainfall simulation experiments were undertaken: one in spring 2009 and one in spring 2011. Six treatments consisted of four rates of FGD gypsum (0, 2.2, 4.5, and 9.0 Mg ha) with poultry litter (13.5 Mg ha and two controls) in a randomized, complete-block design with three replications. Each replicate 4- × 6-m plot contained a single 1- × 2-m subplot that was delineated by metal plates and a flume that captured total overland flow or runoff. Rainfall was applied at ∼64 mm h. Volume of overland runoff was measured and subsampled for analysis every 10 min for 1 h. Flow-weighted concentrations, total loads, and soil concentrations of were determined. was not detected in runoff. No significant differences between treatments were observed for the 2009 rainfall simulation. However, after 3 yr of FGD gypsum applications, the highest rate of FGD gypsum resulted in decreased flow-weighted concentrations and total loads of . Flue gas desulfurization gypsum applications may be a management practice that reduces microbial contamination of surface waters from manure applied to agricultural fields in the southeastern United States.

Rate of adaptation in large sexual populations.

Adaptation often involves the acquisition of a large number of genomic changes that arise as mutations in single individuals. In asexual populations, combinations of mutations can fix only when they arise in the same lineage, but for populations in which genetic information is exchanged, beneficial mutations can arise in different individuals and be combined later. In large populations, when the product of the population size N and the total beneficial mutation rate U(b) is large, many new beneficial alleles can be segregating in the population simultaneously. We calculate the rate of adaptation, v, in several models of such sexual populations and show that v is linear in NU(b) only in sufficiently small populations. In large populations, v increases much more slowly as log NU(b). The prefactor of this logarithm, however, increases as the square of the recombination rate. This acceleration of adaptation by recombination implies a strong evolutionary advantage of sex.

Intake and digestibility of 'coastal' bermudagrass hay from treated swine waste using subsurface drip irrigation.

Waste handling systems for confined swine production in the upper South (approximately 32-37 degrees N and 79-93 degrees W) depend mainly on anaerobic lagoons and application of the waste effluent to cropland. The main objective of this study was to evaluate the quality of 'Coastal' bermudagrass [Cynodon dactylon (L.) Pers.] hay receiving effluent generated from a raw swine waste treatment system designed to reduce P and K concentrations and delivered by subsurface drip irrigation (SDI) compared with hay produced from commercial N fertilizer. Eight treatments, consisting of commercial N fertilizer or effluent, each irrigated at two irrigation rates (75 and 100% of estimated evapotranspiration) and two lateral spacings (0.6 and 1.2 m), were compared with a control treatment of commercial N fertilizer without irrigation. Three harvests were taken in each of 2 yr and five of the six evaluated using wether sheep (30-45 kg). Greatest dry matter intake (DMI) per unit body weight occurred for the control vs. all irrigated treatments (1.94 vs. 1.77 kg 100(-1) kg; P = 0.02; SEM = 0.11). Among irrigated treatments, DMI was greatest from commercial N vs. effluent (1.81 vs. 1.71 kg 100(-1) kg; P = 0.05; SEM = 0.11). Dry matter intake was similar for the 75% rate treatments and the non-irrigated treatment (mean, 1.87 kg 100(-1) kg) but was reduced for the 100% rate (1.94 vs. 1.72 kg 100(-1) kg; P = 0.03; SEM = 0.11). Hay from the 75% rate was more digestible than hay from the 100% rate (527 vs. 508 g kg(-1); P = 0.03; SEM = 21). The SDI system functioned well, and lateral spacing did not alter hay quality. Treated waste from a raw waste treatment system was readily delivered by SDI at the recommended rate to produce bermudagrass hay of adequate quality for ruminant production systems.

Most probable number methodology for quantifying dilute concentrations and fluxes of Escherichia coli O157:H7 in surface waters.

AIMS: To better understand the transport and enumeration of dilute densities of Escherichia coli O157:H7 in agricultural watersheds, we developed a culture-based, five tube-multiple dilution most probable number (MPN) method. METHODS AND RESULTS: The MPN method combined a filtration technique for large volumes of surface water with standard selective media, biochemical and immunological tests, and a TaqMan confirmation step. This method determined E. coli O157:H7 concentrations as low as 0.1 MPN per litre, with a 95% confidence level of 0.01-0.7 MPN per litre. Escherichia coli O157:H7 densities ranged from not detectable to 9 MPN per litre for pond inflow, from not detectable to 0.9 MPN per litre for pond outflow and from not detectable to 8.3 MPN per litre for within pond. The MPN methodology was extended to mass flux determinations. Fluxes of E. coli O157:H7 ranged from <27 to >10(4) MPN per hour. CONCLUSION: This culture-based method can detect small numbers of viable/culturable E. coli O157:H7 in surface waters of watersheds containing animal agriculture and wildlife. SIGNIFICANCE AND IMPACT OF THE STUDY: This MPN method will improve our understanding of the transport and fate of E. coli O157:H7 in agricultural watersheds, and can be the basis of collections of environmental E. coli O157:H7.

Volatile substance abuse and crime: data from U.K. press cuttings 1996-2007.

Volatile substance abuse (VSA, solvent abuse, 'glue sniffing'), carries a risk of sudden death (some 700 deaths in the UK, 1996-2006). However, mortality data take no account of the social cost of the habit. From press cuttings we have identified 508 instances (569 individuals: 507 male, median age 25 yr, range 8-51 yr and 62 female, median age 18 yr, range 11-36 yr) where VSA, either alone or together with alcohol/other drugs, was reported in association with criminal or antisocial behaviour that resulted in a criminal conviction or caution. The frequency of reports decreased from 84 per annum (1997 and 1998) to 20 (2007). The agents reported (17 individuals, two agents) were 'glue' (225), LPG/'butane'/aerosol propellants (176), 'solvents' (158), and petrol (gasoline) (27). The offences cited (most serious crime) were: homicide (35), rape or other sexual assault (34), arson (25), assault or serious threat of assault (192), child neglect/cruelty (6), attempting to pervert the course of justice (2), criminal damage (41), burglarylrobbery/theft/shoplifting (100), nuisance/ breach of the peace/breach of antisocial behaviour order (104), driving whilst impaired and other vehicle-related offence (22), and supply (non-retail) (8). Thirty offenders were given life sentences or detained indefinitely under mental health legislation. Reports came from all parts of the UK, although most were from Northern England, Northern Ireland, and Scotland. There were many reports of recidivists; one 34-year-old male had made 113 court appearances, and had spent approximately nine years in custody. Although there are severe limitations to data derived from press cuttings and notwithstanding that in some cases VSA may have been raised in mitigation, these data provide an additional insight into the problem posed by VSA in the U.K.

Most probable number methodology for quantifying dilute concentrations and fluxes of Salmonella in surface waters.

AIMS: To better understand and manage the fate and transport of Salmonella in agricultural watersheds, we developed a culture-based, five tube-four dilution most probable number (MPN) method for enumerating dilute densities of Salmonella in environmental waters. METHODS AND RESULTS: The MPN method was a combination of a filtration technique for large sample volumes of environmental water, standard selective media for Salmonella and a TaqMan confirmation step. This method has determined the density of Salmonella in 20-l samples of pond inflow and outflow streams as low as 0.1 MPN l(-1) and a low 95% confidence level 0.015 MPN l(-1). Salmonella densities ranged from not detectable to 0.55 MPN l(-1) for pond inflow samples and from not detectable to 3.4 MPN l(-1) for pond outflow samples. Salmonella densities of pond inflow samples were associated with densities of Escherichia coli and faecal enterococci that indicated stream contamination with faeces and with nondetectable pond outflow densities of the faecal indicator bacteria. The MPN methodology was extended to flux determinations by integrating with volumetric measurements of pond inflow (mean flux of 2.5 l s(-1)) and outflow (mean flux of 5.6 l s(-1)). Fluxes of Salmonella ranged from 100 to greater than 10(4) MPN h(-1). CONCLUSIONS: This is a culture-based method that can detect small numbers of Salmonella in environmental waters of watersheds containing animal husbandry and wildlife. SIGNIFICANCE AND IMPACT OF THE STUDY: Applying this method to environmental waters will improve our understanding of the transport and fate of Salmonella in agricultural watersheds, and can be the basis of valuable collections of environmental Salmonella.

Dry matter intake and digestion of alfalfa harvested at sunset and sunrise.

The preference exhibited by animals in selecting one feed over another is important only if the preferred diet is consumed daily in larger quantities, digested to a greater extent, or both. Six alfalfa (Medicago sativa L.) hays were harvested in pairs at sunset (PM) and sunrise (AM) on consecutive days at three harvest dates. A previous study of these hays demonstrated differences in ruminant preference favoring PM harvests. This study evaluated the effects of time of cutting and harvest date on voluntary DMI and nutrient digestibility. The hays were field-cured, baled, and chopped before evaluation for intake and digestibility. Studies were conducted for sheep (Ovis aries), goats (Capra hircus), and cattle (Bos taurus). Goats, but not steers or sheep, demonstrated differences in nutrient digestibility between PM- and AM-cut hays. Goats consumed more PM than AM hay (2.97 vs. 2.83 kg/100 kg of BW; P = 0.07) and digested it to a greater extent (0.710 vs. 0.696; P = 0.03), resulting in greater digestible DMI (2.11 vs. 1.97 kg/100 kg of BW; P = 0.03). Sheep consumed (mean = 2.52 kg/100 kg of BW; P = 0.59) and digested (mean = 0.681; P = 0.25) PM- and AM-cut hays similarly. Steers consumed larger quantities of PM-than AM-cut hay (2.90 vs. 2.62 kg/100 kg of BW; P = 0.11), but digestion did not differ with cutting time (mean = 0.660; P = 0.75). Difference values (composition of fed hay minus composition of orts) indicated that sheep and goats selected from the feed offered similarly, whereas steers selected differently. Difference values for CP averaged 94 and 101 g/kg for goats and sheep and 32 g/kg for steers (P < 0.01), and difference values for NDF averaged 185 and 196 g/kg for goats and sheep and 73 g/kg for steers (P

The influence of high-nitrogen forages on the voluntary feed intake of sheep.

The objective of this research was to examine the effect of high concentrations of nonprotein nitrogen (NPN) on the voluntary food intake of sheep fed high-quality grasses. Wether lambs (n = 6 per treatment) were fed dried switchgrass (Panicum virgatum L.; Exp. 1) or dried tall fescue (Festuca arundinacea Schreb.; Exp. 2). In both experiments, urea was added to the dried forage at 0 (control), 12, or 24 g of N/kg of DM to increase the NPN concentration. Acid detergent fiber concentrations were 305 g/kg of DM in both experiments, although DM digestibility was 663 and 618 g/ kg of DM in Exp. 1 and Exp. 2, respectively. Voluntary feed intake of the control forage was 28.2 and 19.1 g/ kg of BW in Exp. 1 and Exp. 2, respectively, and decreased for the high-urea treatments to 25.2 and 16.2 g/kg of BW in Exp. 1 (P = 0.07) and Exp 2 (P = 0.03), respectively. Total feed N concentrations increased from 29.5 g to 45.7 g of N/kg of DM in Exp. 1 (P < 0.01) and from 28.4 to 55.9 g of N/kg of DM in Exp. 2 (P < 0.01). Nonprotein N concentrations increased from 28.3 to 53.8% of the total N in switchgrass diets (Exp. 1; P < 0.01), and from 26.4 to 64.0% in tall fescue diets (Exp. 2; P < 0.01). Plasma urea concentrations of the lambs increased from 3.1 to 6.6 mM (Exp. 1; P < 0.01) and from 2.9 to 5.8 mM (Exp. 2; P < 0.01) as the amount of urea added to the diets increased. These changes resulted in an increase in plasma osmolality from 298 to 307 mOsm/kg (Exp. 1; P = 0.04), and from 299 to 307 mOsm/kg (Exp. 2; P = 0.06). Increasing feed N and NPN concentrations through the addition of urea caused a significant decrease in the voluntary feed intake of sheep fed tall fescue and switchgrass. These responses showed no significant cause-and-effect relationship between voluntary feed intake, plasma urea concentrations, and plasma osmolality.

Nonequilibrium dynamics of random field Ising spin chains: exact results via real space renormalization group.

The nonequilibrium dynamics of classical random Ising spin chains with nonconserved magnetization are studied using an asymptotically exact real space renormalization group (RSRG). We focus on random field Ising model (RFIM) spin chains with and without a uniform applied field, as well as on Ising spin glass chains in an applied field. For the RFIM we consider a universal regime where the random field and the temperature are both much smaller than the exchange coupling. In this regime, the Imry-Ma length that sets the scale of the equilibrium correlations is large and the coarsening of domains from random initial conditions (e.g., a quench from high temperature) occurs over a wide range of length scales. The two types of domain walls that occur diffuse in opposite random potentials, of the form studied by Sinai, and domain walls annihilate when they meet. Using the RSRG we compute many universal asymptotic properties of both the nonequilibrium dynamics and the equilibrium limit. We find that the configurations of the domain walls converge rapidly toward a set of system-specific time-dependent positions that are independent of the initial conditions. Thus the behavior of this nonequilibrium system is pseudodeterministic at long times because of the broad distributions of barriers that occur on the long length scales involved. Specifically, we obtain the time dependence of the energy, the magnetization, and the distribution of domain sizes (found to be statistically independent). The equilibrium limits agree with known exact results. We obtain the exact scaling form of the two-point equal time correlation function and the two-time autocorrelations . We also compute the persistence properties of a single spin, of local magnetization, and of domains. The analogous quantities for the +/-J Ising spin glass in an applied field are obtained from the RFIM via a gauge transformation. In addition to these we compute the two-point two-time correlation function which can in principle be measured by experiments on spin-glass-like systems. The thermal fluctuations are studied and found to be dominated by rare events; in particular all moments of truncated equal time correlations are computed. Physical properties which are typically measured in aging experiments are also studied, focusing on the response to a small magnetic field which is applied after waiting for the system to equilibrate for a time t(w). The nonequilibrium fluctuation-dissipation ratio X(t,t(w)) is computed. We find that for (t-t(w)) approximately t(alpha)(w) with alpha;<1, the ratio equal to its equilibrium value X=1, although time translational invariance does not hold in this regime. For t-t(w) approximately t(w) the ratio exhibits an aging regime with a nontrivial X=X(t/t(w)) not equal to 1, but the behavior is markedly different from mean field theory. Finally the distribution of the total magnetization and of the number of domains is computed for large finite size systems. General issues about convergence toward equilibrium and the possibilities of weakly history-dependent evolution in other random systems are discussed.

Depinning with dynamic stress overshoots: mean field theory.

An infinite-range model of an elastic manifold pulled through a random potential by a force F is analyzed focusing on inertial effects. When the inertial parameter M is small, there is a continuous depinning transition from a small- F static phase to a large- F moving phase. When M is increased to M(c), a novel tricritical point occurs. For M>M(c), the depinning transition becomes discontinuous with hysteresis. Yet, the distribution of discrete "avalanche"-like events as the force is increased in the static phase for M>M(c) has an unusual mixture of first-order-like and critical features. The results may be relevant for the onset of crack propagation and for dynamics of geological faults.

Preference by sheep and goats among hay of eight tall fescue cultivars.

Grazing ruminants use both visual cues and taste in selecting their diet. Preference during grazing may not be the same when forage is dried for hay and cut into lengths prior to feeding in confinement. Eight cultivars of tall fescue (Festuca arundinacea Schreb.), previously evaluated for preference while grazed, were harvested three times over a period of 2 yr. The hays were air-dried, baled, and passed through a hydraulic bale processor prior to feeding. Five experiments were conducted. All three harvests were evaluated with sheep and the last two also with goats, using six animals each time. During an adaptation phase, hays were offered alone as meals. In the experimental phase, every possible pair of hays (28 pairs) was presented for a meal. Data were analyzed by multidimensional scaling and by traditional analyses. Preference was significant among cultivars in all experiments. Multidimensional scaling showed that selection was based on two criteria with two dimensions being significant. Sheep preferred KENHY followed by KENTUCKY 31 and STARGRAZER but preferenced against BARCEL. HIMAG, MO-96, and C1 were intermediate and MOZARK was variable. Goats were similar to sheep in preferring KENHY followed by STARGRAZER and selected against MOZARK and BARCEL. KENTUCKY 31, HIMAG, MO-96, and C1 were intermediate. In all five experiments, the general association was positive for available carbohydrate fractions and negative for fiber fractions that contribute to cell wall rigidity.

Intake and chewing behavior of steers consuming switchgrass preserved as hay or silage.

Effect of preservation method on intake and chewing behavior was examined using a first, late vegetative harvest (mid-June) of Kanlow switchgrass (Panicum virgatum L.). For silage (S), forage was harvested with a commercial field chopper (1.5 to 4 cm average chop length) and ensiled directly in silos 1.2 m in diameter and 3.6 m in height. For hay (H), forage was harvested with a flail-chopper (7 to 15 cm average chop length) and cured as hay in a drier at 77 degrees C. Diets of H and S were fed to six Hereford steers (338+/-5 kg) in a single crossover experiment. Chewing behavior was monitored for 4 d with a computerized system. At feeding, H was higher in DM and contained greater concentrations (DM basis) of NDF, CP, and hemicellulose, but lower concentrations of ADF and cellulose, and had lower in vitro DM disappearance values. Steers fed S had higher intakes of DM (P < .02) and NDF (P < .04) and consumed less water from the water supply (P < .01) than animals fed H. However, total amount of water (from water supply and feed) consumed per kilogram of DMI did not differ between diets. Crude protein intake was similar between diets. Preservation method had no effect on eating time, number of boli ruminated, bolus duration, and number of rumination chews per bolus. Steers fed S made fewer eating chews (P < .10) and ruminated for a longer time (P < .05) while making a greater number of rumination chews (P < .04) than steers fed H. Rumination intercycle time was slightly shorter in steers fed H (P < .05) than in steers fed S. When expressed per kilogram of NDF intake, steers fed S spent less time eating (P < .03) and made fewer eating chews (P < .02) than steers fed H; however, rumination time, number of rumination chews, and number of boli ruminated were not affected by preservation method. Steers fed S ingested feed at a greater rate (P < .03), excreted smaller fecal particles (P < .03), had meals of shorter duration (P < .06), spent less time eating during main meals (meals following feed distribution: P < .05), had more rumination periods (P < .01), and a shorter morning (P < .06) latency time (interval between end of main meal and onset of rumination) than steers fed H. These results indicate that preservation method with its concomitant differences in chop length affected forage chemical composition and voluntary intake, and that differences in chewing behavior occurred mostly during eating.

Variation in ruminants' preference for tall fescue hays cut either at sundown or at sunup.

Plants vary diurnally in concentrations of nonstructural carbohydrates. If ruminants prefer forages with higher total nonstructural carbohydrates (TNC), then the preference for hays harvested within the same 24-h period may vary. An established field of tall fescue (Festuca arundinacea Schreb.) was harvested six times in the vegetative stage. Harvests were paired such that each cutting at sundown (PM) was followed by a cutting the next morning at sunup (AM). We harvested in this manner three times, resulting in six hays. The hays were field-dried, baled, and passed through a hydraulic bale processor prior to feeding. Experiments were conducted with sheep, goats, and cattle, using six animals in each case. During an adaptation phase, hays were offered alone as meals. In the experimental phase, every possible pair of hays (15 pairs) was presented for a meal. Data were analyzed by multidimensional scaling and by traditional analyses. Multidimensional scaling indicated that selection was based on a single criterion. Preference for PM hays was greater than for AM hays (P < .01) in all experiments. Increased preference was associated with increased TNC (P < .01) and in vitro true DM disappearance (P < .01) and decreased fiber concentration (P < .01; NDF, ADF, cellulose, and ADL). Mowing hay late in the day was effective in increasing forage preference.

Random walkers in one-dimensional random environments: exact renormalization group analysis.

Sinai's model of diffusion in one dimension with random local bias is studied by a real space renormalization group, which yields exact results at long times. The effects of an additional small uniform bias force are also studied. We obtain analytically the scaling form of the distribution of the position x(t) of a particle, the probability of it not returning to the origin, and the distributions of first passage times, in an infinite sample as well as in the presence of a boundary and in a finite but large sample. We compute the distribution of the meeting time of two particles in the same environment. We also obtain a detailed analytic description of the thermally averaged trajectories by computing quantities such as the joint distribution of the number of returns and of the number of jumps forward. These quantities obey multifractal scaling, characterized by generalized persistence exponents theta(g) which we compute. In the presence of a small bias, the number of returns to the origin becomes finite, characterized by a universal scaling function which we obtain. The full statistics of the distribution of successive times of return of thermally averaged trajectories is obtained, as well as detailed analytical information about correlations between directions and times of successive jumps. The two-time distribution of the positions of a particle, x(t) and x(t') with t>t', is also computed exactly. It is found to exhibit "aging" with several time regimes characterized by different behaviors. In the unbiased case, for t-t' approximately t'alpha with alpha>1, it exhibits a ln t/ln t' scaling, with a singularity at coinciding rescaled positions x(t)=x(t'). This singularity is a novel feature, and corresponds to particles that remain in a renormalized valley. For closer times alpha<1, the two-time diffusion front exhibits a quasiequilibrium regime with a ln(t-t')/ln t' behavior which we compute. The crossover to a t/t' aging form in the presence of a small bias is also obtained analytically. Rare events corresponding to intermittent splitting of the thermal packet between separated wells which dominate some averaged observables are also characterized in detail. Connections with the Green function of a one-dimensional Schrödinger problem and quantum spin chains are discussed.

The utilization of multidimensional scaling to identify forage characteristics associated with preference in sheep.

Forage preference is difficult to assess but is likely an important factor in determining DM intake. In two experiments, six sheep (wethers, Exp. 1; ewes, Exp. 2) were used to obtain preference ratings on nine hays (Exp. 1) or nine fresh forages (Exp. 2). The statistical procedure of multidimensional scaling was used to develop orthogonal dimensions to account for the observed variation in preference for hays and fresh forages. This analysis produced three dimensions that accounted for 54% of the variation in mean 3-d preference for hays (Exp. 1). The three dimensions were subsequently associated by regression analysis with seven compositional variables. These were IVDMD and concentrations of monosaccharides, short-chain polysaccharides (SCP), and disaccharides in dimension 1(R2 = .99); acid detergent insoluble ash (ADIA) concentration, monosaccharide and SCP concentrations, and masticate NDF in dimension 2 (R2 = .99); and disaccharide and starch concentrations in dimension 3 (R2 = .65). Three dimensions accounting for 51% of the variation in fresh forage preference were found and related to four variables by regression analysis. These were disaccharide concentration and median particle size in dimension 1 (R2 = .76) and starch and monosaccharide + disaccharide concentrations in dimension 3 (R2 = .97). No physicochemical variables analyzed in this study were found to be significantly associated with the coordinates for the forages in dimension 2. Multidimensional scaling accounted for more than half the observed variation in animal preference and, in all but one case, these dimensions could be associated with physicochemical characteristics of the forages.

Changes in forage quality, ingestive mastication, and digesta kinetics resulting from switchgrass maturity.

Five maturities of switchgrass hay harvested at 14-d intervals (vegetative through 20% heading) were fed to Hereford steers (297 kg) in a 5 x 5 Latin square. Relationships with switchgrass maturity were negative and quadratic (P < .05) for DMI and cubic (P < .05) for digestible DMI. Declines in apparent digestibilities of DM, ADF, and cellulose were cubic (P < .05), whereas these were quadratic (P < .05) for NDF, hemicellulose, and CP. Whole masticates from the least, mid, and most mature hays showed linear (P < .05) declines in DM concentration and IVDMD with increasing maturity, whereas NDF concentrations increased linearly (P < .05). Mean retention time of gastrointestinal DM increased linearly (P < .01) from 64 to 94 h from the least to the most mature hay, and the associated rate of passage declined linearly (P < .01) from 3.3 to 2.1%/h. Sieving of masticate DM showed a reduced proportion of large particles (> or = 2.8 mm) and an increased proportion of small particles (< or = .5 mm) with advancing forage maturity. More than 94% of the sieved fecal DM passed a 1.0-mm sieve, but particle sizes showed the same relationship with forage maturity as noted for masticate DM. This occurred despite the comminution from the rumination and digestive processes.

Modeling ruminant feed intake with protein, chemostatic, and distention feedbacks.

Little progress has been made in modeling intake regulation in spite of the many mechanisms identified as important. A model with relatively simple inputs was developed that included compartments for protein, soluble carbohydrate, digestible fiber, and very slowly digesting fiber. Distention and chemostatic feedbacks were combined using a previously published equation. The ratio of current ruminal fill to a modulating parameter for ruminal fill represented distention feedback. The ratio of the current flow of available energy to a modulating parameter for chemostatic demand represented chemostatic feedback. The modulating parameter for ruminal fill was based on literature reports of ruminal contents. Intake was adjusted based on current fill and energy flow relative to modulating parameters for fill and chemostatic feedback. The effect of the digestible organic matter (DOM) to CP ratio on DOM intake was modeled to adjust rates of digestion, rates of passage, and the chemostatic feedback. The model tested an integrated concept of intake regulation with only CP, IVDMD, and NDF as inputs. In spite of relatively simple inputs, the model behavior in response to variation in protein, digestibility, and fiber was similar to observations of animal responses.

The social marketing of project ARIES: overcoming challenges in recruiting gay and bisexual males for HIV prevention counseling.

This paper reports on the development, implementation, and evaluation of a social marketing campaign designed to recruit clients Project ARIES, and AIDS prevention study funded by the National Institute of Mental Health. Marketing channels employed for the campaign included advertising in the gay press, generating coverage in the mainstream press, distributing materials to HIV testing centers and other health and social service providers, and displaying posters in gay bars and baths. While these approaches all succeeded in eliciting inquiries from individuals engaging in high risk sexual behaviors, they differed in several respects, including their ability to reach specific subgroups that are often underserved by more traditional programs, such as men of color, younger men, and men who self-report as being closeted. Promotional materials displayed in gay bars and baths resulted in the highest percentage of callers who, after inquiring about the program, decided to participate in the counseling. Coverage in the mainstream press was the most successful in reaching closeted men, men who were less active in the gay community, and individuals who did not self-identify as gay. Display and classified ads in the gay press produced the highest number of initial inquiries. Finally, recruitment of participants via materials distributed to HIV test sites and other service providers was the most effective in reaching men who were HIV-positive.