Search Results

Herbicide resistance is ‘wicked’ in nature; therefore, results of the many educational efforts to encourage diversification of weed control practices in the United States have been mixed. It is clear that we do not sufficiently understand the totality of the grassroots obstacles, concerns, challenges, and specific solutions needed for varied crop production systems. Weed management issues and solutions vary with such variables as management styles, regions, cropping systems, and available or affordable technologies. Therefore, to help the weed science community better understand the needs and ideas of those directly dealing with herbicide resistance, seven half-day regional listening sessions were held across the United States between December 2016 and April 2017 with groups of diverse stakeholders on the issues and potential solutions for herbicide resistance management. The major goals of the sessions were to gain an understanding of stakeholders and their goals and concerns related to herbicide resistance management, to become familiar with regional differences, and to identify decision maker needs to address herbicide resistance. The messages shared by listening-session participants could be summarized by six themes: we need new herbicides; there is no need for more regulation; there is a need for more education, especially for others who were not present; diversity is hard; the agricultural economy makes it difficult to make changes; and we are aware of herbicide resistance but are managing it. The authors concluded that more work is needed to bring a community-wide, interdisciplinary approach to understanding the complexity of managing weeds within the context of the whole farm operation and for communicating the need to address herbicide resistance.

Seven half-day regional listening sessions were held between December 2016 and April 2017 with groups of diverse stakeholders on the issues and potential solutions for herbicide-resistance management. The objective of the listening sessions was to connect with stakeholders and hear their challenges and recommendations for addressing herbicide resistance. The coordinating team hired Strategic Conservation Solutions, LLC, to facilitate all the sessions. They and the coordinating team used in-person meetings, teleconferences, and email to communicate and coordinate the activities leading up to each regional listening session. The agenda was the same across all sessions and included small-group discussions followed by reporting to the full group for discussion. The planning process was the same across all the sessions, although the selection of venue, time of day, and stakeholder participants differed to accommodate the differences among regions. The listening-session format required a great deal of work and flexibility on the part of the coordinating team and regional coordinators. Overall, the participant evaluations from the sessions were positive, with participants expressing appreciation that they were asked for their thoughts on the subject of herbicide resistance. This paper details the methods and processes used to conduct these regional listening sessions and provides an assessment of the strengths and limitations of those processes.

A significant portion of ruminant production in the tropics relies on the grazing of native grasses growing in acid, low-fertility soils. Under these conditions, animal production is generally limited by the low quality and availability of forage supply. The introduction of forage legumes into grazing systems is commonly accepted as a way to alleviate this problem. However, many of the tropical forage legumes adapted to acid soils and selected on the basis of good agronomic performance have limited feeding value. This could be associated with increased production of secondary metabolites such as condensed tannins (CT), which have the ability to bind and precipitate proteins, carbohydrates and other molecules (Mueller-Harvey and McAllan, 1992). High intake of CT by ruminants has been associated with depressed intake and reduced digestibilities of protein and cell wall of temperate (Barry and Duncan, 1984; Pritchard et al, 1988) and tropical (Carulla, 1994) forage legumes. However, more recent work showed that intake and digestibility of tropical legumes was not only influenced by CT concentration but also by cell wall content (Barahona et al, 1997). In the ongoing process of identifying legume germplasm for acid soils, the use of in vitro techniques has been of great benefit. Gas production methods have considerable appeal in this respect due to their ability to evaluate digestion kinetics and their potential to simulate digestion processes in the rumen. Pendong et al. (1996) using temperate forages, showed that the pressure transducer gas technique of Theodorou et al. (1994) could be used to assess digestible organic matter disappearance as well as fermentation kinetics. A similar assessment was undertaken in the current study in which the tannin contents and cell-wall characteristics of tanniniferous legumes from Colombia were determined and related using measurements made in laboratories in Colombia and the United Kingdom.

In addition to assessing rate and extent of gas production from fermenting forages in vitro with rumen micro-organisms, gas production methods (e.g. Theodorou et at, 1994) may be used also to study the degradation kinetics of forage dry matter and its fractions. As the substrate dry matter can be lost only through fermentation or solution, this removes the error inherent in the polyester bag method caused by fine particle losses from bags being deemed part of the ‘soluble’ fraction.

The pressure transducer technique (PTT) of Theodorou et al. (1994) was used to measure gas production from nine tropical forage samples (Table 1). Nine bottles were prepared from each of the forage samples. Two bottles of each forage were harvested after 8, 24 and 48 h of incubation and a further three bottles at 72 h, to determine dry matter (DM) and organic matter (OM) losses. The same nine forages were assessed using the polyester bag method (Mehrez and Ørskov, 1977) to obtain DM and OM disappearance after rumen incubations of 4, 8, 24, 48 and 72 h. The soluble fraction was determined by hand washing. The reproducibility of measured losses, at given times, was examined using concordance (rc ) correlation (Lin, 1989) and mean square prediction error (MSPE, Bibby and Toutenberg, 1977). Also the simple exponential model was used to estimate the fractional rate of DM degradation (kd ) and asymptote A (%) for each forage and the values obtained using PTT (kd,ptt ) and in situ (kd,bag) compared using rc and MSPE.

Sugar cane bagasse is produced in large quantities in Brazil. The cultivated area of sugar cane in recent years has been around 4.2 X 106 ha/year, with a production of about 270 X 106 t/year of cane. As each tonne of cane produces around 300 kg of bagasse by-product, a large quantity of bagasse is generated.

Bagasse is of low dry matter (DM) digestibility (about 250 g/kg), because of lignification. Efforts have been made to improve the digestibility of bagasse using treatment with chemicals (sodium hydroxide, ammonia) or steam (Abdalla et al., 1990). Although steam and pressure treatments have improved in situ degradability, intake and digestibility in cattle were disappointing (Mello et al, 1989). Recently treatment of bagasse with irradiation and ammonia have been investigated.

At maintenance at least, the whole tract digestibility of several foods in sheep and cattle is similar, consequently much of the information on the nutritive value of dairy cow foods in food composition tables is derived from studies conducted in sheep. However, Adesogan (1996) reported that in whole-crop wheat (WCW), starch digestibility is higher in sheep than in dairy cows. This study examined the validity of using sheep to model the ruminal degradation of WCW in cows by comparing the degradability of dry matter (DM) and nitrogen (N) of urea-treated WCW in both species.

Winter wheat (cv. Hussar) was harvested at 540 g DM per kg and conserved following urea application at target rates of 20 or 40g/kg DM (WCW2 and WCW4 respectively). The degradability of the forages was examined in dairy cows given 6 kg dairy concentrate and grass silage ad libitum and in wethers given 2.4 kg/day of grass silage supplemented with 0.36kg/day of rolled, mineralized barley.

Ruminant feeding standards in Brazil are generally based on systems developed for temperate regions and there is a serious lack of information on grazed tropical pasture which is the main feedstuff. Signal grass (Brachiaria decumbens) represents half of the total cultivated pastures in Brazil (Miles et al., 1996). This study investigated the intake and digestibility by sheep of signal grass hay cut after re-growths of 28 and 56 days to represent the range used in practice in the Brazilian savanna. Lucerne hay was included as a positive control. The hays were offered at two levels of intake to Santa Ines wether sheep.

In the Central Kenyan Highlands, dairy cattle ownership is a crucial element in poverty alleviation. For example, in Kiambu district just north of Nairobi, out of the population of 744010, 48% of 189709 households stall feed dairy cattle. Farm sizes average 1.1 to 2.0 ha per household. Producing sufficient forage for dairy cattle is difficult and low dry matter intake constrains dairy production and there is a positive correlation between stover intake and milk yield.. Napier grass comprised 40% of the total dry matter fed to cattle and maize forage 24% according to the project’s Rapid Rural Appraisal, maize thinnings and stover being routinely fed to livestock. In another survey, dry maize stover accounted for nearly 65% of dry matter intake of dairy cattle during October.

Speech disfluencies can guide the ways in which listeners interpret spoken language. Here, we examined whether three-year-olds, five-year-olds, and adults use filled pauses to anticipate that a speaker is likely to refer to a novel object. Across three experiments, participants were presented with pairs of novel and familiar objects and heard a speaker refer to one of the objects using a fluent (“Look at the ball/lep!”) or disfluent (“Look at thee uh ball/lep!”) expression. The salience of the speaker's unfamiliarity with the novel referents, and the way in which the speaker referred to the novel referents (i.e., a noun vs. a description) varied across experiments. Three- and five-year-olds successfully identified familiar and novel targets, but only adults’ looking patterns reflected increased looks to novel objects in the presence of a disfluency. Together, these findings demonstrate that adults, but not young children, use filled pauses to anticipate reference to novel objects.

This paper reviews some of the research that has been carried out at the University of Liverpool where the Flight Science and Technology Research Group has developed its Heliflight-R full-motion research simulator to create a simulation environment for the launch and recovery of maritime helicopters to ships. HELIFLIGHT-R has been used to conduct flight trials to produce simulated Ship-Helicopter Operating Limits (SHOLs). This virtual engineering approach has led to a much greater understanding of how the dynamic interface between the ship and the helicopter contributes to the pilot's workload and the aircraft's handling qualities and will inform the conduct of future real-world SHOL trials. The paper also describes how modelling and simulation has been applied to the design of a ship's superstructure to improve the aerodynamic flow field in which the helicopter has to operate. The superstructure aerodynamics also affects the placement of the ship's anemometers and the dispersion of the ship's hot exhaust gases, both of which affect the operational envelope of the helicopter, and both of which can be investigated through simulation.

To achieve their conservation goals individuals, communities and organizations need to acquire a diversity of skills, knowledge and information (i.e. capacity). Despite current efforts to build and maintain appropriate levels of conservation capacity, it has been recognized that there will need to be a significant scaling-up of these activities in sub-Saharan Africa. This is because of the rapid increase in the number and extent of environmental problems in the region. We present a range of socio-economic contexts relevant to four key areas of African conservation capacity building: protected area management, community engagement, effective leadership, and professional e-learning. Under these core themes, 39 specific recommendations are presented. These were derived from multi-stakeholder workshop discussions at an international conference held in Nairobi, Kenya, in 2015. At the meeting 185 delegates (practitioners, scientists, community groups and government agencies) represented 105 organizations from 24 African nations and eight non-African nations. The 39 recommendations constituted six broad types of suggested action: (1) the development of new methods, (2) the provision of capacity building resources (e.g. information or data), (3) the communication of ideas or examples of successful initiatives, (4) the implementation of new research or gap analyses, (5) the establishment of new structures within and between organizations, and (6) the development of new partnerships. A number of cross-cutting issues also emerged from the discussions: the need for a greater sense of urgency in developing capacity building activities; the need to develop novel capacity building methodologies; and the need to move away from one-size-fits-all approaches.

Low birth weight is associated with increased risk of cardiovascular disease in adulthood. Intrauterine growth restriction (IUGR) hearts have fewer CMs in early postnatal life, which may impair postnatal cardiovascular function and hence, explain increased disease risk, but whether the cardiomyocyte deficit persists to adult life is unknown. We therefore studied the effects of experimentally induced placental restriction (PR) on cardiac outcomes in young adult sheep. Heart size, cardiomyocyte number, nuclearity and size were measured in control (n=5) and PR (n=5) male sheep at 1 year of age. PR lambs were 36% lighter at birth (P=0.007), had 38% faster neonatal relative growth rates (P=0.001) and had 21% lighter heart weights relative to body weight as adults (P=0.024) than control lambs. Cardiomyocyte number, nuclearity and size in the left ventricle did not differ between control and PR adults; hearts of both groups contained cardiomyocytes (CM) with between one and four nuclei. Overall, cardiomyocyte number in the adult left ventricle correlated positively with birth weight but not with adult weight. This study is the first to demonstrate that intrauterine growth directly influences the complement of CM in the adult heart. Cardiomyocyte size was not correlated with cardiomyocyte number or birth weight. Our results suggest that body weight at birth affects lifelong cardiac functional reserve. We hypothesise that decreased cardiomyocyte number of low birth weight individuals may impair their capacity to adapt to additional challenges such as obesity and ageing.