Brevetoxin exposure in bottlenose dolphins (Tursiops truncatus) associated with Karenia brevis blooms in Sarasota Bay, Florida

Bottlenose dolphins (Tursiops truncatus) face a variety of threats, including risk of exposure to brevetoxins produced by blooms of the harmful alga Karenia brevis. This study investigated brevetoxin exposure in a population of dolphins inhabiting Sarasota Bay, Florida, USA (27°N, 82°W), utilizing tissues from dolphins recovered between 1994 and 2003. Brevetoxin levels detected by ELISA in tissues, gastric samples and excreta from dolphin carcasses (n = 19) associated with K. brevis blooms were compared with with levels in carcasses (n = 16) associated with background K. brevis conditions. In the K. brevis-exposed set, 84% of dolphin carcasses recovered during K. brevis blooms had detectable brevetoxin levels, with values ranging between 7 and 2,896 ng PbTx-3 eq g⁻¹. Over 50% of dolphin carcasses recovered during non-bloom conditions also tested positive by ELISA for brevetoxins, with concentrations ranging from 6 to 44 ng PbTx-3 eq g⁻¹. Control samples from the east coast of Florida were negative by the ELISA. Results from this study establish baseline brevetoxin body burdens in a dolphin population frequently exposed to K. brevis blooms, and data indicate that dolphin carcasses not associated with large-scale mortality events can contain levels of brevetoxins comparable to carcasses stranding during such events.     

The effect of navigational expertise on wayfinding in new environments

Becoming proficient at navigation in urban environments is something that we all aspire to. Here we asked whether being an expert at wayfinding in one environment has any effect on learning new spatial layouts. Licensed London taxi drivers are among the most proficient urban navigators, training for many years to find their way around a complex and irregularly-laid out city. We first tested how well they could learn the layout of an unfamiliar town compared with a group of non-taxi drivers. Second, we investigated how effectively taxi drivers could integrate a new district into their existing spatial representation of London. We found that taxi drivers were significantly better than control participants at executing routes through the new town, and representing it at a map-like survey level. However, the benefits of navigational expertise were not universal. Compared with their performance in the new town, taxi drivers were significantly poorer at learning the layout of a new area that had to be integrated with their existing knowledge of London. We consider reasons for this picture of facilitation and limitation, in particular drawing parallels with how knowledge acquisition occurs in the context of expertise in general.     

What aspect of dietary modification in broilers controls litter water-soluble phosphorus: dietary phosphorus, phytase, or calcium?

Environmental concerns about phosphorus (P) losses from animal agriculture have led to interest in dietary strategies to reduce the concentration and solubility of P in manures and litters. To address the effects of dietary available phosphorus (AvP), calcium (Ca), and phytase on P excretion in broilers, 18 dietary treatments were applied in a randomized complete block design to each of four replicate pens of 28 broilers from 18 to 42 d of age. Treatments consisted of three levels of AvP (3.5, 3.0, and 2.5 g kg(-1)) combined with three levels of Ca (8.0, 6.9, and 5.7 g kg(-1)) and two levels of phytase (0 and 600 phytase units [FTU]). Phytase was added at the expense of 1.0 g kg(-1) P from dicalcium phosphate. Fresh litter was collected from pens when the broilers were 41 d of age and analyzed for total P, soluble P, and phytate P as well as P composition by (31)P nuclear magnetic resonance (NMR) spectroscopy. Results indicated that the inclusion of phytase at the expense of inorganic P or reductions in AvP decreased litter total P by 28 to 43%. Litter water-soluble P (WSP) decreased by up to 73% with an increasing dietary Ca/AvP ratio, irrespective of phytase addition. The ratio of WSP/total P in litter decreased as the dietary Ca/AvP ratio increased and was greater in the phytase-amended diets. This study indicated that while feeding reduced AvP diets with phytase decreased litter total P, the ratio of Ca/AvP in the diet was primarily responsible for effects on WSP. This is important from an environmental perspective as the amount of WSP in litter could be related to potential for off-site P losses following land application of litter.     

Impact of diet, moisture, location, and storage on soluble phosphorus in broiler breeder manure

Decreasing dietary phosphorus (P) has the potential to reduce P excreted in manure and therefore alleviate the environmental degradations associated with intensive animal farming. We evaluated reducing dietary P for broiler breeders as an aid to reduce manure total and water soluble phosphorus (WSP). Broiler breeders were fed diets high and low in dietary P, with and without phytase, from 22 to 64 wk of age. At the end of the 42-wk production period, manure was collected from four locations in each two-thirds slat, one-third litter breeder pen: the litter scratch area, under the drinker in the slat area, under the feeder in the slat area, and in a clean area of the slat area away from feeder or drinker. After the initial sampling, all manure was removed from pens and representative samples were stored for 6 mo with and without feed mixed in to simulate the effect of spilled feed. Total P was determined on all pen samples, and moisture and WSP determined on the pen and stored samples. The manure collected under the drinker had much greater moisture due to spilled water. This was associated with much greater WSP in this location, showing the importance of good water management. The manure from under the feeder had similar WSP as manure from the clean area, so spilled feed did not significantly affect WSP. Dietary phytase either had no effect or significantly decreased manure WSP. However, addition of dietary phytase to the feed led to slightly elevated manure moisture. Since moisture was correlated with manure WSP this may explain some of the variability in WSP results between studies. Over 6 mo of storage WSP increased and generally followed the same ranking order at 168 d as at 1 d among the dietary treatments (high>high+phytase>low>low+phytase). Combining decreased dietary P and phytase reduced both manure total P and WSP by 42%. As total P and WSP are indicators of the long and short term impacts manure applications can have on P losses from manured soils, diet modification should be seen as environmentally beneficial.     

Individual attributes and leadership style: predicting the use of punishment and its effects

This study examined attributes of leaders that influenced their use of contingent and noncontingent punishment and the results of using punishment on leader effectiveness. Results indicated that leaders with higher levels of physical fitness and moral reasoning were more likely to use contingent punishment, while those with lower self-esteem were more likely to use noncontingent punishment. Noncontingent punishment negatively impacted leader effectiveness, while contingent punishment positively impacted leader effectiveness. © 1998 John Wiley & Sons, Ltd.     

A clash of cultures (and lawyers): Anglo Platinum and mine-affected communities in Limpopo Province,South Africa

The human rights related controversies surrounding Anglo Platinum's Mogalakwena mine in South Africa's Limpopo Province hit the world stage in 2008, attracting public scrutiny and instigating much debate in the realm of international business and human rights discussions. We provide an in-depth analysis of the controversies at Mogalakwena, and Anglo Platinum's responses. This case study contributes to ongoing debates on mining company-community relations in the context of the emerging business and human rights agenda, specifically with respect to the notion of human rights ‘due diligence’. We argue that the Mogalakwena case study illustrates the risks of companies adhering to and emphasizing the technical and logistical facets of due diligence, without sufficient attention to the relational, communicative and emergent aspects, which are closely tied to corporate culture. We highlight the complexities of company-community relationships, with particular reference to the issues of legitimate community representation and participatory decision-making, and discuss the role that organizational culture plays in exacerbating or mitigating corporate-community conflict. The case study demonstrates how legal challenges often exacerbate rather than resolve the conflicts that arise due to a clash between corporate and community cultures. We suggest the need for corporate leaders to become more conscious of this cultural dimension of effective social management, particularly when interacting with communities whose cultures are markedly different from those of business corporations.     

Evaluation of phosphorus characterization in broiler ileal digesta, manure, and litter samples: (31)P-NMR vs. HPLC

Using 31-phosphorus nuclear magnetic resonance spectroscopy ((31)P-NMR) to characterize phosphorus (P) in animal manures and litter has become a popular technique in the area of nutrient management. To date, there has been no published work evaluating P quantification in manure/litter samples with (31)P-NMR compared to other accepted methods such as high performance liquid chromatography (HPLC). To evaluate the use of (31)P-NMR to quantify myo-inositol hexakisphosphate (phytate) in ileal digesta, manure, and litter from broilers, we compared results obtained from both (31)P-NMR and a more traditional HPLC method. The quantification of phytate in all samples was very consistent between the two methods, with linear regressions having slopes ranging from 0.94 to 1.07 and r(2) values of 0.84 to 0.98. We compared the concentration of total monoester P determined with (31)P-NMR with the total inositol P content determined with HPLC and found a strong linear relationship between the two measurements having slopes ranging from 0.91 to 1.08 and r(2) values of 0.73 to 0.95. This suggests that (31)P-NMR is a very reliable method for quantifying P compounds in manure/litter samples.