Semi-automated camera trap image processing for the detection of ungulate fence crossing events

Remote cameras are an increasingly important tool for ecological research. While remote camera traps collect field data with minimal human attention, the images they collect require post-processing and characterization before it can be ecologically and statistically analyzed, requiring the input of substantial time and money from researchers. The need for post-processing is due, in part, to a high incidence of non-target images. We developed a stand-alone semi-automated computer program to aid in image processing, categorization, and data reduction by employing background subtraction and histogram rules. Unlike previous work that uses video as input, our program uses still camera trap images. The program was developed for an ungulate fence crossing project and tested against an image dataset which had been previously processed by a human operator. Our program placed images into categories representing the confidence of a particular sequence of images containing a fence crossing event. This resulted in a reduction of 54.8% of images that required further human operator characterization while retaining 72.6% of the known fence crossing events. This program can provide researchers using remote camera data the ability to reduce the time and cost required for image post-processing and characterization. Further, we discuss how this procedure might be generalized to situations not specifically related to animal use of linear features.     

Demonstrating trend reversal of groundwater quality in relation to time of recharge determined by 3H/3He

Recent EU legislation is directed to reverse the upward trends in the concentrations of agricultural pollutants in groundwater. However, uncertainty of the groundwater travel time towards the screens of the groundwater quality monitoring networks complicates the demonstration of trend reversal. We investigated whether trend reversal can be demonstrated by relating concentrations of pollutants in groundwater to the time of recharge, instead of the time of sampling. To do so, we used the travel time to monitoring screens in sandy agricultural areas in the Netherlands, determined by (3)H/(3)He groundwater dating. We observed that concentrations of conservative pollutants increased in groundwater recharged before 1985 and decreased after 1990. Thereby, we demonstrated trend reversal of groundwater quality. From this research we concluded that (3)H/(3)He dating can be used to facilitate (re)interpretation of existing groundwater quality data. The presented approach is widely applicable in areas with unconsolidated granular aquifers and large agricultural pressures on groundwater resources.     

Significantly higher number of fetal cells in the maternal circulation of women with pre-eclampsia

Although the pathophysiology of pre-eclampsia is unknown, several studies have indicated that abnormal placentation early in pregnancy might play a key role. It has recently been suggested that this abnormal placentation may result in transfusion of fetal cells (feto-maternal transfusion) in women with pre-eclampsia. In the present study, fetal nucleated red blood cells were isolated from 20 women with pre-eclampsia and 20 controls using a very efficient magnetic activated cell sorting (MACS) protocol. The number of male cells was determined using two-color fluorescence in situ hybridization (FISH) for X and Y chromosomes. Significantly more XY cells could be detected in women with pre-eclampsia (0.61±1.2 XY cells/ml blood) compared to women with uncomplicated pregnancies (0.02±0.04 XY cells/ml blood) (Mann–Whitney U-test, p<0.001). These results suggest that fetal cell trafficking is enhanced in women with pre-eclampsia, and this finding may contribute to the understanding of the pathophysiology of the disease. Copyright © 2001 John Wiley & Sons, Ltd.     

Development of biodiversity in field margins recently taken out of production and adjacent ditch banks in arable areas

Taking field margins out of intensive cultivation is a common form of agri-environmental scheme and on-farm nature management. Typically, no nutrients or pesticides are applied in these margins, which may be sown either with a crop or with grasses and native flowering plants. In some cases the margins are mown, while in others they are left alone. Newly established grass margins are less species-rich than field boundaries or road verges with a long history, justifying the expectation that field margins, if properly managed and given time and appropriate seed sources, could develop into relatively species-rich vegetation. We studied the biodiversity of both margins taken out of production and adjacent ditch banks in the years following initial establishment of the margins. To this end we combined the data of three different projects in order to increase the sensitivity of the statistical analyses. The results showed that the plant species richness of the field margins increased in the years following establishment over a period of four years. In addition, shifts in species composition indicated a decrease in soil nitrate concentrations. The species richness of both butterflies and dragonflies may increase. The most striking result was the marked increase in the plant species richness of the adjacent ditch banks in the five years following creation of the margins. Here, too, changes in species composition indicated a decrease in soil nitrate. In the years following establishment of the field margins there was no increase in the cover of agriculturally harmful weeds in these margins. However, the number of harmful nematodes increased. Our results show the short term effect of establishing field margins. Long term effects are still in need for further research.     

European Union waste management strategy and the importance of biogenic waste

In the European Union (EU), waste management is almost totally regulated by EU directives, which supply a framework for national regulations. The main target in view of sustainability is the prevention of direct disposal of reactive waste in landfills. The tools to comply with these principles are recycling and material recovery as well as waste incineration with energy recovery for final inertization. The adaptation of the principles laid down in EU directives is an ongoing process. A number of countries have already enacted respective national regulations and their realization shows that recycling and incineration are not in competition but are both essential parts of integrated waste management systems. In the EU, the amount of residual waste available for energy recovery can supply approximately 1% of the primary energy demand. About 50% of the energy inventory of municipal solid waste (MSW) in most EU countries is of biogenic origin, and MSW is to the same extent to be looked upon as regenerative fuel. Hence part of the CO₂ released from waste incineration is climate neutral. In the EU, this share could produce savings of the order of 1% of annual CO₂ emissions if energy from MSW replaced that derived from fossil fuel.     

Altered fetal cardiac flow patterns in pure red cell anaemia (the Blackfan-Diamond syndrome)

In a case of fetal anaemia due to pure red cell anaemia (Blackfan-Diamond syndrome), two-dimensional fetal Doppler echocardiography revealed an altered blood flow velocity pattern with entire incorporation of the atrial contraction component in the early passive filling phase of the right ventricle. Intracardiac blood velocities were increased, whereas cardiac output was only moderately increased. The fetal heart rate was normal. It is concluded that in fetal anaemia the compensatory mechanisms are limited and restricted to an increase in stroke volume. The hypothesis that chronic fetal anaemia is associated with ‘high output cardiac failure’ corresponds well with the present findings. The technique described may prove to be useful in the early diagnosis of fetal anaemia.     

A pilot study to assess residential endotoxin and blood IgE in a group of pregnant women from Trujillo, Peru

OBJECTIVE: This November 2003 pilot study investigates the correlation between serum IgE and residential endotoxin levels from a group of 18 pregnant women living in Trujillo, Peru, and investigates the impact of the demographic and lifestyle factors of this group on the IgE and endotoxin levels measured. METHODS: Serum samples were collected from 19 subjects and analyzed for IgE. Dust samples were collected from the mattresses of 18 subjects and measured for endotoxin levels. A questionnaire was used to obtain demographic, socioeconomic, and lifestyle information for each subject. RESULTS: Geometric means for IgE and endotoxin were 246.8 (GSD=4.3, n=19) IU/mL and 66.5 EU/mg (GSD=1.7, n=18), respectively. Log-transformed IgE and endotoxin were not correlated (R2=0.02; p=0.60). CONCLUSIONS: Residential endotoxin and serum IgE were not correlated in this group. Potential selection bias and sample size are major limitations of the study. However, 74% (14/19) of the subjects in this study had an IgE over 100 IU/mL, a level generally considered elevated.