[Cost estimation of an epidemiological surveillance network for animal diseases in Central Africa: a case study of the Chad network]. / Estimation du coûét d'un réseau d'épidèmiosurveillance des maladies animales en Afrique centrale: le cas du réseau tchadien.

In sub-Saharan Africa, most epidemiological surveillance networks for animal diseases were temporarily funded by foreign aid. It should be possible for national public funds to ensure the sustainability of such decision support tools. Taking the epidemiological surveillance network for animal diseases in Chad (REPIMAT) as an example, this study aims to estimate the network's cost by identifying the various costs and expenditures for each level of intervention. The network cost was estimated on the basis of an analysis of the operational organisation of REPIMAT, additional data collected in surveys and interviews with network field workers and a market price listing for Chad. These costs were then compared with those of other epidemiological surveillance networks in West Africa. The study results indicate that REPIMAT costs account for 3% of the State budget allocated to the Ministry of Livestock. In Chad in general, as in other West African countries, fixed costs outweigh variable costs at every level of intervention. The cost of surveillance principally depends on what is needed for surveillance at the local level (monitoring stations) and at the intermediate level (official livestock sectors and regional livestock delegations) and on the cost of the necessary equipment. In African countries, the cost of surveillance per square kilometre depends on livestock density.

[Economic management of health crises affecting production animals in Europe]. / Instruments de gestion economique des crises sanitaires touchant les animaux de production en Europe.

The importance of animal health crises has considerably increased over the last few years. When a crisis occurs, farmers can receive financial support through various public, private and mixed compensation schemes. Economic losses resulting from diseases may be direct and indirect. If a disease is covered by European Union regulations then countries have a legal obligation to partly compensate farmers for direct losses, either directly through the national budget, or through a specific fund. The European Veterinary Fund also co-finances these losses. Only a few countries provide compensation for indirect losses. The private insurance sector also provides protection against some direct and indirect losses but the risks covered are variable. To encourage farmers to subscribe to this kind of insurance, some public authorities provide subsidies to help pay the premium. Insurance companies do not generally cover the risks linked to contagious diseases, but some companies do extend cover to include this type of risk. Several alternatives, such as mutual funds, are available to improve risk coverage. There is a lack of harmonisation among the various compensation schemes of different countries. Public authorities cannot provide full compensation, but mutual funds and private insurance companies are alternatives that should be further investigated and their use should be extended to other countries. A classification of diseases would harmonise the situation at the European level.

The effects of microstructure, Nb content and secondary Ruddlesden-Popper phase on thermoelectric properties in perovskite CaMn1-x Nb x O3 (x = 0-0.10) thin films.

CaMn1-x Nb x O3 (x = 0, 0.5, 0.6, 0.7 and 0.10) thin films have been grown by a two-step sputtering/annealing method. First, rock-salt-structured (Ca,Mn1-x ,Nb x )O thin films were deposited on 11̄00 sapphire using reactive RF magnetron co-sputtering from elemental targets of Ca, Mn and Nb. The CaMn1-x Nb x O3 films were then obtained by thermally induced phase transformation from rock-salt-structured (Ca,Mn1-x Nb x )O to orthorhombic during post-deposition annealing at 700 °C for 3 h in oxygen flow. The X-ray diffraction patterns of pure CaMnO3 showed mixed orientation, while Nb-containing films were epitaxially grown in [101] out of-plane-direction. Scanning transmission electron microscopy showed a Ruddlesden-Popper (R-P) secondary phase in the films, which results in reduction of the electrical and thermal conductivity of CaMn1-x Nb x O3. The electrical resistivity and Seebeck coefficient of the pure CaMnO3 film were measured to 2.7 Ω cm and -270 µV K-1 at room temperature, respectively. The electrical resistivity and Seebeck coefficient were reduced by alloying with Nb and was measured to 0.09 Ω cm and -145 µV K-1 for x = 0.05. Yielding a power factor of 21.5 µW K-2 m-1 near room temperature, nearly eight times higher than for pure CaMnO3 (2.8 µW K-2 m-1). The power factors for alloyed samples are low compared to other studies on phase-pure material. This is due to high electrical resistivity originating from the secondary R-P phase. The thermal conductivity of the CaMn1-x Nb x O3 films is low for all samples and is the lowest for x = 0.07 and 0.10, determined to 1.6 W m-1 K-1. The low thermal conductivity is attributed to grain boundary scattering and the secondary R-P phase.

[Acute respiratory distress syndrome in childhood: Changing definition and news from the Pediatric Consensus Conference]. / Syndrome de détresse respiratoire aiguë de l'enfant : évolution de la définition et nouveautés de la conférence de consensus pédiatrique.

Acute respiratory distress syndrome (ARDS) is a rapidly progressive hypoxemic respiratory insufficiency induced by alveolar filling mainly caused by alveolocapillary wall disruption, following direct or indirect pulmonary injury. Much less frequent in children than in adults, pediatric intensivists had long applied adult guidelines to their daily practice. In 2015, experts from the Pediatric Acute Lung Injury Consensus Conference (PALICC) published the first international guidelines specifically dedicated to pediatric ARDS. After a short summary of the history of the ARDS definition since its first report in 1967, we describe the main diagnostic and therapeutic guidelines for PALICC.

Serum lipoprotein and apolipoprotein profiles of the genetically obese ob/ob mouse.

The lipid transport system of 3-month-old male C57BL/6J obese (ob/ob) mice was investigated. Serum lipoproteins were separated by density gradient ultracentrifugation and characterized by their chemical and electrophoretic properties as well as their relative apolipoprotein contents, defined according to molecular weight and charge. Obese, ob/ob mice exhibited a marked hyperlipoproteinemia resulting from large increases in low-density lipoproteins (LDL, d 1.021-1.058 g/ml) and high-density lipoproteins (HDL, d 1.058-1.137 g/ml), particularly, the HDL2 subclass (d 1.058-1.109 g/ml). This increase in lipoproteins was entirely responsible for their hypercholesterolemia and hyperphospholipidemia. By contrast, these obese mice had a net decrease in very-low-density lipoproteins (VLDL, d less than 1.016 g/ml) and intermediate-density lipoproteins (IDL, d 1.016-1.021 g/ml), which accounted for their moderate hypotriglyceridemia. The chemical composition of heterogeneous light LDL (d 1.021-1.040 g/ml and dense LDL (d 1.040-1.058 g/ml) overlapped by HDL-like particles was highly modified. These modifications consisted of increases in the percentages of cholesteryl ester and phospholipid and decreases in that of triacylglycerol. There were also marked changes in the relative values of the apolipoproteins of VLDL, but principally, IDL and LDL. IDL and light LDL were poorer in apolipoproteins BH (Mr 340,000-320,000) and eventually in apolipoprotein BL (Mr 220,000-200,000) and enriched in apolipoproteins E (Mr 37,000-35,000) and C-A-II (Mr approximately equal to 12,000). A similar and very significant change occurred in VLDL for both the apolipoproteins BL and C-A-II. Dense LDL, mainly poorer in apolipoprotein BH and enriched in apolipoprotein A-I (Mr 28,000-27,000), closely resembled HDL2 in all the groups, and were enriched in apolipoproteins C-A-II in only the obese mice. We suggest that ob/ob mice are probably protected against atheromata because of the low VLDL and IDL levels, and the increase in HDL2.

A genetic linkage map of the male goat genome.

This paper presents a first genetic linkage map of the goat genome. Primers derived from the flanking sequences of 612 bovine, ovine and goat microsatellite markers were gathered and tested for amplification with goat DNA under standardized PCR conditions. This screen made it possible to choose a set of 55 polymorphic markers that can be used in the three species and to define a panel of 223 microsatellites suitable for the goat. Twelve half-sib paternal goat families were then used to build a linkage map of the goat genome. The linkage analysis made it possible to construct a meiotic map covering 2300 cM, i.e., > 80% of the total estimated length of the goat genome. Moreover, eight cosmids containing microsatellites were mapped by fluorescence in situ hybridization in goat and sheep. Together with 11 microsatellite-containing cosmids previously mapped in cattle (and supposing conservation of the banding pattern between this species and the goat) and data from the sheep map, these results made the orientation of 15 linkage groups possible. Furthermore, 12 coding sequences were mapped either genetically or physically, providing useful data for comparative mapping.

Beta 1 adrenergic receptor and G alpha s mRNAs in rat heart as a function of mechanical load and thyroxine intoxication.

OBJECTIVE: The aim of this study was to determine the expression of genes coding for the beta 1 adrenergic receptor and the alpha subunit of Gs in the adult rat normal and hypertrophied left ventricle, and in the left ventricle of the hypophysectomised rat after T4 intoxication. METHODS: Total RNA was extracted from normal, control, or hypertrophied left ventricles 5 weeks after aortic stenosis, and from left ventricles of control or T4 injected hypophysectomised animals. The expression of beta 1 adrenergic receptor and G alpha s mRNAs was quantitated by northern blot analysis and hybridisation with specific 32P-dCTP labelled DNA probes. RESULTS: beta 1 Adrenergic receptor mRNA was decreased (by 33%) in compensated left ventricular hypertrophy without modification of the relative level of G alpha s mRNA. The relative level of beta 1 adrenergic receptor mRNA correlated negatively with the degree of left ventricular hypertrophy, suggesting that the expression of the beta 1 adrenergic receptor gene is not activated by pressure overload. In the left ventricle of the hypophysectomised rat, a rapid increase in beta 1 adrenergic receptor mRNA (by 180% 3 h after hormone injection) was observed in response to T4, with no change in the relative content of G alpha s mRNA. These results provide evidence that beta 1 adrenergic receptor mRNA and G alpha s mRNA accumulate to different levels of abundance in the adult left ventricle, as indicated by their ratios (0.053 and 0.043 in sham operated and hypertrophied left ventricles respectively). This suggests that distinct mechanisms are involved in the control of the accumulation of these two mRNAs in cardiac tissue. CONCLUSIONS: The reduction in beta 1 adrenergic receptor density in the hypertrophied rat left ventricle is associated with a parallel reduction in the level of beta 1 adrenergic receptor mRNA. The beta 1 adrenergic receptor gene may belong to a group of genes which are not activated by pressure overload, but are responsive to thyroid hormone.

A Mobile, Collaborative, Real Time Task List for Inpatient Environments.

BACKGROUND: Inpatient teams commonly track their tasks using paper checklists that are not shared between team members. Team members frequently communicate redundantly in order to prevent errors. METHODS: We created a mobile, collaborative, real-time task list application on the iOS platform. The application listed tasks for each patient, allowed users to check them off as completed, and transmitted that information to all other team members. In this report, we qualitatively describe our experience designing and piloting the application with an inpatient pediatric ward team at an academic pediatric hospital. RESULTS: We successfully created the tasklist application, however team members showed limited usage. CONCLUSION: Physicians described that they preferred the immediacy and familiarity of paper, and did not experience an efficiency benefit when using the electronic tasklist.

A critical and previously unsuspected role for doublecortin at the neuromuscular junction in mouse and human.

Mutations in the microtubule-associated protein doublecortin (DCX) cause type I (X-linked or XLIS) lissencephaly in hemizygous males and subcortical band heterotopia (SBH) in females, with defects in neuron migration during development affecting cortical lamination. We found that besides its well-established expression in migrating neurons of the brain, doublecortin (Dcx in mice) is also expressed in motor neurons and skeletal muscle in embryonic neuromuscular junctions (NMJs), raising the possibility of a role in synaptogenesis. Studies with whole-mount preparations of embryonic mouse diaphragm revealed that loss of Dcx leads to abnormal presynaptic arborization and a significantly increased incidence of short axonal extensions beyond innervated acetylcholine receptor (AChR) clusters in the developing NMJ. This phenotype, albeit relatively mild, suggests that Dcx contributes to a stop/stabilizing signal at the synapse, which normally limits further axonal growth following establishment of synaptic contact with the postsynaptic element. Importantly, we also identified abnormal and denervated NMJs in a muscle biopsy from a 16-year-old female patient with SBH, showing both profound presynaptic and postsynaptic morphological defects. Overall, these combined results point to a critical role of doublecortin in the formation of the NMJ.

Heart transplantation changes the expression of distinct gene families.

We took advantage of the combination of a rat heart transplantation model with a modified differential display RT-PCR method to identify transcriptome changes in the right atria from transplanted compared with native hearts. Based on sequence homology search, the 37 cDNAs differentially displayed both 2 and 7 days posttransplantation were categorized into 7 unknown transcripts, 16 expressed sequence tags (ESTs), and 14 partially or completely characterized genes. The last group cDNAs, validated by relative RT-PCR, belonged to diverse gene families involved in specific metabolisms, protein synthesis, cell signaling, and transcription. Furthermore, we identified differential transcripts corresponding to denervation and fetal gene reexpression. We found coordinate downregulation of genes involved in energy metabolism and protein synthesis regulation, similar to that reported for senescent skeletal muscle. From these transcriptome changes, we propose that heart transplants and senescent muscles share common molecular mechanisms.

Decreased accumulation of beta 1-adrenergic receptor, G alpha s and total myosin heavy chain messenger RNAs in the left ventricle of senescent rat heart.

The expression of genes coding for the beta 1-adrenergic receptor (beta 1-AR), the alpha subunit of Gs and total myosin heavy chain (MHC) was compared between left ventricles (LV's) from young (6-7 weeks old) and old (22 months old) rats. The mRNA levels were quantitated by Northern or Slot blots analyses using specific DNA probes. Ageing was found to be associated with a reduction in beta 1-AR (77%), G alpha s (33%) and, total MHC (51%) mRNA levels with no concomitant change in 18S RNA and poly(A+) mRNA levels. These results indicate that transcriptional and/or post-transcriptional mechanisms participate in the control of beta-adrenergic receptor density during ageing. As in the senescent LV, beta 1-AR mRNA level is reduced in the hypertrophied LV, whereas the level of G alpha s mRNA is reduced in the senescent but not in the hypertrophied LV. From our data we conclude (1) that a dual mechanism may operate during ageing, mechanical factors indirectly regulating beta 1-AR mRNA level, while changes in G alpha s mRNA level do not depend on hemodynamic load and (2) that the re-expression of beta-MHC mRNA does not compensate for the decreased accumulation of alpha-MHC mRNA which results in a large decrease in the level of total MHC mRNA in the senescent LV.

Beta-adrenergic and muscarinic receptor mRNA accumulation in the sinoatrial node area of adult and senescent rat hearts.

The sinoatrial (SA) node is the cardiac pacemaker and changes in its adrenergic-muscarinic phenotype have been postulated as a determinant of age-associated modifications in heart rate variability. To address this question, right atria were microdissected, the SA node area was identified by acetylcholinesterase staining, and, using a RT-PCR method, the accumulation of mRNA molecules encoding beta1- and beta2-adrenergic (beta1- and beta2-AR) and muscarinic (M2-R) receptor was quantified to define the proportion between beta-AR and M2-R mRNAs within the sinoatrial area of adult (3 months) and senescent (24 months) individual rat hearts. In adult hearts, the highest M2-R/beta-AR mRNA ratio was observed within the sinoatrial area compared with adjacent atrial myocardium, while in the senescent hearts, no difference was observed between sinoatrial and adjacent areas. This change was specific of the sinoatrial area since adult and senescent whole atrial or ventricular myocardium did not differ in their M2-R/beta-AR mRNA ratio, and was associated with a fragmentation of acetylcholinesterase staining of the senescent SA node. Quantitative changes in the expression of genes encoding proteins involved in heart rate regulation specifically affect the sinoatrial area of the senescent heart.

Lipogenesis in primary cultures of adipoblasts derived from genetically obese Zucker rats.

Adipocyte precursor cultures prepared from the epididymal fat pads of genetically obese (fa/fa) and lean (Fa/Fa) Zucker rats grow similarly in culture. Addition of enriched medium (EM) containing human serum, insulin, and glucose stimulated lipid filling of the adipocyte precursors in both cultures. However, [3H] H2O incorporation into total lipids, fatty acid synthetase and lipoprotein lipase activities, and cytosolic protein contents are all decreased in the fa/fa compared with the Fa/Fa cultures. Substitution of lean or obese rat serum for human serum in the enriched medium does not alter the decreased lipogenic capacity of the fa/fa adipocyte precursor cultures.

B-Lynch suture for postpartum hemorrhage.

BACKGROUND: Postpartum hemorrhage is a major contributor to maternal morbidity and mortality. Numerous medical and surgical therapies have been used, but none has been uniformly successful. CASE: Two women with postpartum hemorrhage due to uterine atony after cesarean for twins are presented. Neither responded to medical management. In the first subject, O'Leary uterine artery ligation and utero-ovarian branch ligations were done without benefit. The B-Lynch suture immediately sustained correction of hemorrhage in both subjects. Magnetic resonance imaging and hysterosalpingogram after the first case showed no uterine defects. CONCLUSION: The B-Lynch suture might be a valuable addition to the surgical treatment of postpartum hemorrhage due to uterine atony.

In-vitro bactericidal activity of four oral antibiotics against pathogens responsible for acute otitis media in children.

This study was designed to test the in-vitro activity of four oral antibiotics against the four microorganisms most frequently isolated in acute otitis media: beta-lactamase-positive Haemophilus influenzae (N = 10), beta-lactamase-positive Moraxella catarrhalis (N = 10), penicillin-sensitive Streptococcus pneumoniae (N = 11) and methicillin-sensitive Staphylococcus aureus (N = 10), by the bactericidal curve method. Bactericidal kinetics were determined for concentrations of antibiotic equivalent to those found in the middle ear after treatment: amoxycillin-clavulanic acid (2.5 mg l-1/0.6 mg l-1 and 2.5 mg l-1/1.2 mg l-1), cefaclor (1 mg l-1), erythromycin (0.5 mg l-1) and erythromycin/sulfisoxazole (0.2/3 mg l-1). The inoculum was of 10(6) colony-forming units (cfu) ml-1. The bacterial counts were performed after 5 h and 24 h using a spiral inoculator system. The results showed that amoxycillin-clavulanic acid had rapid bactericidal activity (< 24 h) on the tested organisms at each of the doses used (reduction < or = 3 log10 cfu ml-1) which was not observed with the other antibiotics at either 5 or 24 h. Erythromycin alone or combined with sulfisoxazole had a bacteriostatic effect on Moraxella catarrhalis and Streptococcus pneumoniae but not on Haemophilus influenzae or Staphylococcus aureus. Cefaclor had no bactericidal action under these conditions.

A rapid spectrophotometric blood cyanide determination applicable to emergency toxicology.

Cyanide determination in whole blood can be performed by spectrophotometry after using diffusion coupled with coloration by hydroxocobalamin in a Conway dish. The technique may be accelerated by the use of a heating sheet at 45 degrees C. The method proved to be specific, sensitive, and fast, thus permitting measurements in emergency situations.

Shoulder disorders related to work organization and other occupational factors among supermarket cashiers.

The study was designed to examine, in 210 supermarket cashiers, the cross-sectional relationships between shoulder disorders according to location and chronicity of pain as well as personal and occupational factors and store and workstation characteristics. The factors associated with shoulder disorders differed for the right and left sides. Age and psychological disorders were significant risk factors. Among occupational factors, duration of employment, job control, wage dependence on efficiency, exposure to cold, movements and postures such as stooping, working with arms above shoulder level and holding heavy loads in position, and using a laser scanner were associated with shoulder disorders, especially on the left. These results confirm the multifactorial origin of shoulder disorders, and show the importance of psychosocial work factors, movements and postures, and the laser scanner as occupational risk factors, and the need to consider right and left shoulder disorders in cashiers separately.

Genetic linkage mapping of quantitative trait loci for behavioral and neuroendocrine stress response traits in pigs.

A QTL analysis of behavioral and neuroendocrine responses to a "novel environment" stress was conducted in a three-generation experimental cross between Meishan and Large White pig breeds. A total of 186 F2 males and 182 F2 females were studied for their behavioral and neuroendocrine reactivity to a novel environment test at 6 wk of age. Locomotion, vocalization, and defecation rate, as well as exploration time, were measured for 10 min. Blood samples were taken immediately before and after the test to measure plasma levels of ACTH, cortisol, and glucose. Animals were typed for a total of 137 markers covering the entire porcine genome. Analyses were performed using two interval mapping methods: a line-cross regression method, where founder lines were assumed to be fixed for different QTL alleles, and a half-/full-sib maximum likelihood method where allele substitution effects were estimated within each half-/full-sib family. Both methods revealed a highly significant gene effect for poststress cortisol level (P < 0.001) and a significant effect for basal cortisol level (P < 0.05) at the end of the q arm of chromosome 7, explaining, respectively, 20% and 7% of the phenotypic variance. Meishan alleles are associated with higher cortisol levels and are partially dominant (for poststress levels) over Large White alleles. Other significant gene effects on biological measures were detected on chromosomes 1 and 17 (ACTH response to stress), 3, 5, and 8 (glucose levels). The SSC 17 QTL explains 12% of the phenotypic variance of poststress ACTH levels, with a suggestive evidence of imprinting effects. Meishan alleles are associated with lower poststress ACTH levels. Gene effects of low amplitude only were found for behavioral reactivity traits. Considering the effects of stress neuroendocrine systems on energy fluxes and protein deposition, and the importance of stress reactivity for meat quality and animal welfare, these results open new perspectives for pig selection.

[Action of ifenprodil tartrate in obliterative arteriopathies of the lower limbs. Combined studies using proximal blood flow and distal transcutaneous oxygen pressure]. / Action du tartrate d'ifenprodil dans l'artériopathie oblitérante des membres inférieurs. Mesures couplées par débitmétrie proximale et pression d'oxygène transcutanée distale.

A simultaneous analysis of both the variations of the flow in the stenosis artery and the distal PO2, was carried out during an injection of an alpha-blocker: the Tartrate d'Ifenprodil, on twenty-five patients afflicted with occlusive disease of the lower limbs requiring surgery. The measurements were taken under general anaesthesia, before any surgical operation, the hemodynamic and ventilatory balance being monitored by radial manometry and arterial gas analysis. We observe an increase of proximal arterial flow and at the same time an improvement of the distal TcPO2. Moreover, the variations of microcirculation flow measured by TcPO2 are correlated with proximal flow variations, this relation: delta TcPO2 = K delta Q + A is more true in the first and the second stages of Fontaine. With the same (Tartrate d'Ifenprodil) posology, the distal benefit measured by transcutaneous oximetry is less important in advanced stages compared with other stages (everything else being equal). The transcutaneous measurement of the distal oxygen pressure, allows an objective view of microcirculatory improvement obtained by a vasoactive substance (ifenprodil tartrate) considering the specific nature of each patient arteriopathy.

Quantitative estimation of sampling uncertainties for mycotoxins in cereal shipments.

Many countries receive shipments of bulk cereals from primary producers. There is a volume of work that is on-going that seeks to arrive at appropriate standards for the quality of the shipments and the means to assess the shipments as they are out-loaded. Of concern are mycotoxin and heavy metal levels, pesticide and herbicide residue levels, and contamination by genetically modified organisms (GMOs). As the ability to quantify these contaminants improves through improved analytical techniques, the sampling methodologies applied to the shipments must also keep pace to ensure that the uncertainties attached to the sampling procedures do not overwhelm the analytical uncertainties. There is a need to understand and quantify sampling uncertainties under varying conditions of contamination. The analysis required is statistical and is challenging as the nature of the distribution of contaminants within a shipment is not well understood; very limited data exist. Limited work has been undertaken to quantify the variability of the contaminant concentrations in the flow of grain coming from a ship and the impact that this has on the variance of sampling. Relatively recent work by Paoletti et al. in 2006 [Paoletti C, Heissenberger A, Mazzara M, Larcher S, Grazioli E, Corbisier P, Hess N, Berben G, Lübeck PS, De Loose M, et al. 2006. Kernel lot distribution assessment (KeLDA): a study on the distribution of GMO in large soybean shipments. Eur Food Res Tech. 224:129-139] provides some insight into the variation in GMO concentrations in soybeans on cargo out-turn. Paoletti et al. analysed the data using correlogram analysis with the objective of quantifying the sampling uncertainty (variance) that attaches to the final cargo analysis, but this is only one possible means of quantifying sampling uncertainty. It is possible that in many cases the levels of contamination passing the sampler on out-loading are essentially random, negating the value of variographic quantitation of the sampling variance. GMOs and mycotoxins appear to have a highly heterogeneous distribution in a cargo depending on how the ship was loaded (the grain may have come from more than one terminal and set of storage silos) and mycotoxin growth may have occurred in transit. This paper examines a statistical model based on random contamination that can be used to calculate the sampling uncertainty arising from primary sampling of a cargo; it deals with what is thought to be a worst-case scenario. The determination of the sampling variance is treated both analytically and by Monte Carlo simulation. The latter approach provides the entire sampling distribution and not just the sampling variance. The sampling procedure is based on rules provided by the Canadian Grain Commission (CGC) and the levels of contamination considered are those relating to allowable levels of ochratoxin A (OTA) in wheat. The results of the calculations indicate that at a loading rate of 1000 tonnes h(-1), primary sample increment masses of 10.6 kg, a 2000-tonne lot and a primary composite sample mass of 1900 kg, the relative standard deviation (RSD) is about 1.05 (105%) and the distribution of the mycotoxin (MT) level in the primary composite samples is highly skewed. This result applies to a mean MT level of 2 ng g(-1). The rate of false-negative results under these conditions is estimated to be 16.2%. The corresponding contamination is based on initial average concentrations of MT of 4000 ng g(-1) within average spherical volumes of 0.3 m diameter, which are then diluted by a factor of 2 each time they pass through a handling stage; four stages of handling are assumed. The Monte Carlo calculations allow for variation in the initial volume of the MT-bearing grain, the average concentration and the dilution factor. The Monte Carlo studies seek to show the effect of variation in the sampling frequency while maintaining a primary composite sample mass of 1900 kg. The overall results are presented in terms of operational characteristic curves that relate only to the sampling uncertainties in the primary sampling of the grain. It is concluded that cross-stream sampling is intrinsically unsuited to sampling for mycotoxins and that better sampling methods and equipment are needed to control sampling uncertainties. At the same time, it is shown that some combination of cross-cutting sampling conditions may, for a given shipment mass and MT content, yield acceptable sampling performance.