Geostatistical methods were used to describe and map nonrandom distribution and variation (standard deviation) of shoot density and root growth across a well-established patch of Canada thistle, a perennial weed. Semivariogram functions and kriging, an interpolation method, were used to prepare isoarithmic contour maps and associated error maps. Maps consisted of interpolated contours of uniform weed density and other measured or calculated regionalized variables between measured X-Y control points, as well as maps of error (standard deviation) associated with contour estimation. Mapped regions of greatest shoot density across a patch not only had the greatest underlying root biomass and, often, greatest density of adventitious root buds, but also had more deeply growing root biomass.

Three methods of predicting the impact of weed interference on crop yield and expected economic return were compared to evaluate the economic importance of weed spatial heterogeneity. Density of three weed species was obtained using a grid sampling scheme in 11 corn and 11 soybean fields. Crop yield loss was predicted assuming densities were homogeneous, aggregated following a negative binomial with known population mean and k, or aggregated with weed densities spatially mapped. Predicted crop loss was lowest and expected returns highest when spatial location of weed density was utilized to decide whether control was justified. Location-specific weed management resulted in economic gain as well as a reduction in the quantity of herbicide applied.

Geostatistical techniques were used to describe and map the spatial distribution of crenate broomrape populations parasitizing broad bean over 6 yr (from 1985 to 1990). In the first year, the spatial distribution was random, but from 1986 to 1989, crenate broomrape populations were clearly aggregated. The crenate broomrape infection severity (IS: number of emerged broomrape m−2) increased every year, from an average of 0.45 in 1985 to 29.4 in 1989, with a slight decrease the following year (IS = 27.4). Spherical functions provided the best fit because the cross-validation criteria were accomplished in all study cases. Kriged estimates were used to draw contour maps of the populations. About 34.3, 43.3, and 74.3% of the field plot surface exhibited an IS ≥ 1 (economic threshold) in 1985, 1986, and 1987, respectively, and nearly 100% of the area exceeded the economic threshold from 1988 to 1990; 1985 and 1986 were key years for control of the parasitic weed population. The percentage of infested area at different IS intervals in each year's map obtained by kriging was used to estimate the percentage of yield losses in each infested area (YA) with the equation: YA = A ∗ Ymax ∗ (1 − IS ∗ 0.124), where A is the infested area at a given IS interval and Ymax is the expected broomrape-free broad bean yield. Yield losses under different IS intervals were compared with yield loss attributable to a uniform distribution of crenate broomrape. Results showed that yield loss assuming a uniform distribution of crenate broomrape was clearly overestimated, which is important to avoid overuse of herbicides.

The size, location, and variation in time of weed patches within an arable field were analyzed with the ultimate goal of simplifying weed mapping. Annual and perennial weeds were sampled yearly from 1993 to 1997 at 410 permanent grid points in a 1.3-ha no-till field sown to row crops each year. Geostatistical techniques were used to examine the data as follows: (1) spatial structure within years; (2) relationships of spatial structure to literature-derived population parameters, such as seed production and seed longevity; and (3) stability of weed patches across years. Within years, densities were more variable across crop rows and patches were elongated along rows. Aggregation of seedlings into patches was strongest for annuals and, more generally, for species whose seeds were dispersed by combine harvesting. Patches were most persistent for perennials and, more generally, for species whose seeds dispersed prior to expected dates of combine harvesting. For the most abundant weed in the field, the annual, Setaria viridis, locations of patches in the current year could be used to predict patch locations in the following year, but not thereafter.

Introduction: Clear paramedic-physician telecommunications (patches) are critical in systems utilizing on-line medical control. In systems using extensive medical directives individual paramedics patch infrequently. Investigations of specific problem calls indicated that communication problems were more common than believed. Existing literature on this topic is sparse. This project is a quality assurance exercise undertaken to understand the extent and nature of problems in paramedic-physician telecommunications Methods: Retrospective analysis of anonymized transcriptions made from MP3 audio files recorded as part of normal operating procedures by the Central Ambulance Communication Centre during January-March 2014. All calls where telecommunication occurred between paramedics from 4 ambulance services and base hospital physicians providing on-line medical oversight during ambulance calls were included. Transcripts were read multiple times and data extracted onto spreadsheets for frequency analysis. Further thematic framework analysis of emergent themes was done. Results: All 42 patches were transcribed and used for analysis. 36 (85.7%) were for termination of resuscitation orders, 4 (9.5%) were for advice, and 2 (4.8%) were for orders not covered by medical directives. Communication problems were identified in 40 (95.2%) patches. Most had multiple problems. These included disconnections (23.8%), difficulty hearing one another (40.5%) - indicated by phrases such as “sorry?” “what?”, “I can’t hear you” - or caused by individuals interrupting each other (83.3%), and talking simultaneously (47.6%). Signaling the end of “talk turns” - such as “10-4” or “over” - was never used. Instead, terms like “yah” and “OK” were used. When communication went awry, time was spent trying to repair the mis/poor communication. This led to repeating information or attempting to ‘sell’ the case by providing information unnecessary for decision making - such as during a request for termination of resuscitation, “there is vomit on the floor”. Conclusion: Paramedic-physician telecommunication problems were extremely common. They involved technical (mechanical problems) and human factors (disorganized radio ‘technique’). The high incidence of telecommunication problems identified is concerning. Critical clinical decisions (e.g. ceasing resuscitation) depend on clear communication. Further study of these issues is warranted.

Introduction: A variety of patch materials have been used in the repair of intracardiac defects. We evaluated the short- and mid-term clinical and echocardiography results of glutaraldehyde-preserved bovine pericardium patches used to repair intracardiac defects in our clinic. Methods and results: This study examines the short- (up to 30 days post-operatively) and mid-term (up to 24 months post-operatively) results of 533 patients with intracardiac defects who underwent surgical correction with glutaraldehyde-preserved bovine pericardium patches between 2004 and 2010 at a university clinic. Short- and mid-term post-operative echocardiographic studies showed no evidence of calcification, thrombus, or aneurysmal dilatation on the patch. Vegetation developed in two (0.37%) of the 533 patients. Conclusion: These results that have been obtained from a group of large number of patients imply that the glutaraldehyde-preserved bovine pericardium patches may be preferable in the closure of cardiac defects because of their low complication rates and ease of use.

The effect of landscape on populations is of great importance, especially given the number of species inhabiting patchy landscapes. Developments in geographical information systems are facilitating a greater application of spatial analyses to threatened species, such as the Endangered giant panda Ailuropoda melanoleuca, for which habitat patchiness and quality are key limiting factors. Of all factors that influence the suitability of habitat for the giant panda, topography is not subject to change. Here, we report a spatial and statistical analysis of the high quality topographic habitat preferred by the giant panda across its stronghold in the Qinling Mountains, China. High quality topographic habitat, as indicated by a combination of elevation, slope and aspect, covers 92,788 ha, accounting for 15% of the current range of the species. The distribution of the giant panda closely follows patterns of topography and areas with patches of high quality topographic habitat are strongly associated with areas supporting greater numbers of giant pandas. However, comparisons between our model and the existing reserve system reveals a number of inadequacies. Some of the reserves contain little high quality topographic habitat and many patches of high quality topographic habitat are unprotected. Given the importance of topography and the decisive role it plays in shaping habitat, landscapes containing high quality topographic features must be a critical consideration in the design of reserves for the giant panda. The existing system of nature reserves is heavily weighted towards judicial and administrative boundaries, to the detriment of other factors such as topography.

Spatial models are increasingly employed to help understand the distribution of organisms and establish conservation priorities. Classic patch-orientated models may have limited power to accurately predict the organisms' distributions. Pond breeding amphibians are appropriate study organisms because of their complex life cycle, low dispersal and sensitivity to environmental conditions. Here connectivity metrics and niche modelling were used to predict the occurrence of the northern crested newt in a rural landscape from central Romania. Pond-related variables, such as macrophyte cover and the presence of predatory fish, were the most important predictors of newt occurrence, followed by one landscape-related variable (urbanization) and a connectivity metric (nearest neighbouring occupied pond). Most of the landscape and connectivity variables were not adequate predictors, presumably because most of the terrestrial habitats in this traditionally used rural landscape are ecologically optimal for amphibians. Conservation measures for the northern crested newt should promote the preservation of traditional extensive agricultural practices and discourage stocking of ponds with predatory fish.

In this paper, with the assumptions that an infectious disease has a fixedlatent period in a population and the latent individuals of the population maydisperse, we reformulate an SIR model for the population living in two patches(cities, towns, or countries etc.), which is a generalization of the classicKermack-McKendrick SIR model. The model is given by a system of delaydifferential equations with a fixed delay accounting for the latency andnon-local terms caused by the mobility of the individuals during the latentperiod. We analytically show that the model preserves some properties that theclassic Kermack-McKendrick SIR model possesses: the disease always dies out,leaving a certain portion of the susceptible population untouched (calledfinal sizes). Although we can not determine the two final sizes, we are able toshow that the ratio of the final sizes in the two patches is totally determinedby the ratio of the dispersion rates of the susceptible individuals between thetwo patches. We also explore numerically the patterns by which the disease diesout, and find that the new model may have very rich patterns for the diseaseto die out. In particular, it allows multiple outbreaks of the disease before itgoes to extinction, strongly contrasting to the classic Kermack-McKendrick SIRmodel.

During development, the projection from the lateral geniculate nucleus to striate cortex becomes segregated into monocular regions called ocular dominance columns. Prior studies in cats have suggested that experimental strabismus or alternating monocular occlusion increases the width and segregation of columns. In the squirrel monkey, strabismus has been reported to induce the formation of ocular dominance columns. However, these studies are difficult to interpret because no animal can serve as its own control and the degree of inter-individual variability among normal subjects is considerable. We have re-examined the effect of strabismus on ocular dominance columns in a large group of strabismic and normal squirrel monkeys. Five animals rendered strabismic at age one week had well-developed, widely spaced columns. Among 16 control animals, a wide spectrum of column morphology was encountered. Some control animals lacked ocular dominance columns, whereas others had columns similar to those observed in strabismic animals. Natural variation in column expression in normal squirrel monkeys, and potential uncontrolled genetic influences, made it impossible to determine if strabismus affects ocular dominance columns. It was evident however, that strabismus does not affect the binocular projection from the lateral geniculate nucleus to each CO patch in the upper layers. In strabismic monkeys, just as in normal animals, each patch received input from geniculate afferents serving both the left eye and the right eye. In addition, in strabismic monkeys, as in normal animals, patches were not aligned with ocular dominance columns.