Chemotaxis and Motility of Spongospora subterranea Zoospores in Response to Potato Root Exudate Constituents and pH.

Spongospora subterranea f. sp. subterranea is an important pathogen of potato responsible for major losses in most potato growing regions of the world. Infection is initiated by biflagellated motile zoospores released from long-lived resting spores. Zoospore chemotaxis to the host plant root is widely believed to be stimulated by host root exudate compounds, although direct evidence is lacking. This study refined the traditional chemotaxis capillary assay, with which we provided the first empirical evidence of S. subterranea zoospore chemotaxis. Individual potato root exudate metabolites were either taxis neutral, inhibitory, or attractant to the zoospores. L-Glutamine was the strongest chemoattractant, while spermine was the most inhibitory. Zoospore motility and chemotaxis were constrained by strongly acidic or alkaline solutions of pH < 5.3 and >8.5, respectively. Beyond pH, ionic constituents of the test solution affected zoospore motility as Sorensen's phosphate buffer stalled zoospore motility, but HEPES buffer at the same concentration and pH had little or no negative motility effect. Zoospore motility, as characterized by several parameters, influenced chemotaxis. Among the parameters measured, total distance traveled was the best predictor of zoospore chemotaxis. The characterization of environmental and ecological effects on zoospore motility and chemotaxis highlights useful targets for S. subterranea disease control through manipulation of zoospore taxis or selection of host resistance traits.

Formalizing planning and information search in naturalistic decision-making.

Decisions made by mammals and birds are often temporally extended. They require planning and sampling of decision-relevant information. Our understanding of such decision-making remains in its infancy compared with simpler, forced-choice paradigms. However, recent advances in algorithms supporting planning and information search provide a lens through which we can explain neural and behavioral data in these tasks. We review these advances to obtain a clearer understanding for why planning and curiosity originated in certain species but not others; how activity in the medial temporal lobe, prefrontal and cingulate cortices may support these behaviors; and how planning and information search may complement each other as means to improve future action selection.

Biochemical evaluation of storage lesion in canine packed erythrocytes.

OBJECTIVES: To describe the biochemical changes - also known as the storage lesion - that occur in canine packed red blood cells during ex vivo storage. MATERIALS AND METHODS: Ten 125-mL units of non-leuco-reduced packed red blood cells in citrate phosphate dextrose adenine were obtained from a commercial blood bank within 24 hours of donation. Samples were aseptically collected on days 1, 4, 7, 14, 28, 35 and 42 for measurement of sodium, potassium, chloride, lactate, glucose, pH and ammonia concentrations. All units were cultured on day 42. Friedman's repeated measures test with Dunn's multiple comparison test was used for non-parametric data. A repeated-measures analysis of variance with Tukey's multiple comparison test was used for parametric data. Alpha was set to 0·05. RESULTS: All analytes changed significantly during storage. The mean ammonia on day 1 (58·14 g/dL) was significantly lower (P<0·05) than those on days 28 (1266 g/dL), 35 (1668 g/dL) and 42 (1860 g/dL). A significant increase in median lactate concentration over time was also observed, with day 1 (4·385 mmol/L) being significantly less (P<0·05) than days 14 (19·82 mmol/L), 21 (22·81 mmol/L), 35 (20·31 mmol/L) and 42 (20·81 mmol/L). Median pH was significantly decreased after day 7. All bacterial cultures were negative. CLINICAL SIGNIFICANCE: Many biochemical alterations occur in stored canine packed red blood cells, although further studies are required to determine their clinical importance.

The concurrent emergence and causes of double volcanic hotspot tracks on the Pacific plate.

Mantle plumes are buoyant upwellings of hot rock that transport heat from Earth's core to its surface, generating anomalous regions of volcanism that are not directly associated with plate tectonic processes. The best-studied example is the Hawaiian-Emperor chain, but the emergence of two sub-parallel volcanic tracks along this chain, Loa and Kea, and the systematic geochemical differences between them have remained unexplained. Here we argue that the emergence of these tracks coincides with the appearance of other double volcanic tracks on the Pacific plate and a recent azimuthal change in the motion of the plate. We propose a three-part model that explains the evolution of Hawaiian double-track volcanism: first, mantle flow beneath the rapidly moving Pacific plate strongly tilts the Hawaiian plume and leads to lateral separation between high- and low-pressure melt source regions; second, the recent azimuthal change in Pacific plate motion exposes high- and low-pressure melt products as geographically distinct volcanoes, explaining the simultaneous emergence of double-track volcanism across the Pacific; and finally, secondary pyroxenite, which is formed as eclogite melt reacts with peridotite, dominates the low-pressure melt region beneath Loa-track volcanism, yielding the systematic geochemical differences observed between Loa- and Kea-type lavas. Our results imply that the formation of double-track volcanism is transitory and can be used to identify and place temporal bounds on plate-motion changes.

Biochemical evaluation of the effects of storage on feline erythrocytes.

OBJECTIVE: To describe the biochemical changes that occur during storage of feline packed red blood cells. METHODS: Feline packed red blood cells were obtained from the manufacturer via overnight delivery immediately following collection. Bag spikes were placed using aseptic technique and samples were drawn on days 1, 4, 7, 14, 21, 28 and 35. Sodium, potassium, chloride, glucose, lactate, pH and ammonia were measured at each time point. Aerobic and anaerobic bacterial cultures were submitted following collection on day 35. RESULTS: There were statistically significant increases in the median concentrations of lactate and ammonia within the first 2 weeks of storage to a concentration of 12·38 mmol/L and 447·96 µmol/L, respectively. Glucose concentrations decreased significantly by day 28 to a mean of 1·86 mmol/L. Median sodium and chloride concentrations increased throughout the course of storage to a concentration of 158·20 and 131·00 mmol/L, respectively. Mean potassium concentrations decreased to a concentration of 2·40 mmol/L. CLINICAL SIGNIFICANCE: These results show that biochemical derangements within feline packed red blood cells are progressive, with some alterations, such as lactate and ammonia, occurring early within the storage periods, while others, including glucose and electrolytes, are slower to develop. Additional prospective research evaluating the clinical effects of these biochemical alterations is required.

Arsenic toxicosis in cattle: meta-analysis of 156 cases.

BACKGROUND: Arsenic toxicosis is uncommon in cattle and successful treatment is rarely reported. OBJECTIVES: This analysis reviews all cases of acute arsenic toxicosis in cattle reported in the literature and describes cases from Purdue University that had a favorable outcome. Clinical presentation of the disease, treatments, and variables associated with survival are described. ANIMALS: One hundred and fifty-six cattle with arsenic toxicosis from 16 outbreaks. METHODS: Meta-analysis. RESULTS: The most common clinical signs were sudden death (68%), diarrhea (33%), ataxia (29%), dehydration (22%), and respiratory distress (4%). The most common clinicopathologic abnormalities included azotemia (100%), hematuria (100%), increased liver enzyme activity (86%), and increased hematocrit (60%). One percent of cattle survived and the survival time for nonsurvivors ranged from 20 hours to 21 days. None of the clinical signs or clinicopathologic findings was associated with survival. Treatment was attempted in 24% of cases and was not associated with survival (P = .055), but administration of an antidote and administration of fluids were associated with better outcome (P = .036 and P = .009, respectively). In the animals presented to Purdue University, treatment with IV fluids and sodium thiosulfate resulted in decreased blood arsenic concentrations in all animals (P = .009) and a survival rate of 50%. CONCLUSIONS AND CLINICAL IMPORTANCE: Although acute arsenic toxicosis has a poor prognosis, survival is possible if aggressive fluid therapy and antidotes are administered.

Genetic and host-associated differentiation within Thrips tabaci Lindeman (Thysanoptera: Thripidae) and its links to Tomato spotted wilt virus-vector competence.

Of eight thelytokous populations of onion thrips (Thrips tabaci) collected from potato (three populations), onion (four) or Chrysanthemum (one) hosts from various regions of Australia, only those from potato were capable of transmitting Tomato spotted wilt virus (TSWV) in controlled transmission experiments. Genetic differentiation of seven of these eight populations, and nine others not tested for TSWV vector competence, was examined by comparison of the DNA sequences of mitochondrial cytochrome oxidase subunit 1 (COI) gene. All Australian populations of T. tabaci grouped within the European 'L2' clade of Brunner et al. (2004). Within this clade the seven populations from potato, the three from onion, and the four from other hosts (Chrysanthemum, Impatiens, lucerne, blackberry nightshade) clustered as three distinct sub-groupings characterised by source host. Geographical source of thrips populations had no influence on genetic diversity. These results link genetic differentiation of thelytokous T. tabaci to source host and to TSWV vector capacity for the first time.

Ten-year follow-up of skin-sparing mastectomy followed by immediate breast reconstruction.

BACKGROUND: The oncological safety of skin-sparing mastectomy (SSM) followed by immediate breast reconstruction (IBR) is debated owing to a presumed compromise in the completeness of mastectomy. Current evidence is poor as it is based mostly on short-term follow-up data from highly selected patients. METHODS: A prospectively maintained institutional database was searched to identify patients who underwent SSM and IBR between 1995 and 2000. A retrospective review of medical records was carried out, including only patients with ductal carcinoma in situ and invasive breast cancer. During this time all patients treated with mastectomy were offered IBR regardless of tumour stage. RESULTS: Follow-up data from 253 consecutive patients with IBR were reviewed. Patients with incomplete follow-up data and those undergoing SSM for recurrent disease following previous lumpectomy were disregarded, leaving 207 for analysis. Offering IBR to all women requiring mastectomy resulted in a large proportion of patients with advanced disease. During a median follow-up of 119 months, 17 (8·2 per cent) locoregional, six (2·9 per cent) local and 22 (10·6 per cent) distant recurrences were detected; the overall recurrence rate was 39 (18·8 per cent). Overall recurrence rate was associated with axillary lymph node metastasis (P = 0·009), higher stage (P < 0·001) and higher tumour grade (P = 0·031). The breast cancer-specific survival rate was 90·8 per cent (19 of 207 women died from recurrence). CONCLUSION: Based on these long-term follow-up data, SSM combined with IBR is an oncologically safe treatment option regardless of tumour stage.

Impact of national guidelines on family history breast cancer surveillance.

The breast cancer risk of women already under family history surveillance was accurately assessed according to national guidelines in an attempt to rationalize the service. Women attending two breast units in Glasgow between November 2003 and February 2005 were included. One thousand and five women under annual surveillance were assessed and had their relatives diagnoses verified. Four hundred and ninety-seven women were at significantly increased risk and eligible for follow-up. Five hundred and eight (50%) women attending were not eligible for family history surveillance, and 498 (98%) of these women accepted discharge. In conclusion, national guidelines have helped to more clearly define women who should undergo surveillance. This avoids unnecessary and potentially harmful routine investigations, and the service has been improved.

Anisotropic mesh adaptivity for multi-scale ocean modelling.

Research into the use of unstructured mesh methods in oceanography has been growing steadily over the past decade. The advantages of this approach for domain representation and non-uniform resolution are clear. However, a number of issues remain, in particular those related to the computational cost of models produced using unstructured mesh methods compared with their structured mesh counterparts. Mesh adaptivity represents an important means to improve the competitiveness of unstructured mesh models, where high resolution is only used when and where necessary. In this paper, an optimization-based approach to mesh adaptivity is described where emphasis is placed on capturing anisotropic solution characteristics. Comparisons are made between the results obtained with uniform isotropic resolution, isotropic adaptive resolution and fully anisotropic adaptive resolution.

Addition of fornix transection to frontal-temporal disconnection increases the impairment in object-in-place memory in macaque monkeys.

Both frontal-inferotemporal disconnection and fornix transection (Fx) in the monkey impair object-in-place scene learning, a model of human episodic memory. If the contribution of the fornix to scene learning is via interaction with or modulation of frontal-temporal interaction--that is, if they form a unitary system--then Fx should have no further effect when added to frontal-temporal disconnection. However, if the contribution of the fornix is to some extent distinct, then fornix lesions may produce an additional deficit in scene learning beyond that caused by frontal-temporal disconnection. To distinguish between these possibilities, we trained three male rhesus monkeys on the object-in-place scene-learning task. We tested their learning on the task following frontal-temporal disconnection, achieved by crossed unilateral aspiration of the frontal cortex in one hemisphere and the inferotemporal cortex in the other, and again following the addition of Fx. The monkeys were significantly impaired in scene learning following frontal-temporal disconnection, and furthermore showed a significant increase in this impairment following the addition of Fx, from 32.8% error to 40.5% error (chance = 50%). The increased impairment following the addition of Fx provides evidence that the fornix and frontal-inferotemporal interaction make distinct contributions to episodic memory.

Glycoproteomic profiling of serum peptides in canine lymphoma and transitional cell carcinoma.

Differential expression of fucosylated glycoproteins has been correlated with malignancy and metastatic potential in various types of neoplasia. Utilizing glycoproteomics techniques, changes in fucosylated serum peptides associated with naturally occurring canine lymphoma and transitional cell carcinoma (TCC) have been evaluated. In both types of neoplasia, the majority of the fucosylated peptides that changed increased with the cancer. In one lymphoma case that was examined over the course of the disease, the same fucosylated peptides that increased during pre-chemotherapy decreased during post-chemotherapy, and then subsequently increased upon recurrence of the lymphoma. When comparing all the fucosylated peptides that increased in both types of cancer, there were only two peptides in common allowing discrimination between lymphoma and TCC based on their peptide profiles. These results emphasize the prospect of glycopeptide profiling in proteomics for use in discovering a panel of non-invasive, diagnostic or prognostic biomarkers of cancer.

Satellite gravity measurements confirm accelerated melting of Greenland ice sheet.

Using time-variable gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) satellite mission, we estimate ice mass changes over Greenland during the period April 2002 to November 2005. After correcting for the effects of spatial filtering and limited resolution of GRACE data, the estimated total ice melting rate over Greenland is -239 +/- 23 cubic kilometers per year, mostly from East Greenland. This estimate agrees remarkably well with a recent assessment of -224 +/- 41 cubic kilometers per year, based on satellite radar interferometry data. GRACE estimates in southeast Greenland suggest accelerated melting since the summer of 2004, consistent with the latest remote sensing measurements.

The metabolic syndrome and the heart--a considered opinion.

The metabolic syndrome (MS) is a multifactorial, heterogeneous group of risk factors for the development of cardiovascular disease. Here we review the evidence in support of the hypothesis that metabolic dysregulation of the body as a whole leads to contractile dysfunction of the heart due to an imbalance of substrate uptake (increased) and substrate oxidation (decreased). The consequences of this imbalance were already recognized 150 years ago by Virchow when he described "fatty atrophy" of the heart as a "true metamorphosis of the heart muscle cell."

Immediate breast reconstruction does not lead to a delay in the delivery of adjuvant chemotherapy.

Immediate breast reconstruction (IBR) has been considered by some to lead to a delay in the delivery of adjuvant chemotherapy. Our aim was to determine whether IBR led to a delay when compared to conservation surgery and non-reconstructive mastectomy. Ninety-five cases of IBR receiving chemotherapy were reviewed. These were compared to 95 consecutively treated patients undergoing conservation surgery and 95 undergoing non-reconstructive mastectomy. Our data shows that IBR does not lead to a delay in the delivery of adjuvant chemotherapy when compared to standard non-reconstructive surgery and should not adversely affect breast cancer outcome.

Effect of Inoculum Density of Sclerotium cepivorum on the Ability of Trichoderma koningii to Suppress White Rot of Onion.

Amendment of soil with Trichoderma koningii strain Tr5 grown on autoclaved white millet grain provided between 63 and 79% control of white rot of onion when added to soil containing 10, 25, 50, or 100 sclerotia of Sclerotium cepivorum per kilogram of soil at the time of onion seed sowing. There was no significant difference in the proportion of S. cepivorum infections suppressed among the different sclerotial density treatments. Rhizosphere colonization by T. koningii Tr5 was assessed by incubating onion roots sampled from plants growing in soil with the appropriate density of sclerotia, on a Trichoderma selective medium (Rose bengall-Allisan-streptomycin-Previcur agar) developed for the purpose of the study. Trichoderma spp. isolated were typed by comparison of culture morphology as well as polygalacturonase (PG) (EC 3.2.1.15) and pectinesterase (PE) (EC 3.1.1.11) isozyme profiles to the series of one PG and two PE isozymes known to be produced by T. koningii Tr5. The method was used successfully to assess rhizosphere colonization. Three rates of a millet grain formulation colonized by T. koningii Tr5 were added to soil (1,590, 3,180, and 4,770 kg/ha). At the lowest of these rates, 97% of roots were found to be colonized by isolates which could not be distinguished from T. koningii Tr5, whereas 8% of the roots from nontreated controls were colonized by such isolates. An objective of the study was to determine whether the ability of T. koningii Tr5 to suppress S. cepivorum infections was influenced by increased concentrations of both S. cepivorum sclerotia and T. koningii Tr5-colonized millet grain, and it was found that no further improvements in the percentage of disease suppression were recorded as a result of adding T. koningii Tr5-colonized millet to the soil at more than 1,590 kg/ha at any of the sclerotium concentrations tested.

Dietary microbial toxins and type 1 diabetes.

Toxins may promote type 1 diabetes by modifying or damaging the beta cell causing release of autoantigens. Streptomyces is a common soil bacterium that produces many toxic compounds. Some Streptomyces can infect vegetables, raising the possibility of dietary exposure to toxins. We aimed to identify toxins that erode cellular proton gradients in extracts of Streptomyces and infested vegetables and to establish the effect of low doses of these toxins on pancreatic islets in mice. The vacuolar ATPase inhibitors, bafilomycin and concanamycin, and the ionophore, nigericin, were identified in extracts from 4 of 13 Streptomyces isolated from infested potatoes and in potatoes themselves. Injection of bafilomycin A1 into mice impaired glucose tolerance, reduced islet size, and decreased relative beta cell mass. Thus, exposure to small quantities of bafilomycin in the diet may contribute to the cause of type 1 diabetes.