Disruptive coloration and perceptual grouping.

Camouflage is the primary defence of many animals and includes multiple strategies that interfere with figure-ground segmentation and object recognition. While matching background colours and textures is widespread and conceptually straightforward, less well explored are the optical ‘tricks’, collectively called disruptive colouration, that exploit perceptual grouping mechanisms. Adjacent high contrast colours create false edges, but this is not sufficient for an object’s shape to be broken up; some colours must blend with the background. We test the novel hypothesis that this will be particularly effective when the colour patches on the animal appear to belong to, not merely different background colours, but different background objects. We used computer-based experiments where human participants had to find cryptic targets on artificial backgrounds. Creating what appeared to be bi-coloured foreground objects on bi-coloured backgrounds, we generated colour boundaries that had identical local contrast but either lay within or between (illusory) objects. As predicted, error rates for targets matching what appeared to be different background objects were higher than for targets which had otherwise identical local contrast to the background but appeared to belong to single background objects. This provides evidence for disruptive colouration interfering with higher-level feature integration in addition to previously demonstrated low-level effects involving contour detection. In addition, detection was impeded in treatments where targets were on or in close proximity to multiple background colour or tone boundaries. This is consistent with other studies which show a deleterious influence of visual ‘clutter’ or background complexity on search

The blaSHV-5 gene is encoded in a compound transposon duplicated in tandem in Enterobacter cloacae

AbstractThe presence of blaSHV-5 is described in a compound transposon, duplicated in tandem and flanked by IS26 copies on a 70-kb conjugative plasmid (pHNM1), in an Enterobacter cloacae strain associated with a nosocomial outbreak that occurred in Mexico

Lessons from the operation of the "Penning-Fluorescent" TPC and prospects

We have recently reported the development of a new type of high-pressure Xenon time projection chamber operated with an ultra-low diffusion mixture and that simultaneously displays Penning effect and fluorescence in the near-visible region (300 nm). The concept, dubbed `Penning-Fluorescent' TPC, allows the simultaneous reconstruction of primary charge and scintillation with high topological and calorimetric fidelity

A new method to quantify and compare the multiple components of fitness-A study case with kelp niche partition by divergent microstage adaptations to Temperature

Point 1 Management of crops, commercialized or protected species, plagues or life-cycle evolution are subjects requiring comparisons among different demographic strategies. The simpler methods fail in relating changes in vital rates with changes in population viability whereas more complex methods lack accuracy by neglecting interactions among vital rates. Point 2 The difference between the fitness (evaluated by the population growth rate.) of two alternative demographies is decomposed into the contributions of the differences between the pair-wised vital rates and their interactions. This is achieved through a full Taylor expansion (i.e. remainder = 0) of the demographic model. The significance of each term is determined by permutation tests under the null hypothesis that all demographies come from the same pool. Point 3 An example is given with periodic demographic matrices of the microscopic haploid phase of two kelp cryptic species observed to partition their niche occupation along the Chilean coast. The method provided clear and synthetic results showing conditional differentiation of reproduction is an important driver for their differences in fitness along the latitudinal temperature gradient. But it also demonstrated that interactions among vital rates cannot be neglected as they compose a significant part of the differences between demographies. Point 4 This method allows researchers to access the effects of multiple effective changes in a life-cycle from only two experiments. Evolutionists can determine with confidence the effective causes for changes in fitness whereas population managers can determine best strategies from simpler experimental designs.CONICYT-FRENCH EMBASSADY Ph.D. gran

Pre-exenterative chemotherapy, a novel therapeutic approach for patients with persistent or recurrent cervical cancer

BACKGROUND: Most cervical cancer patients with pelvic recurrent or persistent disease are not candidates for exenteration, therefore, they only receive palliative chemotherapy. Here we report the results of a novel treatment modality for these patients pre-exenterative chemotherapy- under the rational that the shrinking of the pelvic tumor would allow its resection. METHODS: Patients with recurrent or persistent disease and no evidence of systemic disease, considered not be candidates for pelvic exenteration because of the extent of pelvic tumor, received 3-courses of platinum-based chemotherapy. Response was evaluated by CT scan and bimanual pelvic examination; however the decision to perform exenteration relied on the physical findings. Toxicity to chemotherapy was evaluated with standard criteria. Survival was analyzed with the Kaplan-Meier method. RESULTS: Seventeen patients were studied. The median number of chemotherapy courses was 4. There were 9 patients who responded to chemotherapy, evaluated by bimanual examination and underwent pelvic exenteration. Four of them had pathological complete response. Eight patients did not respond and were not subjected to surgery. One patient died due to exenteration complications. At a median follow-up of 11 months, the median survival for the whole group was 11 months, 3 months in the non-operated and 32 months in those subjected to exenteration. CONCLUSION: Pre-exenterative chemotherapy is an alternative for cervical cancer patients that are no candidates for exenteration because of the extent of the pelvic disease. Its place in the management of recurrent disease needs to be investigated in randomized studies, however, its value for offering long-term survival in some of these patients with no other option than palliative care must be stressed

Synergistic Antimicrobial Effects of Silver/Transition-metal Combinatorial Treatments

Due to the emergence of multi-drug resistant strains, development of novel antibiotics has become a critical issue. One promising approach is the use of transition metals, since they exhibit rapid and significant toxicity, at low concentrations, in prokaryotic cells. Nevertheless, one main drawback of transition metals is their toxicity in eukaryotic cells. Here, we show that the barriers to use them as therapeutic agents could be mitigated by combining them with silver. We demonstrate that synergism of combinatorial treatments (Silver/transition metals, including Zn, Co, Cd, Ni, and Cu) increases up to 8-fold their antimicrobial effect, when compared to their individual effects, against E. coli and B. subtilis. We find that most combinatorial treatments exhibit synergistic antimicrobial effects at low/ non-toxic concentrations to human keratinocyte cells, blast and melanoma rat cell lines. Moreover, we show that silver/(Cu, Ni, and Zn) increase prokaryotic cell permeability at sub-inhibitory concentrations, demonstrating this to be a possible mechanism of the synergistic behavior. Together, these results suggest that these combinatorial treatments will play an important role in the future development of antimicrobial agents and treatments against infections. In specific, the cytotoxicity experiments show that the combinations have great potential in the treatment of topical infections

Neurobiological Mechanisms That Contribute to Stress-related Cocaine Use

The ability of stressful life events to trigger drug use is particularly problematic for the management of cocaine addiction due to the unpredictable and often uncontrollable nature of stress. For this reason, understanding the neurobiological processes that contribute to stress-related drug use is important for the development of new and more effective treatment strategies aimed at minimizing the role of stress in the addiction cycle. In this review we discuss the neurocircuitry that has been implicated in stress-induced drug use with an emphasis on corticotropin releasing factor actions in the ventral tegmental area (VTA) and an important pathway from the bed nucleus of the stria terminalis to the VTA that is regulated by norepinephrine via actions at beta adrenergic receptors. In addition to the neurobiological mechanisms that underlie stress-induced cocaine seeking, we review findings suggesting that the ability of stressful stimuli to trigger cocaine use emerges and intensifies in an intake-dependent manner with repeated cocaine self-administration. Further, we discuss evidence that the drug-induced neuroadaptations that are necessary for heightened susceptibility to stress-induced drug use are reliant on elevated levels of glucocorticoid hormones at the time of cocaine use. Finally, the potential ability of stress to function as a “stage setter” for drug use – increasing sensitivity to cocaine and drug-associated cues – under conditions where it does not directly trigger cocaine seeking is discussed. As our understanding of the mechanisms through which stress promotes drug use advances, the hope is that so too will the available tools for effectively managing addiction, particularly in cocaine addicts whose drug use is stress-driven

TRY plant trait database - enhanced coverage and open access

Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

Mexican design of a tokamak experimental facility

Mexico presents its proposal Tokamak Experimental Facility design under the necessary effort to develop Science and Technology into the thermonuclear magnetic confinement fusion area. This Research and Development Project (R+D) was approved by the Mexican Education Ministry (SEP, spanish acronyms) in 2007 for its actual development stage at Facultad de Ingenier´ıa Mec´anica y El´ectrica (FIME) - Universidad Aut´onoma de Nuevo Le´on (UANL).We have made this effort in order to unify and consolidate under a tokamak experimental configuration the Mexican Energy Fusion Program and generate an attractive scientific technological proposal to the mexican research centres with main objective to participate in ITER (International Thermonuclear Experimental Reactor) development. This present design aims to generate, innovate, understand and develop scientific and technological fusion knowledge, also to form researchers in fusion confinement area. We consider at this time that nuclear fusion represents an attractive, powerful and clean energy source. This R+D Project involves multidisciplinary physics and engineering areas that coexists into a nuclear fusion reactor, science and technology works together to establish a natural symbiosis between theory and experiments. Our tokamak facility design, at this time, is being developed and simulated under the use of COMSOL Multiphysics and 3D CAD software, all programs running under Gentoo GNU/Linux installed in our SGI Altix XE250 Platform. With this resources we can develop entirely systems involved in our magnetic confinement fusion research line, focused in the stronger application of engineering, technology and science concepts, developing systems and devices into this energy source generation. Taking advantage of this computational infrastructure we have proposed the possibility to participate throught this tokamak facility, studying and developing research over plasmas stability, confinement regimes and resonant magnetic field perturbation

Linear-in-the-parameters oblique least squares (LOLS) provides more accurate estimates of density-dependent survival

Survival is a fundamental demographic component and the importance of its accurate estimation goes beyond the traditional estimation of life expectancy. The evolutionary stability of isomorphic biphasic life-cycles and the occurrence of its different ploidy phases at uneven abundances are hypothesized to be driven by differences in survival rates between haploids and diploids. We monitored Gracilaria chilensis, a commercially exploited red alga with an isomorphic biphasic life-cycle, having found density-dependent survival with competition and Allee effects. While estimating the linear-in-the-parameters survival function, all model I regression methods (i.e, vertical least squares) provided biased line-fits rendering them inappropriate for studies about ecology, evolution or population management. Hence, we developed an iterative two-step non-linear model II regression (i.e, oblique least squares), which provided improved line-fits and estimates of survival function parameters, while robust to the data aspects that usually turn the regression methods numerically unstable