Multi-Locus Phylogenetic Analyses of the Almadablennius Clade Reveals Inconsistencies with the Present Taxonomy of Blenniid Fishes

We used a multi-locus phylogenetic approach (i.e., combining both mitochondrial and nuclear DNA fragments) to address some long-standing taxonomic inconsistencies within the diverse fish clade of Combtooth Blennies (Blenniidae—unranked clade Almadablennius). The obtained phylogenetic trees revealed some major inconsistencies in the current taxonomy of Parablennini, such as the paraphyletic status of the Salaria and Parablennius genera, casting some doubt regarding their actual phylogenetic relationship. Furthermore, a scarce-to-absent genetic differentiation was observed among the three species belonging to the genus Chasmodes. This study provides an updated taxonomy and phylogeny of the former genus Salaria, ascribing some species to the new genus Salariopsis gen. nov., and emphasizes the need for a revision of the genus Parablennius

Data collection challenges in community settings: Insights from two field studies of patients with chronic disease

Purpose Collecting information about health and disease directly from patients can be fruitfully accomplished using contextual approaches, ones that combine more and less structured methods in home and community settings. This paper's purpose is to describe and illustrate a framework of the challenges of contextual data collection. Methods A framework is presented based on prior work in community-based participatory research and organizational science, comprised of ten types of challenges across four broader categories. Illustrations of challenges and suggestions for addressing them are drawn from two mixed-method, contextual studies of patients with chronic disease in two regions of the US. Results The first major category of challenges was concerned with the researcher-participant partnership, for example, the initial lack of mutual trust and understanding between researchers, patients, and family members. The second category concerned patient characteristics such as cognitive limitations and a busy personal schedule that created barriers to successful data collection. The third concerned research logistics and procedures such as recruitment, travel distances, and compensation. The fourth concerned scientific quality and interpretation, including issues of validity, reliability, and combining data from multiple sources. The two illustrative studies faced both common and diverse research challenges and used many different strategies to address them. Conclusion Collecting less structured data from patients and others in the community is potentially very productive but requires the anticipation, avoidance, or negotiation of various challenges. Future work is necessary to better understand these challenges across different methods and settings, as well as to test and identify strategies to address them

Synchronous primary colorectal and liver metastasis: impact of operative approach on clinical outcomes and hospital charges

AbstractObjectivesThe management of patients with colorectal cancer (CRC) and synchronous colorectal liver metastasis (CLM) remains controversial. The present study was conducted in order to assess the clinical and economic impacts of managing synchronous CLM with a staged versus a simultaneous surgery approach.MethodsA total of 224 patients treated for synchronous CLM during 1990–2012 were identified in the Johns Hopkins Hospital liver database. Data on clinicopathological features, perioperative outcomes and total hospital charges (inflation-adjusted) were collected and analysed.ResultsOverall, 113 (50.4%) patients underwent staged surgery and 111 (49.6%) were submitted to a simultaneous CRC and liver operation. At surgery, liver-directed therapy included hepatectomy (75.0%) or combined resection and ablation (25.0%). Perioperative morbidity (30.0%) and mortality (1.3%) did not differ between groups (both P > 0.05). Median total length of hospitalization was longer in the staged (13 days) than the simultaneous (7 days) surgery group (P < 0.001). Median total hospital charges were higher among patients undergoing staged surgery (US$61 938) than among those undergoing a simultaneous operation (US$34 114) (P < 0.01). Median (simultaneous, 32.4 months versus staged, 39.6 months; P = 0.65) and 5-year (simultaneous, 27% versus staged, 29%; P = 0.60) overall survival were similar between groups.ConclusionsPatients with synchronous CLM managed with either simultaneous or staged surgery have comparable perioperative and longterm outcomes. However, patients treated with simultaneous surgery spent an average of 6 days fewer in hospital, resulting in a reduction of median hospital charges of US$27 824 (55.1%). When appropriate and technically feasible, the simultaneous surgery approach to synchronous CLM should be preferred

Exciton spin relaxation in single semiconductor quantum dots

We study the relaxation of the exciton spin (longitudinal relaxation time $T_{1}$) in single asymmetrical quantum dots due to an interplay of the short--range exchange interaction and acoustic phonon deformation. The calculated relaxation rates are found to depend strongly on the dot size, magnetic field and temperature. For typical quantum dots and temperatures below 100 K, the zero--magnetic field relaxation times are long compared to the exciton lifetime, yet they are strongly reduced in high magnetic fields. We discuss explicitly quantum dots based on (In,Ga)As and (Cd,Zn)Se semiconductor compounds.Comment: accepted for Phys. Rev.

Automatic Non-functional Testing of Code Generators Families

International audienceThe intensive use of generative programming techniques provides an elegant engineering solution to deal with the heterogeneity of platforms and technological stacks. The use of domain-specific languages for example, leads to the creation of numerous code generators that automatically translate highlevel system specifications into multi-target executable code. Producing correct and efficient code generator is complex and error-prone. Although software designers provide generally high-level test suites to verify the functional outcome of generated code, it remains challenging and tedious to verify the behavior of produced code in terms of non-functional properties. This paper describes a practical approach based on a runtime monitoring infrastructure to automatically check the potential inefficient code generators. This infrastructure, based on system containers as execution platforms, allows code-generator developers to evaluate the generated code performance. We evaluate our approach by analyzing the performance of Haxe, a popular high-level programming language that involves a set of cross-platform code generators. Experimental results show that our approach is able to detect some performance inconsistencies that reveal real issues in Haxe code generators

Alignment dependent chemisorption of vibrationally excited CH4(ν3) on Ni(100), Ni(110), and Ni(111)

International audienceWe present a stereodynamics study of the dissociative chemisorption of vibrationally excited methane on the (100), (110), and (111) planes of a nickel single crystal surface. Using linearly polarized infrared excitation of the antisymmetric C-H stretch normal mode vibration (ν3), we aligned the angular momentum and C-H stretch amplitude of CH4(ν3) in the laboratory frame and measured the alignment dependence of state-resolved reactivity of CH4 for the ν3 = 1, J = 0-3 quantum states over a range of incident translational energies. For all three surfaces studied, in-plane alignment of the C-H stretch results in the highest dissociation probability and alignment along the surface normal in the lowest reactivity. The largest alignment contrast between the maximum and minimum reactivity is observed for Ni(110), which has its surface atoms arranged in close-packed rows separated by one layer deep troughs. For Ni(110), we also probed for alignment effects relative to the direction of the Ni rows. In-plane C-H stretch alignment perpendicular to the surface rows results in higher reactivity than parallel to the surface rows. The alignment effects on Ni(110) and Ni(100) are independent of incident translational energy between 10 and 50 kJ/mol. Quantum state-resolved reaction probabilities are reported for CH4(ν3) on Ni(110) for translational energies between 10 and 50 kJ/mol

Transformation Pathways of Silica under High Pressure

Concurrent molecular dynamics simulations and ab initio calculations show that densification of silica under pressure follows a ubiquitous two-stage mechanism. First, anions form a close-packed sub-lattice, governed by the strong repulsion between them. Next, cations redistribute onto the interstices. In cristobalite silica, the first stage is manifest by the formation of a metastable phase, which was observed experimentally a decade ago, but never indexed due to ambiguous diffraction patterns. Our simulations conclusively reveal its structure and its role in the densification of silica.Comment: 14 pages, 4 figure