Isotopic and mineralogic bias introduced by pulverization of aragonite.

RATIONALE: Stable carbon and oxygen isotope data of biogenic and abiogenic aragonite are of fundamental relevance in paleoclimate research. Wet-chemical analysis of such materials requires well-homogenized, fine-grained powder. In the present study, the effect of different grinding/milling methods on sample homogeneity and the potential risk of unintentional calcite formation and isotope shift were evaluated. METHODS: Shells of Arctica islandica and aragonite sputnik crystals were pulverized using a set of commonly used methods, including a hand-held drill, a vibromill operated at various settings (with and without liquid nitrogen cooling, changes in ball diameters, frequencies, and processing durations), and an agate mortar and pestle. Stable isotope values were measured using an isotope ratio mass spectrometer operated in continuous flow mode. Identification of mineral phases was obtained by powder X-ray diffraction (PXRD), Raman spectroscopy, and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. Calcite content was quantified by PXRD Rietveld refinement. RESULTS: Samples showed substantial homogeneity, in particular after vibromilling (duration 3-10 min). More vigorous grinding resulted in larger fractions of calcite (0.5-4.2 wt%) and a concomitant δ18O and δ13C decrease, specifically in bivalve shells. The only method for producing pure aragonite powder was by pounding the aragonite sputniks manually with an agate mortar and pestle. CONCLUSIONS: None of the studied, commonly used machine-based pulverization methods produced pure aragonite powder from samples consisting originally of aragonite. These findings have significant implications for light-stable isotope-based paleoclimate reconstructions. Except for abiogenic aragonite powder produced by pounding in an agate mortar, paleotemperatures would be overestimated.

Risk analysis of critical infrastructure with the MOSAR method.

The smooth running of the electric energy system is crucial, especially given the current geopolitical environment. To achieve this goal, it is essential to establish a solid infrastructure that is both accessible and safe. We protect consumer reputation and trust, reduce financial losses, and lessen unfavourable effects on employees and business owners by maintaining continuous functioning. This study has discovered several important concerns using the Method Organised Systematic Analysis of Risk (MOSAR). These include the possibility of cyberattacks, the availability of information and technology systems, the loss of critical individuals, and network problems. To address these risks, it is necessary to deliver electrical energy on time and at a high standard, to be responsive to client requests, and to follow best practices, technical standards, and personal and environmental protection measures. The findings of this study make valuable contributions to risk assessment efforts, allowing us to identify potential threats to the security and reliability of national power systems. Overall, it is essential to maintain a robust and resilient energy infrastructure to ensure uninterrupted operation and mitigate risks effectively.

Erratum: Publisher Correction: Multi-experiment nonlinear mixed effect modeling of single-cell translation kinetics after transfection.

[This corrects the article DOI: 10.1038/s41540-018-0079-7.].

Multi-experiment nonlinear mixed effect modeling of single-cell translation kinetics after transfection.

Single-cell time-lapse studies have advanced the quantitative understanding of cellular pathways and their inherent cell-to-cell variability. However, parameters retrieved from individual experiments are model dependent and their estimation is limited, if based on solely one kind of experiment. Hence, methods to integrate data collected under different conditions are expected to improve model validation and information content. Here we present a multi-experiment nonlinear mixed effect modeling approach for mechanistic pathway models, which allows the integration of multiple single-cell perturbation experiments. We apply this approach to the translation of green fluorescent protein after transfection using a massively parallel read-out of micropatterned single-cell arrays. We demonstrate that the integration of data from perturbation experiments allows the robust reconstruction of cell-to-cell variability, i.e., parameter densities, while each individual experiment provides insufficient information. Indeed, we show that the integration of the datasets on the population level also improves the estimates for individual cells by breaking symmetries, although each of them is only measured in one experiment. Moreover, we confirmed that the suggested approach is robust with respect to batch effects across experimental replicates and can provide mechanistic insights into the nature of batch effects. We anticipate that the proposed multi-experiment nonlinear mixed effect modeling approach will serve as a basis for the analysis of cellular heterogeneity in single-cell dynamics.

Attention Deficit Hyperactivity Disorder: Unique Considerations in Athletes.

CONTEXT: Attention deficit hyperactivity disorder (ADHD) is a common psychiatric condition in the general population, with evidence suggesting that it may be more common among athletes. EVIDENCE ACQUISITION: Literature searches were performed on PubMed, MEDLINE, and Cochrane databases for the years 2000 to 2016 utilizing the following key search terms: ADHD, ADD, guidelines, diagnosis, athlete, sports, treatment, pharmacotherapy, stimulants, risk, cardiovascular effects, concussion, and traumatic brain injury (TBI). STUDY DESIGN: Clinical review. LEVEL OF EVIDENCE: Level 4. RESULTS: ADHD exists among athletes at all levels of play, and symptomatology overlaps significantly with that of concussion. Treatment with stimulants has cardiovascular effects and may not be permitted by the athlete's governing body. An athlete's level of competition and individual cardiovascular risk factors may therefore affect medication choices. CONCLUSION: ADHD diagnosis and treatment are paramount to optimal quality of life and functioning in affected individuals. Pharmacologic treatment options should not specifically be avoided in athletes; however, stimulant use is an independent risk factor for heat illness. Concussion, a common athletic injury, may have an altered course in those affected by ADHD, specifically with regard to neurocognitive testing and recovery.

Hip pain · difficulty walking · tenderness along the anteromedial thigh and groin · Dx?

A 14-year-old Caucasian boy presented to our clinic with a complaint of left anterior hip pain. The patient had been running during a flag football match when he suddenly developed a sharp, stabbing pain in his left hip. He said he felt a "pop" in his left groin while his left foot was planted and he was cutting to the right. The patient said this was followed by worsening pain with ambulation and hip flexion. The patient had considerable difficulty walking into the exam room. On physical examination, he had significant tenderness to palpation along the anteromedial thigh and groin. The patient's strength was 1/5 with left hip flexion. There was apparent muscle firing, but no significant leg movement. He had full passive range of motion and there was no soft-tissue swelling, erythema, or other integumentary changes.