Pheromone synthesis in a biomicroreactor coated with anti-adsorption polyelectrolyte multilayer

To prepare a biosynthetic module in an infochemical communication project, we designed a silicon/glass microreactor with anti-adsorption polyelectrolyte multilayer coating and immobilized alcohol acetyl transferase (atf), one of the key biosynthetic enzymes of the pheromone of Spodoptera littoralis, on agarose beads inside. The system reproduces the last step of the biosynthesis in which the precursor diene alcohol (Z,E)-9,11-tetradecadienol is transformed into the major component (Z,E)-9,11-tetradecadienyl acetate. The scope of this study was to analyze and implement a multilayer, anti-adsorption coating based on layer-by-layer deposition of polyethylenimine/dextransulfate sodium salt (PEI/DSS). The multilayers were composed of two PEI with molecular weights 750 and 1.2 kDa at pH 9.2 or 6.0. Growth, morphology, and stability of the layers were analyzed by ellipsometry and atomic force microscopy (AFM). The anti-adsorption functionality of the multilayer inside the microreactor was validated. The activity of His(6)-(atf) was measured by gas chromatography coupled to mass spectrometer (GC-MS).     

热带钢轧机过程控制新技术

新技术的极用产生了更完美的过程控制技术。这与有效的研究与开发手段结合,成为提高质量、生产率和革新的基础。现代技术的快速和智能化的应用对钢铁工业面临的新的挑战作出了回应。     

Amateur scientists, the international geophysical year, and the ambitions of Fred Whipple

The contribution of amateur scientists to the International Geophysical Year (IGY) was substantial, especially in the arena of spotting artificial satellites. This article examines how Fred L. Whipple and his colleagues recruited satellite spotters for Moonwatch, a program for amateur scientists initiated by the Smithsonian Astrophysical Observatory (SAO) in 1956. At the same time, however, the administrators with responsibility for the IGY program closely monitored and managed--sometimes even contested--amateur participation. IGY programs like Moonwatch provided valuable scientific information and gave amateurs opportunities to contribute actively to the research of professional scientists. Moonwatch, which operated until 1975, eventually became the public face of a vast satellite-tracking network that expanded the SAO's global reach and helped further Whipple's professional goals. Understanding amateurs' interactions with the professional science community enables us better to understand the IGY as a phenomenon that enlisted broad participation and transcended traditional boundaries between professional and amateur scientists.     

The moderating capacity of racial identity between perceived discrimination and psychological well-being over time among African American youth

This study examined the influence of racial identity in the longitudinal relation between perceptions of racial discrimination and psychological well-being for approximately 560 African American youth. Latent curve modeling (LCM) and parallel process multiple-indicator LCMs with latent moderators were used to assess whether perceptions of racial discrimination predicted the intercept (initial levels) and the slope (rate of change) of psychological well-being over time, and whether racial identity moderates these relations. The results indicated that African American adolescents who reported higher psychological responses to discrimination frequency levels at the first time point had lower initial levels of well-being. Regressing the slope factor for psychological well-being on the frequency of discrimination also revealed a nonsignificant result for subsequent well-being levels.     

Increased expression of aquaporin-4 in human traumatic brain injury and brain tumors

Objective:To characterize the expression of aquaporin-4(AQP4),one of the aquaporins(AQPs),in human brainspecimens from patients with traumatic brain injury or brain tumors.Methods:Nineteen hnman brain specimens were obtahledfrom the patients with traumatic brain injury,brain tumors,benign meningioma or early stage hemorrhagic stroke.MRI or CTimaging was used to assess brain edema.Hematoxylin and eosm staining were used to evaluate cell damage,Immunohistochem-istry was used to detect the AQP4 expression.Results:AQP4 expression was increased from 15 h to at least 8 d after injury.AQP4immunoreactivity was strong around astrocytomas,ganglioglioma and metastatic adenocarcinoma.However,AQP4 immunore-activity was only found in the centers of astrocytomas and ganglioglioma,but not in metastatic adenocarcinoma derived from lung.Conclusion:AQP4 expression increases in human brains alter traumatic brain injury,within brain-derived tumors,and aroundbrain tumors.     

Evaluation of bidirectional interstimulus interval (ISI) shift in auditory delay eye-blink conditioning in healthy humans

Delay eye-blink conditioning is an associative learning task that can be utilized to probe the functional integrity of the cerebellum and related neural circuits. Typically, a single interstimulus interval (ISI) is utilized, and the amplitude of the conditioned response (CR) is the primary dependent variable. To study the timing of the CR, an ISI shift can be introduced (e.g., shifting the ISI from 350 to 850 ms). In each phase, a conditioned stimulus (e.g., a 400- or 900-ms tone) coterminates with a 50-ms corneal air puff unconditioned stimulus. The ability of a subject to adjust the CR to the changing ISI constitutes a critical timing shift. The feasibility of this procedure was examined in healthy human participants (N = 58) using a bidirectional ISI shift procedure while cortical event-related brain potentials were measured. CR acquisition was faster and the responses better timed when a short ISI was used. After the ISI shift, additional training was necessary to allow asymptotic responding at the new ISI. Interestingly, auditory event-related potentials to the CR were not associated with conditioning measures at either ISI.     

Self-reported disciplinary practices among women in the child welfare system: association with domestic violence victimization

OBJECTIVE: To examine the association between physical domestic violence victimization (both recent and more than a year in past measured by self-report) and self-reported disciplinary practices among female parents/caregivers in a national sample of families referred to child welfare. METHODS: Cross-sectional survey of more than 3,000 female caregivers in the National Survey of Child and Adolescent Well-being (NSCAW) study, a nationally representative sample of children and their families referred to child welfare agencies for investigation of abuse and neglect. Women reported physical domestic violence victimization and their disciplinary practices for their child on different versions of the Conflict Tactics Scales. RESULTS: Four hundred and forty-three women reported prior year domestic violence, 1,161 reported domestic violence but not in the past 12 months, and 2,025 reported no domestic violence exposure. Any prior domestic violence exposure was associated with higher rates of self-reported psychological aggression, physical aggression and neglectful disciplinary behaviors as compared to those with no domestic violence victimization in bivariate comparisons. After controlling for child behavior, demographic factors, and maternal characteristics, those with remote and recent domestic violence victimization employed more self-reported psychological aggression, while only caregivers with recent DV reported more physical aggression or neglectful behaviors. CONCLUSIONS: In a national child welfare sample, self-reported aggressive and neglectful parenting behaviors were common. In this sample, domestic violence victimization is associated with more self-reported aggressive and neglectful disciplinary behaviors among female caregivers. The mechanism for these associations is not clear. PRACTICE IMPLICATIONS: Rates of aggressive and neglectful disciplinary practices are especially high among female parents/caregivers exposed to domestic violence. Child welfare agencies should plan routine and structured assessments for domestic violence among parents/caregivers and implement parenting interventions to reduce harmful disciplinary practices for those families identified.