5,358 research outputs found
Spin-dependent direct gap emission in tensile-strained Ge films on Si substrates
The circular polarization of direct gap emission of Ge is studied in
optically-excited tensile-strained Ge-on-Si heterostructures as a function of
doping and temperature. Owing to the spin-dependent optical selection rules,
the radiative recombinations involving strain-split light (cG-LH) and heavy
hole (cG-HH) bands are unambiguously resolved. The fundamental cG-LH transition
is found to have a low temperature circular polarization degree of about 85%
despite an off-resonance excitation of more than 300 meV. By photoluminescence
(PL) measurements and tight binding calculations we show that this
exceptionally high value is due to the peculiar energy dependence of the
optically-induced electron spin population. Finally, our observation of the
direct gap doublet clarifies that the light hole contribution, previously
considered to be negligible, can dominate the room temperature PL even at low
tensile strain values of about 0.2%
Like grandparents, like parents: Empirical evidence and psychoanalytic thinking on the transmission of parenting styles
The authors discuss the issue of intergenerational transmission of parenting from an empirical and psychoanalytic perspective. After presenting a framework to explain their conception of parenting, they describe intergenerational transmission of parenting as a key to interpreting and eventually changing parenting behaviors. Then they present (1) the empirical approach aimed at determining if there is actually a stability across generations that contributes to harsh parenting and eventually maltreatment and (2) the psyphoanalytic thinking that seeks to explain the continuity in terms of representations and clinical phenomena. The authors also discuss the relationship between the attachment and the caregiving systems and hypothesize a common base for the two systems in childhood experience. Finally, they propose the psychoanalytic perspective as a fruitful theoretical framework to integrate the evidence for the neurophysiological mediators and moderators of intergenerational transmission. Psychoanalytically informed research can provide clinically relevant insights and hypotheses to be tested
Closure theorems for orientor fields and weak convergence
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46195/1/205_2004_Article_BF00250438.pd
Determination of daptomycin in human plasma and breast milk by UPLC/MS-MS
During the lactation, the choice of a proper antibiotic is crucial since the drug can cross into breast milk causing toxicity to the infant. Therefore, an extraction protocol and LC/MS-MS method for the determination of daptomycin in human milk and plasma were developed, validated and applied to a case of a breastfeeding mother affected by a purulent acute soft skin infection treated with daptomycin. Because of daptomycin high protein binding and its high molecular weight, the optimisation of the extraction protocol and analytical conditions were deeply investigated, and several parameters were taken into account: in particular the type of extraction, internal standard, the type of organic modifier, pH of the aqueous solution, and gradient. The use of a protein precipitation protocol coupled to a C8-reverse phase LC-MS/MS allows for a reliable quantification of daptomycin in both plasma (in the range of 19\u2013199 \u3bcg/mL) and breast milk (in the range of 0.12\u20130.32 \u3bcg/mL). The determination of milk/plasma (M/P) ratio, which ranged from 0.002 to 0.006, allowed to assess that daptomycin, effective for the mother, was contemporarily safe for the breastfed newborn
Geometric and analytic views in existence theorems for optimal control. II. Distributed and boundary controls
Existence theorems are proved for Lagrange problems of optimization in a given domain G with possibly unbounded distributed controls in G and on the boundary of G , and with functional relations on G and on the boundary represented by closed operators, not necessarily linear. The case where the functional relations are partial differential equations is emphasized. Recent work concerning the reduction or elimination of seminormality requirements is taken into account. Many examples are given.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45200/1/10957_2004_Article_BF00933208.pd
Doing good by doing new things with others: insights into developing sustainability-oriented innovations in the agri-food value chain
Towards an integrated model to explain the factors affecting collaborative innovation processes – insights from the agrifood sector
This study explores the relevant factors to involve multiple actors who develop and implement new technologies to build sustainable agrifood systems. By examining 11 cases, we found that technological, organization, environmental, behavioural and interorganizational factors (all mentioned in current literature) as well as collaborative business models (not mentioned in current literature) affect such initiatives. Based on this, we propose an integrated model. The agrifood sector is one of the first sectors in which a collaborative transition unfolds. As other sectors are likely to undergo similar transitions in the near future, lessons learnt from the agrifood sector can guide these transitions
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