Model studies on the pattern of volatiles generated in mixtures of amino acids, lipid oxidation-derived aldehydes, and glucose

The development of flavor and browning in thermally treated foods results mainly from the Maillard reaction and lipid degradation but also from the interactions between both reaction pathways. To study these interactions, we analyzed the volatile compounds resulting from model reactions of lysine or glycine with aldehydes originating from lipid oxidation [hexanal, (E)-2-hexenal, or (2E,4E)-decadienal] in the presence and absence of glucose. The main reaction products identified in these model mixtures were carbonyl compounds, resulting essentially from amino-acid-catalyzed aldol condensation reactions. Several 2-alkylfurans were detected as well. Only a few azaheterocyclic compounds were identified, in particular 5-butyl-2-propylpyridine from (E)-2-hexenal model systems and 2-pentylpyridine from (2E,4E)-decadienal model reactions. Although few reaction products were found resulting from the condensation of an amino acid With a lipid-derived aldehyde, the amino acid plays an important role in catalyzing the degradation and further reaction of these carbonyl compounds. These results suggest that amino-acid-induced degradations and further reactions of lipid oxidation products may be of considerable importance in thermally processed foods

Identified hadron production at high transverse momenta in p+p collisions at sqrt(NN) = 200 GeV in STAR

We report the transverse momentum (pT) distributions for identified charged pions, protons and anti-protons using events triggered by high deposit energy in the Barrel Electro-Magnetic Calorimeter (BEMC) from p + p collisions at psNN = 200 GeV. The spectra are measured around mid-rapidity (|y|<0.5) over the range of 3<pT<15 GeV/c with particle identification (PID) by the relativistic ionization energy loss (rdE/dx) in the Time Projection Chamber (TPC) in the Solenoidal Tracker at RHIC (STAR). The charged pion, proton and anti-proton spectra at high pT are compared with published results from minimum bias triggered events and the Next-Leading-Order perturbative quantum chromodynamic (NLO pQCD) calculations (DSS, KKP and AKK 2008). In addition, we present the particle ratios of pi-/pi+, pbar/p, p/pi+ and pbar/pi- in p + p collisions.Comment: 4 pages, 4 figures, Hot Quark 2008 proceedin

Aggregate Hazes in Exoplanet Atmospheres

Photochemical hazes have been frequently used to interpret exoplanet transmission spectra that show an upward slope towards shorter wavelengths and weak molecular features. While previous studies have only considered spherical haze particles, photochemical hazes composed of hydrocarbon aggregate particles are common throughout the solar system. We use an aerosol microphysics model to investigate the effect of aggregate photochemical haze particles on transmission spectra of warm exoplanets. We find that the wavelength dependence of the optical depth of aggregate particle hazes is flatter than for spheres since aggregates grow to larger radii. As a result, while spherical haze opacity displays a scattering slope towards shorter wavelengths, aggregate haze opacity can be gray in the optical and NIR, similar to those assumed for condensate cloud decks. We further find that haze opacity increases with increasing production rate, decreasing eddy diffusivity, and increasing monomer size, though the magnitude of the latter effect is dependent on production rate and the atmospheric pressure levels probed. We generate synthetic exoplanet transmission spectra to investigate the effect of these hazes on spectral features. For high haze opacity cases, aggregate hazes lead to flat, nearly featureless spectra, while spherical hazes produce sloped spectra with clear spectral features at long wavelengths. Finally, we generate synthetic transmission spectra of GJ 1214b for aggregate and spherical hazes and compare them to space-based observations. We find that aggregate hazes can reproduce the data significantly better than spherical hazes, assuming a production rate limited by delivery of methane to the upper atmosphere.Comment: 17 figures, accepted to Ap

Hyperelliptic Integrable Systems on K3 and Rational Surfaces

We show several examples of integrable systems related to special K3 and rational surfaces (e.g., an elliptic K3 surface, a K3 surface given by a double covering of the projective plane, a rational elliptic surface, etc.). The construction, based on Beauvilles's general idea, is considerably simplified by the fact that all examples are described by hyperelliptic curves and Jacobians. This also enables to compare these integrable systems with more classical integrable systems, such as the Neumann system and the periodic Toda chain, which are also associated with rational surfaces. A delicate difference between the cases of K3 and of rational surfaces is pointed out therein.Comment: LaTeX2e using packages "amsmath,amssymb", 15 pages, no figur

Siege and Response: Families’ Everyday Lives and Experiences with Children’s Residential Mental Health Services (FULL REPORT)

Purpose Our purpose in interviewing parents with a child placed in residential mental health treatment was threefold: (1) to understand the functioning of children requiring residential mental health treatment before, during, and after treatment; (2) to characterize parents’ perceptions of their families’ involvement with residential treatment; and, (3) to address the popular notion that children requiring residential treatment come from highly dysfunctional and potentially harmful families by describing prevalent family functioning patterns. Methodology|This report is based on information obtained by interviewing 29 primary caregivers who had a child placed in residential care at one of two Ontario children’s mental health agencies. Parents were visited in their homes by an interviewer to engage in one-on-one dialogue to explore dimensions of their everyday lives and reflect on their service experiences. Interviews consisted of a series of open ended questions and were approximately 1 ½ to 2 hours in length. Because of the labour intensive nature of qualitative investigations, there are limitations to the number of cases that can practically be included in a study; however, what is lost in generalizability is compensated for by a richer sense of the struggles facing these families. Parents’ Perceptions of Residential Services Parents were generally pleased with their child’s placement in a residential treatment center. Parents feel respected, valued, and understood by service providers. They experience staff as competent, compassionate, and helpful. Residential services offered respite for families and containment for focal children. Many parents reported gains made for themselves and their children. Yet only 17% of parents felt that sufficient gains had been made to warrant the discharge of their child from the center. Parents tended not to blame the residential center for the lack of progress. The also seemed unable to articulate what the residential center could have done differently. Yet these parents, extremely hopeful when they first had their child placed in residence, had to come to terms with the realization that service outcomes had not matched their hopes. These stories highlight both the complexity and the tenacious nature of these children’s mental health difficulties. They also provide a challenge to service providers. What do we do when good is not good enough? Changes in Child Functioning Before, During and After Residential CareThese stories provide dramatic testimony that most of the older cohort children in this study leaving residential care had very serious ongoing problems in daily living. Problems which in many cases rivaled or exceeded the challenges faced prior to entering residential care. About one-third of these children had left home and many had unstable living arrangements or were “on the streets”. With the exception of living on their own and involvement in delinquent activities, and notwithstanding moderately more evidence of “successful” or partially “successful” adaptations, the after care daily living portraits of younger cohort residential care graduates were not notably more encouraging. About half of these younger children did not return to their original homes 6 after residential care. Serious areas of concern shared by both groups of children include continuing major adaptation problems at school and continued high levels of pressure on the parents and siblings of many of these children. Parent and Family FunctioningCaring for the focal child permeates every facet of daily life for these families including work, health, and relationships. Parents experience prolonged elevated levels of daily stress trying to juggle work schedules, appointments with professionals, household activities, and the needs of family members with caring for the focal child. Family climate is markedly tense and frequently involves conflict, particularly with the focal child. Relationships among other family members suffer as well, with parents reporting increased marital strain and little time to devote to siblings of the focal child. Caring for the focal child is taxing on parents’ own physical and mental health. Most families (70%) reported experiencing substantial relief, at least for a short period of time, from tensions within the home when the focal child entered residential care. Child Functioning Over Three Selected Developmental PeriodsOne of the interpretative challenges inherent in these stories is understanding the connection between the behaviour of these children, which is strikingly similar, and evidence suggestive of these children having a variety of problems, life histories and family environments. It can be argued that these children arrive at a similar point from many different trajectories. Who are the children represented in this sample? How are we to understand their difficulties? When it comes to understanding the behaviour of the focal children, both its presentation and its genesis, these stories raise as many questions as they answer. These stories challenge the notion of a single or root cause of extreme unmanageable behaviour. Instead they offer a complex and unsettling portrayal of these children, their familial and social environments, life histories, their strengths and challenges. These stories caution against the use of blanket or catch-all interpretations to help us understand the problematic behaviour of these children. ConclusionDespite the positive view of residential treatment held by parents long after treatment ends, the data suggest relatively poor outcome patterns for children leaving residential care. Serious areas of concern shared by both groups of children include continuing major adaptation problems at school and continued high levels of pressure on the parents and siblings of many of these children. The clearest area of benefit from these residential placements, at least in the short run, is for family members other than the focal child. This is an important consideration, given the incredible pressures families manage when the focal child is at home, and the extreme disruptions in family life described in these stories. An obvious question emanating from these stories is what can be expected for these children - in school, employment and relationships - over the years ahead. There is almost no support in our study for helping strategies predicated on “curing” or changing the focal child through short-term or medium-term interventions so that he or she can prosper in everyday life. Variations in living arrangements, enhancing school and employment opportunities, and continuing support to these children and their families with the challenges of daily living merit serious attention

Chiral Dirac fermions on the lattice using Geometric Discretisation

A new approach to the problem of doubling is presented with the Dirac-Kahler (DK) theory as a starting point and using Geometric Discretisation providing us with a new way of extracting the Dirac field in the discrete setting of a hyper-cubic complex.Comment: Lattice2003(Chiral), 3 page

Target mass effects in polarized deep-inelastic scattering

We present a computation of nucleon mass corrections to nucleon structure functions for polarized deep-inelastic scattering. We perform a fit to existing data including mass corrections at first order in $m^2/Q^2$ and we study the effect of these corrections on physically interesting quantities. We conclude that mass corrections are generally small, and compatible with current estimates of higher twist uncertainties, when available.Comment: 22 pages Latex, uses epsfig.sty, 10 eps figures include

String Percolation and the Glasma

We compare string percolation phenomenology to Glasma results on particle rapidity densities, effective string or flux tube intrinsic correlations, the ridge phenomena and long range forward-backward correlations. Effective strings may be a tool to extend the Glasma to the low density QCD regime. A good example is given by the minimum of the negative binomial distribution parameter k expected to occur at low energy/centrality.Comment: Submitted to Phys. Lett

Siege and Response: Families’ Everyday Lives and Experiences with Children’s Residential Mental Health Services (SUMMARY REPORT)

Our purpose in interviewing families who had a child placed in residential children’s mental health treatment was to provide insight into the lives and service experiences of these families as they struggle to care for their child and find appropriate services. As we endeavored to code, categorize, and make sense of the information shared with us by families several other more pointed purposes emerged as integral to our efforts. More specifically we became interested in understanding the functioning of children requiring residential mental health treatment before, during, and after treatment with the aim to comment on general patterns of change for these children across these three time periods. Secondly, we also aimed to characterize parents’ perceptions of their families’ involvement with residential treatment. In particular we address parents’ understanding of the services, their relationships with service providers, and parents’ perceptions of their children’s experiences. And thirdly, in order to provide a family context for children’s difficulties and the ensuing service involvement, we also discuss family functioning highlighting key family patterns under the domains of work, daily life, and relationships. The inclusion of prevalent family functioning patterns also helps us to address the popular notion that children requiring residential treatment come from highly dysfunctional and potentially 3 harmful families. Each of these three purposes are addressed in turn in an effort to provide a more complete picture of the families involved in residential treatment and their service experiences. We conclude with some implications for service delivery and thoughts to pursue in future investigations