A fundamental analysis of equilibrium and transport processes in the drying of vegetable foodstuffs

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Docosahexaenoic acid promotes photoreceptor differentiation without altering Crx expression

PURPOSE: The precise molecular cues required for photoreceptor development are still unknown. Pax6 and Crx are essential during early retinal development and for photoreceptor differentiation, respectively. The lipid molecule docosahexaenoic acid (DHA) has also been shown to promote photoreceptor differentiation. Pax6 expression during the early steps in photoreceptor development and whether the mutual contribution of Crx and DHA enhances photoreceptor differentiation were investigated. METHODS: Neuroblast proliferation, Crx, and Pax6 expression were investigated in rat retinas in vivo and in neuronal cultures with or without DHA. BrdU incorporation, nestin and opsin expression, apical differentiation, and axonal outgrowth were determined by phase microscopy and immunochemistry. RESULTS: Pax6 expression occurred in all proliferating retinal neuroblasts in vivo; however, after their last mitotic division, photoreceptors stopped expressing Pax6 and started expressing Crx. In vitro, photoreceptor progenitors also showed a switch from Pax6 to Crx expression immediately after they exited the cell cycle and started differentiation. In contrast, those progenitors differentiating into amacrine neurons continued expressing Pax6 and did not express Crx. Most postmitotic photoreceptors expressing Crx showed little axon development and few of them expressed opsin. The addition of DHA dramatically increased differentiation in Crx-positive photoreceptors, enhancing opsin expression, apical differentiation, and axonal outgrowth, without affecting Crx expression. CONCLUSIONS: The results suggest that Pax6 and Crx expression are mutually exclusive during photoreceptor differentiation. Onset of Crx expression may provide a permissive stage that is essential to initiate photoreceptor differentiation, but additional support of DHA, among other environmental signals, is necessary to accomplish further differentiation.Fil: Garelli, Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Rotstein, Nora Patricia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; ArgentinaFil: Politi, Luis Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentin

Towards semi-inclusive deep inelastic scattering at next-to-next-to-leading order

In this paper, we compute the first set of ${\cal O}(\alpha_s^2)$ corrections to semi-inclusive deep inelastic scattering structure functions. We start by studying the impact of the contribution of the partonic subprocesses that open at this order for the longitudinal structure function. We perform the full calculation analytically, and obtain the expression of the factorized cross section at this order. Special care is given to the study of their flavour decomposition structure. We analyze the phenomenological effect of the corrections finding that, even though expected to be small a priori, it turns out to be sizable with respect to the previous order know, calling for a full NNLO calculation.Comment: 25 pages, 5 figure

Front motion for phase transitions in systems with memory

We consider the Allen-Cahn equations with memory (a partial integro-differential convolution equation). The prototype kernels are exponentially decreasing functions of time and they reduce the integrodifferential equation to a hyperbolic one, the damped Klein-Gordon equation. By means of a formal asymptotic analysis we show that to the leading order and under suitable assumptions on the kernels, the integro-differential equation behave like a hyperbolic partial differential equation obtained by considering prototype kernels: the evolution of fronts is governed by the extended, damped Born-Infeld equation. We also apply our method to a system of partial integro-differential equations which generalize the classical phase field equations with a non-conserved order parameter and describe the process of phase transitions where memory effects are present

Pelvic floor dysfunction after childbirth : symptoms, diagnosis, treatment

Vaginal delivery is a trauma to the levator ani muscles, the perineal muscles, and the anal sphincter complex (1-3). A levator ani deficiency cannot be surgically remedied and increases the risk of pelvic floor dysfunction later in life (4-6). Contrarily, an injury to the perineal body can be sutured directly following vaginal birth, however, perineal trauma may in the aftermath result in a deficient perineum. There is a lack of knowledge regarding the natural history of recovery after vaginal childbirth, which symptoms are reported, and how high the prevalence of persistent symptoms is. Thus, there is a need for improved tools to identify and diagnose women displaying symptoms of deficiencies in either level of the pelvic floor and develop refined treatment options, with the ultimate goal of improved quality of life. Therefore, the overall aim of this thesis was to explore the symptoms, diagnostics, and possible surgical treatment associated with a deficient perineum and concomitant levator ani muscle defects. Study I was a prospective cohort study investigating symptoms in non-instrumentally delivered primiparas with no more than a second-degree perineal tear, one year after delivery. In total, 410 women completed an inventory of questions encompassing fecal incontinence, bowel emptying difficulties, and sexual dysfunction. The results showed that symptoms from the posterior compartment were common irrespective of the extent of the perineal tear. In conclusion, these symptoms must be considered and addressed in all women after vaginal delivery. Study II was an observational study to evaluate how consistently different raters can assess levator ani defects using the Levator Ani Deficiency (LAD) score system in a subsample of primiparas from study I. In addition, rates of LAD in this low-risk subsample were estimated. By using two different endovaginal probes, three-dimensional ultrasound volumes of 141 women were assessed on two occasions. Correlations of scores and categories within and between raters and probes were calculated using Kendall’s tau-b coefficient. Overall, intra- and interrater, and -probe correlations were very high with correlations for intrarater comparisons of >0.79 and interrater comparisons of >0.78. However, the rate of LAD in this low-risk subsample was, as expected, low, 13-15% had scores correlating to a moderate or severe injury. In conclusion, the LAD scoring system can be reproduced consistently. Study III was a mixed methods study to construct and initially validate an inventory to estimate symptoms of a deficient perineum. The preliminary inventory was tested on 170 patients diagnosed with a deficient perineum and results were compared to 54 primiparous women one year after elective caesarian section and 338 nulliparous women. Results showed that the final 11-item inventory, the 'Karolinska Symptoms After Perineal Tear Inventory' (KAPTAIN) could discern patients with symptoms such as an acquired sensation of wide vagina, vaginal flatulence, and bowel emptying difficulties, from the two control groups with high sensitivity (100%) and specificity (87–91%) when using a cut-off of 8 points out of a maximum score of 33 points. To conclude, the KAPTAIN inventory can detect symptomatic women with high accuracy and might be used to identify women in need of further support and investigation after vaginal birth. Study IV was a follow-up study one year after standardized perineal reconstructive surgery of 131 patients with long-term symptoms of a deficient perineum. Patients with symptoms e.g., an acquired sensation of wide vagina, and a confirmed perineal body defect, completed the KAPTAIN inventory preoperatively and at one-year follow-up. All patients were examined with 3D ultrasound to evaluate concomitant LAD. The hypothesis that the primary outcome “sensation of wide vagina” would not improve as much in patients with LAD as in patients with an intact levator ani muscle was rejected. There was an overall significant score reduction after surgery for the whole group. In conclusion, a standardized perineal reconstruction can alleviate symptoms of a deficient perineum independent of LAD