In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Context: Excessive infant crying, or infantile colic, is a common and often stress-inducing problem for parents that can ultimately result in child abuse. From previous research it is known that maternal depression is related to excessive crying, but so far little is known about the influence of paternal depression.', "In a prospective, population-based study, we obtained information on both maternal and paternal depressive symptoms at 20 weeks of pregnancy by using the Brief Symptom Inventory. Parental depressive symptoms were related to excessive crying in 4426 two-month-old infants. The definition of excessive crying was based on the widely used Wessel's criteria (ie, crying >3 hours for >3 days in the past week).", 'After adjustment for depressive symptoms of the mother and relevant confounders, we found a 1.29 (95% confidence interval: 1.09-1.52) higher risk of excessive infant crying per SD of paternal depressive symptoms.\Question: Are paternal depressive symptoms during pregnancy related to excessive infant crying?
Our findings indicate that paternal depressive symptoms during pregnancy might be a risk factor for excessive infant crying. This finding could be related to genetic transmission, interaction of a father with lasting depressive symptoms with the infant, or related indirectly through contextual stressors such as marital, familial, or economic distress.

Context: Cord blood (CB) hematopoietic stem cell transplantation has often been limited by the scarcity of stem cells. Therefore, the number of CB hematopoietic stem/progenitor cells (HSPCs) should be increased while maintaining the stem cell characteristics.', 'We designed an ex vivo culture system using endothelial progenitor cells (EPCs) as stroma to determine the capacity of expanding CB-HSPCs in a defined medium, the effect on engraftment of the expanded cells in a mouse model and the underlying mechanism.', "After 7 days of culture, compared with those cultured with cytokines alone (3.25 ± 0.59), CD34+ cells under contact and non-contact co-culture with EPCs were expanded by 5.38 ± 0.61 (P = 0.003) and 4.06 ± 0.43 (P = 0.025)-fold, respectively. Direct cell-to-cell contact co-culture with EPCs resulted in more primitive CD34+ CD38- cells than stroma-free culture (156.17 ± 21.32 versus 79.12 ± 19.77-fold; P = 0.010). Comparable engraftment of day 7 co-cultured HSPCs with respect to HSPCs at day 0 in nonobese diabetic-severe combined immunodeficiency disease (NOD/SCID) mice was measured as a percentage of chimerism (13.3% ± 11.0% versus 16.0% ± 14.3%; P = 0.750). EPCs highly expressed interleukin 6 (IL6) and angiopoietin 1 (ANGPT1), the hematopoietic- related cytokines. A higher transcriptional level of WNT5A genes in EPCs and co-cultured HSPCs suggests that the activation of Wnt signaling pathway may play a role in HSPCs' expansion ex vivo.\Question: Do endothelial progenitor cells promote efficient ex vivo expansion of cord blood-derived hematopoietic stem/progenitor cells?
These data demonstrated that EPCs improve the CD34+ population but do not compromise the repopulating efficacy of the amplified HSPCs, possibly via cytokine secretion and Wnt signaling pathway activation.

Context: D-serine, the endogenous co-agonist of N-methyl-D-aspartate receptors (NMDARs), is considered to be essential for learning and memory. The aim of the current investigation was to systematically evaluate the role of D-serine on addiction behaviors considered to be mediated by the nucleus accumbens (NAc).', 'D-Serine concentration in the NAc was measured by high-performance liquid chromatography (HPLC). Cocaine-induced behavioral sensitization and conditioned place preference (CPP) models were used to evaluate the relation between changes in serine in the nucleus accumbens and cocaine-induced behavioral effects. The expression of serine racemase (SR), D-amino acid oxidase (DAAO), the cAMP response element-binding protein (CREB) and upstream kinases, and N-methyl-D-aspartate (NMDA) receptors subunits were analyzed by western blot. Long-term depression (LTD) in the NAc was investigated by electrophysiological methods.', 'The NAc slices obtained from the behavioral sensitization rats presented significantly reduced D-serine concentrations, increased expression of DAAO, and down-regulated expression of SR in a dose-dependent manner. Furthermore, D-serine injections into the nucleus accumbens blocked the development of behavioral sensitization and caused extinction of CPP. The ERK-CREB-Fos pathway and the NMDA receptor NR2B subunits in the NAc were involved in the cocaine-induced behavioral sensitization. We also found that D-serine was essential for NMDAR-dependent LTD and D-serine-regulated LTD in a bell-shaped concentration-dependent manner. The disrupted NMDAR-dependent LTD in the NAc of cocaine-treated rats was reversed by D-serine.\Question: Does d-Serine in the nucleus accumbens region modulate behavioral sensitization and extinction of conditioned place preference?

Our results provide evidence for a critical role of D-serine in synaptic plasticity relevant to cocaine addiction and indicate that D-serine may be an effective therapeutic agent for cocaine addiction.