Non-negative matrix analysis for effective feature extraction in X-ray spectromicroscopy

X-Ray absorption spectromicroscopy provides rich information on the chemical organization of materials down to the nanoscale. However, interpretation of this information in studies of "natural" materials such as biological or environmental science specimens can be complicated by the complex mixtures of spectroscopically complicated materials present. We describe here the shortcomings that sometimes arise in previously-employed approaches such as cluster analysis, and we present a new approach based on non-negative matrix approximation (NNMA) analysis with both sparseness and cluster-similarity regularizations. In a preliminary study of the largescale biochemical organization of human spermatozoa, NNMA analysis delivers results that nicely show the major features of spermatozoa with no physically erroneous negative weightings or thicknesses in the calculated image

Reactive oxygen species and male reproductive hormones

Reports of the increasing incidence of male infertility paired with decreasing semen quality have triggered studies on the effects of lifestyle and environmental factors on the male reproductive potential. There are numerous exogenous and endogenous factors that are able to induce excessive production of reactive oxygen species (ROS) beyond that of cellular antioxidant capacity, thus causing oxidative stress. In turn, oxidative stress negatively affects male reproductive functions and may induce infertility either directly or indirectly by affecting the hypothalamus-pituitary-gonadal (HPG) axis and/or disrupting its crosstalk with other hormonal axes. This review discusses the important exogenous and endogenous factors leading to the generation of ROS in different parts of the male reproductive tract. It also highlights the negative impact of oxidative stress on the regulation and cross-talk between the reproductive hormones. It further describes the mechanism of ROS-induced derangement of male reproductive hormonal profiles that could ultimately lead to male infertility. An understanding of the disruptive effects of ROS on male reproductive hormones would encourage further investigations directed towards the prevention of ROS-mediated hormonal imbalances, which in turn could help in the management of male infertility

Sperm DNA fragmentation: A new guideline for clinicians

Sperm DNA integrity is crucial for fertilization and development of healthy offspring. The spermatozoon undergoes extensive molecular remodeling of its nucleus during later phases of spermatogenesis, which imparts compaction and protects the genetic content. Testicular (defective maturation and abortive apoptosis) and post-testicular (oxidative stress) mechanisms are implicated in the etiology of sperm DNA fragmentation (SDF), which affects both natural and assisted reproduction. Several clinical and environmental factors are known to negatively impact sperm DNA integrity. An increasing number of reports emphasizes the direct relationship between sperm DNA damage and male infertility. Currently, several assays are available to assess sperm DNA damage, however, routine assessment of SDF in clinical practice is not recommended by professional organizations

Children\u27s Storytelling and Movement Behavior in Relation to Aggression, Affect States, Defense Mechanisms and Psychological Strengths and Vulnerabilities

A psychoanalytically-informed study of aggression, including verbal and nonverbal behavioral manifestations, related affects and drives were examined herein. This archival study of 30 mother-child dyads was used to investigate the relationship of maternal reflective functioning (RF), defense mechanisms (DM) employed by children, in the context of storytelling and pretend play, as well as their movement patterns. Defense mechanisms of 17 girls and 13 boys (age M= 5.07, SD = .5) were assessed with the Defense Mechanisms Manual for Children\u27s Doll Play (Nimroody, Hoffman, Christian, & Rice, 2016). Children\u27s nonverbal behavior was observed and coded using variables of the Kestenberg Movement Profile (KMP) (Kestenberg-Amighi J, Loman, Lewis, & Sossin, 1999). Specifically, elements from sub-systems of pre-efforts, efforts, shaping in directions, shaping in planes were utilized, as well as bound, free and neutral tension flow attributes, and growing and shrinking shape flow attributes. The Reflective Functioning Scale (Fonagy, Target, Steele, & Steele, 1998) was used to assess maternal RF and for the purposes of this study was dichotomously classified as either high or low. Two-way random absolute single measure Intraclass Coefficients were computed to assess interrater reliability, which was found to be fair, good or excellent (Cicchetti, 1994) for 23 out of 29 variables. Pearson coefficient correlations between RF, DMs and KMP variables revealed several significant findings, some of which confirmed findings of previous studies, as well as posed questions and one hypothesis at the outset of this study. Due to the exploratory nature of this study several findings were unanticipated and novel. Analyses revealed that high RF is negatively correlated with frequency and degree of aggression, Aggression Total (AggT) (r = -.423, p \u3c .020), Aggression Highest (AggH) (r = -.401, p \u3c .028), and Aggression against the Self (AggS) (r = -.416, p \u3c .022). Positive correlations were found between KMP elements (up and AggT, AggH, AggS; down and AggT, AggH, AggS; sum of Shaping in Directions and AggT, AggH, AggS), which point to an interesting relationship between uninhibited movements, indicative of willingness to interact and confront the task, and DMs. The implications of these and other finding, correspondences among maternal RF, children\u27s verbalized and embodied expressions of aggression and DMs will be discussed in this paper