The structure of trees.

Trees are, by definition, the tallest land plants. To grow tall over multiple years they must solve several problems: structural strength; carbohydrate and nutrient storage capacity to survive and regrow after periods of stress; and conductive capacity for water, carbohydrates and nutrients must be increased/renewed over time to keep pace with increases in canopy size. Additionally, apical meristems must be capable of surviving through periods of stress (especially over winter or during drought). Structural strength, storage capacity and water, carbohydrate and nutrient conductive capacity are provided by cells derived from a sheath of meristematic cells (vascular cambium) that surround the body of trees (shoots, stems, branches, trunk, perennial roots). This chapter describes the structure of fruit trees.

Arresting chromosome replication upon energy starvation in Escherichia coli

Most organisms possess several cell cycle checkpoints to preserve genome stability in periods of stress. Upon starvation, the absence of chromosomal duplication in the bacterium Escherichia coli is ensured by holding off commencement of replication. During normal growth, accumulation of the initiator protein DnaA along with cell cycle changes in its activity, ensure that DNA replication starts only once per cell cycle. Upon nutrient starvation, the prevailing model is that an arrest in DnaA protein synthesis is responsible for the absence of initiation. Recent indications now suggest that DnaA degradation may also play a role. Here we comment on the implications of this potential new layer of regulation.

CLINICAL AND DEMOGRAPHIC PROFILE OF ADULT ACNE – A HOSPITAL BASED OBSERVATIONAL STUDY

OBJECTIVE - The study was done to observe the clinical & demographic prole of acne in adult patients and the correlation of different types of acne lesions according to age and sex. MATERIAL AND METHODS- this study was a hospital based observational study conducted on patients who attended OPD of Sawai Man Singh Hospital , Jaipur. RESULTS- 150 cases were analysed in this study . Among 150 patients , 86 ( 57.3% ) were males and 64 ( 42.7 %) were females. In the present study maximum number of patients belonged to the age group 25-30 years with 117 patients , followed by 30-35 years with 22 patients. 112 patients had duration of lesions between 5 – 10 years , 24 patients had duration more than 10 years. 52 patients had papules , which was most predominant lesions , nodules & cyst were present in 12 patients. Among 150 patients studied 36 had scars , of which 14 patients had ice pick scars . 116 (58%) patients had lesions only on the face , 10 patients had lesions on face, back and chest . 23 patients were having seasonal exacerbation , while 31 patients had ares of acne with periods of stress . Out of 150 patients 68 had moderate acne and 14 patients had severe acne. Out of 150 subjects , 11 subjects were having menstrual irregularities , 3 subjects were having seborrheic capitis

FKBP39 controls nutrient dependent Nprl3 expression and TORC1 activity in Drosophila

Target of Rapamycin Complex 1 (TORC1) is a master regulator that coordinates nutrient status with cell metabolism. The GTPase-activating protein towards Rags complex 1 (GATOR1) inhibits TORC1 activity and protects cells from damage during periods of stress. Here we characterize multiple pathways that regulate the expression of the GATOR1 component Nprl3 in Drosophila. We determine that the stability of Nprl3 is impacted by the Unassembled Soluble Complex Proteins Degradation (USPD) pathway. In addition, we find that FK506 binding protein 39 (FKBP39)-dependent proteolytic destruction maintains Nprl3 at low levels in nutrient replete conditions. Nutrient starvation abrogates the degradation of the Nprl3 protein and rapidly promotes Nprl3 accumulation. Consistent with a role in promoting the stability of a TORC1 inhibitor, mutations in fkbp39 decrease TORC1 activity and increase autophagy. Finally, we show that the 5′UTR of nprl3 transcripts contain a functional upstream open reading frame (uORF) that inhibits main ORF translation. In summary, our work has uncovered novel mechanisms of Nprl3 regulation and identifies an important role for FKBP39 in the control of cellular metabolism.

Module 9: Emotion Coaching

In Module 9, parents are introduced to their important role in helping their children with attention-deficit/hyperactivity disorder (ADHD) learn to regulate strong emotions. Parents are the child’s first teachers for how to regulate emotions and serve the role of “external regulator” for their children. Children with ADHD are more sensitive to their environments and look to their parents for signs of how to react to a situation or stressor. The goal is for parents to stay calm and collected, modeling effective emotion regulation for their child during periods of stress. When parents learn to be “emotion coaches,” they are more likely to consider the child’s emotions without judgment and decrease critical or invalidating responses. By serving as the child’s “emotion coach” (noticing, tolerating and labeling the child’s emotion), the child learns “emotion language” so that acting out in response to emotions is not necessary to express how they are feeling.

Are Corporate Bond Defaults Contagious across Sectors?

Corporate bond defaults in different sectors often increase suddenly at roughly similar times, although some sectors see default rates jump earlier than others. This could reflect contagion among sectors—specifically, defaults in one sector leading to credit stresses in other sectors of the economy that would not otherwise have seen stresses. To complicate matters, simple correlation-based tests for contagion are often biased, reflecting increased volatility in periods of stress. This paper uses sectoral default data from over 30 sectors to test for signs of contagion over the past 30 years. While jumps in sectoral default rates do often coincide, there is no consistent evidence of contagion across different periods of stress from unbiased test results. Instead, coincident jumps in sectoral default rates are likely to reflect common macroeconomic shocks.

A conserved ATG2-GABARAP interaction is critical for phagophore closure

The intracellular trafficking pathway, macroautophagy, acts as a recycling and disposal service that can be upregulated during periods of stress, to maintain cellular homeostasis. An essential transition point in the pathway is the sealing of the immature phagophore to form an autophagosome, isolating unwanted cargo prior to lysosomal degradation. However, little mechanistic detail is known about phagophore closure. Human ATG2A and ATG2B proteins, through their interaction with WIPI proteins, are thought to be key players during phagophore closure. We have identified a highly-conserved motif driving the interaction between human ATG2 and GABARAP proteins that is in close proximity to the ATG2-WIPI4 interaction site. We show that the ATG2-GABARAP interaction mutants are unable to close phagophores resulting in blocked autophagy, similar to ATG2A/ATG2B double knock-out cells. In contrast, the ATG2-WIPI4 interaction mutant fully restored phagophore closure and autophagy flux, similar to wild type ATG2. Taken together, we provide new mechanistic insights to the requirements for ATG2 function at the phagophore and suggest that an ATG2-GABARAP interaction is essential for phagophore closure, whereas ATG2-WIPI4 interaction is dispensable.