Asynchronous formation of Hesperian and Amazonian-aged deltas on Mars and implications for climate

Most fluvial and lacustrine landforms on Mars are thought to be old and have formed more than ~3.8 Gyr ago, in the Noachian period. After a major climatic transition, surface liquid water became less abundant and finally disappeared almost completely. Recent work has shown that observational evidence for Hesperian and Amazonian aqueous processes is more common than previously recognized, but their nature is poorly understood. Moreover, it is not clear how the paleoclimate of Mars can be constrained by this activity. Here we report our investigation of a population of deltas around the ancient impact basin Chryse Planitia. To test whether the results are globally applicable, we also studied selected deltas with similar morphologies in the eastern hemisphere and found that the results are consistent. We compared the morphology of deltas, feeder channels, and receiving lakes, dated deltas by crater counting and searched for alteration minerals in hyperspectral images. The valleys and associated late-stage deltas were formed by short-lived aqueous processes, as suggested by their morphology and the general lack of associated aqueous alteration minerals. The likely source of water was neither widespread precipitation nor a regionally connected groundwater aquifer, but water mobilized locally from the cryosphere. Delta formation in our study areas occurred from the Early Hesperian to the Late Amazonian and did not require sustained periods of global climatic conditions favoring widespread precipitation. Liquid surface water has been locally present on Mars even after the Noachian, although only episodically, for transient intervals, and widely separated in space

Ccdc94 Protects Cells from Ionizing Radiation by Inhibiting the Expression of p53

DNA double-strand breaks (DSBs) represent one of the most deleterious forms of DNA damage to a cell. In cancer therapy, induction of cell death by DNA DSBs by ionizing radiation (IR) and certain chemotherapies is thought to mediate the successful elimination of cancer cells. However, cancer cells often evolve to evade the cytotoxicity induced by DNA DSBs, thereby forming the basis for treatment resistance. As such, a better understanding of the DSB DNA damage response (DSB–DDR) pathway will facilitate the design of more effective strategies to overcome chemo- and radioresistance. To identify novel mechanisms that protect cells from the cytotoxic effects of DNA DSBs, we performed a forward genetic screen in zebrafish for recessive mutations that enhance the IR–induced apoptotic response. Here, we describe radiosensitizing mutation 7 (rs7), which causes a severe sensitivity of zebrafish embryonic neurons to IR–induced apoptosis and is required for the proper development of the central nervous system. The rs7 mutation disrupts the coding sequence of ccdc94, a highly conserved gene that has no previous links to the DSB–DDR pathway. We demonstrate that Ccdc94 is a functional member of the Prp19 complex and that genetic knockdown of core members of this complex causes increased sensitivity to IR–induced apoptosis. We further show that Ccdc94 and the Prp19 complex protect cells from IR–induced apoptosis by repressing the expression of p53 mRNA. In summary, we have identified a new gene regulating a dosage-sensitive response to DNA DSBs during embryonic development. Future studies in human cancer cells will determine whether pharmacological inactivation of CCDC94 reduces the threshold of the cancer cell apoptotic response

Predicting microbial water quality with models: Over-arching questions for managing risk in agricultural catchments

The application of models to predict concentrations of faecal indicator organisms (FIOs) in environmental systems plays an important role for guiding decision-making associated with the management of microbial water quality. In recent years there has been an increasing demand by policy-makers for models to help inform FIO dynamics in order to prioritise efforts for environmental and human-health protection. However, given the limited evidence-base on which FIO models are built relative to other agricultural pollutants (e.g. nutrients) it is imperative that the end-user expectations of FIO models are appropriately managed. In response, this commentary highlights four over-arching questions associated with: (i) model purpose; (ii) modelling approach; (iii) data availability; and (iv) model application, that must be considered as part of good practice prior to the deployment of any modelling approach to predict FIO behaviour in catchment systems. A series of short and longer-term research priorities are proposed in response to these questions in order to promote better model deployment in the field of catchment microbial dynamics

Returning to work after stroke: perspectives of employer stakeholders, a qualitative study.

Purpose: More than 40 % of working age adults with stroke fail to return to work. The work context is a key factor in return to work, but little is known about the experiences of employers in supporting employees with stroke. The aim of this study was to explore return to work after stroke from the employer perspective, to identify key features associated with success and to seek participants’ views regarding the role of healthcare in return to work. Methods: Data was gathered through 18 semi-structured interviews with employer stakeholders and included small business owners, line managers, human resources and occupational health staff. Data was analysed thematically. Results: The main themes identified were: the impact of stroke on the employer, characteristics of the employee, communication, knowledge and information, experience of other stakeholders, integrating healthcare in return to work. Conclusion: Employers face complex emotional and practical issues when helping an employee return to work after stroke, for which many lack knowledge and experience. The range and quality of support networks that they access is variable and advice and support from clinicians is welcomed. Further research is necessary to investigate how such support could be funded and integrated within existing service provision

Influence of soil water content and atmospheric conditions on leaf water potential in cv. "Touriga Nacional" deep-rooted vineyards

Abstract In this study, the influence of soil and atmosphere conditions on noon and basal leaf water potential of vines ‘‘Touriga Nacional’’ in the Da˜o region submitted to different irrigation treatments is analysed. Both indicators showed to be dependent on environmental conditions at the time of measurement. Leaf water potential at noon of fully watered plants was linearly related with atmospheric conditions, with values registered when vapour pressure deficit (VPD) was higher than approximately 3 kPa being no different from the values registered in stressed plants. Therefore, this indicator cannot be reliably used to distinguish different plant water stress levels when atmospheric conditions induce high evaporative demands. The basal leaf water potential (wb) was also influenced by VPD at the time of measurement for all soil water conditions. In well irrigated plants, it was even possible to establish a baseline that can therefore be used to identify nonwater stressed conditions (wb (MPa) = -0.062–0.0972 VPD (kPa), r2 = 0.78). A good correlation was found between soil humidity and wb. However, more than the average value of the whole thickness of soil monitored, the wb values were dependent on the distribution of soil humidity, with the plants responding to the presence of wet layers

Total and corrected antioxidant capacity in hemodialyzed patients

BACKGROUND: Oxidative stress may play a critical role in the vascular disease of end stage renal failure and hemodialysis patients. Studies, analyzing either discrete analytes and antioxidant substances, or the integrated total antioxidant activity of human plasma during hemodialysis, give contradictory results. METHODS: Recently, we have introduced a new automated method for the determination of Total Antioxidant Capacity (TAC) of human plasma. We have serially measured TAC and corrected TAC (cTAC: after subtraction of the interactions due to endogenous uric acid, bilirubin and albumin) in 10 patients before the onset of the dialysis session, 10 min, 30 min, 1 h, 2 h and 3 h into the procedure and after completion of the session. RESULTS: Our results indicate that TAC decreases, reaching minimum levels at 2 h. However, corrected TAC increases with t(1/2 )of about 30 min. We then repeated the measurements in 65 patients undergoing dialysis with different filters (36 patients with ethylene vinyl alcohol copolymer resin filter -Eval-, 23 patients with two polysulfone filters -10 with F6 and 13 with PSN140-, and 6 patients with hemophan filters). Three specimens were collected (0, 30, 240 min). The results of this second group confirm our initial results, while no significant difference was observed using either filter. CONCLUSIONS: Our results are discussed under the point of view of possible mechanisms of modification of endogenous antioxidants, and the interaction of lipid- and water-soluble antioxidants

"I am becoming more and more like my eldest brother!": the relationship between older siblings, adolescent gambling severity, and the attenuating role of parents in a large-scale nationally representative survey study

The present study examined the association between having older siblings who gamble and adolescent at-risk/problem gambling and how parents (i.e., parental knowledge of their whereabouts) and peers might moderate such effects. Data were drawn from the ESPAD®Italia2012 survey (European School Survey Project on Alcohol and Other Drugs) comprising a nationally representative Italian sample of adolescents. The analysis was carried out on a subsample of 10,063 Italian students aged 15–19 years (average age = 17.10; 55 % girls) who had at least one older sibling and who had gambled at some point in their lives. Respondents’ problem gambling severity, older gambler sibling, gambler peers, parental knowledge, and socio-demographic characteristics were individually assessed. Multinomial logistic regression analyses including two- and three-way interactions were conducted. The odds of being an at-risk/problem gambler were higher among high school students with older siblings that gambled and those with peers who gambled. Higher parental knowledge (of who the adolescent was with and where they were in their leisure time) was associated with lower rates of at-risk/problem gambling. There was also an interaction between gamblers with older siblings and parental knowledge. The combination of having siblings who gambled and a greater level of parental knowledge was associated with lower levels of problem gambling. The present study confirmed the occurrence of social risk processes (older siblings and peers who gambled) and demonstrated that gambling among older siblings and peers represents an important contextual factor for increased at-risk/problem gambling. However, parental knowledge appears to be sufficient to counterbalance the influence of older siblings

The impact of individual Cognitive Stimulation Therapy (iCST) on cognition, quality of life, caregiver health, and family relationships in dementia: a randomized controlled trial

Background: Cognitive Stimulation Therapy (CST) is a well-established group psychosocial intervention for people with dementia. There is evidence that homebased programmes of cognitive stimulation delivered by family caregivers may benefit both the person and the caregiver. However, no previous studies have evaluated caregiver-delivered CST. This study aimed to evaluate the effectiveness of a home-based, caregiver-led individual Cognitive Stimulation Therapy (iCST) program in (i) improving cognition and quality of life (QoL) for the person with dementia and (ii) mental and physical health (wellbeing) for the caregiver. Methods and Findings: A single-blind, pragmatic randomized trial (RCT) at eight study sites across the UK. The intervention and blinded assessment of outcomes were conducted in participants’ homes. 356 people with mild to moderate dementia and their caregivers recruited from memory services, and community mental health teams. Participants were randomly assigned to iCST (75, 30 minute sessions) or treatment as usual (TAU) control over 25 weeks. iCST sessions consisted of themed activities designed to be mentally stimulating and enjoyable. Caregivers delivering iCST received training and support from an unblind researcher. Primary outcomes were cognition (Alzheimer’s Disease Assessment Scale cognitive [ADAS-Cog]) and self-reported quality of life (QoL) (Quality of Life Alzheimer’s Disease [QoL-AD]) for the person with dementia, and general health status (Short Form-12 [SF-12]) for the caregiver. Secondary outcomes included: quality of the caregiving relationship from the perspectives of the person and of the caregiver (Quality of the Carer Patient Relationships Scale), and health-related QoL (EQ5D) for the caregiver. Intention to treat (ITT) analyses were conducted. At the post-test (26 weeks), there were no differences between the iCST and TAU groups in the outcomes of cognition (MD = -0·55, 95% CI -2·00 to 0·90; p=0·45), and self-reported quality of life (QoL) (MD = -0·02, 95% CI -1·22 to 0·82; p= 0·97) for people with dementia, or caregivers’ general health status (MD=0·13, 95% CI -1·65 to 1·91; p=0·89). However, people with dementia receiving iCST rated the relationship with their caregiver more positively (MD = 1·77, 95% CI 0·26 to 3·28; p=0·02) and iCST improved QoL for caregivers (EQ-5D, MD = 0·06, 95% CI 0·02 to 0·10; p=0·01). Forty percent (72/180) of dyads allocated to iCST completed at least two sessions per week, with 22% (39/180) completing no sessions at all. Study limitations include low adherence to the intervention. Conclusions: There was no evidence that iCST has an effect on cognition or QoL for people with dementia. However, participating in iCST appeared to enhance the quality of the caregiving relationship and caregivers’ QoL