Can Martian Life Exist Under Dry Conditions?

Recently, we have begun to hear more and more about news coming from Mars. With the recent confirmation of evidence of liquid water in Mars\u27 past, evidence indicating liquid water in Mars\u27 present, and as many missions planned for this decade and the next than have successfully reached the planet in the last 40 years, life on Mars is beginning to become a more relevant issue in our study of the planet. Although there have been no indications of multicellular life on Mars, there may be a possibility of microbial life in the subsurface. Since it appears that all of the necessary elements for life on Mars exist, it is instrumental for scientists to analyze terrestrial ecosystems that might be analogous to those on Mars. Life on Earth has shown a great amount of diversity in ability to survive extreme environments utilizing a stunning array of energy sources, electron donors, electron acceptors, salinity, pressures, and temperature ranges. From the study of Mars-like terrestrial ecosystems, some scientists have suggested that the methanogens would be a possible candidate to survive Mars\u27 subsurface conditions. There are various Mars\u27 conditions that could be tested on Earth to confirm or deny the methanogens\u27 ability to survive on the planet. Since the survival of methanogens depends on the presence of liquid water, which would probably be seasonal at best on Mars, their ability to survive desiccation will be key in their potential to inhabit Mars\u27 subsurface. In this research, the methanogens Methanobacterium formicicum, Methanothermobacter wolfeii, and Methanosarcina barkeri were grown on JSC Mars-I soil simulant and exposed to varying times of desiccation. Since the byproduct of the methanogens\u27 growth is methane, methane was measured in the head gas of the samples upon rehydration and incubation. These measurements were used to determine survival. The methanogens studied were capable of survival and subsequently methane production upon rehydration after all of the periods of desiccation tested. M. Formicicum was tested over periods of 10 and 27 days, while M. wolfeii and M. barkeri were tested over periods of 10 days. These results support the hypothesis that methanogens could survive in Mars\u27 subsurface if liquid water were present. The methanogens could be a key ingredient in the terraforming of Mars, and at this point remain an increasingly possible candidate for past, present, or future Martian life

Robustness of computer algorithms to simulate optimal experimentation problems.

Three methods have been developed by the authors for solving optimal experimentation problems. David Kendrick (1981, 2002, Ch.10) uses quadratic approximation of the value function and linear approximation of the equation of motion to simulate general optimal experimentation (active learning) problems. Beck and Volker Wieland (2002) use dynamic programming methods to develop an algorithm for optimal experimentation problems. Cosimano (2003) and Cosimano and Gapen (2005) use the Perturbation method to develop an algorithm for solving optimal experimentation problems. The perturbation is in the neighborhood of the augmented linear regulator problems of Hansen and Sargent (2004). In this paper we take an example from Beck and Wieland which fits into the setup of all three algorithms. Using this example we examine the cost and benefits of the various algorithms for solving optimal experimentation problems.

Cowbane, Oxypolis occidentalis, A New Native Vascular Plant Species for the Queen Charlotte Islands, British Columbia

We report the recent discovery of Oxypolis occidentalis, a species that is new to both British Columbia and Canada, disjunct on the Queen Charlotte Islands

Sparse Matrix Multiplication on a Field-Programmable Gate Array

To extract data from highly sophisticated sensor networks, algorithms derived from graph theory are often applied to raw sensor data. Embedded digital systems are used to apply these algorithms. A common computation performed in these algorithms is finding the product of two sparsely populated matrices. When processing a sparse matrix, certain optimizations can be made by taking advantage of the large percentage of zero entries. This project proposes an optimized algorithm for performing sparse matrix multiplications in an embedded system and investigates how a parallel architecture constructed of multiple processors on a single Field-Programmable Gate Array (FPGA) can be used to speed up computations

Two Notions Of Safety

Timothy Williamson (1992, 224–5) and Ernest Sosa (1996) have ar- gued that knowledge requires one to be safe from error. Something is said to be safe from happening iff it does not happen at “close” worlds. I expand here on a puzzle noted by John Hawthorne (2004, 56n) that suggests the need for two notions of closeness. Counterfac- tual closeness is a matter of what could in fact have happened, given the specific circumstances at hand. The notion is involved in the semantics for counterfactuals and is the one epistemologists have typically assumed. Normalized closeness is rather a matter of what could typically have happened, that is, what would go on in a class of normal alternatives to actuality, irrespectively of whether or not they could have happened in the circumstances at hand

Maternal perceptions of supervision in preschool-aged children: a qualitative approach to understanding differences between families living in affluent and disadvantaged areas

Aim: To explore maternal perceptions of supervision and childhood unintentional injury in order to develop understanding and explanation for differences in unintentional injury rates between an advantaged and disadvantaged area. Background: Unintentional injury is the second cause of mortality and a significant cause of morbidity in the zero to four year age group. Children living in socio economic disadvantage are at a greater risk of unintentional injury than their more affluent counter-parts. Methods: Qualitative study using semi-structured interviews; content data analysis was undertaken. Participants included 37 mothers with a child aged less than five years; 16 living in an area of disadvantage (and high rate of childhood unintentional injury) and 21= living in an advantaged area (and low rate of childhood unintentional injury). Findings: Parents in both areas described the importance of parental supervision in reducing child unintentional injury risks. Parents in both areas used listening as a supervision strategy. Parents in both areas described how ‘when the child goes quiet’ that is a cue for them to make a visual check on the child. Listening was used more for boys than girls in both areas, but parents in the advantaged area used listening as a supervision strategy more frequently than those in the disadvantaged area. Parents described supervision strategies as being shaped by child character and age rather than child gender. Parents in both areas described similar strategies for managing distractions. An important difference was found with regard to older siblings; parents living in the advantaged area described older siblings as an injury risk to younger children. Parents in the disadvantaged area described older siblings as providing some supervision for younger children. Parents living in disadvantaged circumstances may face greater challenges with regard to supervision than parents living in advantaged circumstances and this may partly explain differences in injury risk

Developing the Text-Based Writing Instructional Capacity of Middle School Teachers

Text-based writing is a form of academic composition in which many students struggle. Moreover, research into this area reveals that many teachers may not be sufficiently prepared to teach this kind of writing to their students. The purpose of this dissertation’s mixed methods study was to examine the impact of an online, job-embedded PD on middle school English language arts (ELA), mathematics, and science teachers’ knowledge of text-based writing strategies, efficacy for teaching text-based writing, and instructional practices for text-based writing. Eight teachers from a public, mid-Atlantic middle school participated in the study, including three ELA, one mathematics, and four science teachers. Over a period of two and a half months, each of these teachers participated in 10 PD sessions that lasted between 60 and 90 minutes. To measure the impact of this PD on the constructs of interest, pre and post quantitative and qualitative data were gathered. Quantitative data analyses, which included the conducting of Wilcoxon signed-rank tests, suggest that that PD may have made teachers more confident in their ability to impact students’ text-based writing outcomes (i.e., personal efficacy), but it did not appear to make them more confident in their ability to impact these outcomes more than external factors (i.e., general efficacy). Quantitative data analyses also indicate that the PD may have made teachers more likely to shift instructional practices for text-based writing, including their approaches used to teach strategies (i.e., writing strategy instruction) and their ways of teaching these strategies (i.e., instructional writing practices). Because of the small number of participants, however, these results should be interpreted cautiously. Qualitative data show that the PD may have developed teachers’ knowledge of cognitive strategies, instructional strategies, and instructional scaffolds for text-based writing. Furthermore, the qualitative data suggest that engagement in PD activities may have facilitated teachers’ efficacy for teaching text-based writing, and the data show that the instructional practices that teachers intend to implement come from the PD. Findings from the study demonstrate that text-based writing PDs should include cognitive strategy instruction, provide opportunities for application and collaboration, and occur over a sustained period

Child injury prevention: a survey of local authorities and health boards

Aims: Unintentional home injuries are a significant global public health issue and are a major cause of mortality and morbidity. Within each country, injuries disproportionately affect children from low income families. Recent guidance issued in the UK recommends actions to be taken by local authorities to reduce injury rates and inequalities. This study aimed to describe and quantify child home injury prevention activities of local authorities (LAs) in England and health boards (HBs) in Wales. Methods: A questionnaire was sent to Directors of Public Health (DsPH) in all 153 upper-tier LAs in England and 7 HBs in Wales. The questionnaire covered the five broad areas recommended for injury prevention activities by NICE guidelines. Results: A response rate of 58% was achieved. NICE guidance (75%) and Public Health England guidance (57%) were most commonly used to support child injury prevention decision making. Half (50%) of respondents had a child injury prevention alliance in their area. One fifth (19%) reported that their area had a written child injury prevention strategy. Fewer than half of responders provided training to practitioners about child unintentional injury prevention (43%), home safety assessments (43%) or an equipment scheme (43%). Of the 43% of areas with equipment schemes, most (59%) were small scale, supplying up to 200 families per year with equipment. Conclusions: Although some LAs/HBs show implementation of recent guidance on preventing home injuries in childhood, most do not. LAs/HBs are likely to need support to implement guidance in order that child injury rates and inequalities can be reduced