Crater population and resurfacing of the Martian north polar layered deposits

Present-day accumulation in the north polar layered deposits (NPLD) is thought to occur via deposition on the north polar residual cap. Understanding current mass balance in relation to current climate would provide insight into the climatic record of the NPLD. To constrain processes and rates of NPLD resurfacing, a search for craters was conducted using images from the Mars Reconnaissance Orbiter Context Camera. One hundred thirty craters have been identified on the NPLD, 95 of which are located within a region defined to represent recent accumulation. High Resolution Imaging Science Experiment images of craters in this region reveal a morphological sequence of crater degradation that provides a qualitative understanding of processes involved in crater removal. A classification system for these craters was developed based on the amount of apparent degradation and infilling and where possible depth/diameter ratios were determined. The temporal and spatial distribution of crater degradation is interpreted to be close to uniform. Through comparison of the size-frequency distribution of these craters with the expected production function, the craters are interpreted to be an equilibrium population with a crater of diameter D meters having a lifetime of ~30.75D^(1.14) years. Accumulation rates within these craters are estimated at 7.2D^(−0.14) mm/yr, which corresponds to values of ~3–4 mm/yr and are much higher than rates thought to apply to the surrounding flat terrain. The current crater population is estimated to have accumulated in the last ~20 kyr or less

The development of RAPTA compounds for the treatment of tumors

© 2015 Elsevier B.V. Ruthenium(II)-arene RAPTA-type compounds have been extensively explored for their medicinal properties. Herein a comprehensive review of this class of compounds is provided. A discussion of the basic RAPTA structure is given together with the ways it has been modified to elucidate the key role of each part and to afford targeted derivatives. The various mechanistic studies conducted on RAPTA compounds are described and these are linked to the observed macroscopic biological properties. Ultimately, the review shows that certain RAPTA compounds display quite unique properties that point towards a clinical investigation

Leadership Perceptions in Collaborative Marketing Groups: Cases from the Southern Philippines

Numerous smallholder vegetable farmers in the Southern Philippines have been organized into clusters or collaborative marketing groups. The purpose of these clusters is to gain production, marketing and capacity building support, consolidate produce for higher value markets, deliver in bulk to save on transport and transaction costs, and to increase household income. One of the factors influencing the ability of the clusters to achieve these goals is leadership. Using the case study method, this study looks at the leadership traits of cluster leaders in Bukidnon, South Cotabato and Davao City. A total of 35 smallholder farmers from the three areas were interviewed using a structured questionnaire. The research showed that the clusters have trusted leaders. The members have high regard towards their leaders. Their definition of an ideal leader fits the description of their current leaders. The members also trust their leaders to represent them in transactions and meetings

Characterization of the sedimentary record of the AD1755 tsunami in the Martinhal Holocene succession (Algarve, Portugal) Caracterização do registo sedimentar do tsunami de 1755, na sucessão holocénica do Martinhal (Algarve, Portugal)

This study addresses the Holocene sedimentary succession at Martinhal coastal lowland (Algarve), a site recording the AD1755 Lisbon tsunami. Data on twenty-four short cores and sixteen trenches, retrieved from both the literature and new field work were combined to improve the stratigraphic resolution and lateral correlation of sedimentary units accumulated in this lowland. Four fining-upward depositional sequences (S1 to S4) were identified, showing spatial variation with maximum thickness - S1: 0-3 m; S2: 1.0-2.4 m; S3: 0.2-1.0 m; S4: 0.3-2.3 m. Sequences S1, S2 and S3 consist of medium to coarse yellow sands with levels rich in bioclasts that give place upsequence to brown organic silt and clay. Sequences S1 to S3 testify to the progressive infilling of a small estuary, coeval with the progressive development and changes in efficiency of a sandy barrier. The uppermost sequence (S4) is clearly different and also shows contrast in facies at seaward and landward locations. S4 comprises: 1) seaward (ESE), a basal subunit with boulders to pebbly gravels and coarse to medium well sorted sands, interpreted as deposited by the AD1755 tsunami, covered by an upper subunit comprising an alternation of well sorted white sands and brown silts, interpreted as aeolian/washover and flood deposits; 2) upstream (WNW), alternating layers of poorly sorted very coarse to medium sands and brown silts represent flood plain accretion and channel infill within the lowland. Quartz OSL dating was done by measuring small aliquots in samples from the AD1755 event-layer and large aliquots in samples from other deposits. The coarser and more basal sediment of the AD1755 sediment yielded overestimated OSL ages due to partial bleaching; at the top, and in finer sediment, and also in the more landward locations, OSL ages are closer to the true age of this event. At this location, routine Quartz OSL dating using large aliquots can give useful data on the burial ages for a variety of sediments, provided that the burial time exceeds ca. 1 ky. In contrast, recent abrupt-event sediments should be dated by measuring small aliquots or single grains to get a better control on partial bleaching effects on OSL results

Modelling Future Coronary Heart Disease Mortality to 2030 in the British Isles.

OBJECTIVE: Despite rapid declines over the last two decades, coronary heart disease (CHD) mortality rates in the British Isles are still amongst the highest in Europe. This study uses a modelling approach to compare the potential impact of future risk factor scenarios relating to smoking and physical activity levels, dietary salt and saturated fat intakes on future CHD mortality in three countries: Northern Ireland (NI), Republic of Ireland (RoI) and Scotland. METHODS: CHD mortality models previously developed and validated in each country were extended to predict potential reductions in CHD mortality from 2010 (baseline year) to 2030. Risk factor trends data from recent surveys at baseline were used to model alternative future risk factor scenarios: Absolute decreases in (i) smoking prevalence and (ii) physical inactivity rates of up to 15% by 2030; relative decreases in (iii) dietary salt intake of up to 30% by 2030 and (iv) dietary saturated fat of up to 6% by 2030. Probabilistic sensitivity analyses were then conducted. RESULTS: Projected populations in 2030 were 1.3, 3.4 and 3.9 million in NI, RoI and Scotland respectively (adults aged 25-84). In 2030: assuming recent declining mortality trends continue: 15% absolute reductions in smoking could decrease CHD deaths by 5.8-7.2%. 15% absolute reductions in physical inactivity levels could decrease CHD deaths by 3.1-3.6%. Relative reductions in salt intake of 30% could decrease CHD deaths by 5.2-5.6% and a 6% reduction in saturated fat intake might decrease CHD deaths by some 7.8-9.0%. These projections remained stable under a wide range of sensitivity analyses. CONCLUSIONS: Feasible reductions in four cardiovascular risk factors (already achieved elsewhere) could substantially reduce future coronary deaths. More aggressive polices are therefore needed in the British Isles to control tobacco, promote healthy food and increase physical activity

Effect of egg white protein-pectin electrostatic interactions in a high sugar content system on foaming and foam rheological properties

The aim of this study was to evaluate the effect of electrostatic interaction between egg white protein (EW) and pectin in a high sugar content system (80 wt% total solid) on the foaming properties (density, overrun and stability) and foam rheological properties. A central composite rotatable design was carried out to study the effects of biopolymer concentration (1.40-5.60%, w/w) and EW:pectin ratio (7:1-63:1) on the apparent viscosity before whipping, foaming capacity (density and overrun) and foam rheological properties (storage modulus G', loss modulus G" and phase angle δ) of sugar/EW/pectin mixtures at pH 3.0. The apparent viscosity increased as biopolymer concentration increased while EW:pectin ratio had no significant effect (p>0.10) on this response. At 7:1 EW:pectin ratio, the mixture presented low foaming capacity, resulting in foam with less solid character and low stability, possibly due to the pectin excess in the system. At 49:1 EW:pectin ratio, the mixture showed higher foaming capacity and foam elasticity. The formation of soluble complexes between EW and pectin possibly increased the continuous phase viscosity and enhanced the foam stability by slowing liquid drainage

Recommended isolated-line profile for representing high-resolution spectroscopic transitions (IUPAC Technical Report)

The report of an IUPAC Task Group, formed in 2011 on "Intensities and line shapes in high-resolution spectra of water isotopologues from experiment and theory" (Project No. 2011-022-2-100), on line profiles of isolated high-resolution rotational-vibrational transitions perturbed by neutral gas-phase molecules is presented. The well-documented inadequacies of the Voigt profile (VP), used almost universally by databases and radiative-transfer codes, to represent pressure effects and Doppler broadening in isolated vibrational-rotational and pure rotational transitions of the water molecule have resulted in the development of a variety of alternative line-profile models. These models capture more of the physics of the influence of pressure on line shapes but, in general, at the price of greater complexity. The Task Group recommends that the partially Correlated quadratic-Speed-Dependent Hard-Collision profile should be adopted as the appropriate model for high-resolution spectroscopy. For simplicity this should be called the Hartmann--Tran profile (HTP). The HTP is sophisticated enough to capture the various collisional contributions to the isolated line shape, can be computed in a straightforward and rapid manner, and reduces to simpler profiles, including the Voigt profile, under certain simplifying assumptions.Comment: Accepted for publication in Pure and Applied Chemistr

Ears of the Armadillo: Global Health Research and Neglected Diseases in Texas

Neglected tropical diseases (NTDs) have\ud been recently identified as significant public\ud health problems in Texas and elsewhere in\ud the American South. A one-day forum on the\ud landscape of research and development and\ud the hidden burden of NTDs in Texas\ud explored the next steps to coordinate advocacy,\ud public health, and research into a\ud cogent health policy framework for the\ud American NTDs. It also highlighted how\ud U.S.-funded global health research can serve\ud to combat these health disparities in the\ud United States, in addition to benefiting\ud communities abroad

Experiences with the Catholic Relief Services' clustering process for agroenterprise development and some suggestions for improvement

An evaluation of the Catholic Relief Services’ (CRS) eight-step clustering approach to agroenterprise development was a key focus of the Australian Centre for International Agricultural Research (ACIAR) – Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development (PCAARRD) horticulture project on ‘Enhancing the profitability of selected vegetable value chains in the southern Philippines’. The CRS approach encourages farmers to form small, collaborative marketing groups (clusters) and to facilitate the sustainable development of these clusters. The research, which used participative action learning and action research processes, identified that an enhanced clustering approach should incorporate processes that overcome issues such as: input financing arrangements to replace loans from informal moneylenders and traders; risks associated with production failures and pest and disease problems; maintaining relationships with buyers; and building group resilience and independence so that donor agencies have an exit strategy. The research findings suggest that to enhance the sustainability of the clusters the CRS eight-step process should be applied to three phases: (i) establishment, (ii) building resilience and (iii) implementing an exit strategy

Marketing Benefits Derived from Clustering: the Case of Vegetable Clusters in Mindanao

One of the most limiting constraints for improving the profitability of smallholder vegetable farmers is poor marketing. With the lack of knowledge and inability to negotiate with downstream buyers, farmers have little option other than to sell their products to the traditional market. To facilitate access to technical information, credit and institutional markets, smallholder farmers are forming collaborative marketing groups. Clustering is one form of collaborative marketing in which smallholder farmers are organized into small groups within a defined territory or geographic area. Using the CRS Eight Step Plan for Agro-enterprise Development, 29 clusters were formed in three provinces in the Southern Philippines. This study explores the various marketing benefits smallholder farmers have achieved after joining the cluster. After interviewing 61 vegetable farmers from 10 clusters using a structured questionnaire, results show that upon joining the cluster, farmers became more aware of their buyer’s preference for product quality and gained knowledge on how to properly handle and package their produce. Cluster farmers increased their income from vegetable farming by selling a greater product variety, a larger volume and gaining access to high value markets