bluuebunny/crossref_metadata_2025 huggingface dataset:
Using Geospatial Information Technology for Rural Agricultural Development Planning in the Nebo Plateau, South Africa
Authors: Petja Brilliant , Nesamvuni Edward , Nkoana Albertina
Published: March 2014

This study uses geospatial technologies (remote sensing and geographic information system) to assess the agricultural potential of the Nebo Plateau, a rural area in the Limpopo Province of South Africa. This approach entails assessing the suitability in terms of land/soil and climate, which are determinant factors for agricultural development. The environmental requirements of selected crops were analyzed using ArcView™ GIS. Various spatial analysis techniques were used to model and assign classes of suitability based on the most important and yield-limiting parameters such as rainfall, temperature and soil characteristics. Results indicate that the area is potentially suitable to a variety of agricultural commodities where 65% of the area is suitable for cultivation. This is however considerate of environmental and climatic constraints such as the availability of water for irrigation, improvement of the state of the environment, prevention of soil degradation due to erosion and compaction, improvement of soil fertility by means of sound farming and management practices. These outputs are presented within a user friendly GIS platform for a better decision support to the development agencies and government. The results also help to provide inputs for assessing financial feasibility of farming projects. This study therefore emphasizes the importance of geospatial technologies in informing and promoting sustainable agricultural development.
A Review of the Epidemiology of Gastrointestinal Nematode Infections in Sheep and Goats in Ghana
Authors: Blackie Seth
Published: March 2014

In this paper, the gastrointestinal nematode parasites infecting small ruminants (sheep and goats) in Ghana and the epidemiological factors influencing their prevalence are reviewed and discussed. Twelve nematode species belonging to six families have been reported to infect these livestock in the country with Haemonchus contortus being the most prevalent helminth parasite in both animals. Parasitic gastroenteritis is caused by mixed infection of several nematode species. Management /husbandry practices, climate and host influence are found to be the main factors that affect gastrointestinal nematode infections in sheep and goats. Seasonal changes in the level of infective strongylate nematode larvae on pasture in the different agro-ecological zones of Ghana are reviewed. The number of infective larvae on pasture is reported to be directly related to the pattern of rainfall. Consequently, rainfall could be relied on to predict the rate of transmission of infection in grazing animals. Finally, the relevance of epidemiological knowledge in the development of efficient measures for controlling gastrointestinal nematode infections in sheep and goats in Ghana is discussed.
Geo-Assessment of Chemical Composition and Nutritional Evaluation of Moringa oleifera Seeds in Nutrition of Broilers
Authors: Annongu A. , Karim O. R. , Toye A. A. , Sola-Ojo F. E. , Kayode R. M. O. , Badmos A. H. A. , Alli O. I. , Adeyemi K. D.
Published: March 2014

Chemical composition of Moringa oleifera seeds obtained from the middle belt of Nigeria, Benue State, was determined and the seed was blended to form a seed meal. The Moringa oleifera Seed Meal, MOSM was included in diets at graded levels of 2.50, 5.00 and 7.50% and the dietary performance of the broiler chicks on the test diets was compared with that of a corn-soy reference diet. Results on the chemical/nutritional composition of MOSM showed that the full-fat seeds contained (%) on proximate basis, reasonable concentration of 90.38 dry matter, 25.37 crude protein, 14.16 crude fat, 4.03 mineral matter, 30.64 crude fiber, 25.80 soluble carbohydrate and 5.79 kcal/g gross energy. Analyses also gave appreciable quantities of the water and fat soluble vitamins, macro - and micro-minerals. Feeding chicks with the seed meal at graded levels in diets resulted in decrease in feed intake and body weight gain as the inclusion level increased in diets relative to the conventional diet (p < 0.05). Reduction in feed consumption could be attributed to the full-fat nature of the seed meal used which might have imparted extra-caloric effect in the test diets and slowed digestion and absorption as the analyzed nutrients content of diets. A higher ether extract value on Moringa based diets relative to the control diet was obtained. Phytochemical composition of Moringa namely phenols including tannins, saponins, phytate, cyanogenic glucoside, glucosinolates and other numerous chemical constituents affected the body weight of the chicks negatively with increasing dietary MOSM. Decrease in weight gain following increase in dietary seed meal could also be due to decrease in feed intake as a result of the bitter taste of alkaloids, saponins, acting in concert with the other Moringa phytotoxins in test diets. Survival rate (100%) was not affected indicating that the level of highest inclusion in this study (7.50%) was not fatal to the experimental animal models. Further research is progressing to ascertain the highest inclusion level possible to elicit fatality and attempts to detoxify or treat the seed meal before feeding to animals.
Constraints and Challenges Facing the Small Scale Farmers in Limpopo Province, South Africa
Authors: Mpandeli Sylvester , Maponya Phokele
Published: March 2014

Macro- and micro-structural constraints, including those linked to and exacerbated by historical, natural and financial factors are some of the many stressors facing small-scale farmers in Limpopo Province. The challenge is to co-design ways to effectively manage these constraints with development actions. Small scale farmers in South Africa are still facing major challenges in the agricultural sector. In this paper some of the challenges faced by small-scale farmers in the Limpopo Province have been identified. Some of the challenges found during the formal surveys and focus group meetings in the Tshakhuma, Rabali and Tshiombo areas were those linked to financial, assets, land ownership and biophysical factors. Specific constraints included: (a) Market information and market access; (b) Price of inputs, for example fertilizer and herbicides; (c) Availability of inputs; (d) Irrigation; (e) Cost of transport, and Natural constraint.
Ingestive Behavior of Cows in Pastures Andropogon gayanus and Brachiaria decumbens in Southern State of Piauí, Brazil
Authors: Fonseca Wéverton José Lima , Fonseca Wéverson Lima , Araújo de Sousa Paulo Henrique Amaral , Guerra Leandro De Oliveira , Luz Carlos Syllas Monteiro , Santos Tatiano Ribeiro dos , Silva Vogado Gleissa Mayone , Borges Laylson Da Silva , Júnior Teobaldo Florêncio de Almeida , Júnior Severino Cavalcante De Sousa
Published: March 2014

The research was conducted at the experimental farm of the Agricultural College of Bom Jesus, which is located at 135 km 3 BR, in the region of the valley Gurguéia southern state of Piauí. We used 10 crossbred cows of Holstein x Gir. The experimental design was completely randomized with two treatments (the pastures of grasses Andropogon gayanus and Brachiaria decumbens), with five replicates (five animals per treatment). The trial lasted five days. Two evaluations were made with duration of 24 hours each, conducted during a day, and the average of the two ratings was used in the statistical analyzes. The evaluations were performed on 20 to 24 July 2013. The cows grazed more time in the morning around 7-10 hours and late afternoon extending into the night with peak until 19:00 hours. The idle time was greater at the end of the night that matches the period of reduced grazing activity. The cows grazed more time during the day in the pasture of Brachiaria decumbens (8.53 hours) compared to pasture Andropogon gayanus (8.03 hours). With respect to time grazing night, the situation was reversed, the animals grazed longer during the day and slowed down during the night (3.16 hours grazing) in the pasture of Brachiaria decumbens. The animals had a higher number of bits (14128.92) in grazing Brachiaria decumbens compared to Andropogon gayanus (10134.00).
Shattercane X ALS-Tolerant Sorghum F1 Hybrid and Shattercane Interference in ALS-Tolerant Sorghum
Authors: Werle Rodrigo , Schmidt Jared J. , Laborde John , Tran Angela , Creech Cody F. , Lindquist John L.
Published: March 2014

ALS-tolerant grain sorghum cultivars are expected to be available for farmers within the next few years. Knowing that: i) crosses between sorghum and shattercane are likely to occur resulting in crop-to-weed gene flow; ii) ALS-susceptible shattercane X ALS-tolerant grain sorghum F1 hybrids (hybrids) were ultimately resistant to ALS-herbicides under field conditions; and iii) hybrid fitness is equal to, or greater than, the wild parent, we conducted a greenhouse study to compare the competitive effect of shattercane and hybrid on sorghum, and whether or not herbicide application would influence the competitive ability of the hybrid plants. An additive design was used where weed densities varied while that of crop remained constant. The treatment design was a factorial with two weedy genotypes, shattercane and hybrid, with the hybrid being either exposed or not exposed to an ALS-herbicide application (nicosulfuron (26.25 g ai ha-1) + rimsulfuron (13.16 g ai ha-1)), and five weed densities (0, 1, 2, 3, and 4 plants pot-1). Sorghum density was kept at 1 plant pot-1. F-tests were performed to compare differences across treatment levels. Shattercane and hybrid produced similar amounts of total above ground biomass within each density, and herbicide exposure did not decrease hybrid biomass production. Moreover, shattercane and hybrid competed similarly with sorghum, and a herbicide application did not reduce the competitive ability of the hybrid. Sorghum wild relatives must be managed by alternative methods before and during the adoption of ALS-tolerant sorghum technology to avoid gene flow and crop yield loss due to competition.
Grain Yield and Yield Components of Quality Protein Maize Genotypes as Influenced by Irrigation and Plant Population in the Nigerian Savannah
Authors: Sani B. M. , Abubakar I. U. , Falaki A. M. , Mani H. , Jaliya M. M.
Published: March 2014

An experiment was conducted to assess the yield and yield components of QPM genotypes to plant population under irrigated conditions in a semi arid ecology of Northern Nigeria. Field trials were conducted at the Irrigation Research Station, Institute for Agricultural Research, Kadawa (11° 39'N, 08° 20'E) and 500 m above sea level) during dry seasons 2007, 2008 and 2009 to study the effect of (Zea mays L.) genotypes (TZE-W Pop X 1368, EV-DT W99 STR and DMR-ESRW), four plant population (33333, 44444, 55555 and 66666 plants ha-1) and three irrigation scheduling (40, 60 and 80 centibars soil moisture tension) on the growth and yield of quality protein maize. A split plot design was used with combinations of genotypes and irrigation regimes assigned to the main plot and plant population assigned to the sub-plot. The treatments were replicated three times. The study revealed that genotype EV-DT W99 STR had significantly higher weight of ears per plant, cob length, cob diameter, number of rows per cob, 100 grain weight, grain yield, shelling percentage and harvest index than the other two genotypes used in the trial. Irrigating at 40 and 60 centibars significantly increased weight of ears per plant, while delayed irrigation significantly depressed total dry matter production. Based on the results obtained in this study, it can be concluded that the use of genotype EV-DT W99 STR, at 60 centibars irrigation scheduling and population of 55,555 plants ha-1 had resulted in good agro-physiological characters of QPM at Kadawa.
Evaluation of Maize Accessions for Nutrients Composition, Forage and Silage Yields
Authors: Amodu J. T. , Akpensuen T. T. , Dung D. D. , Tanko R. J. , Musa A. , Abubakar S. A. , Hassan M. R. , Jegede J. O. , Sani I.
Published: March 2014

An experiment was conducted to evaluate the yield of forage, silage and nutrients composition of two maize accessions: West Atlantic Seed Alliance 1 (WASA1) and an accession from Shika tagged (SHIMAZ). The maize seeds were planted in plots of 5 m x 5 m (25 m2) size with four replicates for each accession. The results showed that, there was no significant (P > 0.05) difference between the accessions for plant height and number of leaves at 4, 6, 8 and 10 weeks after sowing (WAS), but leaf area index (LAI) was significantly (P < 0.05) higher in SHIMAZ accession at 6 and 10 WAS. The number of leaves per plant, green leaves, leaf area and forage yield at 91, 105 and 119 days after sowing (DAS) were not significant (P > 0.05) in the two accessions of maize, but leaf area and LAI were significantly (P < 0.05) higher in WASA1 accession.. The percentage dry-matter (DM) content was significantly (P < 0.05) lower in WASA1, although leaf, and stem ratios were significantly (P < 0.01) higher at various stages of harvest. The crude protein (CP) and nitrogen free-extract (NFE) were significantly (P < 0.01) higher in WASA1 accession while crude fibre (CF) was significantly (P < 0.01) higher in SHIMAZ. The proximate components (ash, EE and CP) and NDF were significantly (P < 0.01) higher in WASA1 silage, but NFE and ADF were higher (P < 0.05) in SHIMAZ accession.
Growth and Yield Performance of Cowpea (Vigna Unguiculata (L.) Walp) as influenced by Row-Spacing and Period of Weed interference in South-West Nigeria
Authors: Adigun Joseph , Osipitan A. O. , Lagoke Segun Toyosi , Adeyemi Raphael Olusegun , Afolami Stephen Olaoluwa
Published: March 2014

Weed problem appears to be the most deleterious factor causing between 25 and 60% reduction in potential yield of cowpea. Field trials were therefore conducted to study the effect of inter-row spacing and period of weed interference on growth and yield of cowpea (Vigna unguiculata (L) Walp) at the Teaching and Research Farm of the Federal University of Agriculture, Abeokuta (07° 15'; 03° 25' E) in South Western Nigeria during the early and late wet seasons of 2009. The experiment consisted of eight main plots of weed interference which included initial weed removal for 3, 6, 9, and 12 weeks after sowing (WAS) and subsequently weed –infested until harvest as well as initial weed infestation for corresponding periods and thereafter kept weed free until harvest. There were also sub-plot treatments of three inter-row spacing of 60, 75, and 90 cm. All treatments in different combinations were laid out in a split-plot design with three replications. In both trials, the use of inter-row spacing of 60 cm resulted in significant reduction in weed growth as evident in lower weed dry matter production and subsequent higher cowpea pod and grain yields than those of 75 and 90 cm inter-row spacing. Initial weed infestation of up to 3 WAS did not have any adverse effect on crop growth and cowpea grain yields provided the weeds were subsequently removed. On the other hand, cowpea grain yield loss was not significantly averted by keeping the crop weed free for only 3 WAS without subsequent weed removal. In this study, initial weed-infestation for 6 WAS and beyond significantly depressed various crop growth parameter and cowpea grain yield compared with the crop kept weed free throughout its life cycle. In order to obtain optimum yields similar to that of the weed free cowpea field, it was required to keep the crop weed free for 6 WAS and beyond. However, frequent weeding beyond 9 weeks after sowing did not improve cowpea yield significantly and as a matter of fact it may even result in reduction of cowpea grain yield due to mechanical damage of hoe weeding. The practical implication of this finding is that early weeding starting from 3 WAS is very crucial for cowpea production while the critical period of weed removal for optimum yield in cowpea is between 3 and 9 WAS in the forest-savannah transitional zone of south Western Nigeria.
Results of Rearing Broiler Chickens Under Various Systems
Authors: Kuzniacka Joanna , Adamski Marek , Czarnecki Rafal , Banaszak Miroslaw
Published: March 2014

The aim of the study was comparison of the results of rearing broilers kept under intensive and semi-intensive systems, fed with complete feeds with an addition of various proportions of wheat grain. The study was carried out on 100 broilers, HUBBARD – FLEX, of both sexes. The birds were reared up to 42 days of age in an intensive system (group I), as well as in a semi-intensive system (group II). In the 5th week of rearing, in the nutrition of group II, 30% of complete feed was replaced with wheat grain, increasing its proportion in the dose up to 50% in the last week of rearing. System of keeping broilers did not affect significantly their bodyweight at the end of rearing, as well as their meat yield and muscle content in carcasses. Chicken fed with complete feeds, kept under an intensive system were distinguished by higher fattiness expressed as an abdominal fat weight, as well as by lower average intake of feed mixtures per individual broiler.
Evaluation of Agricultural Soil Resources Using Fuzzy Modeling
Authors: Dmitry Kurtener Dmitry , Sukhanov Paul
Published: March 2014

Assessment of agricultural soil resources is a very difficult because exists knowledge is much fuzzy. Developed fuzzy model is effective tool for dealing with randomness and uncertainties. This model is based on a two-level system of fuzzy indicators. The first level - is individual fuzzy indicators (IFI), reflecting the assessment of individual characteristics. Second level - is combined fuzzy indicators (CFI), reflecting a combination of individual indicators. IFI are developed for the four characteristics of the soil (humus, amount absorbed cations, acidity (pH) and physical clay content). The proposed method is illustrated with a simple example.
Book Review: Genetically Modified Crops in Africa: Economic and Policy Lessons from Countries South of the Shara
Authors: Obayelu A. E.
Published: March 2014

In this new book, Genetically Modified Crops in Africa: Economic and Policy Lessons from Countries South of the Shara, José Falck-Zepeda, Guillaume Gruère, and Idah Sithole-Niang present us the case of various hindrance and the feelings of farmers / government towards genetically modified crop technology while at this same time provide scientific evidence for the safe adaptation with the view of significantly increasing the agricultural value in Africa. Read this book review by A. E. Obayelu to find out more about this book.
The Agro-Industrial Sugarcane System in Mexico: Current Status, Challenges and Opportunities
Authors: Sentíes-Herrera Héctor Emmanuel , Gómez-Merino Fernando Carlos , Valdez-Balero Apolonio , Victoria Silva-Rojas Hilda , Trejo-Téllez Libia Iris
Published: March 2014

Sugarcane cultivation in Mexico occurs under a wide range of socioeconomic, environmental and agricultural conditions, with the last three harvests (2010/2011, 2011/2012 and 2012/2013) providing yields ranging from 36-125 t ha-1 (variation > 347%), with an average yield of 70.2 t ha-1, which is below the world average of 80 t ha-1. The total area allocated to sugarcane production in Mexico is close to 800 thousand hectares, and could rise to nearly 5 million hectares given adequate conditions for its cultivation. This activity generates approximately 1 million direct jobs, 2.2 million indirect jobs, and more than 2.5 billion dollars (0.4% of GDP) per year. Climate change and the rapid market penetration of high fructose corn syrup are among the greatest threats to this agribusiness, including severe disintegration of production processes in the field, industry, commerce, and consumption of cane sugar. Technology lags, low investment, high processing costs and shortcomings in production sales are issues the industry must address by leveraging their resources and coordinating processing links to be more efficient and competitive. Political influence has imposed a suboptimal policy framework to achieve the projected potential. To overcome current lags in the field and refineries within the country, significant innovations across the value-chain are underway, including a robust breeding program, digitalization of sugarcane fields and novel investments in research and development. The sugarcane value-chain has great potential for Mexico, and exploiting this potential is possible if technological, organizational and commercial management innovations currently in progress in fields and factories are applied.
Effect of Pig Price Volatility on Sichuan Pig Farmers’ Behavioral Response in China
Authors: Hao Miao , Chen Rong , Fu Xinhong
Published: March 2014

This study aims to analyze cobweb phenomenon of pig price volatility and its effects on pig producers in Sichuan, China. Historical data showed that pig price from 2000 to 2003 pertained to Occlude Cobweb Phenomenon; while pig price from 2004 to 2012 pertained to Divergent Cobweb Phenomenon. Based on Cobweb Phenomenon this article provided a comparative analysis of pig price volatility’s effects on scattered farmers, scale farmers and pig factories via examining their basic information, response to price volatility, reasons leading to such response, and price expectation. The results indicated that scale farmers were the most sensitive to price volatility; hence their production behaviors probably boosted pig price volatility to some degree. Factory farming was the most competitive farming pattern and was bound to be the main trend in pig industry in the future.
Determination of Postharvest Pod Storage on Viability and Seedling Growth Performance of Cocoa (Theobroma cacao L) in the Nursery
Authors: Saajah Joseph Kofi , Maalekuu Bonaventure Kissinger
Published: March 2014

This research was conducted to determine how cocoa pod storage affects seed viability, when stored in containers for a specific period. The objectives were to determine the maximum storage period for maximum seed viability, determine the ideal storage container for maximum germination and finally determine the superior growth performance of the seedlings obtained. The design was a Randomized Complete Block Design (RCBD) in a factorial arrangement involving two factors: storage period and storage container. This arrangement produced interactions between the two factors and increased precision due to “Hidden replication”. Podwere randomly drawn at 5 daily intervals and seed sowed to determine viability through sixteen (16) parameters, which included time to start and end germination, germination percentage, stem girth, canopy spread, shoot length and vigour index. The results generated from this experiment were in respect of interactions and simple effects of the two factors, on viability and seedling growth performance. Interaction effects were pronounced on five parameters which included time taken to start and end germination; vigour index; shoot height and leaf area. Germination speed and percentage were also significantly influenced by storage period. For growth parameters, superior performance (p<0.05), was obtained for variables such as leaves per plant, petiole length, internode length, within 1 day of harvest (DOH)-15 days after harvest (DAH) period. In respect of the type of container used for storage, internode length and dry matter accumulation were significantly influenced. Storage temperature and relative humidity did not affect the results. Pods stored from 1-15 DAH in basket, jute sack or fertilizer sack had maximum viability.
Streptomyces felleus YJ1: Potential Biocontrol Agents Against the Sclerotinia Stem Rot (Sclerotinia sclerotiorum) of Oilseed Rape
Authors: Cheng Guanglong , Huang Yun , Yang Hui , Liu Fan
Published: March 2014

In order to explore the biocontrol potential of Streptomyces felleus YJ1 to sclerotinia stem rot of oilseed rape, we evaluated the effects of YJ1 as antagonistic strain on Sclerotinia sclerotiorum, including germination and formation of sclerotia, ascospore germination, mycelial growth and YJ1 colonization ability. We found the fermentation filtrate of YJ1 could inhibit sclerotia and ascospore germination and mycelial growth. In dual culture the inhibition zone diameter of YJ1 against S. sclerotiorum was 11.0 mm, and the inhibition rate reached to 80.26%. The ascospores germination was also significantly inhibited by YJ1 fermentation filtrate. In addition, YJ1 could colonize stably in rhizosphere and roots of rape. Otherwise, in the greenhouse we found the lesion would become smaller and slighter if the inoculated leaves were pretreated with YJ1 fermentation liquid. Therefore, our results strongly suggested that YJ1 was a promising biocontrol agent for control of oilseed rape sclerotinia stem rot.
The Evaluation of Corn and Peanut Intercropping on Efficiency of Use the Environmental Resource and Soil Fertility
Authors: Rajaii Mahdieh , DahMardeh Mehdi
Published: March 2014

Order to study the effect of density, the control weed and various proportion corn (704 Variety) and peanut (Goli Variety) intercropping an experiment was conducted in 2012 in Research station of agriculture, University of Zabol. The experiment design was factorial in randomized complete block design with three replications. Experiment factors consisted of planting proportions in 4 levels (sole crop of corn, 50% corn + 50% peanut, 100% corn + 100% peanut and sole crop of peanut), control weed in 3 levels (non-weeding, once-weeding and twice-weeding) and the space between rows in 2 level (40 and 50 cm) has been considered. The evaluated Characteristics in environmental sources are (Photosynthetic Active Radiation, Temperature and soil Moisture), the nutrients of soil include (N, K, Na, Mg, Ca, and C) and to evaluate intercropping of pure was used land equivalent ratio and economical yield. All Characteristics of study were affected by planting system.There was significant interaction between planting system, weeding and density in the absorption of light, temperature and moisture of soil. The results showed that photosynthesis active radiation absorbed by the intercropping was higher than sole crop in both plants. The results showed that changes in soil nutrient capacity of single elements (Na and K) in the treatment of mixed and monoculture peanut was more than monoculture corn and divalent elements (Ca and Mg) in mixed and monoculture corn more than mixed replacement and peanut monoculture. The highest land equivalent ratio (1.048) was accounted additive intercropping. Generally the mixed cultures with increasing density and control weed caused increase soil fertility and amount of soil nutrients after harvest. Treatment 100% Corn +100% peanut was the best treatment because using sources and increasing soil fertility and crop yield in comparison to sole crop.
Les lieux de culte comme espaces d’intégration pour les nouveaux arrivants : l’exemple de Sherbrooke
Authors: Gélinas Claude , Vatz-Laaroussi Michèle
Published: March 2014

Les nouveaux arrivants qui s’établissent à Sherbrooke ont peu tendance à se regrouper à l’intérieur de groupes religieux composés en majorité de migrants, contrairement à ce qui prévaut dans la région de Montréal. Ce sont plutôt les groupes religieux composés en majorité de citoyens natifs de tradition chrétienne qui accueillent et intègrent les immigrants, permettant ainsi la création d’espaces interculturels. À partir de données préliminaires, recueillies dans le cadre d’une enquête ethnographique portant sur la diversité religieuse à Sherbrooke, nous soumettons ici aux lecteurs quelques observations préliminaires. Celles-ci permettront de mieux comprendre comment ces groupes donnent ou non aux nouveaux arrivants le moyen de maintenir et d’exprimer leurs particularismes identitaires et culturels et comment ils favorisent ou non l’intégration plus large de ceux-ci dans l’ensemble de la société sherbrookoise.
Constraints on fluid flow processes in the Hellenic Accretionary Complex (eastern Mediterranean Sea) from numerical modeling
Authors: Kufner S.‐K. , Hüpers A. , Kopf A. J.
Published: March 2014

The dynamics of accretionary convergent margins are severely influenced by intense deformation and fluid expulsion. To quantify the fluid pressure and fluid flow velocities in the Hellenic subduction system, we set up 2‐D hydrogeological numerical models following two seismic reflection lines across the Mediterranean Ridge. These profiles bracket the along‐strike variation in wedge geometry: moderate compression and a >4 km thick underthrust sequence in the west versus enhanced compression and <1 km of downgoing sediment in the center. Input parameters were obtained from preexisting geophysical data, drill cores, and new geotechnical laboratory experiments. A permeability‐porosity relationship was determined by a sensitivity analysis, indicating that porosity and intrinsic permeability are small. This hampers the expulsion of fluids and leads to the build up of fluid overpressure in the deeper portion of the wedge and in the underthrust sediment. The loci of maximum fluid pressure are mainly controlled by the compactional fluid source, which generally decreases toward the backstop. However, pore pressure is still high at the decollement level at distances <100 km from the deformation front, either by the incorporation of low permeability evaporites or additional compaction of the wedge sediments in the two profiles. In the west, however, formation of a wide accretionary complex is facilitated by high pore pressure zones. When compared to other large accretionary complexes such as Nankai or Barbados, our results not only show broad similarities but also that near‐lithostatic pore pressures may be easier to maintain in the Hellenic Arc because of accentuated collision, some underthrust evaporates, and a thicker underthrust sequence.
Hysteresis and coercivity of hematite
Authors: Özdemir Özden , Dunlop David J.
Published: March 2014

In room‐temperature hysteresis, 14 submicron hematites (0.12‐0.45 µm) had large coercive forces Hc (150‐350 mT), while 22 natural 1‐5.5 mm hematite crystals had Hc = 0.8‐23 mT (basal‐plane measurements). Single‐domain (SD) and multidomain (MD) hematites owe their high Hc mainly to magnetoelastic anisotropy, caused in fine particles by internal strains and in large crystals by defects like dislocations, with a smaller contribution by triaxial magnetocrystalline anisotropy. A strong correlation between Hc and the defect moment Md measured below hematite's Morin transition also favors magnetoelastic control. Saturation remanence/saturation magnetization ratios Mrs/Ms and coercivity ratios Hcr/Hc (Hcr is remanent coercive force) are distinctive: Mrs/Ms = 0.5‐0.9, Hcr/Hc = 1.02‐1.17 for MD hematites; Mrs/Ms = 0.5‐0.7, Hcr/Hc = 1.45‐1.62 for SD hematites. In high‐temperature (20‐690°C) hysteresis, Hc(T) ~ Ms(T) to a power 1.8‐2.4 above 385°C. Magnetoelastic wall pinning by crystal defects is thus more likely than control by domain nucleation which depends on magnetocrystalline anisotropy. Our results compare well with existing Hc vs. crystal size d data. A suggested peak in Hc around 15 µm and a proposed slope change around 100 µm are both questionable. Using only near‐saturation data, Hc varies continuously as d−0.61 from ≈0.1 µm to 2 mm. The SD threshold size d0 may be >15 µm but there is no strong evidence that d0 ≈100 µm. Direct domain observations are needed to settle the question. Augmented data sets for Hc and Mrs vs. d show that SD hematite is increasingly affected by thermal fluctuations below ≈0.3 µm and generally confirm a superparamagnetic threshold size ds of 0.025‐0.03 µm.
Hedgehog Signalling
Authors: Cruz‐Migoni Sara Betania , Borycki Anne‐Gaëlle
Published: March 2014

Hedgehog (Hh) proteins are a family of secreted factors with morphogen activities that have essential role during embryonic development and in adulthood. Mechanisms underlying the production and reception, as well as the signal transduction pathway of Hh proteins, are highly conserved between invertebrates and vertebrates. However, despite this evolutionary conservation, a major divergence is the pathway's association with primary cilia in vertebrates. Hh proteins act both as short‐range and long‐range factors in the control of cell fate specification and cell differentiation, cell proliferation, tissue patterning and morphogenesis during embryonic development. Hh proteins are also involved in tumour formation. Knowledge of this pathway has been instrumental in recent therapeutic approaches aiming at downregulating Hh signalling in cancers.

Key Concepts:

Hedgehog signalling is conserved during evolution.

Hedgehog is a morphogen, specifying distinct cell types at different concentrations.

Hedgehog acts as a short‐ and long‐range signalling molecule.

Hedgehog has essential role in cell fate specification and differentiation and in cell proliferation and survival.

Hedgehog signalling is implicated in cancer.
Sigma Factors in Gene Expression
Authors: Chandrangsu Pete , Helmann John D
Published: March 2014

Sigma (σ) factors control the promoter selectivity of bacterial RNA polymerase (RNAP). On binding to RNAP, σ factors allow efficient promoter recognition and transcription initiation. Bacterial promoters are typically comprised of two hexameric
deoxyribonucleic acid (DNA)
sequences located approximately 10 and 35 bases upstream of the transcription start site (the −10 and −35 element, respectively). All bacteria contain a primary σ factor that is responsible for transcription of housekeeping genes necessary for growth and survival. In addition, many bacteria encode multiple alternative σ factors. The level and activity of the alternative σ factors are highly regulated and can vary depending on environmental or developmental signals. The synthesis of alternative σ factors allows the coordinated activation of discrete sets of genes through the recognition of distinct promoter sequences and thereby contributes to stress responses, motility, endospore formation and numerous other adaptive responses.

Key Concepts:

σ Factors are necessary for promoter recognition by RNA polymerase and efficient transcription initiation.

Transcription initiation is a highly regulated, multistep process.

σ Factors can be grouped into two families on the basis of their similarity to the housekeeping σ factor, σ
70
, or the nitrogen‐responsive σ factor, σ
54
.

Members of the σ
70
family generally contain four conserved domains (regions 1–4).

Most bacteria encode multiple alternative σ factors that direct transcription of genes in response to environmental cues and developmental transitions. Alternative σ
70
family proteins often lack region 1 and sometimes region 3 (minimally containing conserved regions 2 and 4).

σ Factor activity can be regulated at many levels, such as through sequestration by anti‐σ factors or by protolytic activation.
Poliovirus
Authors: Minor Philip D
Published: March 2014

Poliovirus is a member of the Picornavirus family, positive strand
ribonucleic acid (RNA)
viruses responsible for many human and animal diseases. The atomic structure of poliovirus was solved in the 1980s. Classification is now based on genomic sequences. The growth cycle of polio involves attachment to a specific receptor found only in the Old World monkeys and the higher primates. The viral proteins are translated as a single large precursor that is then cleaved by virus‐encoded proteases; initiation of translation is from an internal ribosomal entry site in the 5' noncoding region. The pathogenesis of poliovirus has been intensively studied, although many aspects remain poorly understood. The disease is most likely to be eradicated in the near future through use of vaccines. Of the three serotypes found in nature, wild‐type 2 has not been isolated since 1999 and no wild‐type 3 has been isolated since November 2012.

Key Concepts:

Picornaviruses are now classified on the basis of sequence comparisons.

Poliomyelitis was rare before the twentieth century when improving hygiene meant that infants were exposed to the virus after maternal antibody had declined.

Picornaviruses are classified into different species on the basis of their sequence, and recombination within a species is common.

High‐resolution molecular structures of the picornaviruses were obtained by X‐ray crystallography in the mid‐1980s.

Polio replication requires a specific receptor site found only in the Old World monkeys and the higher primates. It causes disease only in the higher primates, mostly humans.

Poliovirus initiates translation of its genome into protein through an internal ribosome entry site in contrast to most other eukaryotic messenger RNAs where initiation requires a free capped and methylated 5′ terminus.

Poliovirus replicates primarily in the gut; however, it also replicates in unidentified tissue types, in addition to the motor neurones of the central nervous system.

Live attenuated and killed virus vaccines are both used in controlling and eradicating polio depending on the circumstances.

The Global Polio Eradication Initiative is the largest public health initiative aimed at a single human disease in history.
Protist Evolution and Phylogeny
Authors: Pawlowski Jan
Published: March 2014

The beginning of this century brought spectacular changes in our understanding of eukaryote phylogeny, especially the early evolution of microeukaryotic lineages commonly called protists. Phylogenomic studies based on analysis of more than 200 genes produced a relatively well‐resolved tree of eukaryotes. Metagenetic studies usingenvironmental deoxyribonucleic acid (eDNA)revealed an extraordinary diversity of protist lineages, highlighting their great ecological and evolutionary importance. A new higher level classification of eukaryotes combining the results of microscopic and various ‘omics’ studies has been proposed. In this classification, the majority of eukaryotes are placed in seven monophyletic supergroups: Amoebozoa, Opisthokonta, Archaeplastida, Alveolata, Stramenopiles, Rhizaria and Excavata. Phylogenetic relationships between these supergroups and 11 independent eukaryotic lineages are relatively well established. However, there is no consensus concerning the position of the root of eukaryotic tree. Further single‐cell microscopic and genomic studies are also necessary for exploring the extraordinary diversity of protistan phyla revealed by the eDNA surveys.

Key Concepts:

Molecular phylogenies drastically changed our understanding of eukaryotes evolution.

Phylogenomic data are essential for reconstructing the deep relationships of eukaryotes.

Ribosomal phylogenies are useful for inferring relationships within protistan phyla and for species identification.

Current protist classification comprises 4–7 supergroups and a few independent lineages.

Important part of protist diversity has been uncovered by environmental DNA study.
DNA
Structure: Sequence Effects
Authors: Frank‐Kamenetskii Maxim D
Published: March 2014

Deoxyribonucleic acid (DNA)
sequence significantly affects the local stability of the DNA double helix. Two types of stability of the DNA duplex must be distinguished: thermodynamic stability and kinetic stability. Although stability of the DNA region depends mostly on its G•C content, it is stacking interaction between adjacent base pairs which have dominating contribution into the overall region stability. Sequence effects play especially important role in the stability of DNA helices different from B‐ and A‐forms such as Z‐DNA, parallel duplex, triplexes and quadruplexes. Depending on their particular sequence, different DNA sites are capable of adopting various unusual structures, among them: the cruciform, the triplex H form, the Z form and quadruplexes. These sequence‐dependent structures are stabilized by DNA negative supercoiling. They attract more and more attention in recent years because of their potential as targets for anticancer drugs and as tools in bio‐ and nanotechnology.

Key Concepts:

DNA thermodynamic stability determines equilibrium properties of the double helix but equilibrium is not always achievable.

DNA kinetic stability governs DNA behaviour at the characteristic time of experiment.

Stacking interactions, rather than base pairing, play the decisive role in determining the stability of the DNA double helix.

Highly sequence‐dependent DNA unusual structures dramatically affect DNA structural variability.

Unusual structures are thermodynamically unfavourable in linear DNA but their formation becomes possible in negatively supercoiled DNA.
Developmental Syndromes of Ras/
MAPK
Pathway Dysregulation
Authors: Malaquias Alexsandra C , Jorge Alexander AL
Published: March 2014

The term RASopathies designates a group of developmental syndromes caused by germline mutations in genes that encode proteins of the Ras/mitogen‐activated protein kinase (MAPK) signalling pathway. Ras/MAPK pathway controls several biological functions, such as cell proliferation, migration, differentiation and apoptosis. Similar molecular mechanisms disturbing the Ras/MAPK pathway were described in the RASopathies, including Noonan syndrome, Noonan syndrome with multiple lentigines, Noonan syndrome‐like disorder with loose anagen hair,
CBL
mutation‐associated syndrome, Costello syndrome, cardiofaciocutaneous syndrome, neurofibromatosis type 1 and Legius syndrome. Even though these syndromes share some overlapping features, genotype–phenotype correlations are well established for each of these, supporting the idea that they represent clinically distinct disorders. Owing to the similar mechanism encompassing Ras/MAPK germline and somatic mutations, Ras/MAPK pathway components have been considered a potential therapeutic target for RASopathies by promoting pathway modulation or small‐molecule inhibition.

Key Concepts:

Ras/MAPK is one of the most well‐known signalling pathways and plays an important role in critical cellular functions to normal development.

RASopathies are a group of medical genetic disorders caused by gain‐of‐function germline mutations in components of the Ras/MAPK signalling pathway.

Although the RASopathies may share clinically overlapping features, they also exhibit some individual ones that support the concept that they are distinct disorders.

Ras/MAPK germline mutations are similar to somatic mutations when associated with cancer, but they tend to be weakly activating.

Noonan syndrome is a frequent autosomal dominant disorder characterised by facial dysmorphisms, heart defects, short stature and learning disabilities.

The best clinical practice for each RASopathy could be defined if its genotype–phenotype correlation is understood.
Genetics and Genomics of Malignant Rhabdoid Tumours
Authors: Wei Darmood , Weissman Bernard E
Published: March 2014

Malignant rhabdoid tumours (MRTs) represent an aggressive paediatric cancer with limited treatment options. Although MRTs mainly arise in the kidney and brain of patients under the age of 8 years, they may appear in other major organs as well as in soft tissues. Remarkably, these tumours possess few mutations other than the ones that inactivate the SNF5/INI1 gene, the smallest member of the SWI/SNF chromatin‐remodelling complex. In addition, these cancers lack other hallmarks of adult malignancies including genomic instability, aberrant karyotypes and abnormal regulation of cellular stress‐response pathways. Their major defect appears to arise from epigenetic instability, presumably through changes in nucleosome positioning due to defective chromatin‐remodelling activity. Recent reports have shown that SNF5 loss affects key signalling pathways such as cell cycle regulation,
deoxyribonucleic acid (DNA)
damage repair and gene transcription. Thus, MRTs offer a unique model for studying the role of epigenetics in driving tumourigenesis and for the development of novel treatment approaches.

Key Concepts:

Malignant rhabdoid tumours are rare and aggressive paediatric cancers.

MRT was the first tumour in which mutations in the SWI/SNF chromatin‐remodelling complex were identified.

Inactivation of the SNF5/INI1 tumour suppressor gene drives MRT development.

MRTs often show no changes in copy number or karyotype.

The key mechanisms by which SNF5/INI1 loss induces MRT development remain unclear.

MRTs offer a unique model for epigenetic‐driven tumourigenesis.
Interpreting Disease Relevance of Amino Acid Substitutions
Authors: Vihinen Mauno
Published: March 2014

High‐throughput sequencing methods can generate large amounts of information about genetic variations; however, interpretation of this data has become a severe bottleneck for efficient use of genomic data, for example, in diagnostics. Identification of variations responsible for phenotypes is laborious and many times difficult task. Amino acid substitutions are among most common disease‐causing variants. Human genome codes for, on an average, approximately 11 000 such variants. Computational tools are needed to filter and rank raw variation datasets for further studies. Amino acid substitutions can have numerous effects, and mechanisms behind them are diverse. Therefore, different kinds of methods have been developed. Tolerance predictors aim at finding out likely harmful variants. Mechanism‐ and effect‐specific tools are dedicated for specific outcomes of variants.

Key Concepts:

Amino acid substitution is a change in protein sequence where a single residue is changed.

Benchmark dataset contains cases with known effect. It serves as the gold standard, for example, for method performance assessment and training machine learning‐based methods.

Human variome project (HVP) is an international organisation coordinating research and standards for variation research.

Next generation sequencing methods are fast nucleotide sequencing methods taking benefit of multiplexing and able of sequencing complete genomes very fast.

Performance measures are used to indicate performance of prediction methods. For full picture of performance, a number of measures should be reported.

Tolerance predictors are methods to predict whether amino acid substitutions are tolerated or not in a sequence.

Variation is a change in nucleotide or amino acid sequence in comparison with the reference sequence.
Electrical Properties of Carbon Nanotube Based Fibers and Their Future Use in Electrical Wiring
Authors: Lekawa‐Raus Agnieszka , Patmore Jeff , Kurzepa Lukasz , Bulmer John , Koziol Krzysztof
Published: March 2014

The production of continuous fibers made purely of carbon nanotubes has paved the way for new macro‐scale applications which utilize the superior properties of individual carbon nanotubes. These wire‐like macroscopic assemblies of carbon nanotubes were recognized to have a potential to be used in electrical wiring. Carbon nanotube wiring may be extremely light and mechanically stronger and more efficient in transferring high frequency signals than any conventional conducting material, being cost‐effective simultaneously. However, transfer of the unique properties of individual CNTs to the macro‐scale proves to be quite challenging. This Feature Article gives an overview of the potential of using carbon nanotube fibers as next generation wiring, state of the art developments in this field, and goals to be achieved before carbon nanotubes may be transformed into competitive products.