Platform Off Research Articles

Whole-body vibration on lower limb flexibility and extensibility – a randomized clinical trial

Introduction and aim. The whole-body vibration has become known for optimizing the production of muscle power due to mechanical oscillations that are dependent on vibration frequency. However, the effects of varying the vibration frequency on flexibility have still been little explored. Compare the effects of two frequencies of whole-body vibration on flexibility and extensibility of the lower limbs. Material and methods. Randomized clinical trial with a sample of 42 young adult volunteers of both sexes, who performed squatting sessions with individualized load on a platform and distributed into three groups of vibration frequency: control group (CG), with the platform off; low frequency group (LF), with a frequency of 30 Hz; high frequency group (HF), with a frequency of 45 Hz. In total, the intervention was carried out in 12 sessions and lasted 6 weeks, with 2 sessions per week. Flexibility, evaluated before and after the intervention by the sit and reach test (Wells bench) and by evaluating the extensibility of the ischiotibials by goniometry. Results. No statistical differences were observed for any of the outcomes evaluated. Conclusion. None of the proposed frequencies produced gains in flexibility and extensibility of the lower extremities and there was no superiority of one frequency over another.

Foraminifers associated with macroalgae on a wave-cut platform off Abu Qir coastal area, Egypt

Since their earliest history, benthic foraminifers have diversified to inhabit a vast array of habitats, from semi-terrestrial to the deep-sea floor. Epiphytic foraminifers developed morphologies that have allowed them to inhabit macroalgal fronds and thalli. This study examined the presence of benthic foraminiferal species living on algal species inhabiting rocky coastal environments in the southeastern Mediterranean Sea. Fronds of six algal taxa found abundantly on a carbonate wave-cut platform off the east coast of Alexandria were collected and the associated foraminifers living on each frond were identified. Twenty foraminiferal species were recorded, with seven epiphytic species (Asterigerinata mamilla, Elphidium aculeatum, Elphidium crispum, Peneroplis pertusus, Peneroplis planatus, Rosalina bradyi, and Rosalina macropora) comprising > 80% of the assemblage. Nearly 70% of the foraminiferal specimens were found on two algal species, Caulerpa racemosa and Ellisolandia elongata. Two Indo-Pacific foraminiferal species found in the samples (Amphistegina lobifera and Amphisorus hemprichii), in addition to Caulerpa racemosa, are considered invasive species in the Mediterranean. The widespread occurrence of the opportunistic invasive Caulerpa spp., which apparently provides suitable habitat for many epiphytic foraminifers, may partially compensate for the predicted decline in coralline-algal habitat under the effect of ocean acidification.

Movement patterns of red snapper Lutjanus campechanus based on acoustic telemetry around oil and gas platforms in the northern Gulf of Mexico

Offshore oil and gas platforms in the northern Gulf of Mexico are known aggregation sites for red snapper Lutjanus campechanus. To examine habitat use and potential mortality from explosive platform removals, fine-scale movements of red snapper were estimated based on acoustic telemetry from March 2017 to July 2018. Study sites in the northern Gulf of Mexico, USA, included one platform off coastal Alabama (30.09°N, 87.88°W) and 2 platforms off Louisiana (28.81°N, 91.97°W; 28.92°N, 93.15°W). Red snapper (n = 59) showed a high affinity for platforms, with most (94%) positions being recorded within 95 m of the platforms. Home range areas were correlated with water temperature and inversely correlated with dissolved oxygen concentrations. During summer and fall, red snapper used larger areas and many fish (54%) emigrated from their platforms but most (83%) returned in ≤3 d. Site fidelity for red snapper was 31% yr-1 and residency time was 7 mo, but the probability-of-presence at platforms was 70% after 1 yr, indicating the importance of platforms for this species. Overall fishing mortality was high for platforms (F = 0.86, 95% CL = 0.47-1.40), but since the stock is managed on a quota basis this high mortality should have little effect on total stock abundance. Thus, platforms can still provide an important habitat for red snapper, and consideration of area use patterns, fishing mortality and environmental factors can reduce red snapper mortality when scheduling explosive platform removals. As such, the present study indicates that an optimum time for explosive removal would be in late summer after the red snapper fishing season is completed.

The Cone Shells (Gastropoda: Conidae) of the Abrolhos Platform, Brazil, with the Description of Three New Species

Three new species of cone shells, in the genera Coltroconus, Jaspidiconus, and Poremskiconus, have been discovered on the Abrolhos Platform off central Brazil. These new taxa, Coltroconus valianti n. sp., Jaspidiconus carlagrezziae n. sp., and Poremskiconus uhlei n. sp. are restricted to the coral reef environments of the central platform area and are the newest additions to a highly-endemic localized conid fauna comprising 17 known species

Forecasting the legacy of offshore oil and gas platforms on fish community structure and productivity.

There are currently thousands of offshore platforms in place for oil and gas extraction worldwide, and decommissioning efforts over the next three decades are estimated to cost more than US$200 billion. As platforms reach the end of their useful lifetime, operators and regulatory agencies will assess the environmental impact of potential decommissioning strategies. Among the many factors that will be weighed in preparation for these major economic and engineering challenges is the fate of the fish and invertebrate communities that inhabit the structures underwater. Offshore platforms act as inadvertent artificial reefs, and some are recognized among the most productive fish habitats in the global oceans. We present a model for forecasting changes to fish communities surrounding offshore installations following a series of decommissioning alternatives. Using 24 platforms off southern California, we estimate fish biomass and somatic production under three possible decommissioning scenarios: leave in place, partial removal at 26-m depth, and complete removal of the platform and underlying shell mound. We used fish density and size data from scuba and submersible surveys of the platforms from 1995-2013 to estimate biomass and annual somatic production. Bottom trawl surveys were used to characterize future fish assemblages at platform sites under the complete-removal decommissioning scenario. Based on a conservatively modeled extrapolation of the survey data, we found that complete removal of a platform resulted in 95% or more reduction in the average fish biomass and annual somatic production at the site, while partial removal resulted in far smaller losses, averaging 10% or less. In the event that all surveyed platforms are completely removed, we estimated a total loss of more than 28,000kg of fish biomass in the Southern California Bight. Platform habitats, which attract reef-dwelling fish species, had minimal overlap in community composition with the surrounding soft-bottom habitat. To best serve the wide range of stakeholder interests, the site-specific biomass, productivity and species composition information provided in this study should be incorporated into strategic decommissioning planning. This approach could be used as a model for informing "rigs to reefs" discussions occurring worldwide.

Blackmarket-Driven Collusion Among Retweeters–Analysis, Detection, and Characterization

The growth of online social media has led to a huge increase in the number of users who want to share and publicize various kinds of information. Twitter, the most popular micro-blogging platform, has become a hotbed for users who are involved in different activities such as news publishing, job hunting, recruiting, advertising and publicity. Retweeting a tweet is a major action to broadcast a user’s message out to millions of users. Retweet action has two major advantages: (i) gaining quick exposure to the content, and (ii) increasing likelihood of gaining new Twitter followers in return. The organic way of gaining a larger number of retweets is a time consuming process, which leads to the creation of unfair methods to gain retweets. Thus, Twitter users often approach various blackmarket services to gain retweets inorganically in a short duration. Blackmarkets spread their collusive ecosystem in such a way that Twitter is unable to detect them even after devoting significant effort to purge the platform off bots, trolls, and fake accounts. One major reason behind the evasion is that the collusive users involved in blackmarket services exhibit a mix of organic and inorganic behavior – they organically reweet some genuine tweets; at the same time, they inorganically retweet tweets submitted to blackmarket services. This paper is the first attempt to provide a thorough study of the collusive users involved in two types of blackmarket services – Premium and Freemium. We collect a novel dataset of collusive users comprising of users from both types of blackmarket services. We provide network-centric, profile-centric, timeline-centric and retweet-centric characteristics of these users and show how users involved in premium blackmarket services exhibit diverse behavior as compared to those involved in freemium services. We further employ human annotators to label collusive users into three types: bots, promotional customers, and normal customers. We then curate 63 novel features to run state-of-the-art classifiers in two settings – binary classification (collusive vs. genuine) and multi-class classification (bot, promotional customers, normal customers, and genuine users). Bagging achieves the best accuracy (macro F1-score of 0.892) in the former setting, whereas Random Forest outperforms others (macro F1-score of 0.791) in the latter setting. We also develop a chrome extension, SCoRe++ which can detect collusive retweeters in real time.

Late Quaternary sediments on the carbonate platform off western India: Analogues of ancient platform carbonates

The Late Quaternary carbonate sediments and sedimentary rocks from the platform off western India were reviewed for their genesis and relationship with their ancient counter parts. Sub-marine cemented and vadose diagenetic limestones were recovered at different locations on the platform and, neomorphic limestones and caliche pisolites were recovered on the continental shelf south of the platform. Dolomites on the platform were primary and formed by microbial processes under hypersaline, sulphate-reducing conditions during the lowered sea levels. Aragonite ooids were formed from the mineralization of microbial filaments that enveloped their cortex portions. Phosphorites were found in organic-rich, aragonite muds on the continental slope adjacent to the platform and formed from the microbial mineralization of organic matter and replacement of carbonate by apatite during early diagenesis. Microbial processes thus played an important role in the formation of dolomites, ooids and phosphorites reported here and those in ancient deposits. Halimeda bioherms on the platform were grown luxuriantly from the nutrients brought by upwelling currents during the Late Pleistocene–Early Holocene sea level transgression and are similar to the Holocene–Recent deposits in the Indo-Pacific region. Lime muds were bio-detrital and formed primarily from the disintegration of Halimeda bioherms and carbonate skeletal on the platform and then exported to the slope. They resemble fine-grained limestones abundantly reported in ancient platforms. Thus, the different carbonate components on the platform are genetically related to their ancient ones and serve as Late Quaternary analogues for the ancient platform carbonates.

Bathymetry and sediments on the carbonate platform off western India: Significance of Halimeda bioherms in carbonate sedimentation

Bathymetry across the carbonate platform off western India indicated small-size pinnacles and their lateral coalescence into 2 -6-m high mounds landward, and linear elongated carbonate ridges and troughs, mounds and banks up to a height of 20-m seaward of the platform. Seismic data indicated that these mounds were transparent with no rigid internal structure and can be defined as bioherms. The sediments were abundantly aragonite faecal pellets, Halimeda grains and ooids and their radiocarbon ages ranged from 11 to 7.5 ka BP. It appears that the growth of Halimeda bioherms on the platform was facilitated by intense upwelling during the early Holocene. The terrigenous sediments brought by rivers were deposited in the inner shelf and have not affected the growth of bioherms. It is estimated that the platform comprises at least 1.85 Gt of mass CaCO\(_3\) accumulated during the early Holocene and comparable to those on the Great Barrier Reef. Halimeda bioherms produce abundant carbonate sediments and their growth period represents a geological carbonate sink and release of high CO\(_2\) to the atmosphere. Detailed shallow seismic studies and sediment cores are needed to quantify the exact mass content of CaCO\(_3\) and model climate change during the early Holocene.

Sedimentary infilling of bedrock-controlled palaeo-embayments off Cape Trafalgar, Strait of Gibraltar (Gulf of Cadiz)

This study investigates two bedrock-controlled palaeo-coastal embayments on the Barbate Platform off Cape Trafalgar near the Strait of Gibraltar (Gulf of Cadiz shelf, SW Iberian Peninsula), aiming to reveal their infilling dynamics and the influence of rocky outcrops on shallow-water hydrodynamics and sediment transport. The approach relies on detailed multibeam bathymetric data, high-resolution seismic profiles and tidal current simulations. Elongated rocky outcrops formed a palaeo-coast when sea level was approximately 35 to 20 m below that of the present day, and bound a relatively flat area. However, the seismic profiles enabled to distinguish two main troughs (A and B) that were infilled following a distinctive evolution during the last transgression. Five seismic units were identified (I to V, from base to top). Deposit A is composed of seismic units II to V and is interpreted as a marine embayment infill, here termed the Barbate palaeo-embayment (BPE). Deposit B is composed of seismic units I to IV and is interpreted as a palaeo-valley infill, here termed the Barbate palaeo-valley (BPV). The complex internal stratigraphic architecture depicts an overall evolution from tidal/fluvial deposits to shallow-water marine deposits. Most significant is the occurrence of coupled tidal flats/estuarine sand bars constituting the infilling of the BPE; this suggests the persistence of a high-energy current in a shallow, confined embayment, which was amplified by the rocky outcrop constrictions and possibly facilitated by the episodic movement of a normal fault. In contrast to this active setting, the nearby straight and narrow BPV was subjected to lower-energy infilling dynamics during its initial flooding phases. There, tidal activity was possibly reduced by the straight morphology of the valley and the occurrence of a topographic constriction (i.e. the Barbate Passage) at the mouth of the valley.

Typhoon Haiyan's sedimentary record in coastal environments of the Philippines and its palaeotempestological implications

Abstract. On 8 November 2013, category 5 Supertyphoon Haiyan made landfall on the Philippines. During a post-typhoon survey in February 2014, Haiyan-related sand deposition and morphological changes were documented at four severely affected sites with different exposure to the typhoon track and different geological and geomorphological settings. Onshore sand sheets reaching 100–250 m inland are restricted to coastal areas with significant inundation due to amplification of surge levels in embayments or due to accompanying long-wave phenomena at the most exposed coastlines of Leyte and Samar. However, localized washover fans with a storm-typical laminated stratigraphy occurred even along coasts with limited inundation due to waves overtopping or breaching coastal barriers. On a recent reef platform off Negros in the Visayan Sea, storm waves entrained coral rubble from the reef slope and formed an intertidal coral ridge several hundreds of metres long when breaking at the reef edge. As these sediments and landforms were generated by one of the strongest storms ever recorded, they not only provide a recent reference for typhoon signatures that can be used for palaeotempestological and palaeotsunami studies in the region but might also increase the general spectrum of possible cyclone deposits. Although a rather atypical example for storm deposition due to the influence of infra-gravity waves, it nevertheless provides a valuable reference for an extreme case that should be considered when discriminating between storm and tsunami deposits in general. Even for sites with low topography and high inundation levels during Supertyphoon Haiyan, the landward extent of the documented sand sheets seems significantly smaller than typical sand sheets of large tsunamis. This criterion may potentially be used to distinguish both types of events.

Diurnal Sea Breezes Force Near-Inertial Waves along Rottnest Continental Shelf, Southwestern Australia

AbstractObservations of upper-ocean dynamics close to the critical latitude (ratio of the local inertial to diurnal frequency is 0.94) from a range of platforms (surface currents using HF radar, moored instruments, and satellite remote sensing data) off southwest Australia indicated the presence of energetic, near-inertial waves generated through the diurnal–inertial resonance. During the austral summer, when southerly winds and land–sea breeze (LSB) system dominated the wind regime, strong counterclockwise diurnal motions (amplitudes surpassing 0.3 m s−1) penetrated to 300-m depth with diurnal vertical isotherm fluctuations up to 60 m. The upward phase propagation speed of ~140 m day−1, deep penetration of diurnal currents below the mixed layer, and the ~180° phase difference between the upper and lower water column suggested that the local LSB system caused the resonant diurnal motions. Relative vorticity fluctuations along two cross-shore transects indicated changes to the local effective Coriolis frequency by more than 50% (±0.5f). In the presence of strong and relatively consistent cross-shore diurnal wind forcing in the study area, the main factors that controlled the observed energetic but sporadic near-inertial oscillations were the Leeuwin Current strength and spatial–temporal variations. These variations controlled the effective Coriolis frequency and enabled the effective pumping of diurnal wind energy into the ocean particularly when the effective Coriolis frequency was ~24 h.

RECONSTRUCTION OF A LOST CARBONATE FACTORY BASED ON ITS BIOGENIC DETRITUS (TERNATE-TRAVEDONA FORMATION AND GONFOLITE LOMBARDA GROUP - NORTHERN ITALY)

This work reconstructs a now completely eroded late Eocene to earliest Oligocene carbonate factory of Northern Italy, through the analysis of a carbonate deep-water-fan sequence (Ternate-Travedona Formation) and the limestone detritus dispersed into the late Oligocene clastic-wedge of the Gonfolite Lombarda Group. Textural characteristics and skeletal assemblages of the Gonfolite pebbles were studied and compared to those of the Ternate-Travedona Formation. The same skeletal assemblage and the same taxa were found in samples from both areas, suggesting their common origin. Whereas the Ternate-Travedona Formation skeletal grains were reworked during transport, the Gonfolite Lombarda Group pure-limestone pebbles are pristine fragments of the carbonate platform, that was uplifted and eroded from the late Eocene to the early Oligocene. Using both these sources of information it was possible to reconstruct the late Eocene environment and its facies distribution. The areas undergoing high hydrodynamic energy were dominated by free-living coralline-algal branches, rhodoliths and larger thick-tested benthic foraminifera. A coralline framework, associated with thin-tested benthic foraminifera and boxwork rhodoliths, was present in slightly deeper and sheltered environments. Episodic debris flows, mainly triggered by river floods, supplied the sub-marine fan of the Ternate-Travedona Formation. These events were able to down-cut through the narrow platform and rip off large fragments of the substrate. River runoff probably also supplied large quantities of organic matter, leading to local oxygen-depletion and preservation of organic matter. The combined stressful effects of bottom instability and riverine discharge probably excluded corals from the association. The integrated study of the Ternate-Travedona Formation, and of the limestone pebbles in the Gonfolite Group, have enabled the reconstruction of this otherwise lost Eocene carbonate factory.

Immediate effects of whole-body vibration on neuromuscular performance of quadriceps and oscillation of the center of pressure: A randomized controlled trial

BackgroundWhole body vibration has become a popular practice in training and rehabilitation centers. Although proposed as a useful adjunct to improve various aspects of musculoskeletal function, its real benefits and immediate physiological responses are still uncertain. ObjectivesThis study analyzed the immediate effects of whole-body vibration with two distinct frequencies on neuromuscular performance of the quadriceps femoris and in the postural control of healthy subjects. DesignRandomized controlled trial. MethodsSixty physically active women were submitted to an evaluation of the oscillation of the center of pressure through baropodometry and isokinetic performance of quadriceps femoris muscle of the non-dominant limb, associated with the electromyographic amplitude assessment of vastus lateralis muscle. Subjects were randomly divided into three groups: control group – performed an exercise protocol with the vibrating platform off; 30 and 50 Hz groups – conducted the exercise protocol with the platform on, with a frequency of 30 and 50 Hz, respectively. ResultsThere was a significant reduction in the time of peak torque in three evaluated groups (p < 0.001), with no differences between the groups (p = 0.586). There were no significant differences in pressure center oscillation, peak torque normalized for body weight, total work, and average power nor in the value of the root mean square in any of the groups. ConclusionThis study suggests that the exercise protocol on the vibrating platform does not change neuromuscular performance or the pressure center oscillation of healthy women. ClinicalTrials.gov IdentifierNCT02416362.

Classification of single-trial auditory events using dry-wireless EEG during real and motion simulated flight.

Application of neuro-augmentation technology based on dry-wireless EEG may be considerably beneficial for aviation and space operations because of the inherent dangers involved. In this study we evaluate classification performance of perceptual events using a dry-wireless EEG system during motion platform based flight simulation and actual flight in an open cockpit biplane to determine if the system can be used in the presence of considerable environmental and physiological artifacts. A passive task involving 200 random auditory presentations of a chirp sound was used for evaluation. The advantage of this auditory task is that it does not interfere with the perceptual motor processes involved with piloting the plane. Classification was based on identifying the presentation of a chirp sound vs. silent periods. Evaluation of Independent component analysis (ICA) and Kalman filtering to enhance classification performance by extracting brain activity related to the auditory event from other non-task related brain activity and artifacts was assessed. The results of permutation testing revealed that single trial classification of presence or absence of an auditory event was significantly above chance for all conditions on a novel test set. The best performance could be achieved with both ICA and Kalman filtering relative to no processing: Platform Off (83.4% vs. 78.3%), Platform On (73.1% vs. 71.6%), Biplane Engine Off (81.1% vs. 77.4%), and Biplane Engine On (79.2% vs. 66.1%). This experiment demonstrates that dry-wireless EEG can be used in environments with considerable vibration, wind, acoustic noise, and physiological artifacts and achieve good single trial classification performance that is necessary for future successful application of neuro-augmentation technology based on brain-machine interfaces.

The UK’s wet and stormy winter of 2013/2014

The <scp>UK</scp>’s wet and stormy winter of 2013/2014

Evaluation of Numerical Modeling Methods for the Management of Produced Water Discharges in the Coastal Region with a Canadian Case Study

This study aims at evaluating two numerical methods for 3D simulation of marine pollutant dispersion problems: the random walk particle tracking (RWPT) method and an explicit second-order finite difference method (FDM) for assessing produced water discharges from offshore oil platform. Test cases in a steady flow field were used to evaluate the efficiency and accuracy of simulating pollutant concentration profiles obtained using both the FDM and RWPT method in comparison with an analytical solution. Additionally, a field study was conducted to simulate the lead concentration distribution of produced water discharged from an oil platform off Canada’s east coast, based on the Princeton Ocean Model modeling the ocean flow in the study area with field verifications. Results indicate that, with proper configuration of grid resolution and particle resolution, both FDM and RWPT method can provide accurate results with reasonable computational costs for complex field cases. Particularly, the satisfactory 3D simulations of marine pollutant dispersion in the far field by both FDM and RWPT numerical methods enable effective assessment and management of offshore waste discharges.

Evidence that the Deepwater Horizon Oil Spill Caused a Change in the Nickel, Chromium, and Lead Average Seasonal Concentrations Occurring in Sea Bottom Sediment Collected from the Eastern Gulf of Mexico Continental Shelf Between the Years 2009 and 2011

Preliminary analysis indicates a change with time in nickel (Ni), chromium (Cr), and lead (Pb) concentrations in sea bottom sediment samples which were collected during the falls of 2009, 2010, and 2011 along the continental shelf of the Eastern Gulf of Mexico. These samples bracket the Deepwater Horizon Oil Spill which occurred during the spring and summer of 2010. The sea bottom samples were collected as part of the recurring NOAA small pelagics survey of the continental shelf from Texas to Florida. A Shipek grab sampler was used to retrieve 37 sediment samples from the upper 15 cm of the sea bottom for analysis from the carbonate platform off of the west coast of Florida and relict sand off of the coast of Alabama. The samples were analyzed for six trace metals, Ni, Cr, Pb, vanadium (V), thallium (Tl), and mercury (Hg). The silt/clay fraction of the sediment had the highest adsorption affinity for Ni, Pb, and Tl metals relative to V, Cr, and Hg. A comparative analysis of the trace metal concentrations indicates that there is a statistically significant (at p < 0.05 or p < 0.01) increase in Ni, Cr, and Pb concentrations in sea bottom sediment 3 months after the oil spill. One year later, however, the 2011 samples indicate that Ni, Cr, and Pb significantly decreased (at p < 0.05 or p < 0.01) in comparison to 2010. Vanadium did not statistically change from 2009 to 2011. Crude oil is known to contain V and Ni, and the V–Ni ratio (V/V+Ni) has been used as a fingerprint for the Macondo crude oil source. The V–Ni ratios for the sediment sampling years 2009, 2010, and 2011 were 0.52, 0.46, and 0.57, respectively. In this study, approximately 1 year and 3 months after the oil spill, there is evidence, such as the V–Ni ratio, that trace metal concentrations in sea bottom sediment are approaching pre-spill levels. We conclude these differences in Ni concentrations, and the V–Ni ratios are an effective means of monitoring the impact of an oil spill and the use of dispersants to alleviate the spill impact.

Efeito agudo dos extensores do joelho unilateral na cadeira extensora com e sem estímulos na plataforma vibratória

INTRODUÇÃO: Nos últimos anos muitos estudos foram feitos com o objetivo de avaliar a utilização da vibração mecânica como parte de treinamento para melhora do condicionamento físico. Entretanto, a maioria avaliou os efeitos dos exercícios em conjunto com o treinamento vibratório para determinar se havia melhora após o treinamento, sem avaliar os efeitos dos exercícios realizados na plataforma com e sem vibração. OBJETIVO: Avaliar o efeito agudo do exercício nos extensores do joelho, com e sem o estímulo da plataforma vibratória. MÉTODOS: Trinta indivíduos ativos, do sexo masculino, com idades entre 18 e 45 anos, realizaram, de forma randomizada, três protocolos: grupo plataforma ligada (GPL), grupo plataforma desligada (GPD) e grupo controle (GC). Cada protocolo começava com aquecimento de cinco minutos em bicicleta ergométrica, com carga entre 75 e 100 watts e 70 rotações por minuto, seguido por seis séries de 10 movimentos de agachamento unilateral com intervalo de um minuto entre elas, com ou sem vibração mecânica, e terminava com o Work Test, realizado apenas no membro inferior dominante para determinação das valências físicas: trabalho, força, potência e velocidade. O grupo controle realizou apenas o Work Test após o aquecimento. RESULTADOS: Apenas a variável velocidade apresentou diferença estatisticamente significante (p &lt; 0,05) quando comparado o GPL ao GC. CONCLUSÃO: O estímulo na plataforma vibratória não exerceu influência nas variáveis trabalho e potência dos extensores do joelho unilateral, mas, na velocidade do movimento, exerceu influência negativa causando fadiga.

IMPACT OF OIL EXPLORATION AND EXPLOITATION ON THE NIGER DELTA REGION: ENVIRONMENTAL PERSPECTIVE

Since the discovery of oil in Nigeria in 1956, the country has been suffering the negative environmental consequences of oil exploration and exploitation. Between 1976 and 1996 a total of 4647 incidents resulted in the spill of approximately 2,369,470 barrels of oil into the environment. In addition, between 1997 and 2001, Nigeria also recorded a total number of 2,097 oil spill incidents. In 1998, 40,000 barrels of oil from Mobil platform off the Akwa Ibom coast were split into the environment causing severe damage to the coastal environment. Several oil spill management policy and efforts are in place to reduce the menace of oil spill incidents in the country. Some of these policies and efforts were made by the Federal Government, Non governmental agencies and oil firms in the country. The use of oil trajectory and fat e-models is also incorporated in oil spill management policy in the country. The results from a hypothetical simulation with the model from a point around OPL 250 located about 150km off the Nigerian coastline shows that the simulated oil spill for wet season reached the shore around Penington River after 104hours, about 4.5 days. Also during the dry season, the results from the model indicate that the oil spill reached the shore at the entrance of Benin River after 162 hours, 6.5days. This paper examines the impact of oil exploration and exploitation which encompasses environmental degradation, social annihilation, and economic impoverishment in the Nigeria’s Niger-Delta and the emerging socio-economic multiplier effects on the people of the region. The study employed tables and as well as percentages forms of statistical analysis. Data for the study were mainly secondary sources extracted from the National Bureau of Statistics (NBS) and the United Nations Development Programmes report. The study revealed that the emerging social disorder and HIV/AIDS prevalence in the region is as a result of the social and economic multiplier effects such as unemployment and high level of poverty. The study then recommends an integrated community based approach involving commitment from all stakeholders.

PSEUDOCODIUM MUCRONATUM, A NEW SPECIES FROM NEW CALEDONIA, AND AN ANALYSIS OF THE EVOLUTION OF CLIMATIC PREFERENCES IN THE GENUS (BRYOPSIDALES, CHLOROPHYTA)(1).

A new species, Pseudocodium mucronatum, is described from the Chesterfield platform off the west coast of New Caledonia. The species differs from its congeners in having mucronate utricules. A phylogenetic analysis of rbcL and tufA sequences showed that P. mucronatum is most closely associated with P. natalense De Clerck, Coppejans et Verbruggen and P. devriesii Weber Bosse, with which it shares compressed axes, depressed apices, and plastids in the utricles and the medullar siphons. We studied the evolution of climatic and ecological preferences in the genus using an interdisciplinary approach consisting of relaxed molecular clock analysis, extraction of macroecological data from satellite imagery in a geographic information system (GIS) framework, and ancestral character state estimation. It was shown that the genus originated in tropical waters during the Early Mesozoic. Whereas the P. floridanum-okinawense lineage remained tropical, the lineage including P. natalense, P. devriesii, and P. mucronatum gradually invaded more temperate waters during Cenozoic times. Except for P. devriesii, which occurs in shallow and intertidal habitats, all Pseudocodium species grow in deep-water habitats, and this ecological preference appears to be ancestral.