The ultimate arc: Differential displacement, oroclinal bending, and vertical axis rotation in the External Betic-Rif arc

The External Betic-Rif arc, which lies between the converging African and Iberian plates, is one of the tightest orogenic arcs on Earth. It is a thin-skinned fold and thrust belt formed in Miocene time around the periphery of the Alborán Domain, an older contractional orogen that underwent extensional collapse coevally with the formation of the thrust belt. Restoration of four sections across the thrust belt, together with kinematic and paleomagnetic analysis, allows a reconstruction of the prethrusting geometry of the Alborán Domain, and the identification of the following processes that contributed to the formation of the arc: (1) The Alborán Domain moved some 250 km westward relative to Iberia and Africa during the Miocene. This initiated the two limbs of the arc on its NW and SW margins, closing to the WSW in the region of Cherafat in northern Morocco. The overall convergence direction on the Iberian side of the arc was between 310° and 295°, and on the African side it was between 235° and 215°. The difference in convergence direction between the two sectors was primarily a result of the relative motion between Africa and Iberia. (2) Extensional collapse of the Alborán Domain during the Miocene modified the geometry of the western end of the arc: the Internal Rif rotated anticlockwise to form the present north trending sector of the arc, and additional components of displacement produced by extension were transferred into the external thrust belt along a series of strike-slip faults and shear zones. These allowed the limbs of the arc to rotate and extend, tightening the arc, and creating variations in the amounts and directions of shortening around the arc. The Betic sector of the arc rotated clockwise by 25° during this process, and the southern Rif rotated anticlockwise by ∼55°. (3) Oblique convergence on the two limbs of the arc, dextral in the Betics and sinistral in the southern Rif, resulted in strongly noncoaxial deformation. This had three related effects: (1) large rotations of individual thrust sheets resulted from the oblique propagation of thrusts away from the thrust front, followed by pinning and rotation as the thrust sheets peeled off, (2) continued oblique convergence resulted in distributed shear, particularly in the rear of the thrust wedge, causing rotation of stacks of thrust sheets on the scale of a few tens of kilometers, and (3) distributed shear in the orogen resulted in the rotation of folds as they amplified, the hinges migrating through the rock body, and rotating at a slower rate than the rock. These rotations were substantially larger than the bulk rotations of the limbs of the arc, and they strongly modified the orientations of folds, thrust traces, and the structural indicators of fault slip directions

Primary umbilical endometrioma: Analyzing the pathogenesis of endometriosis from an unusual localization

Objective: This report presents a rare case of symptomatic primary umbilical endometriosis and reviews the literature on the topic with the aim to clarify some questions on the origin of endometriosis. Case Report: A 33-year-old woman with cyclic umbilical bleeding was found to have umbilical endometriosis. She had no history of pelvic or abdominal surgery. There was no past history of endometriosis or endometriosis-associated symptoms. An omphalectomy was performed after explorative laparoscopy to carefully inspect the abdominopelvic cavity and assess any coexisting pelvic endometriotic lesions. Histological examination confirmed the diagnosis of umbilical endometriosis. Conclusion: Umbilical endometriosis is a rare but under-recognized phenomenon. Primary lesions are difficult to recognize, but probably represent an independent nosological entity. The possibility of endometriosis must be considered during the evaluation of an umbilical mass despite the absence of previous surgery. Complete excision and successive histology are highly recommended

Climate Change Impacts on Shrimp Production at the South-West Coastal Region of Bangladesh

Abstract This study was conducted to investigate the changes of climate, salinity and their consequent impacts on shrimp production at Shyamnagar under Satkhira District, Bangladesh. An integrated technique was used including social survey, historical climate data, shrimp production data and field analysis. During 1980-2009, a statistically significant decreasing trend of annual average maximu m temperature but increasing trend of annual average minimu m temperature was found. Maximu m temperature exhibited significant decreasing trend in post-monsoon while, increasing trend in winter. The trend of minimu m temperature was increasing significantly in post monsoon. Significant increase in relat ive humidity trends were found in all seasons. Salin ity levels of the shrimp farm waters were found to exceed the threshold limits for proper shrimp production. Although the total production was increasin g, the rate of shrimp production was decreasing relative to total area of farms. No statistically significant relationships were found between the annual shrimp production and climatic parameters or salin ity levels. Depths of inundation at monsoon season exceeded 180 cm, on contrary, at dry season less than 30 cm which was not proper for shrimps. The surface water salinity ranged from 7-46 ppt making farm waters unsuitable for shrimp production. According to the GM (1,1) model, the production of shrimp was hampered by climat ic hazards, increasing inundations and salinity problems

Geologically constrained evolutionary geomechanical modelling of diapir and basin evolution: a case study from the Tarfaya basin, West African coast

We systematically incorporate burial history, sea floor geometry and tectonic loads from a sequential kinematic restoration model into a 2D evolutionary geomechanical model that simulates the formation of the Sandia salt diapir, Tarfaya basin, NW African Coast. We use a poro-elastoplastic description for the sediment behaviour and a viscoplastic description for the salt. Sedimentation is coupled with salt flow and regional shortening to determine the sediment porosity and strength and to capture the interaction between salt and sediments. We find that temporal and spatial variation in sedimentation rate is a key control on the kinematic evolution of the salt system. Incorporation of sedimentation rates from the kinematic restoration at a location east of Sandia leads to a final geomechanical model geometry very similar to that observed in seismic reflection data. We also find that changes in the variation of shortening rates can significantly affect the present-day stress state above salt. Overall, incorporating kinematic restoration data into evolutionary models provides insights into the key parameters that control the evolution of geologic systems. Furthermore, it enables more realistic evolutionary geomechanical models, which, in turn, provide insights into sediment stress and porosity

phosphorus and potassium fertilizer effects on alfalfa and soil in a non limited soil

Fertilization strategies for high-yielding alfalfa (Medicago sativa L.) should take in account the increase in soil nutritional status that occurred during the last decades in areas with intensive agricultural use. A field study was conducted at the University of Padova, northeastern Italy, to determine the response of alfalfa yield and nutritive value to various combinations of P and K rates in a soil lacking nutrient deficiency. Alfalfa cultivar Delta was seeded in March 2005 on a silt loam soil having 38 mg kg -1 available P and 178 mg kg -1 exchangeable K. Nine treatments deriving from the combination of three P fertilization rates (0, 100, and 200 kg ha -1 P 2 O 5 ) and three K rates (0, 300, and 600 kg ha -1 K 2 O) were compared in a randomized complete block design. Plots were harvested at bud stage during three growing seasons (2005-2007) and dry matter (DM) yield, forage nutritive value, P and K contents, canopy height, and stem density were measured at each harvest. Soil samples were collected at the end of the research period for determination of available P and exchangeable K. The results demonstrated that P application had no impact on yield and did not interact with K in determining productivity, while K had a positive effect on yield. However, the 300 kg ha -1 K 2 O rate appeared sufficient to maximize yield, without adverse effects on the forage nutritive value. Data from soil analyses showed that alfalfa has a high K uptake even when it is fertilized at high rates

Competing biosecurity and risk rationalities in the Chittagong poultry commodity chain, Bangladesh

This paper anthropologically explores how key actors in the Chittagong live bird trading network perceive biosecurity and risk in relation to avian influenza between production sites, market maker scenes and outlets. They pay attention to the past and the present, rather than the future, downplaying the need for strict risk management, as outbreaks have not been reported frequently for a number of years. This is analysed as ‘temporalities of risk perception regarding biosecurity’, through Black Swan theory, the idea that unexpected events with major effects are often inappropriately rationalized (Taleb in The Black Swan. The impact of the highly improbable, Random House, New York, 2007). This incorporates a sociocultural perspective on risk, emphasizing the contexts in which risk is understood, lived, embodied and experienced. Their risk calculation is explained in terms of social consent, practical intelligibility and convergence of constraints and motivation. The pragmatic and practical orientation towards risk stands in contrast to how risk is calculated in the avian influenza preparedness paradigm. It is argued that disease risk on the ground has become a normalized part of everyday business, as implied in Black Swan theory. Risk which is calculated retrospectively is unlikely to encourage investment in biosecurity and, thereby, points to the danger of unpredictable outlier events

Governance in the implementation of the UN sustainable development goals in higher education : global trends

Governance is a key component for implementing sustainable development (SD) initiatives in university teaching, research, and projects. This line of thinking also applies to implementing the United Nations (UN) sustainable development goals (SDGs). Despite the role of governance in guiding processes related to the SDGs, few studies have examined these relations in an integrative manner in higher education. To bridge this knowledge gap, this study assesses the connections between governance and implementing the SDGs at higher education institutions (HEIs). Specifically, it relies on two main methods. The first is a bibliometric analysis, where the literature on the topic has been analyzed. The second method uses case studies from a sample of universities. The combined dual approach has identified the extent to which governance issues influence how these organizations perceive and handle the SDGs. The study provides valuable recommendations that may assist HEIs in implementing the SDGs with a due emphasis on governance.peer-reviewe