Morphological evolution of the murine rodent Paraethomys in response to climatic variations (Mio-Pleistocene of North Africa)

Paleobiology ◽  
1999 ◽  
Vol 25 (3) ◽  
pp. 369-382 ◽  
Author(s):  
Sabrina Renaud ◽  
Mouloud Benammi ◽  
Jean-Jacques Jaeger
Keyword(s):  
North Africa ◽  
Environmental Conditions ◽  
Morphological Evolution ◽  
Middle Pleistocene ◽  
Metabolic Adaptation ◽  
Subsequent Increase ◽  
Evolutionary Patterns ◽  
The North ◽  
Murine Rodent ◽  
Evolutionary Response

The North African murine rodent Paraethomys evolved as an anagenetic lineage from the late Miocene until its extinction in the late—middle Pleistocene. A Fourier analysis of the outlines of the first upper and lower molars of this rodent was used to quantify the evolutionary patterns of this lineage and to compare evolutionary patterns to the climatic record. Morphological evolution and long-term environmental variations are strongly correlated. A change in molar shape, which may be related to the development of a more grass-eating diet, corresponds to the global cooling beginning around 3 Ma and the subsequent increase in aridity in North Africa. Concurrently, size increased, which may be related to increased masticatory efficiency or to metabolic adaptation to the cooler environmental conditions according to Bergmann's rule. This adaptive response to changing environmental conditions corresponds to an acceleration of evolutionary rates in the lineage. The modalities of the evolutionary response in size and shape are probably controlled by intrinsic factors such as different genetic determinisms for both characters.

WTO SUCCESSOR TO GATT

1997 ◽  
Vol 14 (2) ◽  
pp. 172-187
Author(s):  
Arif Sultan
Keyword(s):  
North Africa ◽  
European Economic Community ◽  
Developed Countries ◽  
Economic Community ◽  
Land Area ◽  
The North ◽  
Muslim Countries ◽  
The Pacific ◽  
The World ◽  
The Developed Countries

Within a short span of time a number of economic blocs have emergedon the world horizon. In this race, all countriedeveloped, developingand underdeveloped-are included. Members of the North America FreeTrade Agreement (NAITA) and the European Economic Community(EEC) are primarily of the developed countries, while the EconomicCooperation Organization (ECO) and the Association of South EastAsian Nations (ASEAN) are of the developing and underdevelopedAsian countries.The developed countries are scrambling to create hegemonies throughthe General Agreement on Tariff and Trade (GATT). In these circumstances,economic cooperation among Muslim countries should be onthe top of their agenda.Muslim countries today constitute about one-third of the membershipof the United Nations. There are around 56 independentMuslim states with a population of around 800 million coveringabout 20 percent of the land area of the world. Stretchingbetween Atlantic and the Pacific Oceans, the Muslim Worldstraddles from North Africa to Indonesia, in two major Islamicblocs, they are concentrated in the heart of Africa to Indonesia,in two major blocs, they are concentrated in the heart of Africaand Asia and a smaller group in South and Southeast Asia.'GATT is a multilateral agreement on tariffs and trade establishing thecode of rules, regulations, and modalities regulating and operating internationaltrade. It also serves as a forum for discussions and negotiations ...

scholarly journals Identification and Characterization of the Most Common Genetic Variant Responsible for Acephalic Spermatozoa Syndrome in Men Originating from North Africa

2021 ◽  
Vol 22 (4) ◽  
pp. 2187
Author(s):  
Caroline Cazin ◽  
Yasmine Boumerdassi ◽  
Guillaume Martinez ◽  
Selima Fourati Ben Mustapha ◽  
Marjorie Whitfield ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
North Africa ◽  
Posterior Part ◽  
North African ◽  
The North ◽  
Transmission Electron ◽  
Variant Filtering ◽  
North African Population ◽  
Sperm Nuclei

Acephalic spermatozoa syndrome (ASS) is a rare but extremely severe type of teratozoospermia, defined by the presence of a majority of headless flagella and a minority of tail-less sperm heads in the ejaculate. Like the other severe monomorphic teratozoospermias, ASS has a strong genetic basis and is most often caused by bi-allelic variants in SUN5 (Sad1 and UNC84 domain-containing 5). Using whole exome sequencing (WES), we investigated a cohort of nine infertile subjects displaying ASS. These subjects were recruited in three centers located in France and Tunisia, but all originated from North Africa. Sperm from subjects carrying candidate genetic variants were subjected to immunofluorescence analysis and transmission electron microscopy. Moreover, fluorescent in situ hybridization (FISH) was performed on sperm nuclei to assess their chromosomal content. Variant filtering permitted us to identify the same SUN5 homozygous frameshift variant (c.211+1_211+2dup) in 7/9 individuals (78%). SUN5 encodes a protein localized on the posterior part of the nuclear envelope that is necessary for the attachment of the tail to the sperm head. Immunofluorescence assays performed on sperm cells from three mutated subjects revealed a total absence of SUN5, thus demonstrating the deleterious impact of the identified variant on protein expression. Transmission electron microscopy showed a conserved flagellar structure and a slightly decondensed chromatin. FISH did not highlight a higher rate of chromosome aneuploidy in spermatozoa from SUN5 patients compared to controls, indicating that intra-cytoplasmic sperm injection (ICSI) can be proposed for patients carrying the c.211+1_211+2dup variant. These results suggest that the identified SUN5 variant is the main cause of ASS in the North African population. Consequently, a simple and inexpensive genotyping of the 211+1_211+2dup variant could be beneficial for affected men of North African origin before resorting to more exhaustive genetic analyses.

A reinterpretation of Scottish ‘hummocky moraine’ and its significance for the deglaciation of the Scottish Highlands during the Younger Dryas or Loch Lomond Stadial

1993 ◽  
Vol 130 (3) ◽  
pp. 301-318 ◽  
Author(s):  
Matthew R. Bennett ◽  
Geoffrey S. Boulton
Keyword(s):  
Environmental Conditions ◽  
Field Survey ◽  
Spatial Scales ◽  
Younger Dryas ◽  
North West ◽  
Scottish Highlands ◽  
Ice Cap ◽  
The North ◽  
Loch Lomond

AbstractThe aim of this paper is to demonstrate that much of the ‘hummocky moraine’ present within the northern part of the LochLomond Readvance ice cap formerly situated in the North West Scottish Highlands may be interpreted as suites of ice-front moraines deposited during active decay. These landforms can be used to reconstruct ice cap decay, whichleads to important insights into the shrinking form of the ice cap and associated environmental conditions. Evidence has been collected from 10803 airphotographs and from detailed field survey. It is presented at three spatial scales.

scholarly journals Courage and Cowardice in the North African Campaign: The Eighth Army and Defeat in the Summer of 1942

2013 ◽  
Vol 20 (1) ◽  
pp. 99-122 ◽  
Author(s):  
Jonathan Fennell
Keyword(s):  
North Africa ◽  
The State ◽  
The Other ◽  
Human Dimension ◽  
North African ◽  
The North ◽  
High Level ◽  
Eighth Army

High rates of desertion and surrender during the battles in North Africa in the summer of 1942 were a major factor in Eighth Army’s poor combat performance. At the time, some suggested that these problems were symptomatic of a lack of courage or even of cowardice. There are two broad strands to the conceptualization of courage and cowardice. One focuses on the willingness of the person to fight; the other puts emphasis on how actions express an individual’s ability to cope with fear. Whichever conceptualization is used, high morale motivates the soldier to fight and shields the ordinary recruit from his fear, preventing it from overcoming him in battle. Where morale fails, the soldier is left demotivated and burdened with his terror and, therefore, and is therefore prone to desertion or surrender. Because it is extremely difficult to maintain morale at a continuously high level in an environment governed by chance and managed by humans, all soldiers can find themselves in situations where their actions may be judged as cowardly. Alternatively, if they are properly motivated to fight and prepared by the state and military to deal with the unavoidable fear of combat, all soldiers can be labelled courageous. Accordingly, emotive terms should be avoided when attempting to describe rationally explainable outcomes. The undoubtedly negative connotations attached to cowardice in battle and the positive ones attached to courage are, therefore, arguably unhelpful in understanding Eighth Army’s performance in the summer of 1942 and the human dimension in warfare more generally.

scholarly journals Magnetic Survey at the Roman Military Camp of el Benian in Mauretania Tingitana (Morocco): Results and Implications

2020 ◽  
Vol 13 (1) ◽  
pp. 28
Author(s):  
Francesco Martorella
Keyword(s):  
Roman Empire ◽  
North Africa ◽  
Geophysical Survey ◽  
Magnetic Survey ◽  
North East ◽  
The North ◽  
Military Camp ◽  
Building Activity ◽  
Economic Studies

The topic of military settlements and the role of troops in the northern provinces of North Africa during the age of the Roman Empire has recently gained a strong interest in historical, archaeological, epigraphical, and economic studies. In particular, at Mauretania Tingitana (in the north-east area of modern-day Morocco), the presence of numerous military camps in the Early and Later Roman Empire has now been assessed. In this framework, the present work deals with the geophysical survey, by means of magnetometry, at the site of el Benian, where the largest military camp is located. In particular, the magnetic survey has highlighted the organization of the camp, almost totally unknown previously. The result of the magnetic survey has confirmed intense building activity over the centuries and made it possible to identify and characterize the structures typical of a military field.

Meridional Tripole Mode of Winter Precipitation over the Arctic and Continental North Africa–Eurasia

2021 ◽  
pp. 1
Author(s):  
Xiaolin Liu ◽  
Jianhua Lu ◽  
Yimin Liu ◽  
Guoxiong Wu
Keyword(s):  
Time Series ◽  
North Africa ◽  
North Atlantic ◽  
Hadley Cell ◽  
The Arctic ◽  
Positive Phase ◽  
The North ◽  
Ferrel Cell ◽  
The North Atlantic ◽  
Westerly Jets

AbstractWintertime precipitation is vital to the growth of glaciers in the northern hemisphere. We find a tripole mode of precipitation (PTM), with each pole of the mode extending zonally over the eastern hemisphere roughly between 30°W and 120°E, and the positive/negative/positive structure for its positive phase extending meridionally from the Arctic to the continental North Africa–Eurasia. The large-scale dynamics associated with the PTM is explored. The positive phase of the PTM is associated with the negative while eastward-shifted phase of the North Atlantic Oscillation (NAO) and a zonal band of positive SST anomaly in the tropics, together with a narrowed Hadley cell and weakened Ferrel cell. While being north-eastward tilted and separated from their North Africa-Eurasia counterpart in the climatological mean, the upper-tropospheric westerly jets over the east Pacific and north Atlantic become extending zonally and shifting southward and hence form a circumpolar subtropical jet as a whole by connecting with the westerly jets over the North Africa-Eurasia. The enhanced zonal winds over the north Atlantic promote more synoptic-scale transient eddies which are waveguided by the jet streams. The polar vortex weakens and cold air dips southward from the North Pole. Further diagnosis of the E-vectors suggests that transient eddies have a positive feedback on the weakening of Ferrel cell. Opposite features are associated with the negative phase of the PTM. The reconstructed time series using multiple linear regression on the NAO index and the tropical SST averaged over 20°S– 20°N, can explain 62.4% of the variance of the original the original precipitation time series.

scholarly journals The North African “Extremistan” of the Islamic State Caliphate

2016 ◽  
Vol 22 (1) ◽  
pp. 10-13
Author(s):  
Adrian Cosmin Basarabă ◽  
Maria-Mihaela Nistor
Keyword(s):  
Middle East ◽  
Real Estate ◽  
North Africa ◽  
Islamic State ◽  
North African ◽  
Boko Haram ◽  
Ongoing Process ◽  
The North ◽  
Terrorist Groups ◽  
Cellular Matrices

Abstract This article aims at presenting ISIS expansion in North Africa in the first quarter of 2016, with its subsequent implication in the wider framework of Jihadist proliferation worldwide. It can be argued that, while losing real estate in the Middle East, ISIS has started a permanent search for extra-cellular matrices or an ongoing process of de- and reterritorialization. The allegiance and support pledged by other African-based terrorist groups or organizations such as Boko Haram, al-I’tisam of the Koran and Sunnah in Sudan, al-Huda Battalion in Maghreb of Islam, The Soldiers of the Caliphate, al-Ghurabaa, Djamaat Houmat ad-Da’wa as-Salafiya and al-Ansar Battalion in Algeria, Islamic Youth Shura Council, Islamic State Libya (Darnah), in Libya, Jamaat Ansar Bait al-Maqdis, Jund al-Khilafah and Mujahideen Shura Council in the Environs of Jerusalem in Egypt, Okba Ibn Nafaa Battalion, Mujahideen of Tunisia of Kairouan and Jund al-Khilafah in Tunisia and al-Shabaab Jubba Region Cell Bashir Abu Numan in Somalia is an alarming hypothesis of Jihadism reaching “the threshold of inevitability”- syntagm existent in the network theories of David Singh Grewal- turning a whole region, continent of even world into what Nassim Nicholas Taleb would call Extremistan.

scholarly journals Variations in mid-latitude North Atlantic surface water properties during the mid-Brunhes (MIS 9–14) and their implications for the thermohaline circulation

2010 ◽  
Vol 6 (4) ◽  
pp. 531-552 ◽  
Author(s):  
A. H. L. Voelker ◽  
T. Rodrigues ◽  
K. Billups ◽  
D. Oppo ◽  
J. McManus ◽  
...  
Keyword(s):  
Surface Water ◽  
North Atlantic ◽  
Current System ◽  
Middle Pleistocene ◽  
Boundary Current ◽  
Upwelling System ◽  
The North ◽  
Eastern Boundary ◽  
Stable Conditions ◽  
Hydrographic Conditions

Abstract. Stable isotope and ice-rafted debris records from three core sites in the mid-latitude North Atlantic (IODP Site U1313, MD01-2446, MD03-2699) are combined with records of ODP Sites 1056/1058 and 980 to reconstruct hydrographic conditions during the middle Pleistocene spanning Marine Isotope Stages (MIS) 9–14 (300–540 ka). Core MD03-2699 is the first high-resolution mid-Brunhes record from the North Atlantic's eastern boundary upwelling system covering the complete MIS 11c interval and MIS 13. The array of sites reflect western and eastern basin boundary current as well as north to south transect sampling of subpolar and transitional water masses and allow the reconstruction of transport pathways in the upper limb of the North Atlantic's circulation. Hydrographic conditions in the surface and deep ocean during peak interglacial MIS 9 and 11 were similar among all the sites with relative stable conditions and confirm prolonged warmth during MIS 11c also for the mid-latitudes. Sea surface temperature (SST) reconstructions further reveal that in the mid-latitude North Atlantic MIS 11c is associated with two plateaus, the younger one of which is slightly warmer. Enhanced subsurface northward heat transport in the eastern boundary current system, especially during early MIS 11c, is denoted by the presence of tropical planktic foraminifer species and raises the question how strongly it impacted the Portuguese upwelling system. Deep water ventilation at the onset of MIS 11c significantly preceded surface water ventilation. Although MIS 13 was generally colder and more variable than the younger interglacials the surface water circulation scheme was the same. The greatest differences between the sites existed during the glacial inceptions and glacials. Then a north – south trending hydrographic front separated the nearshore and offshore waters off Portugal. While offshore waters originated from the North Atlantic Current as indicated by the similarities between the records of IODP Site U1313, ODP Site 980 and MD01-2446, nearshore waters as recorded in core MD03-2699 derived from the Azores Current and thus the subtropical gyre. Except for MIS 12, Azores Current influence seems to be related to eastern boundary system dynamics and not to changes in the Atlantic overturning circulation.

scholarly journals Berber Factor in North Africa: Common Features and Local Peculiarities

2017 ◽  
pp. 42-51
Author(s):  
Yu. Zinin
Keyword(s):  
North Africa ◽  
Arab Spring ◽  
Local Conditions ◽  
Common Features ◽  
Political Processes ◽  
The North ◽  
The Arab Spring ◽  
The Impact

The article considers a place and influence of Berber-speaking communities in each of five countries of the North Africa: Algeria, Morocco, Libya, Mauritania and Tunis.After gaining the independence, demands are growing in all these states to recognize cultural, regional, and sometimes political peculiarities of Berbers.The situation in every country is different due to local conditions and background of interactions of Amazigs (self-designation of Berber) with the Arab speaking majority, as well as their participation in political processes.The author investigates and discuss the impact of the Arab Spring on the rise of self-consciousness, solidarity and consolidation of Amazig minority. It is Berber, often European educated elite which usually expresses and propagates such conceptions and trends.

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