Small rodent communities (Muridae) in Gabonese savannas: species diversity and biogeographical affinities

Mammalia ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Jean-François Mboumba ◽  
Maxime R. Hervé ◽  
Véronique Guyot ◽  
Frederic Ysnel

Abstract The study contributes to the knowledge of species composition and biogeographical affinities of savannas rodent in Gabon. Unlike small rodents in Gabonese forests, there is little data on the diversity of small rodents in Gabonese savannas. The diversity and distribution of rodent murid communities was studied in four different types of savanna in Gabon: Coastal Basin (South-West), Lopé/Okanda (in the Center), Batéké Plateaux (Southeastern) and Ngougnié/ N’yanga (in the South). A total of 428 individuals representing six species were captured over 11,920 trap nights. Trap success was highly variable (2.2–6.9 %). The most abundant species were Mus minutoides (69%) followed by Lemniscomys striatus (21.5%). Indices of species richness varied from 2 to 5 and diversity (Shannon and Weaver) was low in the four savannas with the highest value at Ngougnié/N’yanga (H′ = 1.2). Species distributions show that Gabonese savanna small rodents conform to four distribution types, with one species known from Zambesian savannas exhibiting austral affinities (Pelomys campanae: occurs in three southern savannas). This new information provides important insight into the biogeography of small rodents at a local and regional level. Moreover, the correspondence analysis highlighted an influence of local ecological factors on population abundance.

2007 ◽  
Vol 11 (1) ◽  
pp. 57 ◽  
Author(s):  
José Cimé-Pool ◽  
Silvia F. Hernández-Betancourt ◽  
Juan Chablé-Santos

Abstract. A small rodent species was studied in two agroecosystems from Yucatan: (1) a traditional cornfield and (2) an induced grassland. A total of 87 individuals of six species in two families (Heteromyidae y Cricetidae) were captured rendering an effort of  2,544 nights/trap. Heteromys gaumeri and Peromyscus yucatanicus were the most abundant species with 57.5% and 17.2% of total captures, respectively. Highest captures were recorded in the traditional cornfield and the highest species richness was obtained in the grassland. No significant differences in diversity were found between sites (p > 0.05). It seems that the cornfield plays an important role on both the diversity and population dynamics of small rodents because it presents the highest values in captures, density, recruitment, and in reproductive individuals. This may be related to a greater variety of cultivated plant species in this agroecosystem. Key words: Small mammals, rodents, Cornfield, Grassland, Yucatan, Mexico. Palabras clave: Pequeños mamíferos, roedores, milpa, pastizal, Yucatán, México.


Radiocarbon ◽  
2020 ◽  
Vol 62 (4) ◽  
pp. 989-999 ◽  
Author(s):  
Christopher Bronk Ramsey ◽  
Timothy J Heaton ◽  
Gordon Schlolaut ◽  
Richard A Staff ◽  
Charlotte L Bryant ◽  
...  

ABSTRACTTerrestrial plant macrofossils from the sedimentary record of Lake Suigetsu, Japan, provide the only quasi-continuous direct atmospheric record of radiocarbon (14C) covering the last 50 ka cal BP (Bronk Ramsey et al. 2012). Since then, new high precision data have become available on U-Th dated speleothems from Hulu Cave China, covering the same time range (Cheng et al. 2018). In addition, an updated varve-based chronology has also been published for the 2006 core from Lake Suigetsu (SG06) based on extended microscopic analysis of the sediments and improved algorithms for interpolation (Schlolaut et al. 2018). Here we reanalyze the radiocarbon dataset from Suigetsu based on the new varve counting information and the constraints imposed by the speleothem data. This enables the new information on the calendar age scale of the Suigetsu dataset to be used in the construction of the consensus IntCal calibration curve. Comparison of the speleothem and plant macrofossil records provides insight into the mechanisms underlying the incorporation of carbon into different types of record and the relative strengths of different types of archive for calibration purposes.


2021 ◽  
pp. 174804852199056
Author(s):  
Baruch Shomron ◽  
Amit Schejter

This study examines how media representations of Palestinian-Israeli politicians, can help community members realize their capabilities. The study’s database is comprised of 1,207 interviews conducted with Palestinian-Israeli politicians on news and current affairs programs on the three national television channels and the two national radio stations in Israel, for 24 months (2016-2017). We identified and analyzed the differences in the modes of representation between national and local Palestinian-Israeli politicians and between Palestinian-Israeli parliament members in the Joint List and Palestinian-Israeli parliament members in Zionist parties, all through the capabilities prism. In this study, we demonstrated how different types of Palestinian-Israeli politicians may potentially affect the realization of different political functions and capabilities. Analyzing political representations in the media through the theoretical framework of the ‘capabilities approach’ contributes to a more comprehensive insight into the roles the media can play promoting people’s wellbeing and human rights, relative to traditional media theories.


2021 ◽  
pp. 026975802110106
Author(s):  
Raoul Notté ◽  
E.R. Leukfeldt ◽  
Marijke Malsch

This article explores the impact of online crime victimisation. A literature review and 41 interviews – 19 with victims and 22 with experts – were carried out to gain insight into this. The interviews show that most impacts of online offences correspond to the impacts of traditional offline offences. There are also differences with offline crime victimisation. Several forms of impact seem to be specific to victims of online crime: the substantial scale and visibility of victimhood, victimisation that does not stop in time, the interwovenness of online and offline, and victim blaming. Victims suffer from double, triple or even quadruple hits; it is the accumulation of different types of impact, enforced by the limitlessness in time and space, which makes online crime victimisation so extremely invasive. Furthermore, the characteristics of online crime victimisation greatly complicate the fight against and prevention of online crime. Finally, the high prevalence of cybercrime victimisation combined with the severe impact of these crimes seems contradictory with public opinion – and associated moral judgments – on victims. Further research into the dominant public discourse on victimisation and how this affects the functioning of the police and victim support would be valuable.


Oecologia ◽  
2020 ◽  
Author(s):  
Harry P. Andreassen ◽  
Janne Sundell ◽  
Fraucke Ecke ◽  
Stefan Halle ◽  
Marko Haapakoski ◽  
...  

AbstractMost small rodent populations in the world have fascinating population dynamics. In the northern hemisphere, voles and lemmings tend to show population cycles with regular fluctuations in numbers. In the southern hemisphere, small rodents tend to have large amplitude outbreaks with less regular intervals. In the light of vast research and debate over almost a century, we here discuss the driving forces of these different rodent population dynamics. We highlight ten questions directly related to the various characteristics of relevant populations and ecosystems that still need to be answered. This overview is not intended as a complete list of questions but rather focuses on the most important issues that are essential for understanding the generality of small rodent population dynamics.


2020 ◽  
Vol 287 (1939) ◽  
pp. 20202127
Author(s):  
S. Hervías-Parejo ◽  
C. Tur ◽  
R. Heleno ◽  
M. Nogales ◽  
S. Timóteo ◽  
...  

Many vertebrate species act as both plant pollinators and seed-dispersers, thus interconnecting these processes, particularly on islands. Ecological multilayer networks are a powerful tool to explore interdependencies between processes; however, quantifying the links between species engaging in different types of interactions (i.e. inter-layer edges) remains a great challenge. Here, we empirically measured inter-layer edge weights by quantifying the role of individually marked birds as both pollinators and seed-dispersers of Galápagos plant species over an entire year. Although most species (80%) engaged in both functions, we show that only a small proportion of individuals actually linked the two processes, highlighting the need to further consider intra-specific variability in individuals' functional roles. Furthermore, we found a high variation among species in linking both processes, i.e. some species contribute more than others to the modular organization of the multilayer network. Small and abundant species are particularly important for the cohesion of pollinator seed-dispersal networks, demonstrating the interplay between species traits and neutral processes structuring natural communities.


1937 ◽  
Vol 74 (8) ◽  
pp. 337-359 ◽  
Author(s):  
C. T. Trechmann

1. The coral-rock commences nearly everywhere with a basal bed of varying thickness containing a fauna of pre-Pleistocene aspect among which the genus Haliotis (absent from these coasts at the present day), Pleurotomaria, Meiocardia, etc., are noticeable. This faunule may have lived at a depth of 700–1,000 feet.2. The supposition that the southerly anticlines are a later uplift than the main portion of Barbados is supported by the absence of ravines, and the presence of post-coral-rock beds which occur as coastal veneers at low altitudes, and in greater thickness in the south-east corner near Whitehaven.3. The south-east part of the island from Consett Point to Ragged Point has probably extended further seawards in comparatively recent times ; the series of converging faults and dislocations in the cliff sections suggest that the thrusts from the west or south-west may have been resisted by this part of the island.4. The relative claims of fault-scarping or marine erosion in production of the rising terraces is discussed ; and new information regarding the thickness of the coral-rock at sea-level from a boring is detailed.5. The finding of a faunule with Pliocene or possibly Miocene affinities at the base of the coral-rock puts the Oceanic series further back, into the Miocene.


1980 ◽  
Vol 60 (3) ◽  
pp. 541-548 ◽  
Author(s):  
M. SCHNITZER ◽  
D. A. HINDLE

Three humic and one fulvic acid were degraded by mild chemical oxidation with peracetic acid, with special emphasis on the effects of this type of oxidation on N-containing components. The different types of N that were considered were NH4+-N, amino acid-N, amino sugar-N, NO2−-N + NO3−-N, and by difference from total N, "unknown" N. The behaviour toward mild chemical oxidation of all four preparations was essentially similar: there were decreases in mino acid-N, amino sugar-N and "unknown" N, increases in NH4+-N, NO2−-N + NO3−-N with one material, and in N-gases. The "unknown" N was not inert. Between 16.6 and 59.1% of the latter appeared to be converted, as a result of mild chemical oxidation, to NH3 and N-gases which were expelled from the systems. The results presented provide an insight into what happens to N-containing humic components as a result of mild oxidation.


1981 ◽  
Vol 4 (1) ◽  
pp. 19-28 ◽  
Author(s):  
Magnús Pétursson

In modern Icelandic, spoken in the South, West, and North-West of Iceland, there is a phonemic opposition between voiced and voiceless nasals before stop consonants. For the present investigation the research instrument was the velograph. The purpose of the research was to investigate patterns of velar movement associated with each type of nasal consonants. The results show different types of velar movement organized according to two separate temporal patterns. For the voiceless nasals the movement of the velum is more rapid and begins earlier than for the voiced nasals. There are also significant differences in the nasalization of the preceding vowel according to whether the following nasal consonant is voiced or voiceless.


Author(s):  
Parisa Dehghani ◽  
Monireh Esameili Rad ◽  
Atefeh Zarepour ◽  
Ponnurengam Malliappan Sivakumar ◽  
Ali Zarrabi

: Diabetes mellitus (DM) is a type of chronic metabolic disease that has affected millions of people worldwide and is known with a defect in the amount of insulin secretion, insulin functions, or both. This deficiency leads to an increase in the amounts of glucose, which could be accompanied by long-term damages to other organs such as eyes, kidneys, heart, and nervous system. Thus, introducing an appropriate approach for diagnosis and treatment of different types of DM is the aim of several researches. By the emergence of nanotechnology and its application in medicine, new approaches were presented for these purposes. The object of this review article is to introduce different types of polymeric nanoparticles (PNPs), as one of the most important classes of nanoparticles, for diabetic management. To achieve this goal, at first, some of the conventional therapeutic and diagnostic methods of DM will be reviewed. Then, different types of PNPs, in two forms of natural and synthetic polymers with different properties, as a new method for DM treatment and diagnosis will be introduced. In the next section, the transport mechanisms of these types of nano-carriers across the epithelium, via paracellular and transcellular pathways will be explained. Finally, the clinical use of PNPs in the treatment and diagnosis of DM will be summarized. Based on the results of this literature review, PNPs could be considered one of the most promising methods for DM management.


Sign in / Sign up

Export Citation Format

Share Document