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The digital urban frontier : disparities in social media activity between consolidated and newly urbanized areas in Africa
No full textImproved murine model for the intravital microscopic examination of manifest tumors
No full textAnimal models are essential for studying tumor pathophysiology; however, most lack the capacity for repeated in vivo observation of tumor growth and vascularization over extended periods. This study aimed to establish a novel in vivo model using the mouse dorsal skinfold chamber. Tumor induction was performed using different membrane types (two polytetrafluoroethylene meshes and a polydioxanone plate), followed by monitoring of tumor vascularization via intravital fluorescence microscopy (IVM). Tumors developed successfully over six weeks, demonstrating sustained vascular supply and enabling, for the first time, the investigation of vascular networks in advanced tumors. Among the membranes tested, the polydioxanone membrane facilitated easier chamber preparation but may negatively affect angiogenesis and promote inflammation. IVM revealed persistent microcirculation in manifested tumors over six consecutive days, allowing detailed assessment of microvascular parameters, leukocyte–endothelial interactions, and functional capillary density. This model enables repetitive, high-resolution visualization of tumor microcirculation dynamics in vivo. In conclusion, this improved mouse dorsal skinfold chamber combined with IVM provides a powerful tool for investigating tumor angiogenesis and evaluating therapeutic interventions in advanced tumors
Recombination velocities at grain boundaries in solar-cell absorbers : revisited
No full textThe present work revisits the recombination velocities (sGB) of minority-charge carriers determined at grain boundaries in polycrystalline
absorber materials for solar cells. The equations describing sGB as well as the barriers for electrons and holes were derived. It is shown that
for given net-doping density and absolute temperature, the experimentally determined recombination velocity of a specific grain boundary
can be described by sGB ¼ sn
GB,0 exp ΦGB(NGB,charge)=(kBT)
, where ΦGB is the band bending induced by the excess-charge density
NGB,charge at the grain boundary, and kB as well as T are the Boltzmann constant and the absolute temperature; i.e., sGB depends only on the
excess-charge density at this planar defect as well as on the prefactor sn
GB,0 describing the nonradiative recombination. Value ranges for these
two quantities can be determined for any measured sGB value. When analyzing sGB datasets acquired on various (Ag,Cu)(In,Ga)Se2 and
microcrystalline Si absorbers, it is apparent that both the excess-charge density and the prefactor sn
GB,0 remain within about the same orders
of magnitude for all grain boundaries analyzed in a specific absorber. The broad range of the recombination velocities over several orders of
magnitude indicates upward as well as downward band bending, and the band-bending values are on the order of several +10 meV for all
materials analyzed
A late Glacial and Holocene sugar biomarker-based δ18O paleoclimate record from the Afro-alpine Central Lake, Bale Mountains, Ethiopia
No full textThe Eastern African region is an amalgamation of complex climate systems nestled in contrasting topographic barriers. Although rift basins are prime targets for studying the climate of the past, high-altitude climate archives in the context of paleoclimate research also offer invaluable insight and have yet to be fully explored. Here, we present a 17 kyr hydroclimate history of the Afro-alpine (4121 m a.s.l) Central Lake using a δ18O record established by analyzing hemicellulose-derived sugar biomarkers. The sugar biomarker patterns with a dominance of fucose indicate the predominance of autochthonous sedimentary organic matter. Therefore, the oxygen isotopic variability of the sugar biomarkers in general and of fucose in particular (δ18Ofucose) reflects δ18Olake water being controlled by climatic conditions, particularly lake water 18O enrichment by evaporation. Our δ18Ofucose record from Central Lake indicates strong enrichment during the Late Glacial. Around 15 cal kyr BP, the onset of more humid climate marks the beginning of the African Humid Period (AHP) in the Bale Mountains. The AHP was interrupted by an arid period during the Late Glacial – Holocene transition roughly coinciding with the Younger Dryas (YD). After the YD, humid climatic conditions prevailed again until the Late Holocene when a gradual shift towards drier climate started. Our δ18Ofucose record and interpretation agree well with the findings from adjacent low-altitude archives of Eastern Africa, the Indian Ocean paleoclimate records and the Asian Monsoon Domain, which suggests region-wide hydro-climatic teleconnections
MLUH-E-106_3, Falco tinnunculus Linnaeus, 1758, eggshell
No full textInventory No.: MLUH-E-106_3, Object: eggshell, Species: Falco tinnunculus Linnaeus, 1758, Preservation: complete preservation, Locality_loc.: Neuroda, Locality today: Neuroda, Country: GermanyDate: ?, Collection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 192, Identification by: M. Schönwetter, Aquisition: 1905, Aquired from: M. Schönwette
MLUH-E-323_1, Aquila chrysaetos chrysaetos (Linnaeus, 1758), eggshell
No full textInventory No.: MLUH-E-323_1, Object: eggshell, Species: Aquila chrysaetos chrysaetos (Linnaeus, 1758), Preservation: complete preservation, Locality_loc.: Muonioniska; Lappland, Locality today: Muonio; Fjell-Lappland, Country: FinlandDate: 07/05/1883, Collection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 171, Identification by: M. Schönwetter, Aquisition: 1938, Aquired from: Berlin, ex Collection: ex. Coll. W. Lietz; ex. Coll. Berli
MLUH-E-128_3, Pandion haliaetus carolinensis (Gmelin, JF, 1788), eggshell
No full textInventory No.: MLUH-E-128_3, Object: eggshell, Species: Pandion haliaetus carolinensis (Gmelin, JF, 1788), Preservation: complete preservation, Locality_loc.: Little Tybee Chatham County Georgia, Locality today: Tybee Island, Country: USACollector_leg.: K. M. Purse, Date: 15/05/1906, Collection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 178, Identification by: M. Schönwetter, Aquisition: 1926, Aquired from: E. Short, ex Collection: ex. Coll. G. R. Rossignol Jr.; ex. Coll. K. M. Purs
MLUH-E-252_1, Buteo hemilasius Temminck and Schlegel, 1845, eggshell
No full textInventory No.: MLUH-E-252_1, Object: eggshell, Species: Buteo hemilasius Temminck and Schlegel, 1845, Preservation: complete preservation, Locality_loc.: Kojisara; Ostturkestan, Locality today: Xinjiang Uygur Autonomous Region, Country: ChinaDate: ?, Collection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 164, Identification by: M. Schönwetter, Aquisition: 1906, Aquired from: O. Bamberg, ex Collection: ex. Coll. O. Bamber
MLUH-E-174_1, Accipiter gentilis gentilis (Linnaeus, 1758), eggshell
No full textInventory No.: MLUH-E-174_1, Object: eggshell, Species: Accipiter gentilis gentilis (Linnaeus, 1758), Preservation: slight damage, Locality_loc.: Burgtonnaer Holz bei Gotha, Locality today: Burgtonna, Country: GermanyCollector_leg.: O. Martin, Date: 20/04/1912, Collection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 157, Identification by: M. Schönwetter, Aquisition: 1912, Aquired from: O. Martin, ex Collection: ex. Coll. O. Marti
MLUH-E-278_1, Aquila rapax vindhiana Franklin, 1831, eggshell
No full textInventory No.: MLUH-E-278_1, Object: eggshell, Species: Aquila rapax vindhiana Franklin, 1831, Preservation: heavy damage, Locality_loc.: Sikkim, Locality today: Sikkim, Country: IndiaDate: 10/04/1886, Collection_coll.: M. Schönwetter, published in Handbuch der Oologie, Schönwetter, Max: Vol. I, p. 172, Identification by: M. Schönwetter, Aquisition: 1909, Aquired from: M. Kuschel, ex Collection: ex. Coll. M. Kusche