Fe-rich pentlandite in Allende bulk samples and separates: Mössbauer spectroscopy analysis.

Published versio

Ferric ion phases in Mössbauer spectra of “oxidized” and “reduced” CV3 chondrites.

Accepted versio

Effects of meteorological factors on epidemic malaria in Ethiopia: a statistical modelling approach based on theoretical reasoning.

This study was conducted to quantify the association between meteorological variables and incidence of Plasmodium falciparum in areas with unstable malaria transmission in Ethiopia. We used morbidity data pertaining to microscopically confirmed cases reported from 35 sites throughout Ethiopia over a period of approximately 6-7 years. A model was developed reflecting biological relationships between meteorological and morbidity variables. A model that included rainfall 2 and 3 months earlier, mean minimum temperature of the previous month and P. falciparum case incidence during the previous month was fitted to morbidity data from the various areas. The model produced similar percentages of over-estimation (19.7% of predictions exceeded twice the observed values) and under-estimation (18.6%, were less than half the observed values). Inclusion of maximum temperature did not improve the model. The model performed better in areas with relatively high or low incidence (>85% of the total variance explained) than those with moderate incidence (55-85% of the total variance explained). The study indicated that a dynamic immunity mechanism is needed in a prediction model. The potential usefulness and drawbacks of the modelling approach in studying the weather-malaria relationship are discussed, including a need for mechanisms that can adequately handle temporal variations in immunity to malaria

Arresting gully formation in the Ethiopian highlands

Over the past five decades, gullying has been widespread and has become more severe in the Ethiopian highlands. Only in very few cases, rehabilitation of gullies has been successful in Ethiopia due to the high costs. The objective of this paper is to introduce cost effective measures to arrest gully formation. The research was conducted in the Debre-Mewi watershed located at 30 km south of Bahir Dar, Ethiopia. Gullying started in the 1980s following the clearance of indigenous vegetation and intensive agricultural cultivation, leading to an increase of surface and subsurface runoff from the hillside to the valley bottoms. Gully erosion rates were 10–20 times the measured upland soil losses. Water levels, measured with piezometers, showed that in the actively eroding sections, the water table was in general above the gully bottom and below it in the stabilized sections. In order to develop effective gully stabilizing measures, we tested and then applied the BSTEM and CONCEPT models for their applicability for Ethiopian conditions where active gully formation has been occurring. We found that the model predicted the location of slips and slumps well with the observed groundwater depth and vegetation characteristics. The validated models indicated that any gully rehabilitation project should first stabilize the head cuts. This can be achieved by regrading these head cuts to slope of 40 degrees and armoring it with rock. Head cuts will otherwise move uphill in time and destroy any improvements. To stabilize side walls in areas with seeps, grass will be effective in shallow gullies, while deeper gullies require reshaping of the gullies walls, then planting the gully with grasses, eucalyptus or fruit trees that can be used for income generation. Only then there is an incentive for local farmers to maintain the structures

Phylogenetic Relationships Among Four Western Atlantic Cynoscion Species Based on DNA Sequences From 11 Nuclear Introns, Two Mitochondrial Genes, and Genotypes From 32 Microsatellite Markers

Four species of Cynoscion occur in the waters off the Atlantic and Gulf coasts of North America, where they are targeted by commercial and recreational fisheries. Previous studies have not resolved the phylogenetic relationships of the four species, largely due to uncertainty as to whether the spotted seatrout, Cynoscion nebulosus, or silver seatrout, Cynoscion nothus, is the most divergent member of the North American assemblage. This study used DNA sequences from the nuclear and mitochondrial genes and multilocus genotypes from microsatellite markers to infer relationships among these species. Together, these three techniques strongly suggest that the weakfish, Cynoscion regalis, and the sand seatrout, Cynoscion arenarius, are the most closely related species, and that C. nothus is the most divergent from all the others

Intel HEXL: Accelerating Homomorphic Encryption with Intel AVX512-IFMA52

Modern implementations of homomorphic encryption (HE) rely heavily on polynomial arithmetic over a finite field. This is particularly true of the CKKS, BFV, and BGV HE schemes. Two of the biggest performance bottlenecks in HE primitives and applications are polynomial modular multiplication and the forward and inverse number-theoretic transform (NTT). Here, we introduce Intel Homomorphic Encryption Acceleration Library (Intel HEXL), a C++ library which provides optimized implementations of polynomial arithmetic for Intel processors. Intel HEXL takes advantage of the recent Intel Advanced Vector Extensions 512 (Intel AVX512) instruction set to provide state-of-the-art implementations of the NTT and modular multiplication. On the forward and inverse NTT, Intel HEXL provides up to 7.2x and 6.7x speedup, respectively, over a native C++ implementation. Intel HEXL also provides up to 6.0x speedup on the element-wise vector-vector modular multiplication, and 1.7x speedup on the element-wise vector-scalar modular multiplication. Intel HEXL is available open-source at https://github.com/intel/hexl under the Apache 2.0 license and has been adopted by the Microsoft SEAL and PALISADE homomorphic encryption libraries

Development of microsatellite markers for Permit (Trachinotus falcatus), cross-amplification in Florida Pompano (T. carolinus) and Palometa (T. goodei), and species delineation using microsatellite markers

Three of the 20 species in the genus Trachinotus, in the jack family, Carangidae, are found in Florida waters. These are Florida Pompano (T. carolinus), Permit (T. falcatus), and Palometa (T. goodei). Florida Pompano is a coastal pelagic species found in estuarine and marine waters; it spawns in multiple batches in offshore waters. Permit is the largest and longest lived of the three species and also spawns offshore in multiple batches, near reefs. As adults, Permit can be found nearshore and offshore and are often associated with reefs, but as juveniles they are common estuarine inhabitants. Palometa is a marine species, similar in size to Florida Pompano, and has the widest latitudinal distribution of the three species. Palometa spawn in offshore waters throughout the year with two peaks of activity. All three species support commercial or recreational fisheries on both the Gulf of Mexico coast and Atlantic coast of Florida. Very little has been done to evaluate movement patterns of Trachinotus species. Based on a few tagging studies, it appears that Pompano do not travel far from coastal waters. The only preliminary investigation of genetic stock structure for the Florida Pompano population from Tampa Bay, FL, and Puerto Rico was based on microsatellite markers developed for the Pompano. The report’s key conclusion was that Pompano from Puerto Rico and from Florida belong to two highly distinct genetic stocks. This study was conducted to re-examine, using different microsatellite markers, the genetic status of Pompano stocks in Florida and Puerto Rico. The objectives of this study, therefore, were the following: 1) to develop microsatellite markers for Permit; 2) to cross-amplify the markers in Pompano and Palometa; and 3) to use these markers to confirm the status of Puerto Rico Pompano as a novel genetic stock using the methods of Bayesian population assignment, phylogenetic clustering, and factorial correspondence analysis. ... Three methods were used to investigate the relationship among the taxa using the microsatellite genotype data obtained from the samples. The results from the three analytical methods, based on Bayesian population assignment tests, phylogenetic clustering, and factorial correspondence analysis of genetic relationships among the four Trachinotus samples, showed that Florida and Puerto Rico Pompano samples belong to two highly distinct gene pools. But other multiple molecular tools, particularly nuclear-DNA sequences from many introns, and nonmolecular tools, such as morphological and meristic data, should be used together to determine species-level categorical designation for the Puerto Rico Pompano

Study Of Mechanical Alloying Of Sm And Fe

Mechanical alloying of Sm and Fe with the composition of SmFe3 was studied using x-ray-diffraction (XRD), Mossbauer, and magnetization measurements. Data taken as a function of milling time for up to 20 h show significant changes occurring during ball milling. The XRD studies show that the initial crystalline Bragg reflections changed to a broad maximum, which is attributed to the formation of an amorphous phase. The initial six-line pattern in the Mossbauer spectrum, characteristic of magnetic ordering, changed to a broad singlet, characteristic of a nonmagnetic material. Magnetization measurements revealed that the coercive field was at its maximum after 5 h of milling and decreased sharply as the milling time increased. The remanent magnetization was at its maximum between 5 and 10 h of milling. The final product of the ball milling, which exhibited the characteristics of an amorphous paramagnetic material in its XRD and Mossbauer spectrum, was studied after heat treatment. The XRD and the Mossbauer spectra of the heat treated alloy show that substantial changes occurred during heat treatment in that sharp Bragg reflections, characteristic of crystalline materials, reappear and the alloy changed from a paramagnetic to a ferromagnetic state. (C) 1997 American Institute of Physics

Impact of Soil Conservation and Eucalyptus on Hydrology and Soil Loss in the Ethiopian Highlands

The Ethiopian highlands suffer from severe land degradation, including erosion. In response, the Ethiopian government has implemented soil and water conservation practices (SWCPs). At the same time, due to its economic value, the acreage of eucalyptus has expanded, with croplands and pastures converted to eucalyptus plantations. The impact of these changes on soil loss has not been investigated experimentally. The objective of this study, therefore, is to examine the impacts of these changes on stream discharge and sediment load in a sub-humid watershed. The study covers a nine-year period that included installation of SWCPs, a three-fold increase from 1.5 ha in 2010 to 5 ha in 2018 in eucalyptus, and the upgrading of an unpaved to the paved road. Precipitation, runoff, and sediment concentration were monitored by installing weirs at the outlets of the main and four nested watersheds. A total of 867 storm events were collected in the nine years. Runoff and sediment concentration decreased by more than half in nine years. In the main watershed W5, we estimated that evapotranspiration by eucalyptus during the dry phase (November to May) increased approximately from 30 mm a−1 in 2010 to 100 mm a−1 in 2018. In watershed W3 it increased from 2 mm a−1 to 400 mm a−1, requiring more rainfall before saturation excess runoff began in the rain phase. The reduction in runoff led to a decreased sediment load from 70 Mg ha−1 a−1 in 2010 to 2.8 Mg ha−1 a−1 in 2018, though the reduction in discharge may have negative impacts on ecology and downstream water resources. SWCPs became sediment-filled and minimally effective by 2018. This indicates that these techniques are either inappropriate for this sub-humid watershed or require improved design and maintenance