Chemometric study on the forensic discrimination of soil types using their infrared spectral characteristics

Soil has been utilized in criminal investigations for some time because of its prevalence and transferability. It is usually the physical characteristics that are studied; however, the research carried out here aims to make use of the chemical profile of soil samples. The research we are presenting in this work used sieved (2 mm) soil samples taken from the top soil layer (about 10 cm) that were then analyzed using mid-infrared spectroscopy. The spectra obtained were pretreated and then input into two chemometric classification tools: nonlinear iterative partial least squares followed by linear discriminant analysis (NIPALS-LDA) and partial least squares discriminant analysis (PLS-DA). The models produced show that it is possible to discriminate between soil samples from different land use types and both approaches are comparable in performance. NIPALS-LDA performs much better than PLS-DA in classifying samples to location.     

Record of metal workshops in peat deposits: history and environmental impact on the Mont Lozère Massif, France

This study aims to document the history of the metallurgical activities on the Mont Lozère massif in the Cévennes Mountains in Southern France. Many medieval sites of metallurgical wastes (slags) have been reported on the massif. These sites are thought to represent ancient lead workshops. The impact of past metallurgical activity on the environment was studied using geochemical and palynological techniques on a core collected in the Narses Mortes peatland near medieval smelting area. Two main periods of smelting activities during the last 2200 years were revealed bythe lead concentration and isotopic composition along the core profile: the first period corresponds to the Gallic period (approximately ca. 300 B.C. to ca. 20 A.D.) and the second one to the Medieval period (approximately ca. 1000-1300 A.D.). Forest disturbances are associated with lead anomalies for the two metallurgical activities described. The impact of the first metallurgy was moderate during the Gallic period, during which beech and birch were the tree species most affected. The second period corresponds to the observed slag present in the field. Along with agropastoral activities, the medieval smelting activities led to the definitive disappearance of all tree species on the summit zones of Mont Lozère. The abundance of ore resources and the earlier presence of wood on the massif justify the presence of workshops at this place. The relationship between mines and ores has been documented for the Medieval period.There is no archaeological proof concerning the Gallic activity. Nevertheless, 2500-2100 years ago, the borders of the Gallic Tribe territory, named the Gabales, were the same as the present-day borders of the Lozère department. Julius Caesar reported the existence of this tribe in 58 B.C. in "De Bello Gallico", and in Strabon (Book IV, 2.2) the "Gabales silver" and a "treasure of Gabales" are mentioned, but to this day, they have not been found.     

Construction of an Optimal Sequential Plan for Testing a Treatment for an Adverse Effect

Abstract

Classical sequential procedures that collect a single observation at a time are often found impractical, expensive, and time consuming. Sequentially planned procedures, or simply sequential plans, extend and generalize the concepts of sequential analysis by allowing observations to be collected in groups of variable sizes. After every group, all of the previously collected data are used to determine the next course of action. An optimal (Bayes) sequential plan minimizes the (Bayes) risk function that combines the decision loss, observation (variable) cost, and group (fixed) cost. In general, determining the optimal sequential plan remains an open and challenging problem mainly because it requires risk optimization over a huge and rather unstructured set of all sequential plans. This article demonstrates how to obtain the optimal solution for a particular class of problems that may arise in testing a treatment for a rare but severe adverse effect. This solution is obtained by studying a number of properties of the Bayes sequential plan such as transitivity and monotonicity. This allows one to reduce the search to a small, manageable set of sequential plans within which the optimal plan can be calculated.     

Sequential Bonferroni Methods for Multiple Hypothesis Testing with Strong Control of Family-Wise Error Rates I and II

Abstract

Sequential procedures are developed for simultaneous testing of multiple hypotheses in sequential experiments. Proposed stopping rules and decision rules achieve strong control of both family-wise error rates I and II. The optimal procedure is sought that minimizes the expected sample size under these constraints. Bonferroni methods for multiple comparisons are extended to sequential setting and are shown to attain an approximately 50% reduction in the expected sample size compared with the earlier approaches. Asymptotically optimal procedures are derived under Pitman alternative.     

Impact of apple procyanidins on sensory perception in model cider (part 2): Degree of polymerization and interactions with the matrix components

The impact of the degree of polymerization (DP) of procyanidins and its interactions with fructose, acidity and alcohol in a model solution of cider was investigated. Four sensory characteristics (bitterness, astringency, sweetness and sourness) were studied. At 750 mg/L of procyanidins, the DP impacted astringency and bitterness but not sweetness or sourness. The medium DP (tetramer) of apple procyanidins was the most bitter and astringency increased with the DP. The impact of ethanol, fructose and acidity on the four sensory attributes was also examined. These results provide insights into how the components interact to produce the taste of cider.     

Effect of dry heating on the microbiological quality,functional properties,and natural bacteriostatic ability of egg white after reconstitution

Spray-dried egg white (powder) is widely used in the food industry because of its variety of functional properties and its practical advantages. Moreover, egg white powder is generally considered safe because it can withstand high temperatures that allow for the destruction of all pathogens, especially Salmonella. In France, two types of treatments are used to improve the functional properties (whipping and gelling) of dried egg white: standard storage at 67 degrees C for about 15 days and storage at 75 to 80 degrees C for 15 days. The objective of this study was to investigate the effects of two dry-heating treatments (storage at 67 and 75 degrees C for 15 days) on the subsequent ability of egg white to resist Salmonella growth after reconstitution. The impact on the endogenous microflora of the powder and on its functional properties was also considered. Both dry-heating treatments were efficient in destroying a large number of Salmonella. Dry heating at 75 degrees C affected the bacteriostatic ability of reconstituted egg white to a greater extent than did dry heating at 67 degrees C. This loss of bacteriostatic ability could be attributable to the thermal denaturation of ovotransferrin, resulting in a reduction in its activity as an iron chelator. However, dry heating at 75 degrees C resulted in improved functional properties. Ultimately, no complete compromise between better functional quality and the preservation of the bacteriostatic ability of egg white after reconstitution is possible. Our results underline the importance of the use of hygienic conditions with egg white powder, especially with powder subjected to high-temperature treatments.     

Electrical characteristics of a vertically integrated field-effect transistor using non-intentionally doped Si nanowires

In this paper, we report the fabrication and the electrical characterization of Vertical Gate All Around Field-Effect Transistors (GAA-FET) using nonintentionally doped Silicon NanoWires (SiNWs) grown by Chemical Vapour Deposition (CVD) using the Vapour-Liquid-Solid (VLS) mechanism as conduction channel. The SiNWs GAA-FET devices exhibited n-channel type semiconductor behaviour whereas the as-grown SiNW FET present p-type behaviour. This effect may be due to positive fixed charge located in the oxide shell or at the Si/SiO₂ interface. Moreover we show that the threshold voltage at room temperature is around −0.95 V, a high I_ON/I_OFF ratio up to 10⁶ with a low I_OFF current about 1 pA, a maximum transconductance (g_m,max ∼ 0.9 μS at V_GS = −0.65 V and V_DS = 1 V) and a minimum inverse subthreshold slope around 145 mV/decade. In light of these characteristics, these devices can be suitable for high performance, low power consumption components and especially for high density integration in integrated circuits (ICs) interconnections regarding to their 3D architecture.     

Study of CVD nanowire high-k metal interface quality for interconnect level MOS devices

We report a study of low temperature gate stack on silicon nanowires compatible with Back-End-Of-Line (BEOL) integration. The same gate stack is deposited at low temperature on Si nanowires obtained thanks to either Chemical Vapor Deposition (CVD) or Selective Epitaxial Growth (SEG) in patterns. Gate stack characterization on CVD nanowires (NWs) shows low leakages and good agreement with simulated curves without interface states. A dramatic decrease of the capacitance in accumulation region and faster electron generation are observed and attributed to NW defects. In contrast, SEG devices reveals lower capacitance decrease with frequency but higher interface state density of about 10¹³ cm⁻².     

Neuromotor outcomes at school age after extremely low birth weight: Early detection of subtle signs.

Objective: Motor impairments are prevalent in children born at extremely low birth weight (ELBW;     

Fiber Classification and the Influence of Average Air Humidity

The use of man-made vitreous fibers (MMVFs) as a substitute for asbestos in industrial and residential applications has raised the concerns of the potential hazards associated with inhalable aerosolized fibers. The complex movement of fiber makes it difficult to predict the pattern of fiber deposition in human airways from the behavior of spherical particles. Difficulties in producing monodisperse length fibers has been an obstacle to study fibrous particle deposition in the human respiratory system. To address this problem, a narrow length distribution of fibers was generated using dielectrophoretic classification. Dielectrophoresis is the motion of neutral matter in a nonuniform electric field due to an induced dipole moment. It is sensitive to the conductivity of the matter in the field. A fiber classifier has been used to study the influence of atmospheric humidity on the behavior of glass fibers. Glass fibers, as insulators, can not be classified by the dielectrophoretic classifier. However, our study shows that a humidity higher than 15% RH can change the conductivity of the glass fibers so as to permit their effective classification.