130,878 research outputs found
sfgallen/RICoTTa: RICoTTa
No full textRICoTTa - River Inversion Model using Cosmogenic Radionuclide, Marine Terrace, and Low-Temperature Thermochronological Data
Sean F. Gallen and Christoph Glotzbach
RICoTTa is a data-driven river profile inversion code originally developed by Glotzbach (2015). The version provided here is a modified version of the original code presented in Gallen et al. (2023). See the read me page on the associated GitHub repository for important information on the code as well as the two papers cited above.
This is a citable repository as Gallen and Glotzbach, 2023, RICoTTa v1.0, http://doi.org/10.5281/zenodo.7671209.
Note that the codes presented in this repository might be updated from time to time on the associated GitHub page linked here: https://github.com/sfgallen/RICoTTa
Code description and disclaimer:
This series of codes takes a suite of data sets (i.e., longitudinal river profiles, cosmogenic radionuclide concentrations, marine terrace rock uplift calculations, and low-temperature thermochronometric ages) and uses a Bayesian inversion to constrain rock uplift histories and parameters in the detachment-limited stream power model.
These codes are modified versions of the algorithm described in Glotzbach (2015). The version of the codes in this repository was applied in Gallen et al. (2023). Please see those references for details on the model.
The three example scripts provided will run an abbreviated simulation using the datasets in Gallen et al. (2023). Note that the data provided with the examples was prepared using SRTM digital elevation models and TopoToolbox v2 (Schwanghart and Scherler, 2014) and ChiProfiler (Gallen and Wegmann, 2017).
Disclaimer:
We strongly recommend that only expert Matlab users deeply familiar with the forward and inverse models used in this software modify the codes provided. We make this disclaimer because it is fairly easy to make mistakes that will inhibit the usefulness of the model results.
Furthermore, before attempting to apply these codes to another study area, it is important to make sure that a number of assumptions in the natural setting are met. These assumptions include, but are not limited to:
The catchment is an erosional, fluvially-dominated, bedrock system (i.e., no deposition, no evidence of past glaciation, and no alluvial rivers).
The catchment network has no obvious evidence of recent reorganization or unstable drainage divides (e.g., no evidence of recent river capture or strongly asymmetric drainage divides).
Erodibility is relatively uniform throughout the catchment (i.e., roughly uniform rock type, no strong precipitation gradients).
Rock uplift appears spatially uniform (i.e., no evidence of local or regional tilting and no active faults cutting the catchment).
The uplift and exhumation history can reasonably be approximated as one-dimentionsal in the vertical direction (i.e., no significantly horizontal tectonic velocities).
The catchments are not too large (no firm size threshold, but the larger the basin, the more likely the assumptions will be violated).
The outlet location is fixed with time.
Note that this is not a comprehensive list, but these are some of the assumptions that must be met for this code to be meaningfully applied to a given catchment.
For an example of working through a list of assumptions in conducting similar catchment-scale inversions, please see Gallen and Fernández-Blanco (2021).
If you use these codes of modified versions of these codes for scientific research, cite Glotzbach (2015) and Gallen et al. (2023). The code is also citable as a Zenodo repository as Gallen and Glotzbach, 2023, RICoTTA v1.0, http://doi.org/10.5281/zenodo.7671209.
References:
Gallen, S.F., Seymour, N.M., Glotzbach, C., Stockli, D.F., O'Sullivan, P., 2023, Calabrian forearc uplift paced by slab-mantle interactions during subduction retreat: Nature Geoscience. https://doi.org/10.1038/s41561-023-01185-4 [shareable link]
Gallen, S.F. and Fernández-Blanco, D., 2021, A New Data-driven Bayesian Inversion of Fluvial Topography Clarifies the Tectonic History of the Corinth Rift and Reveals a Channel Steepness Threshold: JGR-Earth Surface, v. 126, p. e2020JF005651. https://doi.org/10.1029/2020JF005651.
Gallen, S.F. and Wegmann, K.W., 2017, River profile response to fault growth and linkage: An example from the Hellenic forearc, south-central Crete, Greece: Earth Surface Dynamics, v. 5, p. 161-186. https://doi.org/10.5194/esurf-5-161-2017/
Schwanghart, W. and Scherler, D., 2014. TopoToolbox 2–MATLAB-based software for topographic analysis and modeling in Earth surface sciences. Earth Surface Dynamics, 2(1), pp.1-7. https://doi.org/10.5194/esurf-2-1-2014
Glotzbach, C., 2015. Deriving rock uplift histories from data-driven inversion of river profiles: Geology, 43(6), pp.467-470. https://doi.org/10.1130/G36702.
Measuring taxonomic diversity with parametric information functions
No full textThis paper discusses the measurement of taxonomic diversity of a given community or set of species. First, given D, the matrix of pairwise distances between species, I propose to summarize taxonomic diversity through Rényi's information-theoretical parametric formalism on D. In this way, a family of taxonomic diversity indices is obtained which shows different sensitivity to the presence of species with different levels of taxonomic distinctness. The adequacy of information-theoretical indices for quantifying taxonomic diversity is discussed
Using satellite imagery to assess plant species richness: The role of multispectral systems
No full textQuestion: The use of variations in the spectral responses of remotely sensed images was recently proposed as an indicator of plant species richness (Spectral Variation Hypothesis, SVH). In this paper we addressed the issue of the potential use of multispectral sensors by testing the hypothesis that only some of the bands recorded in a remotely sensed image contain information related to the variation in species richness.Location: Montepulciano Lake, central Italy.Methods: We assessed how data compression techniques, such as Principal Component Analysis (PCA), influence the relationship between spectral heterogeneity and species richness and evaluated which spectral interval is the most adequate for predicting species richness by means of linear regression analysis. Results: The original multispectral data set and the first two non-standardized principal components can both be used as predictors of plant species richness (R2 0.48; p < 0.001), confirming that PCA is an effective tool for compressing multispectral data without loss of information. Using single spectral bands, the near infrared band explained 41% of variance in species richness (p < 0.01), while the visible wavelengths had much lower prediction powers. Conclusions: The potential of satellite data for estimating species richness is likely to be due to the near infrared bands, rather than to the visible bands, which share highly redundant information. Since optimal band selection for image processing is a crucial task and it will assume increasing importance with the growing accession-num of hyperspectral data, in this paper we suggest a 'near infrared way' for assessing species richness directly from remotely sensed data
Are landscapes as crisp as we may think?
No full textGeographic information is traditionally represented by a one-entity–one-class method, assuming that each geographical entity in the map can be unambiguously assigned to a single thematic class. Also, thematic map classes are assumed to be exhaustive and mutually exclusive. By contrast, fuzzy classifications overcome the traditional limitations on the mutually exclusive nature of map classes assigning varying levels of class membership for individual map entities. The aim of this paper is to show that the substitution of fuzzy set theory for classical set theory is an essential improvement for representing geographic information using hierarchical classification schemes
Rarefy: Rarefaction Method
No full textRarefy includes functions for the calculation of spatially and non-spatially explicit rarefaction curves using different indices of taxonomic, functional and phylogenetic diversity. The user can also rarefy any biodiversity metric as provided by a self-written function (or an already existent one) that gives as output a vector with the values of a certain index of biodiversity calculated per plot (Ricotta, C., Acosta, A., Bacaro, G., Carboni, M., Chiarucci, A., Rocchini, D., Pavoine, S. (2019) ; Bacaro, G., Altobelli, A., Cameletti, M., Ciccarelli, D., Martellos, S., Palmer, M. W., . . . Chiarucci, A. (2016) ; Bacaro, G., Rocchini, D., Ghisla, A., Marcantonio, M., Neteler, M., & Chiarucci, A. (2012)
Antihypertensive peptides from ultrafiltration and fermentation of the ricotta cheese exhausted whey: Design and characterization of a functional ricotta cheese
No full textAiming at valorizing the ricotta cheese exhausted whey (RCEW), one of the most abundant by-products from the dairy industry, a biotechnological protocol to obtain bioactive peptides with angiotensin-I-converting enzyme (ACE)--inhibitory activity was set up. The approach was based on the combination of membrane filtration and fermentation. A Lactobacillus helveticus strain selected to be used as starter for the fermentation of the ultrafiltration protein-rich retentate (R-UF) obtained from RCEW. The fermented R-UF was characterized by a high anti-ACE activity. Peptides responsible for the bioactivity were purified and identified through nano-LC–ESI–MS/MS. The sequences identified in the purified active fractions of the fermented R-UF showed partial or complete overlapping with previously reported κ-casein antihypertensive fragments. The fermented R-UF was spray-dried and used to enrich ricotta cheese at different fortification level (1 and 5% w/w). An integrated approach including the assessment of the microbiological, chemical, functional, textural, and sensory properties was used to characterize the fortified products. A significantly higher antiACE activity was found in the ricotta cheese fortified with fermented R-UF as compared to the control and to the samples obtained with the unfermented R-UF fraction at the same levels of fortification. In particular, a 100 g portion of the ricotta cheese produced at 5% fortification level contained circa 30 mg of bioactive peptides. The fortification led to a moderate acidification, increased hardness and chewiness, and decreased the milk odor and taste of the ricotta cheese as compared to the control, while flavor persistence and sapidity improved
using Water Bath Heat Treatment in Vacuum Packed Ricotta Salata Cheese Wedges
No full textRicotta salata cheese is frequently contaminated on the surface with Listeria monocytogenes. Water bath
heat treatment in vacuum packed whole ricotta salata cheese wheels demonstrated to be effective in inactivating
L. monocytogenes. However, the risk of cross-contamination in ricotta salata wedges is increased during cheese cutting.
Therefore, the effectiveness of heat treatment in ricotta salata wedges has to be demonstrated conducting a new validation
study. In this study, 9 different time temperature combinations, 75, 85, and 90 °C applied for 10, 20, and 30 min each,
were tested on artificially contaminated ricotta salata cheese wedges. The extent of the lethal effect on L. monocytogenes
was assessed 1 and 30 d after the application of the hot water bath treatment. Five of 9 combinations, 75 °C for 30 min,
85 °C for 20, and 30 min, and 90°C for 20 and 30 min, demonstrated to meet the process criteria of at least 5 log
reduction. Sensory analyses were also conducted in order to account for the potential impact on sensory features of ricotta
salata wedges, which showed no significant differences between treatments
Arcobacter butzleri and Arcobacter cryaerophilus survival and growth in artisanal and industrial ricotta cheese
No full textRicotta cheese is a ready-to-eat product with properties (pH > 6.0, a(w) > 0.98-0.99) and moisture content (75-80%) that may pose a risk to public health due to postprocess contamination by several bacterial pathogens, including Arcobacters. The objective of the study was to evaluate the behavior of Arcobacter butzleri and Arcobacter cryaerophilus in ricotta cheese during its shelf life assuming postprocessing contamination. Two types of ricotta cheese, artisanal water buffalo (WB) and industrial cow milk ricotta cheese, were experimentally contaminated with A. butzleri and A. cryaerophilus and the count was monitored at 2 different temperatures (6 degrees C and 12 degrees C) during shelf life of 5 d for WB cheese and 22 d for industrial ricotta cheese. In WB ricotta cheese the A. butzleri count remained stable during the 5 d of storage at 6 degrees C, whereas a moderate but significant decrease was observed in A. cryaerophilus count. The counts of both species increased when WB ricotta cheese was stored at 12 degrees C. In industrial ricotta cheese stored at 6 degrees C, a significant reduction was observed both in A. butzleri and A. cryaerophilus counts during the 22-d storage period; at 12 degrees C storage, a count increase was observed for both Arcobacter species up to d 14 of storage after which the log cfu/g count resulted constant until d 22 of storage. The ability of A. butzleri and A. cryaerophilus to survive at 6 degrees C and to grow at 12 degrees C in ricotta cheese has significant food safety implications
Invited review : Dairy intake and bone health : a viewpoint from the state of the art
No full textThe aim of this review was to focus on the complex relationships between milk and dairy products intake and bone health, with particular emphasis on osteoporosis. The literature was extensively examined to provide an objective overview of the most significant achievements on the subject. Osteoporosis can be defined as a disease characterized by low bone mass and microarchitectural deterioration of bone tissue, leading to enhanced bone fragility and a consequent increase in fracture risk. Although the major determinants of peak bone mass and strength are genetic, major factors during childhood and adolescence may affect the ability to achieve peak bone mass. These include nutrition, particularly calcium and protein intake, physical activity, endocrine status, as well as exposure to a wide variety of risk factors. The role of calcium intake in determining bone mineral mass is well recognized to be the most critical nutritional factor to achieve optimal peak bone mass. The greatest amount of dietary calcium is obtained from milk and dairy foods, which also provide the human diet with vitamin D (particularly for products fortified with vitamin D), potassium, and other macro- and micronutrients. Although studies supporting the beneficial effects of milk or calcium on bone health are predominant in the literature, perplexity or discordance on this subject was expressed by some authors. Discordant data, mainly on the risk of fractures, provided limited proof of the unfavorable effect of dairy intake. More often, discordant works indicate no effect of dairy consumption on bone safety. Some considerations can be drawn from this viewpoint. Milk and dairy products are an optimal source of calcium as well as of other limiting nutrients (e.g., potassium and magnesium), with important effects on bone health. Bioactive components occurring in milk and dairy products may play an essential role on bone metabolism, as shown by in vivo and in vitro studies on colostrum acidic proteins and milk basic proteins. Calcium intake positively affects bone mass and is crucial in childhood and youth for correct bone development. In elderly people, calcium intake as well as vitamin D availability should be carefully checked. As a general conclusion, calcium is essential for bone health, although it will not prevent bone loss due to other factors; in this context, milk and dairy foods are bioavailable, relatively inexpensive sources of calcium for the human diet
No evidence of increased fire risk due to agricultural land abandonment in Sardinia (Italy)
No full textDifferent land cover types are related to different levels of fire hazard through their vegetation structure and fuel load composition. Therefore, understanding the relationships between landscape changes and fire behavior is of crucial importance for developing adequate fire fighting and fire prevention strategies for a changing world. In the last decades the abandonment of agricultural lands and pastoral activities has been the major driver of landscape transformations in Mediterranean Europe. As agricultural land abandonment typically promotes an increase in plant biomass (fuel load), a number of authors argue that vegetation succession in abandoned fields and pastures is expected to increase fire hazard. In this short paper, based on 28 493 fires in Sardinia (Italy) in the period 2001–2010, we show that there is no evidence of increased probability of fire ignition in abandoned rural areas. To the contrary, in Sardinia the decreased human impact associated with agricultural land abandonment leads to a statistically significant decrease of fire ignition probability
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