Reducing Moisture Swell of Densified Wood With Polycarboxylic Acid Resin

A water-soluble polycarboxylic acid (PCA) resin was assessed for ability to limit moisture swelling of densified wood. Aspen flakes were treated in 0 (control), 1, 5, 10, and 20% PCA resin solutions and drained for 1, 10, and 20-min time periods. Following treatments, flakes were compressed to roughly 50% strain at 170°C. The PCA content of flakes significantly increased with increasing concentration and drain time. Water absorption and thickness swell of flakes decreased with increasing PCA content. Both water absorption and thickness swell of untreated flakes were over 100%; but for PCA-treated flakes, water absorption and thickness swell as low as 45% and 16%, respectively, were achieved. Irreversible thickness swell decreased with increasing PCA content, while reversible thickness swell remained relatively constant. The swelling coefficient decreased with increasing PCA content, a behavior that often is associated with bulking agents for treated, uncompressed wood. However, dynamic mechanical analysis further suggested that PCA resin acts as a cross-linking agent to stabilize the position of the collapsed cell walls

Habitat Preferences of Italian Freshwater Fish: A Systematic Review of Data Availability for Applications of the MesoHABSIM Model

The MesoHABitat SImulation Model (MesoHABSIM) is the preferred method to calculate spatio-temporal variation in the fish habitat availability in Italian rivers. With the aim of improving the applicability of the MesoHABSIM approach in the Italian territory, we carried out a systematic review of physical habitat preferences for 31 freshwater fish species and three freshwater lampreys, representing 75% of the total indigenous freshwater fish community of Italy. Information related to suitable ranges of depth, flow velocity, biotic/abiotic substrates, covers/shelters was collected and summarized for two critical life stages (adult and juvenile) and two bioperiods (rearing/growth and spawning). Overall, 250 publications were reviewed, classified as 206 peer-reviewed papers, 20 books, 7 PhD thesis, and 17 grey literature sources. Our analysis revealed substantial deficits of information about habitat requirements for more than 30% of Italian freshwater fish species. This information is particularly scarce for the most threatened endemic species, especially for their most critical bioperiod (i.e., spawning). With the aim of preserving freshwater fish biodiversity as required in the EU Biodiversity Strategy for 2030 (European Commission, 2020), accurate information on physical habitat requirements for spawning is crucial. As an example application of MesoHABSIM, the collected habitat preference information was used to define and apply mesohabitat suitability criteria for one fish species (Telestes muticellus) in a regulated river reach of Argentina Creek (Province of Imperia, Italy). This analysis demonstrates the potential for applying information from the current review to other fish species

Ecological notes on an endemic freshwater lamprey, Lampetra zanandreai (Vladykov, 1955)

Lampetra zanandreai (Vladykov, 1955) is a non-parasitic, freshwater lamprey endemic to the ancient Po basin. A few, mostly very dated studies have investigated some aspect of the biology of this lamprey, but surprisingly, despite it being considered a threatened species, information on its ecology is practically absent. Specifically, information about habitat preferences is generic and qualitative. Since most of the life cycle is spent in the fossorial larval stage, which is also the only one in which organisms feed, information about ecological requirements of ammocoetes is essential for any conservation strategy. In this study we provide the first data about physical habitat preferences for lamprey ammocoetes by analyzing their presence within sampled hydromorphological units (HMUs), following the approach of habitat attribute description of the MesoHABSIM (MesoHABitat SImulation Model) methodology. To explore the relationship between lamprey presence and HMU characteristics, a random forest (RF) model was developed and tested using data collected in five stream reaches of the Po basin (NW Italy). The final parsimonious RF model performed well in terms of accuracy (95.2%) and true skill statistic (90.4%), allowing us to identify the most significant mesohabitat attributes for the considered species. Furthermore, in the Ghiandone River, where the highest density and number of individuals were found, a granulometric analysis of the riverbed material was carried out. Results showed that selected strains of sand and fine gravel, with low organic content, are preferred by ammocoetes. To our knowledge, this is the first study exploring the habitat preference of this endangered species, listed in Annex II of the European Habitats Directive

Fly fishing no-kill zones: a possible way to conjugate conservation issues, sustainable sport enhancement and local development in Alpine areas?

The promotion of sustainable tourism and outdoor sports can represent an important way to couple environmental conservation strategies and economic enhancement in marginal and Alpine areas. In this context catch and release fly fishing zones can represent an interesting tool, although no data is available on the effectiveness of these practices on Alpine salmonid population dynamics. Salmonids are the main group of fish in alpine rivers and they are the only actively targeted by anglers. Aim of this work is filling this gap, with a pilot study on two no-kill zones (Po and Pellice rivers, NW Italy). We conducted a temporal and spatial comparison between free-fishing and catch and release management river sections, with a detailed analysis on the Po River site. Our results support the hypothesis that catch and release management allows a numerical increase in wild trout populations. In particular, we detected a massive and rapid increase in younger individuals, possibly linked to a stop on the removal of large-sized reproducers. Protecting trout by the implementation of this practice can at the same time allow the increase of sustainable economic development and sport in marginal areas

Beta-diversity and stressor specific index reveal patterns of macroinvertebrate community response to sediment flushing

Anthropogenic increase of fine sediment loading is one of the main pressures for rivers worldwide. Particularly, Alpine streams are increasingly facing this issue due to sediment flushing operations from hydropower reservoirs, aimed at recovering storage for preserving electricity generation. Although Controlled Sediment Flushing Operations (CSFOs) are becoming increasingly frequent, ecological indicators to adequately assess and monitor their impact on the stream ecosystem have been poorly developed. In this work, we aimed to perform a screening of currently available biomonitoring tools to evaluate the CSFO effects on the riverine biota and adequately assess its recovery, starting from the recognition of the main ecological mechanisms triggered by the mentioned activities on benthic macroinvertebrate communities. We used two independent datasets concerning two reservoirs in the central Italian Alps to investigate the temporal effects of CSFOs repeated for four consecutive years (case-study I), and the impact of a single CSFO at a seasonal scale through a before/after-control/impact approach (case-study II). Initially, we quantified the CSFO impact on the richness and beta-diversity of macroinvertebrate communities by combining multivariate and univariate statistical techniques. Then, we compared the performance of the Siltation Index for LoTic EcoSystems (SILTES), recently developed for detecting siltation impact in Alpine streams, with that of the generic index currently adopted to assess the ecological status (sensu Water Framework Directive) of the Italian rivers, and of another sediment-specific index, but developed for a different bio-geographical area. The analysis of the two case-studies demonstrated that the nestedness (i.e. taxa loss) is the primary source of biological impairment caused by CSFOs. Moreover, we found that SILTES was more effective than the other indices because of its strong correlation with the nestedness, and since it properly discriminated impaired and pristine conditions, at both multi-annual and seasonal scale. In the first case-study, a threshold in the temporal trend of this index was detected, indicating a recovery within three months. In the second one, SILTES showed a recovery to pre-event seasonal values after nine months from the CSFO, due to larger and more persistent sediment deposition. This study demonstrates that SILTES could be adopted as a benchmark to improve the management of CSFOs from an ecological viewpoint. Our findings can be extended to the management of other sediment-related activities affecting mountainous streams worldwide, and, more generally, the adopted approach can be replicated for developing new ecological tools to manage other disturbances to river environments

Dual Effect of Methylprednsolone Pulses on Apoptosis of Peripheral Leukocytes in Patients with Renal Diseases

It is well known that change in apoptosis may modulate the natural story of illness, and that many drugs may act through modulation of apoptosis, but the role of steroids in acting through apoptosis in different settings, including renal diseases, has still to be elucidated. We studied the in vivo effects of steroids by oral assumption (10 to 25 mg/deltacortene) or by intravenous pulses (300 to 1000 mg/dose) on apoptosis and cellular subsets of peripheral lymphocytes, by evaluating DNA-fragmentation and lymphocyte subsets in 79 subjects: 22 controls and 57 patients with various renal diseases (25 Lupus-GN, 19 membranous-GN (MGN), 6 rapidly progressive-GN (RPGN), 2 acute interstitial nephritis (AIN), 5 on chronic dialysis. Baseline apoptosis was present in 1/22 (4.5%) of controls, 3/25 (12%) SLE, 2/6 (33.3%) RPGN and 10/19 (52.6%) MGN. A significant decrease in CD3+CD8+ cell count and a significant increase of the CD3+CD4/CD3+CD8+ ratio were found in apoptosis-positive subjects. DNA fragmentation did not change after oral steroids, paralleling a 22 to 32% decrease in total lymphocytes. Following intravenous methylprednisolone pulses, a deeper drop of all lymphocyte subsets was observed, while DNA fragmentation turned from present to absent in 2 MGN, but not in 2 RPGN, and from absent to present in 1 ARF and 1 SLE, independently of the dosage. We demonstrated that the presence of apoptosis in renal diseases is associated with decreased CD3+CD8+ cell count. Furthermore, steroid intravenous pulses, besides inducing a profound decrease in lymphocyte subsets, do exert a dual effect on baseline leukocyte apoptosis, eventually leading to a reversal of baseline patterns, either turning from negative to positive or from positive to negative. Oral steroid therapy did not influence baseline apoptosis

Fluid Flow Thermometry Using Thermographic Phosphors

Phosphor thermometry is a non-intrusive thermometry technique that allows for spatially and temporally resolved surface temperature measurements. The thermographic method has been employed in a number of applications that include combustion, sprays, and gas flows. In the current work, we investigate the implementation of thermographic phosphors in liquid flows, which is of interest in a wide range of applications in heat transfer, fluid mechanics, and thermal systems. Zinc oxide doped with Zinc (ZnO:Zn) was the phosphor employed for experimentation due to its high emission intensity and insolubility. In order to explore this application, the phosphor powder was uniformly dispersed in water using a magnetic stirring rod. The phosphor was excited by the third harmonic 355 nm output of a Nd:YAG laser, and the luminescence was examined using a fiber-coupled spectrometer. Analysis of the spectral data showed a significant redshift as the temperature approached boiling point. Further characterization of effects of temperature and experimental parameters such as ZnO:Zn concentration on the luminescence signal was performed