Search Results (15)

Wildfires affect and change the burned sites’ condition, functionality, and ecosystem services. Altered hydrologic processes, such as runoff, increased streamflows, and sediment transport, are only a few examples resulting from burned soils, vegetation, and land cover. Such areas are flood-prone and face risks of extreme peak flows, reduced infiltration, water pollution affecting habitats, and hydromorphological changes. In this study, we present the different post-fire erosion and flood protection treatments that have been developed to avoid and mitigate the consequences and risks mentioned above. We categorize them into Land, Channel, Barrier, and Road treatments and analyze their types, such as cover-based methods, barriers, mulching, in-channel treatments, such as check dams, seeding, or even chemical treatments. Examples of how such treatments were used in real cases are provided, commenting on their results in flood and erosion protection. We found that cover changes were more effective than barriers, as they provided an immediate ground-cover increase in both Mediterranean and US sites. We explore the factors that play a role in their effectiveness, including storm duration and intensity, topography and slopes, land cover and uses, treatment implementation-installation, as well as fire-related factors such as burn severity. These factors have different effects on different treatments, so we further discuss the suitability of each one depending on the site’s and treatment’s characteristics. The outcomes of this work are expected to improve the understanding of the practical aspects of these treatments, providing for the first time a synthesis of the available knowledge on the multiple complex factors that can determine their efficiency. Full article

In dairy systems with Zebu breeds, calves are not immediately separated from their dams after calving; consequently, maternal care and protective behavior are important, influencing both productive performance and stockpeople’s safety. Our objectives were to: (1) investigate the effects of a training protocol involving pre-calving positive stimulation, delivered prior to calving, on the maternal care of primiparous Gyr cows; and (2) evaluate the effects of this training protocol on maternal protective behavior towards handlers during the first calf handling. Primiparous dairy Gyr cows (n = 37) were allocated into two groups: training (n = 16) and control (n = 21). Animal behaviors were recorded in three periods: post-calving, first calf handling, and post-handling. Maternal protective behavior during calf handling was assessed from measures of aggressiveness, attention, displacement, and agitation. Calf latency to stand up (p < 0.01) and sex (p < 0.01) differed between the training and control groups. The training group had less touching (p = 0.03), more time not interacting with the calf (p = 0.03), tended to be less protective (p = 0.056), and moved less (p < 0.01) during the first handling of their calves. In conclusion, the primiparous dairy Gyr cows subjected to pre-calving training protocol displayed less maternal care and displacement during the first handling of their calves and tended to be less protective. Full article

Depression is one of the world’s most common and mentally disabling illnesses. Post-partum depression is a subtype of depression that affects one in seven women worldwide. Successful pharmacological treatment must consider the consequences for both, since the mother–child bond is fundamental for the well-being of both mother and infant as well as the general development of the newborn. Changes in maternal physiology and/or behavior can significantly influence the development of breastfed infants. Ketamine has been extensively studied for use as an antidepressant due to its mixed mechanisms of action. Safety and efficacy studies in the cardiovascular and urinary systems of a lactating postpartum depression animal model are essential for contributing toward ketamine’s clinical use in the respective patient population. Thus, this project aimed to study the implications of postpartum maternal exposure to ketamine during lactation on the cardiovascular system of female rats submitted to the depression induction model by maternal separation. This model promotes depressive effects through stress caused by the interruption of mother–infant bond early in the offspring’s life. To achieve depression, each dam was separated from her offspring for 3 h per day, from post-natal day 2 (PND2) to PND12. Experimental groups received daily treatment with either 5, 10, or 20 mg/kg of ketamine intraperitoneally during the lactation period, from PND2 to PND21. Behavioral tests consisted of the maternal and aggressive maternal behavior tests, the olfactory preference test, and the forced swim test. A technique for the detection of catecholamines and indoleamines in the heart muscle was developed for the experimental model groups. The histopathological evaluation was performed on these animals’ cardiac muscles and urinary bladders. Our findings suggest that ketamine is safe for use in postpartum depression and does not induce cardiovascular and/or urinary systems toxicity. Full article

Water and sediment regulation aimed at aquatic ecosystems and preserving reservoir capacity to minimize the negative consequences of dams can fundamentally change the distribution of heavy metals (HMs) in the reservoir and downstream reaches. However, the effects of water and sediment regulation on variation in HMs are still poorly understood. In this study, the variations in concentration, contamination, human health risk, potential sources, and influencing factors of the metalloid As and HMs (Cr, Hg, Ni, Pb, and Zn) in surface water in the reservoir and the downstream reach of the Xiaolangdi Dam (XLD) following the operation of the water-sediment regulation scheme (WSRS) were determined. These results indicate that HM concentrations in the two post-WSRS seasons were much lower than the water quality standards, but were significantly increased over time due to the trapping effects of the XLD (p < 0.05, except for Zn). However, As concentration in the reservoir was significantly lower than that observed in downstream reaches, likely due to anthropogenic input from agricultural activities. Meanwhile, HM concentrations varied with distance to the dam, which displayed a distinct accumulation closer to the dam in the post-WSRS II season. The contamination of HMs, the carcinogenic risk of exposure to As, and the noncarcinogenic risks associated with exposure to Hg, Ni, Pb, and Zn via the direct ingestion pathway of drinking water were all within acceptable levels following the WSRS, but increased over time. The carcinogenic risk of Cr in the post-WSRS II season was at an unacceptably high level, particularly at sites near the dam. Hydrological characteristics (water level and flow rate) were the dominant factors in determining the distribution of HMs. These results can provide new insight for a better understanding of the variations in HMs following the water and sediment regulation practices, and guide future management in regulating the trapping effects of dams. Full article

In recent times, significant research has been carried out into developing and applying soft computing techniques for modeling hydro-climatic processes such as seepage modeling. It is necessary to properly model seepage, which creates groundwater sources, to ensure adequate management of scarce water resources. On the other hand, excessive seepage can threaten the stability of earthfill dams and infrastructures. Furthermore, it could result in severe soil erosion and consequently cause environmental damage. Considering the complex and nonlinear nature of the seepage process, employing soft computing techniques, especially applying pre-post processing techniques as hybrid methods, such as wavelet analysis, could be appropriate to enhance modeling efficiency. This review paper summarizes standard soft computing techniques and reviews their seepage modeling and simulation applications in the last two decades. Accordingly, 48 research papers from 2002 to 2021 were reviewed. According to the reviewed papers, it could be understood that regardless of some limitations, soft computing techniques could simulate the seepage successfully either through groundwater or earthfill dam and hydraulic structures. Moreover, some suggestions for future research are presented. This review was conducted employing preferred reporting items for systematic reviews and meta-analyses (PRISMA) method. Full article

The present study aimed to develop predictive models of calf birth weight (CBW) from liveweight (LW) data collected remotely and individually using an automated in-paddock walk-over-weighing scale (WOW). Twenty-eight multiparous Charolais cows were mated with two Brahman bulls. The WOW was installed at the only watering point to capture LW over five months. Calf birth date and weight were manually recorded, and the liveweight change experienced by a dam at calving (ΔLWC) was calculated as pre-LW minus post-LW calving. Cow non-foetal weight loss at calving (NFW) was calculated as ΔLWC minus CBW. Pearson’s correlational analysis and simple linear regressions were used to identify associations between all variables measured. No correlations were found between ΔLWC and pre-LW (p = 0.52), or post-LW (p = 0.14). However, positive associations were observed between ΔLWC and CBW (p < 0.001, R2 = 0.56) and NFW (p < 0.001, R2 = 0.90). Thus, the results suggest that 56% of the variation in ΔLWC is attributed to the calf weight, and consequently could be used as an indicator of CBW. Remote, in-paddock weighing systems have the potential to provide timely and accurate LW data of breeding cows to improve calving management and productivity. Full article

This study reviews the monsoonal Yangtze and the arid Nile deltas with the objective of understanding how the process–response between river-basin modifications and delta-estuary ecological degradation are interrelated under contrasting hydroclimate dynamics. Our analysis shows that the Yangtze River had a long-term stepwise reduction in sediment and silicate fluxes to estuary due to dam construction since the 1960s, especially after the Three Gorges Dam (TGD) closed in 2003. By contrast, the Nile had a drastic reduction of sediment, freshwater, and silicate fluxes immediately after the construction of the Aswan High Dam (AHD) in 1964. Seasonal rainfall in the mid-lower Yangtze basin (below TGD) complemented riverine materials to its estuary, but little was available to the Nile coast below the AHD in the hyper-arid climate setting. Nitrogen (N) and phosphate (P) fluxes in both river basins have increased because of the overuse of N- and P-fertilizer, land-use changes, urbanization, and industrialization. Nutrient ratios (N:P:Si) in both delta-estuaries was greatly altered, i.e., Yangtze case: 75:1:946 (1960s–1970s), 86:1:272 (1980s–1990s) and 102:1:75 (2000s–2010s); and Nile case: 6:1:32 (1960s–1970s), 8:1:9 (1980s–1990s), and 45:1:22 (2013), in the context of the optimum of Redfield ratio (N:P:Si = 16:1:16). This led to an ecological regime shift evidenced by a long-term change in phytoplankton communities in the Yangtze estuary, where silicious algae tended to lose dominance since the end of the 1990s, when more toxic dinoflagellates began to emerge. In the Nile estuary, such a regime shift was indicated by the post-dam dramatic reduction in zooplankton standing crop and fish landings until the early 2000s when biological recovery occurred due to nutrient inputs from anthropogenic sources. Although the Yangtze had higher human impacts than the Nile in terms of population, industrialization, and fertilizer application, N concentrations in the Nile estuarine waters surpassed the Yangtze in recent decades. However, eutrophication in the Yangtze estuary is much more intensive than in the Nile, leading to the likelihood of its estuarine water becoming more acidic than ever before. Therefore, ecological degradation in both delta-estuaries does not follow a linear trajectory, due not only to different climate dynamics but also to human forcings. The comparative insights of this study should be incorporated into future integrated coastal management of these two important systems. Full article

Due to renewed interest in hydropower dams in the face of climate change, it is important to assess dam operations and management in combination with downstream impacts on rivers in (semi-)arid environments. In this study, the impacts of the Tekeze hydropower dam on downstream hydrology and river morphology were investigated, including impacts under normal and extreme reservoir operation conditions. Field observations, in-depth interviews, repeat terrestrial photographs, multi-year high-resolution satellite images, daily reservoir water levels and data on hourly to daily energy production were collected and studied. The results show that high flows (Q₅) have declined (with factor 5), low flows (Q₉₅) have increased (with factor 27), seasonal flow patterns have smoothened, river beds have incised (up to 4 m) and locally aggraded near tributary confluences. The active river bed has narrowed by 31%, which was accelerated by the gradual emergence of Tamarix nilotica and fruit plantations. A new post-dam equilibrium had been reached until it was disrupted by the 2018 emergency release, caused by reservoir management and above-normal reservoir inflow, and causing extensive erosion and agricultural losses downstream. Increased floodplain occupation for irrigated agriculture consequently provides an additional argument for reservoir operation optimization to avoid future risks for riparian communities. Full article

Here, we used a mouse model with defective autophagy to further decipher the role of Beclin1 in the infection and disease of Zika virus (ZIKV)-R103451. Hemizygous (Becn1^+/−) and wild-type (Becn1^+/+) pregnant mice were transiently immunocompromised using the anti-interferon alpha/beta receptor subunit 1 monoclonal antibody MAR1-5A3. Despite a low mortality rate among the infected dams, 25% of Becn1^+/− offspring were smaller in size and had smaller, underdeveloped brains. This phenotype became apparent after 2-to 3-weeks post-birth. Furthermore, the smaller-sized pups showed a decrease in the mRNA expression levels of insulin-like growth factor (IGF)-1 and the expression levels of several microcephaly associated genes, when compared to their typical-sized siblings. Neuronal loss was also noticeable in brain tissues that were removed postmortem. Further analysis with murine mixed glia, derived from ZIKV-infected Becn1^+/− and Becn1^+/+ pups, showed greater infectivity in glia derived from the Becn1^+/− genotype, along with a significant increase in pro-inflammatory molecules. In the present study, we identified a link by which defective autophagy is causally related to increased inflammatory molecules, reduced growth factor, decreased expression of microcephaly-associated genes, and increased neuronal loss. Specifically, we showed that a reduced expression of Beclin1 aggravated the consequences of ZIKV infection on brain development and qualifies Becn1 as a susceptibility gene of ZIKV congenital syndrome. Full article

Developmental vitamin D (DVD) deficiency is a risk factor for schizophrenia. In rodents we show that DVD-deficiency alters brain development and produces behavioral phenotypes in the offspring of relevance to the positive symptoms of schizophrenia. The aims of this study are to examine behavioral phenotypes specific to the cognitive and negative symptoms of schizophrenia in this model, and to vary the duration of vitamin D deficiency during gestation and beyond birth. We hypothesize that a longer duration of DVD-deficiency would result in greater behavioral impairments. Female vitamin D-deficient Sprague Dawley dams were mated at 10 weeks of age. Dietary vitamin D was reintroduced to dams and/or pups at different developmental time-points: Conception, Birth, Post-natal day (PND) 6 and PND21. Adult male and female offspring were assessed on a battery of behavioral tests, including sucrose preference, open field, novel object recognition (NOR), social approach and social novelty. We find that all windows of DVD-deficiency impaired NOR a cognitive measure that requires intact recognition memory. Sucrose consumption, social approach and social memory negative symptom-like phenotypes were unaffected by any maternal dietary manipulation. In addition, contrary to our hypothesis, we find that rats in the Conception group, that is the shortest duration of vitamin D deficiency, demonstrate increased locomotor activity, and decreased interaction time with novel objects. These findings have implications for the increasing number of studies examining the preclinical consequences of maternal vitamin D deficiency, and continue to suggest that adequate levels of maternal vitamin D are required for normal brain development. Full article

Historically, investigators have assumed microorganisms identified in mother’s milk to be contaminants, but recent data suggest that milk microbiota may contribute to beneficial maternal effects. Microorganisms that colonize the gastrointestinal tracts of newborn mammals are derived, at least in part, from the maternal microbial population. Milk-derived microbiota is an important source of this microbial inocula and we hypothesized that the maternal diet contributes to variation in this microbial community. To evaluate the relationship between a mother’s diet and milk microbiome, we fed female rats a low- or high-protein diet and mated all individuals. Milk and cecal contents were collected from dams at peak lactation (14-day post-partum), and the bacterial composition of each community was assessed by 16S rRNA gene amplicon sequencing. Our findings revealed higher dietary protein intake decreased fecal microbial diversity but increased milk microbial and pup cecum diversity. Further, the higher dietary protein intake resulted in a greater abundance of potentially health-promoting bacteria, such as Lactobacillus spp. These data suggest that dietary protein levels contribute to significant shifts in the composition of maternal milk microbiota and that the functional consequences of these changes in microbial inocula might be biologically important and should be further explored. Full article

Ecohydrological changes in large rivers of the world result from a long history of human dimensions and climate. The increasing human population, intensified land use, and climate change have led to a decline in the most critical aspect of achieving sustainable development, namely, that of water resources. This study assessed recent hydromorphological characteristics of the tropical Tana River in Kenya using flow duration curve, and geospatial techniques to gain a better understanding of human impacts over the last two decades and their consequences for new development projects. The results show that all extremal peak, low, and mean discharges exhibited significant increasing trends over a period of 17 years. Dam construction represents a 13% reduction of the maximum discharge and a 30% decrease in low flows, while post-regulation hydrological changes indicated an increase of 56 and 40% of high flows and low flows respectively. Dominant flow was observed to be higher for the current decade than the previous decade, representing a rise of the dominant streamflow by 33%. The assessment of four morphologically active sites at the downstream reach showed channel adjustments which support the changes in the flow regimes observed. The channel width increased by 8.7 and 1.9% at two sites but decreased by 31.5 and 16.2% for the other two sites under study during the time period. The results underscore the contribution of other main human modifications, apart from regulation, such as increased water abstraction and inter basin transfer, up-stream land use and anthropogenic climate change to assess the ecohydrological status in this river basin. Such streamflow regime dynamics may have implications on water resource management, riverine environments, and development of new water projects. Full article

This article discusses the environmental issues facing small hydropower plants (SHPs) operating in temperate lowland rivers of Lithuania. The research subjects are two medium head reservoir type hydro schemes considered within a context of the global fleet of SHPs in the country. This research considers general abiotic indicators (flow, level, water retention time in the reservoirs) of the stream that may affect the aquatic systems. The main idea was to test whether the hydrologic regime has been altered by small hydropower dams. The analysis of changes in abiotic indicators is a complex process, including both pre- and post-reservoir construction and post commissioning of the SHPs under operation. Downstream hydrograph (flow and stage) ramping is also an issue for operating SHPs that can result in temporary rapid changes in flow and consequently negatively impact aquatic resources. This ramping has been quantitatively evaluated. To avoid the risk of excessive flow ramping, the types of turbines available were evaluated and the most suitable types for the natural river flow regime were identified. The results of this study are to allow for new hydro schemes or upgrades to use water resources in a more sustainable way. Full article

The variation of river flow within a natural range plays an important role in promoting the social-ecological sustainability of a river basin. In order to determine the extent of the natural range of variation, this study assesses hydrologic flow thresholds for the Lower Ganges River Basin. The flow threshold was calculated using twenty-two “Range of Variability (RVA)” parameters. The impact of Farakka Dam on the Lower Ganges River flow was calculated by comparing threshold parameters for the pre-Farakka period (from 1934 to 1974) and the post-Farakka period (1975–2005). The results demonstrate that due to water diversion by the Farakka Dam, various threshold parameters, including the monthly mean of the dry season (December–May) and yearly minimum flows, have been altered significantly. The ecological consequences of such hydrologic alterations include the destruction of the breeding and raising grounds for a number of Gangetic species, the increase of salinity in the southwest coastal region of Bangladesh and a reduction of fish and agricultural diversity. The major findings in this paper have a number of policy-level implications to aid water sharing mechanisms and agreements between the government of Bangladesh and India. The methodological approach presented in this study is applicable to other river basins. Full article

We studied a model of hemorrhagic encephalopathy of prematurity (EP) that closely recapitulates findings in humans with hemorrhagic EP. This model involves tandem insults of 20 min intrauterine ischemia (IUI) plus an episode of elevated venous pressure induced by intraperitoneal glycerol on post-natal day (P) 0. We examined Sur1 expression, which is upregulated after focal ischemia but has not been studied after brief global ischemia including IUI. We found that 20 min IUI resulted in robust upregulation of Sur1 in periventricular microvessels and tissues. We studied tandem insult pups from untreated or vehicle-treated dams (TI-CTR), and tandem insult pups from dams administered a low-dose, non-hypoglycemogenic infusion of the Sur1 blocker, glibenclamide, for 1 week after IUI (TI-GLIB). Compared to pups from the TI-CTR group, pups from the TI-GLIB group had significantly fewer and less severe hemorrhages on P1, performed significantly better on the beam walk and accelerating Rotarod on P35 and in tests of thigmotaxis and rapid learning on P35–49, and had significantly greater body and brain weights at P52. We conclude that low-dose glibenclamide administered to the mother at the end of pregnancy protects pups subjected to IUI from post-natal events of elevated venous pressure and its consequences. Full article