Livestock guarding dogs (LGDs) are used across the world to reduce livestock depredation by free-ranging predatory wildlife. In doing so, they reduce the need for lethal predator control and are considered beneficial for conservation. However, LGDs might be perceived as predators by wildlife and induce a multitude of both positive and negative ecological effects. We conducted a literature review to evaluate the ecological effects of LGDs and found 56 publications reporting LGDs interacting with or affecting wildlife. Featuring in 77% of the publications, LGDs were widely reported to chase and kill wildlife, leading to species-specific behavioural responses. A total of 80 species were affected by LGDs, 11 of which are listed as Near Threatened or higher on the IUCN Red List. Of the affected species, 78% were non-target species, suggesting that any benefits arising from the use of LGDs likely occur simultaneously with unintended ecological effects. However, the frequency of LGD-wildlife interactions and the magnitude of any resulting ecological effects have rarely been quantified. Therefore, more empirical studies are needed to determine the net ecological outcome of LGD use, thereby ensuring that negative outcomes are minimised, while benefiting both farmers and wildlife.
Herbivory on liverworts is rarely reported. We studied the effects of feeding by larvae of the sciarid fly Scatopsciara cunicularius on the growth of the thalloid liverwort Marchantia polymorpha at two different constant temperatures, 12°C and 22°C. Larvae reared at the lower temperature fed slower and over a longer period of time, which resulted in more damage and a greater reduction in the growth of the liverwort than that caused by those reared at the higher temperature. The reduction in growth of the liverwort was positively density-dependent in terms of number of larvae at both temperatures. These results indicate that the larvae of S. cunicularius are likely to be an effective means of controlling M. polymorpha, which is a common weed in plant nurseries and greenhouse cultures., Weerachon Sawangproh, Johan Ekroos, Nils Cronberg., and Obsahuje bibliografii
With the gradual increase of coal mining intensity, many coal pillars need to be left near the stope. The stability of the composite structure of coal pillars and their overlying strata determines the safety of the whole stope and the surface. This paper conducts uniaxial compression tests on coal-rock composite structures with the same lithology and the same coal-rock height ratio and finds the coal-rock composite structure’s mechanical properties and failure characteristics have greater discreteness. Combining the CT images of rock and coal, it is concluded that the main reason for the discreteness of the composite structure test results is the different crack characteristics in the rock specimen and the coal specimen. Therefore, this paper uses the PFC numerical simulation software to analyzes the influence of the crack characteristics on the mechanical properties, failure characteristics, and impact energy index of the coal-rock composite structure. The sensitivity factors are used to analyze the influence of crack angle, crack length, crack number and crack position on the peak stress, total crack number, and impact energy index of the coal-rock composite structure. The research results can provide a theoretical basis and guidance for preventing the instability and failure of the coal pillar-roof composite structure.
Key adaptations enabling mammals to cope with oxygen deficiency at high elevations relate to oxygen transfer into the blood. Among others, the efficiency of this mechanism depends on haematocrit (Hct, the volumetric fraction of red blood cells in blood). Although blood of high-elevation mammals is usually characterised by normal or slightly increased Hct, there are contradictory findings from studies along different elevational gradients. The aim of this study was to explore variability of Hct at both inter- and intraspecific levels in six rodent species from lower and higher elevations of Choke Mountain in Ethiopia. We found that Stenocephalemys sp. A from higher elevation had higher Hct than its congener Stenocephalemys albipes from lower elevation and a similar but weaker tendency was observed intraspecifically in Lophuromys simensis. Furthermore, Hct among four species occupying the high-elevation Afroalpine zone was comparable, and higher than in animals from lower elevations. Higher Hct in the three Afroalpine specialists probably contributes to local adaptations for life in high elevation environments under hypobaric hypoxia.
The average soil temperature was significantly lower in plots covered with hay. Hay mulching, however, did not increase significantly the total number of soil micro-arthropods collected using a soil pin trap and a soil sampler. Significant increases in the number of individuals was recorded only for certain groups. 64% of all the arthropods collected using soil pin traps were collected in hay-covered plots and 36% in control plots. This increase was statistically significant for the orders Entomobryomorpha and Poduromorpha of the subclass Collembola and surface-dwelling (epigeic) Coleoptera. For the samples collected using the soil sampler, 57% of the specimens were collected from hay-covered plots and 43% from control plots. As for the pin traps this was reflected in differences in the numbers of the orders Entomobrhyomorpha and Poduromorpha of the subclass Collembola and Pauropoda, collected in the treated and control plots. We conclude that mulching affected the different arthropod groups differently., Péter Dudás, László Menyhárt, Csongor Gedeon, Gergely Aambrus, Ferenc Tóth., and Obsahuje bibliografii
This study aimed to evaluate the changes in the erythropoietin
level and hematological variables in wrestlers after intermittent
hypoxic exposure (IHE). Twelve wrestlers were assigned into two
groups: hypoxia (sports training combined with IHE, n=6) and
control (sports training, n=6). An IHE was performed for
10 days, with one day off after 6 days, once a day for about
an hour. The concentrations of hydrogen peroxide (H2O2),
nitric oxide (NO), vascular endothelial growth factor (VEGF)
and erythropoietin (EPO), as well as total creatine kinase
activity (CK) were measured. Also, the hematological markers
(Hb -hemoglobin, Ht - hematocrit, RBC - red blood cell, WBC -
white blood cell, Ret - reticulocytes) were analyzed. The 6-day
IHE caused an increase in the levels of H2O2, NO and VEGF.
Similarly, the EPO level and WBC count reached the highest value
after 6 days of IHE. The total Ret number increase constantly
during 10 days of IHE. The hypoxia group showed a higher CK
activity compared to the control. In conclusion, 10-day IHE in
combination with wrestling training elevates levels of H2O2, NO
and VEGF, and improves the oxygen transport capacity by the
release of EPO and Ret in circulation.
Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia associated with a two-fold increase in mortality caused by a higher risk of stroke and heart failure. Currently, AF is present in ~ 2 % of the general population, and its incidence and prevalence are increasing. Obesity, hypertension, diabetes mellitus, obstructive sleep apnea, and alcohol consumption increase the risk of AF. Each unit of increase in BMI increases the risk of AF by 3 %, and intensive weight loss is also associated with reduced AF recurrence. Hypertension increases the risk of AF by 50 % in men and by 40 % in women, and explains ≈ 20 % of new AF cases. Patients with obstructive sleep apnea are at four times higher risk of developing AF than subjects without sleep apnea. Higher concentrations of pro-inflammatory cytokines, higher amounts of epicardial adipose tissue, and a higher degree of ventricular diffuse myocardial fibrosis are present in AF patients and patients with the aforementioned metabolic disorders. Several prospective cohort studies and randomized trials have been initiated to show whether weight loss and treatment of other risk factors will be associated with a reduction in AF recurrences.
After high population densities of insect defoliators there is often a dramatic decrease in their abundance due to various limiting factors. Here, we compared gypsy moth larvae (Lymantria dispar L.) reared singly and in crowded conditions. We compared a number of physiological parameters of these insects and the effect of L. dispar population density on the activation of covert baculovirus infections in the larvae. It was found that the population density of gypsy moth larvae did not affect the mortality due to the activation of the covert virus infection or the total mortality. On the other hand, solitary-reared larvae were heavier, took longer to develop, and showed a four-fold higher concentration of dopamine in their haemolymph than larvae reared in groups. Thus, we demonstrated that an increase in the population density of larvae per se facilitates some changes in fitness and innate immunity traits but is not related to the activation of covert baculovirus infection. We suggest that an increase in population density does not increase the risk of epizootics triggered by the activation of covert baculovirus infection and that researchers should pay more attention to studying density-associated factors, such as starvation.
Perinatal hypoxic-ischemic insult (HII) is one of the main devastating causes of morbidity and mortality in newborns. HII induces brain injury which evolves to neurological sequelae later in life. Hypothermia is the only therapeutic approach available capable of diminishing brain impairment after HII. Finding a novel therapeutic method to reduce the severity of brain injury and its consequences is critical in neonatology. The present paper aimed to evaluate the effect of sulforaphane (SFN) pre-treatment on glucose metabolism, neurodegeneration, and functional outcome at the acute, sub-acute, and sub-chronic time intervals in the experimental model of perinatal hypoxic-ischemic insult in rats. To estimate the effect of SFN on brain glucose uptake we have performed 18F-deoxyglucose (FDG) μCT/PET. The activity of FDG was determined in the hippocampus and sensorimotor cortex. Neurodegeneration was assessed by histological analysis of Nissl-stained brain sections. To investigate functional outcomes a battery of behavioral tests was employed. We have shown that although SFN possesses a protective effect on glucose uptake in the ischemic hippocampus 24 h and 1 week after HII, no effect has been observed in the motor cortex. We have further shown that the ischemic hippocampal formation tends to be thinner in HIE and SFN treatment tends to reverse this pattern. We have observed subtle chronic movement deficit after HII detected by ladder rung walking test with no protective effect of SFN. SFN should be thus considered as a potent neuroprotective drug with the capability to interfere with pathophysiological processes triggered by perinatal hypoxicischemic insult.
Irisin is a myokine secreted during exercise. It has drawn the attention of researchers as it regulates several effects of exercise that are considered beneficial. It has also been proposed as a therapeutic tool to treat metabolic disorders. In recent years, the effect of different types of training on circulating irisin has been studied in large populations. An overall beneficial result has been shown, however, the outcome of the investigations has raised some controversy. Herein we evaluated the existing literature on the effects of different types of training on the circulating irisin levels in healthy subjects and in those displaying different metabolic condition. We conducted queries in the PubMed and Web of Science databases for literature published between January 2010 and January 2021. Thirty-seven original articles were retrieved and they were included in this review. Any letter to the editor, meta-analyses, reviews, and systematic review articles were excluded. From these 37 articles, 19 of them reported increased levels of circulating irisin. The interventions encompassed aerobic, resistance, combined, circuit, and interval training types. Such increase of circulating irisin was reported for healthy subjects and for those displaying different metabolic condition. A training that is steadily kept with a moderate to high intensity, including that characterized by brief highly intense intervals, were distinguishable from the rest. Nevertheless, the training effectiveness as evaluated by the increased circulating irisin levels depends on the subject’s metabolic condition and age.