Negative effects of stagnation and drought on benthic invertebrate communities in lowland streams

2017 ◽  
Vol 68 (2) ◽  
pp. 308 ◽  
Author(s):  
Liliana García ◽  
Isabel Pardo

Streams are extremely vulnerable to water abstraction across the world because of increasing water demand from humans, as well as because precipitation is decreasing in many areas. To determine how water abstraction affects water chemistry, hydromorphological variables and invertebrate assemblages, we conducted an experiment in which we mimicked two levels of disturbance: stagnation and drought. The experiment was performed at two lowland streams in Galicia (north-west Spain), which were similar in physical conditions but differed in trophic status (high v. low P). Samples were taken both before and after manipulation at the upstream control and downstream-disturbed stretches. There was a significant overall effect of water abstraction on both disturbed stretches, but invertebrate assemblages responded differently between streams and within stretches. In the low-P stream, invertebrate densities remained unchanged in the drought stretch but declined in the stagnation stretch relative to the control. At the same time, the high-P stream exhibited a strong loss of diversity in both the stagnation and drought stretches. These results suggest that short-term flow reductions driven by increasing water scarcity and abstraction put benthic communities in lowland streams at risk, and that risk would be greater (in terms of biodiversity loss) in streams that are initially impaired by high-P loading.

2003 ◽  
Vol 18 (10) ◽  
pp. 683-690 ◽  
Author(s):  
GIOVANNI MODANESE

We evaluate the local contribution gμνL of coherent matter with Lagrangian density L to the vacuum energy density. Focusing on the case of superconductors obeying the Ginzburg–Landau equation, we express the relativistic invariant density L in terms of low-energy quantities containing the pairs density. We discuss under which physical conditions the sign of the local contribution of the collective wave function to the vacuum energy density is positive or negative. Effects of this kind can play an important role in bringing the local changes in the amplitude of gravitational vacuum fluctuations — a phenomenon reminiscent of the Casimir effect in QED.


2018 ◽  
Vol 6 (11) ◽  
pp. 95
Author(s):  
Muzaffer Selcuk ◽  
Vedat Cinar ◽  
Mucahit Sarikaya ◽  
Salih Oner

This study aims to observe the possible negative effects that might occur on bio-chemistry and hemogram values of tennis players during the intense competition period by comparing the blood values of pre-competition period with 10 days of intense exercise. Blood samples were obtained from tennis team players who do not have any specific health problems and who study in university and regularly exercise. Mean age of the athletes are 22,40 ± 3,20 years and mean height is 179,83 ± 7,57 cm. This study is performed with 14 volunteer tennis players. Blood samples are obtained during the first day of the intense exercise program after the exercise, last day of the exercises and also right after the exercises. As per the obtained data, descriptive statistics are run (mean and standard deviation) and in order to compare the values of before and after the 10 days of intense exercise, Wilcoxon two related sample test was used. As per the results of the blood tests from before and after the exercise period, it is seen that values such as AST, ALT, MCH, MCHC and CK showed statistical significance (P<0.05). The athletes who prepared for the competitions with these values showed positive increases in bio-chemistry and hemogram values.


2020 ◽  
Author(s):  
Ali osali ◽  
Alireza Rostami

Abstract BackgroundThe purpose of this study was to investigate the effect of 12 months of aerobic exercise combining stachys lavandulifolia (S. lavandulifolia) consumption on anxiety, Metabolic Syndrome profiles and antioxidant defense (Glutathione) and lipid peroxidation (Malondialdehyde) in 50-65 years old women with syndrome metabolic.Methods48 women with syndrome Metabolic were randomly divided into four groups: exercise (n=12), exercise+S. lavandulifolia (n=12), S. lavandulifolia (n=12) and control group (n=12). S. lavandulifolia groups consumed 3 g aerial parts of S. lavandulifolia daily. Training groups performed an exercise protocol of aerobic exercise for 12 months (three sessions per week). Blood samples were obtained before and after training period for antioxidant indicators and lipid degradation measurement. Also, Beck anxiety questionnaire used for evaluating levels of anxiety. T-test and one-way analysis of variance were used for the evaluation of within-group and between-group differences, respectively.ResultsA significant increase was observed in serum levels of Malondialdehyde (P =0.004), Catalase indexes (Pvalue= 0.01), and Glutathione (P=0.001) in the training group and S. lavandulifolia groups after 12 months. Body weight, BMI, and SBP and Anexiety was decreased significantly greater in exercise +S. lavandulifolia group compared to control, exercise and S. lavandulifolia groups (P=0.001)ConclusionAnxiolytic effect and Anti-Oxidative Stress Activity was seen, so taking S. lavandulifolia along with exercises may have beneficial effects on reinforcement the antioxidant system and prevention of anxiety and The negative effects of indicators related to cardiovascular disease in women with metabolic syndrome.


2020 ◽  
Author(s):  
Quyen G To ◽  
Mitch J Duncan ◽  
Anetta Van Itallie ◽  
Corneel Vandelanotte

BACKGROUND Physical activity is an important health behavior, due to its association with many physical and mental health conditions. During distressing events, such as the COVID-19 pandemic, there is a concern that physical activity levels may be negatively impacted. However, recent studies have shown inconsistent results. Additionally, there is a lack of studies in Australia on this topic. OBJECTIVE The aim of this study is to investigate changes in physical activity reported through the 10,000 Steps program and changes in engagement with the program during the COVID-19 pandemic. METHODS Data between January 1, 2018, and June 30, 2020, from registered members of the 10,000 Steps program, which included 3,548,825 days with step data, were used. The number of daily steps were logged manually by the members or synced automatically from their activity trackers connected to the program. Measures on program usage were the number of new registered members per day, the number of newly registered organizations per day, the number of steps logged per day, and the number of step entries per day. Key dates used for comparison were as follows: the first case with symptoms in Wuhan, China; the first case reported in Australia; the implementation of a 14-day ban for noncitizens arriving in Australia from China; the start of the lockdown in Australia; and the relaxing of restrictions by the Australian Government. Wilcoxon signed-rank tests were used to test for significant differences in number of steps between subgroups, between engagement measures in 2019 versus 2020, and before and after an event. RESULTS A decrease in steps was observed after the first case in Australia was reported (1.5%; <i>P</i>=.02) and after the start of the lockdown (3.4%; <i>P</i>&lt;.001). At the time that the relaxing of restrictions started, the steps had already recovered from the lockdown. Additionally, the trends were consistent across genders and age groups. New South Wales, Australian Capital Territory, and Victoria had the greatest step reductions, with decreases of 7.0% (<i>P</i>&lt;.001), 6.2% (<i>P</i>=.02), and 4.7% (<i>P</i>&lt;.001), respectively. During the lockdown, the use of the program increased steeply. On the peak day, there were more than 9000 step entries per day, with nearly 100 million steps logged per day; in addition, more than 450 new users and more than 15 new organizations registered per day, although the numbers decreased quickly when restrictions were relaxed. On average per day, there were about 55 new registered users (<i>P</i>&lt;.001), 2 new organizations (<i>P</i>&lt;.001), 25.6 million steps (<i>P</i>&lt;.001), and 2672 log entries (<i>P</i>&lt;.001) more in 2020 compared to the same period in 2019. CONCLUSIONS The pandemic has had negative effects on steps among Australians across age groups and genders. However, the effect was relatively small, with steps recovering quickly after the lockdown. There was a large increase in program usage during the pandemic, which might help minimize the health impact of the lockdown and confirms the important role of physical activity programs during times of distress and lockdowns.


2020 ◽  
Vol 14 (1) ◽  
pp. 133-138
Author(s):  
Yoshihiro Sato ◽  
Shohei Yamaguchi ◽  
Shota Funaki ◽  
Atsutoshi Kurihara ◽  
Yuki Kumagai ◽  
...  

Remotely operated construction machines are used in cases where the operators are in danger, such as on steep slopes or contaminated sites. However, remote operation differs from what operators perceive during hands-on machine operation. Various studies have focused on improving work efficiency by employing remote control operation to reduce operator workload. In these studies, questionnaires were generally employed to evaluate the operator workload. However, the results obtained from the questionnaires varied depending on the physical conditions and the mood of the person on that day. It was therefore concluded that an accurate evaluation cannot be performed based on this method. Hence, in this study, the eye strain of machine operators was measured using an Auto Refractor/Keratometer. In particular, the ciliary muscle activities were measured before and after operating three display systems used for remote control of construction equipment. A quantitative evaluation was then conducted based on the eye strain data. The 2D display system exhibited low work accuracy and efficiency and resulted in significant eye strain. Although the 3D display system that required glasses exhibited high accuracy and efficiency, it resulted in significant eye strain. The 3D display system that did not require glasses demonstrated high accuracy and lower eye strain. From the results presented above, it was confirmed that the autostereoscopic 3D system is suitable for operators.


2021 ◽  
Author(s):  
Janis Heuel ◽  
Wolfgang Friederich

&lt;p&gt;Over the last years, installations of wind turbines (WTs) increased worldwide. Owing to&lt;br&gt;negative effects on humans, WTs are often installed in areas with low population density.&lt;br&gt;Because of low anthropogenic noise, these areas are also well suited for sites of&lt;br&gt;seismological stations. As a consequence, WTs are often installed in the same areas as&lt;br&gt;seismological stations. By comparing the noise in recorded data before and after&lt;br&gt;installation of WTs, seismologists noticed a substantial worsening of station quality leading&lt;br&gt;to conflicts between the operators of WTs and earthquake services.&lt;/p&gt;&lt;p&gt;In this study, we compare different techniques to reduce or eliminate the disturbing signal&lt;br&gt;from WTs at seismological stations. For this purpose, we selected a seismological station&lt;br&gt;that shows a significant correlation between the power spectral density and the hourly&lt;br&gt;windspeed measurements. Usually, spectral filtering is used to suppress noise in seismic&lt;br&gt;data processing. However, this approach is not effective when noise and signal have&lt;br&gt;overlapping frequency bands which is the case for WT noise. As a first method, we applied&lt;br&gt;the continuous wavelet transform (CWT) on our data to obtain a time-scale representation.&lt;br&gt;From this representation, we estimated a noise threshold function (Langston &amp; Mousavi,&lt;br&gt;2019) either from noise before the theoretical P-arrival (pre-noise) or using a noise signal&lt;br&gt;from the past with similar ground velocity conditions at the surrounding WTs. Therefore, we&lt;br&gt;installed low cost seismometers at the surrounding WTs to find similar signals at each WT.&lt;br&gt;From these similar signals, we obtain a noise model at the seismological station, which is&lt;br&gt;used to estimate the threshold function. As a second method, we used a denoising&lt;br&gt;autoencoder (DAE) that learns mapping functions to distinguish between noise and signal&lt;br&gt;(Zhu et al., 2019).&lt;/p&gt;&lt;p&gt;In our tests, the threshold function performs well when the event is visible in the raw or&lt;br&gt;spectral filtered data, but it fails when WT noise dominates and the event is hidden. In&lt;br&gt;these cases, the DAE removes the WT noise from the data. However, the DAE must be&lt;br&gt;trained with typical noise samples and high signal-to-noise ratio events to distinguish&lt;br&gt;between signal and interfering noise. Using the threshold function and pre-noise can be&lt;br&gt;applied immediately on real-time data and has a low computational cost. Using a noise&lt;br&gt;model from our prerecorded database at the seismological station does not improve the&lt;br&gt;result and it is more time consuming to find similar ground velocity conditions at the&lt;br&gt;surrounding WTs.&lt;/p&gt;


2006 ◽  
pp. 253-270
Author(s):  
Jovan Ilic

The Serbs are first mentioned in the west part of the Balkan peninsula in 822. They populated the regions east of the river Cetina, mountain Pljesevica and the area between the rivers Una and Kupa. It means that the significant part of the present Republic of Croatia had been populated by the Serbs since the settlement of the Slavs. The main regions mostly populated by the Serbs were north-west Dalmatia, the larger part of Lika and Kordun, Banija, west Slavonia and smaller sections in east Slavonia, west Srem and Baranya. Social-political circumstances for the life of the Serbs in Croatia were mostly very unfavorable. Extremely unfavourable circumstances were during World War II in The Independent State of Croatia, when the Croatian ustasha fighters carried out an extensive, systematic, comprehensive and bestial genocide, that is ethnocide over the Serbs. The second genocide, that is ethnocide over the Serbs in Croatia was carried out in the civil ethnic-religious war 1991-1995, specially in 1995. In these years, the nationalist- chauvinist, antiserbian movement and war suddenly flared up in Croatia. The Serbs living there were forced to defend, so on December 19 1991 they proclaimed The Republic of Srpska Krajina. However, the Croatian armed forces were military stronger. The Serbs were defeated and punished by the total destruction of their property and mass expulsion. In that cruel civil-ethnic war, about 276.000 Serbs were expelled from Croatia, several thousand of them were killed. About 40.000 Serbian houses were destroyed and 380 Serbian villages were burnt. Hundreds of Serbian-Orthodox religious edifices were burnt or destroyed. The value of the destroyed or plundered Serbian property in Croatia was estimated at about 30 billion euros. According to the official Croatian data, in the last several years about 60.000 Serbs-refugees returned from Serbia to their native land, mostly older persons or those who returned to sell their property and leave Croatia again. About 40.000 of them went to live abroad. However, the Serbs-returnees still live in very difficult conditions, discriminated in all segments of life primarily when it comes to employment.


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